claude-desktop/src-tauri/src/db.rs

// Claude Desktop — SQLite Datenbankschicht
// Persistiert Guard-Rails, Audit-Log, Memory und Einstellungen

use rusqlite::{params, Connection, Result as SqlResult};
use std::path::Path;
use std::sync::{Arc, Mutex};
use tauri::{AppHandle, Manager};

use crate::audit::{AuditAction, AuditCategory, AuditEntry, AuditStats};
use crate::guard::{Permission, PermissionAction, PermissionType};
use crate::memory::{ContextCategory, MemoryEntry, Pattern};
use crate::strutil::safe_truncate_ellipsis;

/// Eine Claude-Session
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
pub struct Session {
    pub id: String,
    pub claude_session_id: Option<String>,
    pub title: String,
    pub working_dir: Option<String>,
    pub message_count: i64,
    pub token_input: i64,
    pub token_output: i64,
    pub cost_usd: f64,
    pub status: String,
    pub created_at: String,
    pub updated_at: String,
    pub last_message: Option<String>,
}

/// Eine Chat-Nachricht
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
pub struct ChatMessage {
    pub id: String,
    pub session_id: String,
    pub role: String,  // "user", "assistant", "system"
    pub content: String,
    pub model: Option<String>,
    pub agent_id: Option<String>,  // Agent der die Nachricht erzeugt hat
    pub timestamp: String,
}

/// Block C: Suchresultat fuer Cross-Session-Recall (FTS5 auf messages)
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
pub struct PastMessageMatch {
    pub id: String,
    pub session_id: String,
    pub role: String,
    pub snippet: String,            // bis zu 240 Zeichen Anriss
    pub timestamp: String,
    pub session_title: Option<String>,
}

/// Ein Monitor-Event (System-Log)
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
pub struct MonitorEvent {
    pub id: String,
    pub timestamp: String,
    pub event_type: String,  // "api", "tool", "agent", "hook", "mcp", "error", "debug"
    pub summary: String,
    pub details: Option<String>,  // JSON-String
    pub agent_id: Option<String>,
    pub session_id: Option<String>,
    pub duration_ms: Option<i64>,
    #[allow(dead_code)]
    pub error: Option<String>,
}

/// Checkpoint-Eintrag (Datei-Snapshot fuer Accept/Reject + Rewind)
#[allow(dead_code)]
pub struct CheckpointEntry {
    pub tool_id: String,
    pub session_id: String,
    pub tool_name: String,
    pub file_path: String,
    pub content_before: String,
    pub content_after: Option<String>,
    pub status: String,
    pub created_at: String,
}

/// Datenbank-Wrapper
pub struct Database {
    pub(crate) conn: Connection,
}

/// Datenbank-Statistiken
#[derive(Debug, serde::Serialize)]
pub struct DbStats {
    pub permissions: usize,
    pub audit_entries: usize,
    pub memory_entries: usize,
    pub patterns: usize,
    pub db_size_kb: u64,
}

impl Database {
    /// Öffnet oder erstellt die Datenbank
    pub fn open(path: &Path) -> SqlResult<Self> {
        let conn = Connection::open(path)?;

        // WAL-Modus für bessere Performance
        conn.execute_batch("PRAGMA journal_mode=WAL; PRAGMA foreign_keys=ON;")?;

        let db = Self { conn };
        db.create_tables()?;
        Ok(db)
    }

    /// Schema erstellen
    fn create_tables(&self) -> SqlResult<()> {
        self.conn.execute_batch(
            "
            -- Guard-Rails Permissions
            CREATE TABLE IF NOT EXISTS permissions (
                id TEXT PRIMARY KEY,
                pattern TEXT NOT NULL,
                tool TEXT,
                path_pattern TEXT,
                action TEXT NOT NULL DEFAULT 'allow',
                created_at TEXT NOT NULL,
                use_count INTEGER DEFAULT 0,
                last_used TEXT
            );

            -- Audit-Log
            CREATE TABLE IF NOT EXISTS audit_log (
                id TEXT PRIMARY KEY,
                timestamp TEXT NOT NULL,
                category TEXT NOT NULL,
                action TEXT NOT NULL,
                item_id TEXT NOT NULL,
                item_name TEXT NOT NULL,
                old_value TEXT,
                new_value TEXT,
                reason TEXT,
                auto_corrected INTEGER DEFAULT 0,
                session_id TEXT
            );
            CREATE INDEX IF NOT EXISTS idx_audit_timestamp ON audit_log(timestamp DESC);
            CREATE INDEX IF NOT EXISTS idx_audit_category ON audit_log(category);

            -- Memory-Einträge
            CREATE TABLE IF NOT EXISTS memory (
                id TEXT PRIMARY KEY,
                category TEXT NOT NULL,
                key TEXT NOT NULL,
                value TEXT NOT NULL,
                sticky INTEGER DEFAULT 0,
                auto_load INTEGER DEFAULT 0,
                last_used TEXT,
                use_count INTEGER DEFAULT 0
            );
            CREATE INDEX IF NOT EXISTS idx_memory_category ON memory(category);
            CREATE INDEX IF NOT EXISTS idx_memory_sticky ON memory(sticky) WHERE sticky = 1;

            -- Patterns (Vorgehensweisen)
            CREATE TABLE IF NOT EXISTS patterns (
                id TEXT PRIMARY KEY,
                name TEXT NOT NULL,
                description TEXT,
                trigger_text TEXT,
                old_approach TEXT,
                new_approach TEXT,
                reason TEXT,
                occurrence_count INTEGER DEFAULT 1,
                auto_corrected INTEGER DEFAULT 0,
                created_at TEXT NOT NULL,
                updated_at TEXT NOT NULL
            );

            -- Sessions (Claude-Konversationen)
            CREATE TABLE IF NOT EXISTS sessions (
                id TEXT PRIMARY KEY,
                claude_session_id TEXT,
                title TEXT NOT NULL,
                working_dir TEXT,
                message_count INTEGER DEFAULT 0,
                token_input INTEGER DEFAULT 0,
                token_output INTEGER DEFAULT 0,
                cost_usd REAL DEFAULT 0,
                status TEXT NOT NULL DEFAULT 'active',
                created_at TEXT NOT NULL,
                updated_at TEXT NOT NULL,
                last_message TEXT
            );
            CREATE INDEX IF NOT EXISTS idx_sessions_updated ON sessions(updated_at DESC);
            CREATE INDEX IF NOT EXISTS idx_sessions_status ON sessions(status);

            -- Einstellungen (Key-Value)
            CREATE TABLE IF NOT EXISTS settings (
                key TEXT PRIMARY KEY,
                value TEXT NOT NULL,
                updated_at TEXT NOT NULL
            );

            -- Chat-Nachrichten
            CREATE TABLE IF NOT EXISTS messages (
                id TEXT PRIMARY KEY,
                session_id TEXT NOT NULL,
                role TEXT NOT NULL,
                content TEXT NOT NULL,
                model TEXT,
                agent_id TEXT,
                timestamp TEXT NOT NULL,
                FOREIGN KEY (session_id) REFERENCES sessions(id) ON DELETE CASCADE
            );
            CREATE INDEX IF NOT EXISTS idx_messages_session ON messages(session_id, timestamp);

