<?php
/* Page-Operationen für Bericht-Seiten (PWA).
 *
 * DELETE /api/pages.php?id=<page_id>    — Seite löschen
 * POST   /api/pages.php?id=<page_id>    — Body { note: "..." }  — Notiz setzen
 *                                         Body { rotation: 90 } — rotieren
 * POST   /api/pages.php?action=signature&bericht_id=<id>
 *        multipart: file=<PNG> — Unterschrift als neue Seite am Bericht anhängen
 */
require_once __DIR__.'/_inc.php';

api_authenticate();
global $db, $user;

if (!$user->hasRight('bericht', 'write')) api_fail('Permission denied', 403);

$method = $_SERVER['REQUEST_METHOD'];
$action = $_GET['action'] ?? '';

/* ---------- Unterschrift als neue Seite anhängen ---------- */
if ($method === 'POST' && $action === 'signature') {
    $bericht_id = (int) ($_GET['bericht_id'] ?? 0);
    if (!$bericht_id) api_fail('bericht_id fehlt');
    if (empty($_FILES['file']['tmp_name'])) api_fail('file fehlt');

    $bericht = new Bericht($db);
    if ($bericht->fetch($bericht_id) <= 0) api_fail('Bericht nicht gefunden', 404);

    // Parent-Objekt (Kunde) holen — wir brauchen den Kundennamen für die Metadaten
    $parent = bericht_fetch_parent($db, $bericht->element_type, $bericht->fk_element);
    $kundename = $parent && !empty($parent->thirdparty) ? ($parent->thirdparty->name ?? '') : '';
    $parent_ref = $parent ? $parent->ref : '';

    // Zusatz-Felder vom Client
    $signer_name = trim((string) ($_POST['signer_name'] ?? ''));
    $gps_lat = isset($_POST['gps_lat']) ? (float) $_POST['gps_lat'] : null;
    $gps_lon = isset($_POST['gps_lon']) ? (float) $_POST['gps_lon'] : null;

    require_once DOL_DOCUMENT_ROOT.'/core/lib/files.lib.php';
    $workdir = DOL_DATA_ROOT.'/bericht/work/'.$bericht_id;
    if (!is_dir($workdir)) dol_mkdir($workdir);

    // Hash-Verkettung: SHA256 über alle vorherigen Seiten-Quelldateien
    $prev_pages = BerichtPage::fetchAllForBericht($db, $bericht_id);
    $hash_ctx = hash_init('sha256');
    hash_update($hash_ctx, 'bericht:'.$bericht_id.'|ref:'.$bericht->ref);
    foreach ($prev_pages as $pp) {
        $full_pp = bericht_resolve_data_path($pp->source_path);
        if ($full_pp && file_exists($full_pp)) {
            hash_update_file($hash_ctx, $full_pp);
        }
        hash_update($hash_ctx, '|order:'.$pp->page_order.'|note:'.($pp->note ?? ''));
    }
    $chain_hash = hash_final($hash_ctx);

    // Rohe Unterschrift vom Upload
    $raw_sig_png = file_get_contents($_FILES['file']['tmp_name']);
    if (!$raw_sig_png) api_fail('Upload fehlgeschlagen', 500);
    $sig_img = @imagecreatefromstring($raw_sig_png);
    if (!$sig_img) api_fail('PNG ungültig');
    $sig_w = imagesx($sig_img);
    $sig_h = imagesy($sig_img);

    // Composite-Canvas: Metadaten oben, Unterschrift in der Mitte, Footer mit Hash unten
    $canvas_w = max($sig_w, 1200);
    $header_h = 180;
    $footer_h = 120;
    $sig_area_h = 500;
    $canvas_h = $header_h + $sig_area_h + $footer_h;
    $canvas = imagecreatetruecolor($canvas_w, $canvas_h);

    $white = imagecolorallocate($canvas, 255, 255, 255);
    $black = imagecolorallocate($canvas, 0, 0, 0);
    $grey  = imagecolorallocate($canvas, 120, 120, 120);
    $line_grey = imagecolorallocate($canvas, 200, 200, 200);
    $dark_blue = imagecolorallocate($canvas, 51, 122, 183);
    imagefill($canvas, 0, 0, $white);

    // Header-Box
    imagefilledrectangle($canvas, 0, 0, $canvas_w, $header_h, imagecolorallocate($canvas, 245, 248, 252));
    imagerectangle($canvas, 0, 0, $canvas_w - 1, $header_h, $line_grey);

    // Überschrift
    $title = 'ABNAHMEUNTERSCHRIFT';
    imagestring($canvas, 5, 20, 15, $title, $dark_blue);

    // Metadaten Zeile 1
    $line1 = 'Bericht: '.$bericht->ref.'   ·   '.trim($bericht->element_type.' '.$parent_ref);
    imagestring($canvas, 4, 20, 50, $line1, $black);
    // Zeile 2: Kunde
    $line2 = 'Kunde: '.$kundename;
    imagestring($canvas, 4, 20, 75, $line2, $black);
    // Zeile 3: Datum + Zeit (Server) + Unterzeichner
    $datetime = date('Y-m-d H:i:s');
    $line3 = 'Zeit (Server): '.$datetime.'   ·   Unterzeichner: '.($signer_name ?: '—');
    imagestring($canvas, 4, 20, 100, $line3, $black);
    // Zeile 4: GPS
    if ($gps_lat !== null && $gps_lon !== null) {
        $line4 = sprintf('GPS: %.6f, %.6f', $gps_lat, $gps_lon);
        imagestring($canvas, 3, 20, 125, $line4, $black);
    }
    // Bestätigungstext
    $bestaetigung = 'Ich bestaetige hiermit die ordnungsgemaesse Ausfuehrung der dokumentierten Arbeiten.';
    imagestring($canvas, 3, 20, 150, $bestaetigung, $black);