            -- Block C: FTS5-Volltextsuche fuer Cross-Session-Recall.
            -- Externer content-Modus: kein doppelter Speicher, FTS hat nur
            -- die rowid + indizierten Felder. Sync via Trigger.
            CREATE VIRTUAL TABLE IF NOT EXISTS messages_fts USING fts5(
                content,
                tokenize='unicode61 remove_diacritics 2'
            );
            CREATE TRIGGER IF NOT EXISTS messages_fts_ai
                AFTER INSERT ON messages BEGIN
                    INSERT INTO messages_fts(rowid, content) VALUES (new.rowid, new.content);
                END;
            CREATE TRIGGER IF NOT EXISTS messages_fts_ad
                AFTER DELETE ON messages BEGIN
                    DELETE FROM messages_fts WHERE rowid = old.rowid;
                END;
            CREATE TRIGGER IF NOT EXISTS messages_fts_au
                AFTER UPDATE ON messages BEGIN
                    UPDATE messages_fts SET content = new.content WHERE rowid = old.rowid;
                END;

            -- Monitor-Events (System-Log)
            CREATE TABLE IF NOT EXISTS monitor_events (
                id TEXT PRIMARY KEY,
                timestamp TEXT NOT NULL,
                event_type TEXT NOT NULL,
                summary TEXT NOT NULL,
                details TEXT,
                agent_id TEXT,
                session_id TEXT,
                duration_ms INTEGER,
                error TEXT
            );
            CREATE INDEX IF NOT EXISTS idx_monitor_timestamp ON monitor_events(timestamp DESC);
            CREATE INDEX IF NOT EXISTS idx_monitor_type ON monitor_events(event_type);

            -- Threshold-basierter Cleanup: greift nur wenn die Tabelle mehr als
            -- 50_000 Zeilen hat, behaelt dann die juengsten 30_000. Loescht ausserdem
            -- Eintraege aelter als 7 Tage. Verhindert die Endlosschleife aus 04/2026
            -- (Bridge-EPIPE-Crash schrieb 5 Events/s und der Trigger scannte bei
            -- jedem Insert die ganze Tabelle = O(n^2)-Schneeball).
            DROP TRIGGER IF EXISTS cleanup_old_monitor_events;
            CREATE TRIGGER IF NOT EXISTS cleanup_old_monitor_events
            AFTER INSERT ON monitor_events
            WHEN (SELECT COUNT(*) FROM monitor_events) > 50000
            BEGIN
                DELETE FROM monitor_events
                WHERE timestamp < datetime('now', '-7 days')
                   OR id IN (
                        SELECT id FROM monitor_events
                        ORDER BY timestamp ASC
                        LIMIT MAX((SELECT COUNT(*) FROM monitor_events) - 30000, 0)
                   );
            END;

            -- Projekte (für schnellen Wechsel)
            CREATE TABLE IF NOT EXISTS projects (
                id TEXT PRIMARY KEY,
                name TEXT NOT NULL,
                working_dir TEXT NOT NULL,
                claude_md_path TEXT,
                description TEXT,
                last_used TEXT NOT NULL,
                created_at TEXT NOT NULL,
                session_count INTEGER DEFAULT 0
            );
            CREATE INDEX IF NOT EXISTS idx_projects_last_used ON projects(last_used DESC);

            -- Phase 2.0: Fehler-Tracking für Auto-Pattern-Erkennung
            CREATE TABLE IF NOT EXISTS error_tracker (
                error_hash TEXT PRIMARY KEY,
                error_message TEXT NOT NULL,
                tool TEXT NOT NULL,
                occurrence_count INTEGER DEFAULT 1,
                first_seen TEXT NOT NULL,
                last_seen TEXT NOT NULL,
                kb_pattern_id INTEGER,
                UNIQUE(error_hash)
            );
            CREATE INDEX IF NOT EXISTS idx_error_tracker_count ON error_tracker(occurrence_count DESC);

            -- Checkpoints: Datei-Snapshots fuer Accept/Reject und Rewind
            CREATE TABLE IF NOT EXISTS checkpoints (
                tool_id TEXT PRIMARY KEY,
                session_id TEXT NOT NULL,
                tool_name TEXT NOT NULL,
                file_path TEXT NOT NULL,
                content_before TEXT NOT NULL,
                content_after TEXT,
                status TEXT NOT NULL DEFAULT 'pending',
                created_at TEXT NOT NULL DEFAULT (datetime('now'))
            );
            CREATE INDEX IF NOT EXISTS idx_checkpoints_session ON checkpoints(session_id, created_at DESC);
            ",
        )?;
        Ok(())
    }

    // ============ Permissions ============

    /// Speichert eine Permission
    pub fn save_permission(&self, perm: &Permission) -> SqlResult<()> {
        self.conn.execute(
            "INSERT OR REPLACE INTO permissions (id, pattern, tool, path_pattern, action, created_at, use_count, last_used)
             VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7, ?8)",
            params![
                perm.id,
                perm.pattern,
                perm.tool,
                perm.path_pattern,
                format!("{:?}", perm.action).to_lowercase(),
                perm.created_at,
                perm.use_count,
                perm.last_used,
            ],
        )?;
        Ok(())
    }

    /// Lädt alle permanenten Permissions
    pub fn load_permissions(&self) -> SqlResult<Vec<Permission>> {
        let mut stmt = self.conn.prepare(
            "SELECT id, pattern, tool, path_pattern, action, created_at, use_count, last_used FROM permissions"
        )?;

        let perms = stmt.query_map([], |row| {
            let action_str: String = row.get(4)?;
            let action = match action_str.as_str() {
                "deny" => PermissionAction::Deny,
                _ => PermissionAction::Allow,
            };

            Ok(Permission {
                id: row.get(0)?,
                pattern: row.get(1)?,
                tool: row.get(2)?,
                path_pattern: row.get(3)?,
                permission_type: PermissionType::Permanent,
                action,
                created_at: row.get(5)?,
                use_count: row.get(6)?,
                last_used: row.get(7)?,
            })
        })?.collect::<SqlResult<Vec<_>>>()?;

        Ok(perms)
    }

    /// Löscht eine Permission
    pub fn delete_permission(&self, id: &str) -> SqlResult<()> {
        self.conn.execute("DELETE FROM permissions WHERE id = ?1", params![id])?;
        Ok(())
    }

    // ============ Audit-Log ============

    /// Speichert einen Audit-Eintrag
    pub fn save_audit_entry(&self, entry: &AuditEntry) -> SqlResult<()> {
        self.conn.execute(
            "INSERT INTO audit_log (id, timestamp, category, action, item_id, item_name, old_value, new_value, reason, auto_corrected, session_id)
             VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7, ?8, ?9, ?10, ?11)",
            params![
                entry.id,
                entry.timestamp,
                format!("{:?}", entry.category).to_lowercase(),
                format!("{:?}", entry.action).to_lowercase(),
                entry.item_id,
                entry.item_name,
                entry.old_value.as_ref().map(|v| v.to_string()),
                entry.new_value.as_ref().map(|v| v.to_string()),
                entry.reason,
                entry.auto_corrected as i32,
                entry.session_id,
            ],
        )?;
        Ok(())
    }

    /// Lädt die letzten N Audit-Einträge
    pub fn load_audit_log(&self, limit: usize) -> SqlResult<Vec<AuditEntry>> {
        let mut stmt = self.conn.prepare(
            "SELECT id, timestamp, category, action, item_id, item_name, old_value, new_value, reason, auto_corrected, session_id
             FROM audit_log ORDER BY timestamp DESC LIMIT ?1"
        )?;

        let entries = stmt.query_map(params![limit as i64], |row| {
            let cat_str: String = row.get(2)?;
            let act_str: String = row.get(3)?;
            let old_val: Option<String> = row.get(6)?;
            let new_val: Option<String> = row.get(7)?;
            let auto_corr: i32 = row.get(9)?;

            Ok(AuditEntry {
                id: row.get(0)?,
                timestamp: row.get(1)?,
                category: parse_audit_category(&cat_str),
                action: parse_audit_action(&act_str),
                item_id: row.get(4)?,
                item_name: row.get(5)?,
                old_value: old_val.and_then(|s| serde_json::from_str(&s).ok()),
                new_value: new_val.and_then(|s| serde_json::from_str(&s).ok()),
                reason: row.get(8)?,
                auto_corrected: auto_corr != 0,
                session_id: row.get(10)?,
            })
        })?.collect::<SqlResult<Vec<_>>>()?;

        Ok(entries)
    }

    /// Audit-Statistiken
    pub fn audit_stats(&self) -> SqlResult<AuditStats> {
        let total: usize = self.conn.query_row(
            "SELECT COUNT(*) FROM audit_log", [], |row| row.get(0)
        )?;
        let auto_corrected: usize = self.conn.query_row(
            "SELECT COUNT(*) FROM audit_log WHERE auto_corrected = 1", [], |row| row.get(0)
        )?;
        let today: usize = self.conn.query_row(
            "SELECT COUNT(*) FROM audit_log WHERE timestamp LIKE ?1 || '%'",
            params![chrono::Local::now().format("%Y-%m-%d").to_string()],
            |row| row.get(0),
        )?;

        Ok(AuditStats { total, auto_corrected, today })
    }

    // ============ Memory ============

    /// Speichert einen Memory-Eintrag
    #[allow(dead_code)]
    pub fn save_memory_entry(&self, entry: &MemoryEntry) -> SqlResult<()> {
        self.conn.execute(
            "INSERT OR REPLACE INTO memory (id, category, key, value, sticky, auto_load, last_used, use_count)
             VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7, ?8)",
            params![
                entry.id,
                format!("{:?}", entry.category),
                entry.key,
                entry.value.to_string(),
                entry.sticky as i32,
                entry.auto_load as i32,
                entry.last_used,
                entry.use_count,
            ],
        )?;
        Ok(())
    }

    /// Lädt alle Memory-Einträge
    pub fn load_memory_entries(&self) -> SqlResult<Vec<MemoryEntry>> {
        let mut stmt = self.conn.prepare(
            "SELECT id, category, key, value, sticky, auto_load, last_used, use_count FROM memory"
        )?;

        let entries = stmt.query_map([], |row| {
            let cat_str: String = row.get(1)?;
            let val_str: String = row.get(3)?;
            let sticky: i32 = row.get(4)?;
            let auto_load: i32 = row.get(5)?;

            Ok(MemoryEntry {
                id: row.get(0)?,
                category: parse_context_category(&cat_str),
                key: row.get(2)?,
                value: serde_json::from_str(&val_str).unwrap_or(serde_json::Value::String(val_str)),
                sticky: sticky != 0,
                auto_load: auto_load != 0,
                last_used: row.get(6)?,
                use_count: row.get(7)?,
            })
        })?.collect::<SqlResult<Vec<_>>>()?;

        Ok(entries)
    }

    /// Löscht einen Memory-Eintrag
    pub fn delete_memory_entry(&self, id: &str) -> SqlResult<()> {
        self.conn.execute("DELETE FROM memory WHERE id = ?1", params![id])?;
        Ok(())
    }

    // ============ Patterns ============

    /// Speichert ein Pattern
    pub fn save_pattern(&self, pattern: &Pattern) -> SqlResult<()> {
        self.conn.execute(
            "INSERT OR REPLACE INTO patterns (id, name, description, trigger_text, old_approach, new_approach, reason, occurrence_count, auto_corrected, created_at, updated_at)
             VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7, ?8, ?9, ?10, ?11)",
            params![
                pattern.id,
                pattern.name,
                pattern.description,
                pattern.trigger,
                pattern.old_approach,
                pattern.new_approach,
                pattern.reason,
                pattern.occurrence_count,
                pattern.auto_corrected as i32,
                pattern.created_at,
                pattern.updated_at,
            ],
        )?;
        Ok(())
    }

    /// Lädt alle Patterns
    pub fn load_patterns(&self) -> SqlResult<Vec<Pattern>> {
        let mut stmt = self.conn.prepare(
            "SELECT id, name, description, trigger_text, old_approach, new_approach, reason, occurrence_count, auto_corrected, created_at, updated_at FROM patterns"
        )?;

        let patterns = stmt.query_map([], |row| {
            let auto_corr: i32 = row.get(8)?;
            Ok(Pattern {
                id: row.get(0)?,
                name: row.get(1)?,
                description: row.get(2)?,
                trigger: row.get(3)?,
                old_approach: row.get(4)?,
                new_approach: row.get(5)?,
                reason: row.get(6)?,
                occurrence_count: row.get(7)?,
                auto_corrected: auto_corr != 0,
                created_at: row.get(9)?,
                updated_at: row.get(10)?,
            })
        })?.collect::<SqlResult<Vec<_>>>()?;

        Ok(patterns)
    }

    // ============ Sessions ============

    /// Erstellt eine neue Session
    pub fn create_session(&self, session: &Session) -> SqlResult<()> {
        self.conn.execute(
            "INSERT INTO sessions (id, claude_session_id, title, working_dir, message_count, token_input, token_output, cost_usd, status, created_at, updated_at, last_message)
             VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7, ?8, ?9, ?10, ?11, ?12)",
            params![
                session.id,
                session.claude_session_id,
                session.title,
                session.working_dir,
                session.message_count,
                session.token_input,
                session.token_output,
                session.cost_usd,
                session.status,
                session.created_at,
                session.updated_at,
                session.last_message,
            ],
        )?;
        Ok(())
    }

    /// Aktualisiert eine Session
    pub fn update_session(&self, session: &Session) -> SqlResult<()> {
        self.conn.execute(
            "UPDATE sessions SET claude_session_id = ?2, title = ?3, message_count = ?4,
             token_input = ?5, token_output = ?6, cost_usd = ?7, status = ?8,
             updated_at = ?9, last_message = ?10
             WHERE id = ?1",
            params![
                session.id,
                session.claude_session_id,
                session.title,
                session.message_count,
                session.token_input,
                session.token_output,
                session.cost_usd,
                session.status,
                chrono::Local::now().to_rfc3339(),
                session.last_message,
            ],
        )?;
        Ok(())
    }

    /// Lädt alle Sessions (neueste zuerst) — Convenience-Wrapper
    #[allow(dead_code)]
    pub fn load_sessions(&self, limit: usize) -> SqlResult<Vec<Session>> {
        self.load_sessions_filtered(limit, None)
    }

    /// Sessions laden, optional gefiltert nach working_dir (Projekt-Bindung)
    pub fn load_sessions_filtered(&self, limit: usize, working_dir: Option<&str>) -> SqlResult<Vec<Session>> {
        if let Some(dir) = working_dir {
            let mut stmt = self.conn.prepare(
                "SELECT id, claude_session_id, title, working_dir, message_count,
                        token_input, token_output, cost_usd, status, created_at, updated_at, last_message
                 FROM sessions WHERE working_dir = ?1 ORDER BY updated_at DESC LIMIT ?2"
            )?;
            let result = stmt.query_map(params![dir, limit as i64], |row| {
                Ok(Session {
                    id: row.get(0)?, claude_session_id: row.get(1)?, title: row.get(2)?,
                    working_dir: row.get(3)?, message_count: row.get(4)?,
                    token_input: row.get(5)?, token_output: row.get(6)?,
                    cost_usd: row.get(7)?, status: row.get(8)?,
                    created_at: row.get(9)?, updated_at: row.get(10)?,
                    last_message: row.get(11)?,
                })
            })?.collect();
            result
        } else {
            let mut stmt = self.conn.prepare(
                "SELECT id, claude_session_id, title, working_dir, message_count,
                        token_input, token_output, cost_usd, status, created_at, updated_at, last_message
                 FROM sessions ORDER BY updated_at DESC LIMIT ?1"
            )?;
            let result = stmt.query_map(params![limit as i64], |row| {
                Ok(Session {
                    id: row.get(0)?, claude_session_id: row.get(1)?, title: row.get(2)?,
                    working_dir: row.get(3)?, message_count: row.get(4)?,
                    token_input: row.get(5)?, token_output: row.get(6)?,
                    cost_usd: row.get(7)?, status: row.get(8)?,
                    created_at: row.get(9)?, updated_at: row.get(10)?,
                    last_message: row.get(11)?,
                })
            })?.collect();
            result
        }
    }

    /// Holt eine Session nach ID
    pub fn get_session(&self, id: &str) -> SqlResult<Option<Session>> {
        let result = self.conn.query_row(
            "SELECT id, claude_session_id, title, working_dir, message_count,
                    token_input, token_output, cost_usd, status, created_at, updated_at, last_message
             FROM sessions WHERE id = ?1",
            params![id],
            |row| {
                Ok(Session {
                    id: row.get(0)?,
                    claude_session_id: row.get(1)?,
                    title: row.get(2)?,
                    working_dir: row.get(3)?,
                    message_count: row.get(4)?,
                    token_input: row.get(5)?,
                    token_output: row.get(6)?,
                    cost_usd: row.get(7)?,
                    status: row.get(8)?,
                    created_at: row.get(9)?,
                    updated_at: row.get(10)?,
                    last_message: row.get(11)?,
                })
            },
        );
        match result {
            Ok(s) => Ok(Some(s)),
            Err(rusqlite::Error::QueryReturnedNoRows) => Ok(None),
            Err(e) => Err(e),
        }
    }

    /// Löscht eine Session
    pub fn delete_session(&self, id: &str) -> SqlResult<()> {
        // Erst Nachrichten löschen (wegen Foreign Key)
        self.conn.execute("DELETE FROM messages WHERE session_id = ?1", params![id])?;
        self.conn.execute("DELETE FROM sessions WHERE id = ?1", params![id])?;
        Ok(())
    }

    /// Holt die zuletzt aktualisierte aktive Session
    pub fn get_active_session(&self) -> SqlResult<Option<Session>> {
        let result = self.conn.query_row(
            "SELECT id, claude_session_id, title, working_dir, message_count,
                    token_input, token_output, cost_usd, status, created_at, updated_at, last_message
             FROM sessions WHERE status = 'active' ORDER BY updated_at DESC LIMIT 1",
            [],
            |row| {
                Ok(Session {
                    id: row.get(0)?,
                    claude_session_id: row.get(1)?,
                    title: row.get(2)?,
                    working_dir: row.get(3)?,
                    message_count: row.get(4)?,
                    token_input: row.get(5)?,
                    token_output: row.get(6)?,
                    cost_usd: row.get(7)?,
                    status: row.get(8)?,
                    created_at: row.get(9)?,
                    updated_at: row.get(10)?,
                    last_message: row.get(11)?,
                })
            },
        );
        match result {
            Ok(s) => Ok(Some(s)),
            Err(rusqlite::Error::QueryReturnedNoRows) => Ok(None),
            Err(e) => Err(e),
        }
    }

    // ============ Messages ============

    /// Speichert eine Nachricht
    pub fn save_message(&self, msg: &ChatMessage) -> SqlResult<()> {
        self.conn.execute(
            "INSERT OR REPLACE INTO messages (id, session_id, role, content, model, agent_id, timestamp)
             VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7)",
            params![
                msg.id,
                msg.session_id,
                msg.role,
                msg.content,
                msg.model,
                msg.agent_id,
                msg.timestamp,
            ],
        )?;
        Ok(())
    }

    /// Lädt alle Nachrichten einer Session
    pub fn load_messages(&self, session_id: &str) -> SqlResult<Vec<ChatMessage>> {
        let mut stmt = self.conn.prepare(
            "SELECT id, session_id, role, content, model, agent_id, timestamp
             FROM messages WHERE session_id = ?1 ORDER BY timestamp ASC"
        )?;

        let messages = stmt.query_map(params![session_id], |row| {
            Ok(ChatMessage {
                id: row.get(0)?,
                session_id: row.get(1)?,
                role: row.get(2)?,
                content: row.get(3)?,
                model: row.get(4)?,
                agent_id: row.get(5)?,
                timestamp: row.get(6)?,
            })
        })?.collect::<SqlResult<Vec<_>>>()?;

        Ok(messages)
    }

    /// Letzte N User-Nachrichten einer Session laden (für KB-Kontext-Analyse)
    pub fn load_recent_user_messages(&self, session_id: &str, limit: usize) -> SqlResult<Vec<String>> {
        let mut stmt = self.conn.prepare(
            "SELECT content FROM messages
             WHERE session_id = ?1 AND role = 'user'
             ORDER BY timestamp DESC LIMIT ?2"
        )?;
        let messages = stmt.query_map(params![session_id, limit as i64], |row| {
            row.get::<_, String>(0)
        })?.collect::<SqlResult<Vec<_>>>()?;
        Ok(messages)
    }

    /// Löscht alle Nachrichten einer Session
    pub fn clear_messages(&self, session_id: &str) -> SqlResult<()> {
        self.conn.execute("DELETE FROM messages WHERE session_id = ?1", params![session_id])?;
        Ok(())
    }

    /// Block C: Cross-Session-Recall — Volltext-Suche ueber alle Sessions
    /// liefert die top-N relevanten Assistant-Antworten aus der Vergangenheit.
    /// Nutzt FTS5-Index `messages_fts`. Der current_session_id wird ausgeschlossen
    /// damit das Recall sich nicht selbst trifft.
    pub fn search_past_messages(
        &self,
        query: &str,
        current_session_id: Option<&str>,
        limit: usize,
    ) -> SqlResult<Vec<PastMessageMatch>> {
        // FTS5-Query: bei leerem Query nichts. Auch sehr kurze Queries (<3 Zeichen)
        // ueberspringen — bringen nur Rauschen.
        if query.trim().len() < 3 {
            return Ok(Vec::new());
        }

        // Sanitize: FTS5 mag keine ' und " in der Query
        let safe = query
            .replace('"', " ")
            .replace('\'', " ")
            .split_whitespace()
            .filter(|w| w.len() >= 2)
            .take(8)
            .collect::<Vec<_>>()
            .join(" OR ");
        if safe.is_empty() {
            return Ok(Vec::new());
        }

        let mut stmt = self.conn.prepare(
            "SELECT m.id, m.session_id, m.role, m.content, m.timestamp, s.title
             FROM messages_fts
             JOIN messages m ON m.rowid = messages_fts.rowid
             LEFT JOIN sessions s ON s.id = m.session_id
             WHERE messages_fts MATCH ?1
               AND m.role = 'assistant'
               AND length(m.content) > 100
               AND (?2 IS NULL OR m.session_id != ?2)
             ORDER BY rank
             LIMIT ?3"
        )?;

        let rows = stmt.query_map(
            params![safe, current_session_id, limit as i64],
            |row| {
                let content: String = row.get(3)?;
                Ok(PastMessageMatch {
                    id: row.get(0)?,
                    session_id: row.get(1)?,
                    role: row.get(2)?,
                    snippet: safe_truncate_ellipsis(&content, 240),
                    timestamp: row.get(4)?,
                    session_title: row.get(5)?,
                })
            }
        )?.collect::<SqlResult<Vec<_>>>()?;

        Ok(rows)
    }

    /// Einmalige Migration: bestehende messages in den FTS5-Index spielen
    /// (falls die Tabelle vor Block C bereits Eintraege hatte).
    pub fn rebuild_messages_fts(&self) -> SqlResult<usize> {
        // Prefcheck: ist FTS leer aber messages voll?
        let fts_count: i64 = self.conn
            .query_row("SELECT COUNT(*) FROM messages_fts", [], |r| r.get(0))
            .unwrap_or(0);
        let msg_count: i64 = self.conn
            .query_row("SELECT COUNT(*) FROM messages", [], |r| r.get(0))?;
        if fts_count >= msg_count { return Ok(0); }

        self.conn.execute(
            "INSERT INTO messages_fts(rowid, content)
             SELECT rowid, content FROM messages
             WHERE rowid NOT IN (SELECT rowid FROM messages_fts)",
            []
        )?;
        Ok((msg_count - fts_count) as usize)
    }

    /// Zählt Nachrichten einer Session
    pub fn count_messages(&self, session_id: &str) -> SqlResult<usize> {
        self.conn.query_row(
            "SELECT COUNT(*) FROM messages WHERE session_id = ?1",
            params![session_id],
            |row| row.get(0),
        )
    }

    /// Kompaktiert eine Session: Behält die letzten N Nachrichten, fasst ältere zusammen
    /// Gibt die Anzahl der kompaktierten Nachrichten zurück
    pub fn compact_session(&self, session_id: &str, keep_last: usize) -> SqlResult<usize> {
        let total = self.count_messages(session_id)?;
        if total <= keep_last {
            return Ok(0); // Nichts zu kompaktieren
        }

        let to_compact = total - keep_last;

        // Alte Nachrichten holen (die kompaktiert werden sollen)
        let mut stmt = self.conn.prepare(
            "SELECT id, role, content FROM messages
             WHERE session_id = ?1
             ORDER BY timestamp ASC
             LIMIT ?2"
        )?;

        let old_messages: Vec<(String, String, String)> = stmt.query_map(
            params![session_id, to_compact as i64],
            |row| Ok((row.get(0)?, row.get(1)?, row.get(2)?))
        )?.collect::<SqlResult<Vec<_>>>()?;

        if old_messages.is_empty() {
            return Ok(0);
        }

        // Summary erstellen
        let mut summary_parts: Vec<String> = Vec::new();
        for (_, role, content) in &old_messages {
            let preview = if content.len() > 200 {
                // Sicher an Char-Boundary abschneiden (Multi-Byte wie ─, ä, ü)
                let end = content.char_indices()
                    .take_while(|(i, _)| *i < 200)
                    .last()
                    .map(|(i, c)| i + c.len_utf8())
                    .unwrap_or(200.min(content.len()));
                format!("{}...", &content[..end])
            } else {
                content.clone()
            };
            summary_parts.push(format!("[{}] {}", role, preview));
        }
        let summary_content = format!(
            "📦 **Kompaktierter Kontext** ({} Nachrichten)\n\n{}",
            old_messages.len(),
            summary_parts.join("\n\n---\n\n")
        );

        // IDs der alten Nachrichten
        let old_ids: Vec<&str> = old_messages.iter().map(|(id, _, _)| id.as_str()).collect();

        // Alte Nachrichten löschen
        let placeholders: String = old_ids.iter().map(|_| "?").collect::<Vec<_>>().join(",");
        let delete_sql = format!("DELETE FROM messages WHERE id IN ({})", placeholders);

        let params: Vec<&dyn rusqlite::ToSql> = old_ids.iter().map(|id| id as &dyn rusqlite::ToSql).collect();
        self.conn.execute(&delete_sql, params.as_slice())?;

        // Summary-Nachricht einfügen (mit Timestamp vor allen anderen)
        let summary_msg = ChatMessage {
            id: uuid::Uuid::new_v4().to_string(),
            session_id: session_id.to_string(),
            role: "system".to_string(),
            content: summary_content,
            model: None,
            agent_id: None,
            timestamp: "1970-01-01T00:00:00Z".to_string(), // Ganz am Anfang
        };
        self.save_message(&summary_msg)?;

        Ok(old_messages.len())
    }

    // ============ Settings ============

    /// Speichert eine Einstellung
    pub fn set_setting(&self, key: &str, value: &str) -> SqlResult<()> {
        self.conn.execute(
            "INSERT OR REPLACE INTO settings (key, value, updated_at) VALUES (?1, ?2, ?3)",
            params![key, value, chrono::Local::now().to_rfc3339()],
        )?;
        Ok(())
    }

    /// Liest eine Einstellung
    pub fn get_setting(&self, key: &str) -> SqlResult<Option<String>> {
        let result = self.conn.query_row(
            "SELECT value FROM settings WHERE key = ?1",
            params![key],
            |row| row.get(0),
        );
        match result {
            Ok(val) => Ok(Some(val)),
            Err(rusqlite::Error::QueryReturnedNoRows) => Ok(None),
            Err(e) => Err(e),
        }
    }

    /// Lädt alle Einstellungen
    pub fn get_all_settings(&self) -> SqlResult<Vec<(String, String)>> {
        let mut stmt = self.conn.prepare("SELECT key, value FROM settings")?;
        let settings = stmt.query_map([], |row| {
            Ok((row.get(0)?, row.get(1)?))
        })?.collect::<SqlResult<Vec<_>>>()?;
        Ok(settings)
    }

    // ============ Monitor-Events ============

    /// Speichert ein Monitor-Event
    pub fn save_monitor_event(&self, event: &MonitorEvent) -> SqlResult<()> {
        self.conn.execute(
            "INSERT OR REPLACE INTO monitor_events (id, timestamp, event_type, summary, details, agent_id, session_id, duration_ms, error)
             VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7, ?8, ?9)",
            params![
                event.id,
                event.timestamp,
                event.event_type,
                event.summary,
                event.details,
                event.agent_id,
                event.session_id,
                event.duration_ms,
                event.error,
            ],
        )?;
        Ok(())
    }

    /// Lädt die letzten N Monitor-Events
    pub fn load_monitor_events(&self, limit: usize) -> SqlResult<Vec<MonitorEvent>> {
        let mut stmt = self.conn.prepare(
            "SELECT id, timestamp, event_type, summary, details, agent_id, session_id, duration_ms, error
             FROM monitor_events ORDER BY timestamp DESC LIMIT ?1"
        )?;

        let events = stmt.query_map(params![limit as i64], |row| {
            Ok(MonitorEvent {
                id: row.get(0)?,
                timestamp: row.get(1)?,
                event_type: row.get(2)?,
                summary: row.get(3)?,
                details: row.get(4)?,
                agent_id: row.get(5)?,
                session_id: row.get(6)?,
                duration_ms: row.get(7)?,
                error: row.get(8)?,
            })
        })?.collect::<SqlResult<Vec<_>>>()?;

        Ok(events)
    }

    /// Lädt Monitor-Events nach Typ gefiltert
    pub fn load_monitor_events_by_type(&self, event_type: &str, limit: usize) -> SqlResult<Vec<MonitorEvent>> {
        let mut stmt = self.conn.prepare(
            "SELECT id, timestamp, event_type, summary, details, agent_id, session_id, duration_ms, error
             FROM monitor_events WHERE event_type = ?1 ORDER BY timestamp DESC LIMIT ?2"
        )?;

        let events = stmt.query_map(params![event_type, limit as i64], |row| {
            Ok(MonitorEvent {
                id: row.get(0)?,
                timestamp: row.get(1)?,
                event_type: row.get(2)?,
                summary: row.get(3)?,
                details: row.get(4)?,
                agent_id: row.get(5)?,
                session_id: row.get(6)?,
                duration_ms: row.get(7)?,
                error: row.get(8)?,
            })
        })?.collect::<SqlResult<Vec<_>>>()?;

        Ok(events)
    }

    /// Löscht alle Monitor-Events
    pub fn clear_monitor_events(&self) -> SqlResult<usize> {
        let count: usize = self.conn.query_row(
            "SELECT COUNT(*) FROM monitor_events", [], |row| row.get(0)
        )?;
        self.conn.execute("DELETE FROM monitor_events", [])?;
        Ok(count)
    }

    /// Zählt Monitor-Events nach Typ
    pub fn count_monitor_events_by_type(&self) -> SqlResult<Vec<(String, usize)>> {
        let mut stmt = self.conn.prepare(
            "SELECT event_type, COUNT(*) FROM monitor_events GROUP BY event_type"
        )?;
        let counts = stmt.query_map([], |row| {
            Ok((row.get(0)?, row.get(1)?))
        })?.collect::<SqlResult<Vec<_>>>()?;
        Ok(counts)
    }

    // ============ Checkpoints (Accept/Reject + Rewind) ============

    /// Checkpoint speichern (VOR der Aenderung)
    pub fn save_checkpoint(
        &self,
        tool_id: &str,
        session_id: &str,
        tool_name: &str,
        file_path: &str,
        content_before: &str,
    ) -> SqlResult<()> {
        self.conn.execute(
            "INSERT OR REPLACE INTO checkpoints (tool_id, session_id, tool_name, file_path, content_before, status)
             VALUES (?1, ?2, ?3, ?4, ?5, 'pending')",
            params![tool_id, session_id, tool_name, file_path, content_before],
        )?;
        Ok(())
    }

    /// Checkpoint After-Content updaten
    pub fn update_checkpoint_after(&self, tool_id: &str, content_after: &str) -> SqlResult<()> {
        self.conn.execute(
            "UPDATE checkpoints SET content_after = ?1, status = 'completed' WHERE tool_id = ?2",
            params![content_after, tool_id],
        )?;
        Ok(())
    }

    /// Checkpoint abrufen
    pub fn get_checkpoint(&self, tool_id: &str) -> SqlResult<Option<CheckpointEntry>> {
        let mut stmt = self.conn.prepare(
            "SELECT tool_id, session_id, tool_name, file_path, content_before, content_after, status, created_at
             FROM checkpoints WHERE tool_id = ?1"
        )?;
        let result: Vec<CheckpointEntry> = stmt.query_map(params![tool_id], |row| {
            Ok(CheckpointEntry {
                tool_id: row.get(0)?,
                session_id: row.get(1)?,
                tool_name: row.get(2)?,
                file_path: row.get(3)?,
                content_before: row.get(4)?,
                content_after: row.get(5)?,
                status: row.get(6)?,
                created_at: row.get(7)?,
            })
        })?.collect::<SqlResult<Vec<_>>>()?;
        Ok(result.into_iter().next())
    }

    /// Alle Checkpoints einer Session (neueste zuerst)
    pub fn list_checkpoints(&self, session_id: &str) -> SqlResult<Vec<CheckpointEntry>> {
        let mut stmt = self.conn.prepare(
            "SELECT tool_id, session_id, tool_name, file_path, content_before, content_after, status, created_at
             FROM checkpoints WHERE session_id = ?1 ORDER BY created_at DESC LIMIT 100"
        )?;
        let result = stmt.query_map(params![session_id], |row| {
            Ok(CheckpointEntry {
                tool_id: row.get(0)?,
                session_id: row.get(1)?,
                tool_name: row.get(2)?,
                file_path: row.get(3)?,
                content_before: row.get(4)?,
                content_after: row.get(5)?,
                status: row.get(6)?,
                created_at: row.get(7)?,
            })
        })?.collect::<SqlResult<Vec<_>>>()?;
        Ok(result)
    }

    /// Checkpoint-Status auf 'rejected' setzen
    pub fn reject_checkpoint(&self, tool_id: &str) -> SqlResult<()> {
        self.conn.execute(
            "UPDATE checkpoints SET status = 'rejected' WHERE tool_id = ?1",
            params![tool_id],
        )?;
        Ok(())
    }

    /// Checkpoint-Status auf 'accepted' setzen
    pub fn accept_checkpoint(&self, tool_id: &str) -> SqlResult<()> {
        self.conn.execute(
            "UPDATE checkpoints SET status = 'accepted' WHERE tool_id = ?1",
            params![tool_id],
        )?;
        Ok(())
    }

    // ============ Phase 2.0: Fehler-Tracking ============

    /// Fehler-Occurrence zählen und zurückgeben
    /// Gibt (neuer_count, error_message, tool, kb_pattern_id) zurück
    pub fn track_error(&self, error_hash: &str, error_message: &str, tool: &str) -> SqlResult<(i32, Option<i64>)> {
        let now = chrono::Local::now().to_rfc3339();

        // Versuche zu aktualisieren
        let updated = self.conn.execute(
            "UPDATE error_tracker SET
                occurrence_count = occurrence_count + 1,
                last_seen = ?1,
                error_message = ?2
             WHERE error_hash = ?3",
            params![now, error_message, error_hash],
        )?;

        if updated == 0 {
            // Neuer Eintrag
            self.conn.execute(
                "INSERT INTO error_tracker (error_hash, error_message, tool, occurrence_count, first_seen, last_seen)
                 VALUES (?1, ?2, ?3, 1, ?4, ?4)",
                params![error_hash, error_message, tool, now],
            )?;
            return Ok((1, None));
        }

        // Aktuellen Count und kb_pattern_id holen
        let result: (i32, Option<i64>) = self.conn.query_row(
            "SELECT occurrence_count, kb_pattern_id FROM error_tracker WHERE error_hash = ?1",
            params![error_hash],
            |row| Ok((row.get(0)?, row.get(1)?)),
        )?;

        Ok(result)
    }

    /// KB-Pattern-ID für einen Fehler speichern (nachdem Pattern in KB erstellt wurde)
    pub fn set_error_kb_pattern(&self, error_hash: &str, kb_pattern_id: i64) -> SqlResult<()> {
        self.conn.execute(
            "UPDATE error_tracker SET kb_pattern_id = ?1 WHERE error_hash = ?2",
            params![kb_pattern_id, error_hash],
        )?;
        Ok(())
    }

    /// Fehler-Statistiken laden (Top N häufigste Fehler)
    pub fn get_error_stats(&self, limit: usize) -> SqlResult<Vec<(String, String, String, i32, Option<i64>)>> {
        let mut stmt = self.conn.prepare(
            "SELECT error_hash, error_message, tool, occurrence_count, kb_pattern_id
             FROM error_tracker
             ORDER BY occurrence_count DESC
             LIMIT ?1"
        )?;
        let stats = stmt.query_map(params![limit as i64], |row| {
            Ok((row.get(0)?, row.get(1)?, row.get(2)?, row.get(3)?, row.get(4)?))
        })?.collect::<SqlResult<Vec<_>>>()?;
        Ok(stats)
    }

    // ============ Statistiken ============

    /// DB-Statistiken
    pub fn stats(&self) -> SqlResult<DbStats> {
        let permissions: usize = self.conn.query_row(
            "SELECT COUNT(*) FROM permissions", [], |row| row.get(0)
        )?;
        let audit_entries: usize = self.conn.query_row(
            "SELECT COUNT(*) FROM audit_log", [], |row| row.get(0)
        )?;
        let memory_entries: usize = self.conn.query_row(
            "SELECT COUNT(*) FROM memory", [], |row| row.get(0)
        )?;
        let patterns: usize = self.conn.query_row(
            "SELECT COUNT(*) FROM patterns", [], |row| row.get(0)
        )?;

        // DB-Größe ermitteln
        let page_count: u64 = self.conn.query_row(
            "PRAGMA page_count", [], |row| row.get(0)
        )?;
        let page_size: u64 = self.conn.query_row(
            "PRAGMA page_size", [], |row| row.get(0)
        )?;
        let db_size_kb = (page_count * page_size) / 1024;

        Ok(DbStats { permissions, audit_entries, memory_entries, patterns, db_size_kb })
    }
}

// ============ Hilfsfunktionen ============

fn parse_audit_category(s: &str) -> AuditCategory {
    match s {
        "guardrail" | "guard_rail" => AuditCategory::GuardRail,
        "pattern" => AuditCategory::Pattern,
        "hook" => AuditCategory::Hook,
        "skill" => AuditCategory::Skill,
        "setting" => AuditCategory::Setting,
        "mcp" => AuditCategory::MCP,
        "memory" => AuditCategory::Memory,
        _ => AuditCategory::Setting,
    }
}

fn parse_audit_action(s: &str) -> AuditAction {
    match s {
        "create" => AuditAction::Create,
        "update" => AuditAction::Update,
        "delete" => AuditAction::Delete,
        "enable" => AuditAction::Enable,
        "disable" => AuditAction::Disable,
        _ => AuditAction::Update,
    }
}

fn parse_context_category(s: &str) -> ContextCategory {
    match s {
        "Critical" => ContextCategory::Critical,
        "Pattern" => ContextCategory::Pattern,
        "Preference" => ContextCategory::Preference,
        "GuardRail" => ContextCategory::GuardRail,
        "Hook" => ContextCategory::Hook,
        "Skill" => ContextCategory::Skill,
        _ => ContextCategory::Pattern,
    }
}

// ============ Tauri Commands ============

pub type DbState = Arc<Mutex<Database>>;

/// DB initialisieren (falls Frontend es auslösen will)
#[tauri::command]
pub async fn init_database(app: AppHandle) -> Result<DbStats, String> {
    let state = app.state::<DbState>();
    let db = state.lock().unwrap();
    db.stats().map_err(|e| e.to_string())
}

/// DB-Statistiken abrufen
#[tauri::command]
pub async fn get_db_stats(app: AppHandle) -> Result<DbStats, String> {
    let state = app.state::<DbState>();
    let db = state.lock().unwrap();
    db.stats().map_err(|e| e.to_string())
}

/// Einstellung lesen
#[tauri::command]
pub async fn get_setting(app: AppHandle, key: String) -> Result<Option<String>, String> {
    let state = app.state::<DbState>();
    let db = state.lock().unwrap();
    db.get_setting(&key).map_err(|e| e.to_string())
}

/// Einstellung speichern
#[tauri::command]
pub async fn set_setting(app: AppHandle, key: String, value: String) -> Result<(), String> {
    let state = app.state::<DbState>();
    let db = state.lock().unwrap();
    db.set_setting(&key, &value).map_err(|e| e.to_string())
}

/// Alle Einstellungen laden
#[tauri::command]
pub async fn get_all_settings(app: AppHandle) -> Result<Vec<(String, String)>, String> {
    let state = app.state::<DbState>();
    let db = state.lock().unwrap();
    db.get_all_settings().map_err(|e| e.to_string())
}

/// Nachricht speichern
#[tauri::command]
pub async fn save_message(app: AppHandle, message: ChatMessage) -> Result<(), String> {
    let state = app.state::<DbState>();
    let db = state.lock().unwrap();
    db.save_message(&message).map_err(|e| e.to_string())
}

/// Nachrichten einer Session laden
#[tauri::command]
pub async fn load_messages(app: AppHandle, session_id: String) -> Result<Vec<ChatMessage>, String> {
    let state = app.state::<DbState>();
    let db = state.lock().unwrap();
    db.load_messages(&session_id).map_err(|e| e.to_string())
}

/// Alle Nachrichten einer Session löschen
#[tauri::command]
pub async fn clear_messages(app: AppHandle, session_id: String) -> Result<(), String> {
    let state = app.state::<DbState>();
    let db = state.lock().unwrap();
    db.clear_messages(&session_id).map_err(|e| e.to_string())
}

/// Block C: Cross-Session-Recall — sucht in alten Sessions nach aehnlichen
/// Assistant-Antworten. Frontend ruft das beim ersten claude-text auf, damit
/// User sieht "🕒 Schon mal beantwortet" wenn er etwas Aehnliches frueher fragte.
#[tauri::command]
pub async fn search_past_messages(
    app: AppHandle,
    query: String,
    current_session_id: Option<String>,
    limit: Option<usize>,
) -> Result<Vec<PastMessageMatch>, String> {
    let state = app.state::<DbState>();
    let db = state.lock().unwrap();
    db.search_past_messages(&query, current_session_id.as_deref(), limit.unwrap_or(3))
        .map_err(|e| e.to_string())
}

/// Block C: einmalige Migration — bestehende messages in den FTS5-Index spielen.
/// Frontend ruft das einmal beim App-Start auf (idempotent — tut nichts wenn schon synced).
#[tauri::command]
pub async fn rebuild_messages_fts(app: AppHandle) -> Result<usize, String> {
    let state = app.state::<DbState>();
    let db = state.lock().unwrap();
    db.rebuild_messages_fts().map_err(|e| e.to_string())
}

/// Session kompaktieren — fasst alte Nachrichten zusammen
#[tauri::command]
pub async fn compact_session(
    app: AppHandle,
    session_id: String,
    keep_last: Option<usize>,
) -> Result<usize, String> {
    let keep = keep_last.unwrap_or(30); // Standard: letzte 30 Nachrichten behalten
    let state = app.state::<DbState>();
    let db = state.lock().unwrap();
    let compacted = db.compact_session(&session_id, keep).map_err(|e| e.to_string())?;

    if compacted > 0 {
        println!("📦 Session {} kompaktiert: {} Nachrichten zusammengefasst", session_id, compacted);
    }

    Ok(compacted)
}

// ============ Monitor-Events Commands ============

/// Monitor-Event speichern
#[tauri::command]
pub async fn save_monitor_event(app: AppHandle, event: MonitorEvent) -> Result<(), String> {
    let state = app.state::<DbState>();
    let db = state.lock().unwrap();
    db.save_monitor_event(&event).map_err(|e| e.to_string())
}

/// Monitor-Events laden (neueste zuerst)
#[tauri::command]
pub async fn load_monitor_events(app: AppHandle, limit: Option<usize>) -> Result<Vec<MonitorEvent>, String> {
    let limit = limit.unwrap_or(1000); // Standard: letzte 1000 Events
    let state = app.state::<DbState>();
    let db = state.lock().unwrap();
    db.load_monitor_events(limit).map_err(|e| e.to_string())
}

/// Monitor-Events nach Typ laden
#[tauri::command]
pub async fn load_monitor_events_by_type(
    app: AppHandle,
    event_type: String,
    limit: Option<usize>,
) -> Result<Vec<MonitorEvent>, String> {
    let limit = limit.unwrap_or(500);
    let state = app.state::<DbState>();
    let db = state.lock().unwrap();
    db.load_monitor_events_by_type(&event_type, limit).map_err(|e| e.to_string())
}

/// Alle Monitor-Events löschen
#[tauri::command]
pub async fn clear_all_monitor_events(app: AppHandle) -> Result<usize, String> {
    let state = app.state::<DbState>();
    let db = state.lock().unwrap();
    let count = db.clear_monitor_events().map_err(|e| e.to_string())?;
    println!("🗑️ {} Monitor-Events gelöscht", count);
    Ok(count)
}

/// Monitor-Event Statistiken
#[tauri::command]
pub async fn get_monitor_stats(app: AppHandle) -> Result<Vec<(String, usize)>, String> {
    let state = app.state::<DbState>();
    let db = state.lock().unwrap();
    db.count_monitor_events_by_type().map_err(|e| e.to_string())
}

// ============ Phase 2.0: Fehler-Tracking Commands ============

/// Fehler tracken — gibt (count, kb_pattern_id) zurück
#[tauri::command]
pub async fn track_error(
    app: AppHandle,
    error_hash: String,
    error_message: String,
    tool: String,
) -> Result<(i32, Option<i64>), String> {
    let state = app.state::<DbState>();
    let db = state.lock().unwrap();
    db.track_error(&error_hash, &error_message, &tool).map_err(|e| e.to_string())
}

/// KB-Pattern-ID für Fehler setzen
#[tauri::command]
pub async fn set_error_kb_pattern(
    app: AppHandle,
    error_hash: String,
    kb_pattern_id: i64,
) -> Result<(), String> {
    let state = app.state::<DbState>();
    let db = state.lock().unwrap();
    db.set_error_kb_pattern(&error_hash, kb_pattern_id).map_err(|e| e.to_string())
}

/// Fehler-Statistiken laden
#[tauri::command]
pub async fn get_error_stats(
    app: AppHandle,
    limit: Option<usize>,
) -> Result<Vec<(String, String, String, i32, Option<i64>)>, String> {
    let limit = limit.unwrap_or(20);
    let state = app.state::<DbState>();
    let db = state.lock().unwrap();
    db.get_error_stats(limit).map_err(|e| e.to_string())
}

// ============ Projekte ============

/// Ein Projekt für schnellen Wechsel
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
pub struct Project {
    pub id: String,
    pub name: String,
    pub working_dir: String,
    pub claude_md_path: Option<String>,
    pub description: Option<String>,
    pub last_used: String,
    pub created_at: String,
    pub session_count: i64,
}

impl Database {
    /// Alle Projekte laden (zuletzt benutzte zuerst)
    pub fn list_projects(&self) -> SqlResult<Vec<Project>> {
        let mut stmt = self.conn.prepare(
            "SELECT id, name, working_dir, claude_md_path, description, last_used, created_at, session_count
             FROM projects ORDER BY last_used DESC"
        )?;
        let projects = stmt.query_map([], |row| {
            Ok(Project {
                id: row.get(0)?,
                name: row.get(1)?,
                working_dir: row.get(2)?,
                claude_md_path: row.get(3)?,
                description: row.get(4)?,
                last_used: row.get(5)?,
                created_at: row.get(6)?,
                session_count: row.get(7)?,
            })
        })?.collect::<SqlResult<Vec<_>>>()?;
        Ok(projects)
    }

    /// Projekt speichern (INSERT oder UPDATE)
    pub fn save_project(&self, project: &Project) -> SqlResult<()> {
        self.conn.execute(
            "INSERT OR REPLACE INTO projects (id, name, working_dir, claude_md_path, description, last_used, created_at, session_count)
             VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7, ?8)",
            params![
                project.id, project.name, project.working_dir,
                project.claude_md_path, project.description,
                project.last_used, project.created_at, project.session_count,
            ],
        )?;
        Ok(())
    }

    /// Projekt löschen
    pub fn delete_project(&self, id: &str) -> SqlResult<()> {
        self.conn.execute("DELETE FROM projects WHERE id = ?1", params![id])?;
        Ok(())
    }

    /// Projekt als zuletzt benutzt markieren
    pub fn touch_project(&self, id: &str) -> SqlResult<()> {
        self.conn.execute(
            "UPDATE projects SET last_used = datetime('now'), session_count = session_count + 1 WHERE id = ?1",
            params![id],
        )?;
        Ok(())
    }
}

// Tauri-Commands für Projekte

#[tauri::command]
pub async fn list_projects(app: AppHandle) -> Result<Vec<Project>, String> {
    let state = app.state::<DbState>();
    let db = state.lock().unwrap();
    db.list_projects().map_err(|e| e.to_string())
}

#[tauri::command]
pub async fn save_project(app: AppHandle, project: Project) -> Result<(), String> {
    let state = app.state::<DbState>();
    let db = state.lock().unwrap();
    db.save_project(&project).map_err(|e| e.to_string())
}

#[tauri::command]
pub async fn delete_project(app: AppHandle, id: String) -> Result<(), String> {
    let state = app.state::<DbState>();
    let db = state.lock().unwrap();
    db.delete_project(&id).map_err(|e| e.to_string())
}

#[tauri::command]
pub async fn switch_project(app: AppHandle, project_id: String) -> Result<Project, String> {
    let state = app.state::<DbState>();
    let db = state.lock().unwrap();

    // Projekt als benutzt markieren
    db.touch_project(&project_id).map_err(|e| e.to_string())?;

    // Projekt-Daten laden
    let projects = db.list_projects().map_err(|e| e.to_string())?;
    let project = projects.into_iter()
        .find(|p| p.id == project_id)
        .ok_or_else(|| format!("Projekt '{}' nicht gefunden", project_id))?;

    // Sticky-Context aktualisieren: current_project setzen
    let project_json = serde_json::json!({
        "id": project.id,
        "name": project.name,
        "working_dir": project.working_dir,
    }).to_string();

    db.conn.execute(
        "INSERT OR REPLACE INTO sticky_context (key, value, priority, updated_at)
         VALUES ('project:current', ?1, 10, datetime('now'))",
        params![project_json],
    ).map_err(|e| e.to_string())?;

    Ok(project)
}