    // Unterschrift-Bereich mittig einsetzen, auf Breite skalieren
    $max_sig_w = $canvas_w - 80;
    $max_sig_h = $sig_area_h - 60;
    $ratio = min($max_sig_w / $sig_w, $max_sig_h / $sig_h);
    $dw = (int) ($sig_w * $ratio);
    $dh = (int) ($sig_h * $ratio);
    $dx = (int) (($canvas_w - $dw) / 2);
    $dy = $header_h + 30;
    imagecopyresampled($canvas, $sig_img, $dx, $dy, 0, 0, $dw, $dh, $sig_w, $sig_h);
    imagedestroy($sig_img);

    // Trennlinie unter der Unterschrift
    imageline($canvas, 40, $header_h + $sig_area_h - 20, $canvas_w - 40, $header_h + $sig_area_h - 20, $grey);
    imagestring($canvas, 3, (int) ($canvas_w / 2 - 50), $header_h + $sig_area_h - 15,
        'Unterschrift Kunde', $grey);

    // Footer-Box mit Hash
    $fy = $header_h + $sig_area_h;
    imagefilledrectangle($canvas, 0, $fy, $canvas_w, $canvas_h, imagecolorallocate($canvas, 248, 248, 248));
    imagerectangle($canvas, 0, $fy, $canvas_w - 1, $canvas_h - 1, $line_grey);
    imagestring($canvas, 3, 20, $fy + 15, 'Integritaetspruefung (SHA-256 ueber alle vorherigen Seiten):', $grey);
    imagestring($canvas, 2, 20, $fy + 40, $chain_hash, $black);
    imagestring($canvas, 2, 20, $fy + 70, 'Erfasst: '.$datetime.' · Server: '.($_SERVER['SERVER_NAME'] ?? ''), $grey);

    // Schreiben
    $filename = 'signature_'.dol_print_date(dol_now(), '%Y%m%d_%H%M%S').'.png';
    $target = $workdir.'/'.$filename;
    if (!imagepng($canvas, $target, 6)) api_fail('PNG schreiben fehlgeschlagen', 500);
    imagedestroy($canvas);
    $relpath = str_replace(DOL_DATA_ROOT.'/', '', $target);

    // Metadaten als JSON neben der Datei speichern (für spätere Verifikation)
    $meta = array(
        'bericht_id' => $bericht_id,
        'bericht_ref' => $bericht->ref,
        'parent_type' => $bericht->element_type,
        'parent_ref' => $parent_ref,
        'kunde' => $kundename,
        'signer_name' => $signer_name,
        'signed_at' => $datetime,
        'signed_at_unix' => time(),
        'user_id' => $user->id,
        'user_login' => $user->login,
        'gps_lat' => $gps_lat,
        'gps_lon' => $gps_lon,
        'chain_hash_sha256' => $chain_hash,
        'page_count_at_signing' => count($prev_pages),
        'remote_ip' => $_SERVER['REMOTE_ADDR'] ?? '',
    );
    @file_put_contents($target.'.meta.json', json_encode($meta, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE));

    $resm = $db->query("SELECT COALESCE(MAX(page_order),0) AS m FROM ".$db->prefix()."bericht_page WHERE fk_bericht = ".$bericht_id);
    $next = ($resm && ($o = $db->fetch_object($resm))) ? ((int) $o->m) + 1 : 1;

    $page = new BerichtPage($db);
    $page->fk_bericht  = $bericht_id;
    $page->page_order  = $next;
    $page->source_type = 'upload';
    $page->source_path = $relpath;
    $page->note        = 'Unterschrift '.($signer_name ?: 'Kunde').' — '.$datetime;
    if ($page->create() <= 0) api_fail('Page-Insert fehlgeschlagen', 500);

    api_ok(array(
        'page_id' => $page->id,
        'filename' => $filename,
        'chain_hash' => $chain_hash,
        'signed_at' => $datetime,
    ));
}

$page_id = (int) ($_GET['id'] ?? 0);
if (!$page_id) api_fail('id fehlt');

// Page laden + prüfen dass sie zum User-scope gehört (einfach: Admin oder Bericht-schreiben)
$pres = $db->query("SELECT rowid, fk_bericht, source_path, source_type FROM ".$db->prefix()."bericht_page WHERE rowid = ".$page_id);
if (!$pres || !($prow = $db->fetch_object($pres))) api_fail('Seite nicht gefunden', 404);

/* ---------- DELETE page ---------- */
if ($method === 'DELETE' || ($method === 'POST' && ($_GET['delete'] ?? '') === '1')) {
    if (!$user->hasRight('bericht', 'delete')) api_fail('Permission denied', 403);

    // Quell-Datei löschen nur wenn sie im bericht/work/ liegt (nicht bei Anhängen von Auftrag/Rechnung)
    if ($prow->source_path && strpos($prow->source_path, 'bericht/work/') === 0) {
        $full = bericht_resolve_data_path($prow->source_path);
        if ($full && file_exists($full)) @unlink($full);
    }
    // Multi-Image-Slot-Einträge mit löschen
    $db->query("DELETE FROM ".$db->prefix()."bericht_page_image WHERE fk_page = ".$page_id);
    $db->query("DELETE FROM ".$db->prefix()."bericht_page WHERE rowid = ".$page_id);
    api_ok();
}

/* ---------- UPDATE page (note, rotation) ---------- */
if ($method === 'POST') {
    $in = api_input();
    $sets = array();
    if (isset($in['note'])) {
        $note = (string) $in['note'];
        $sets[] = "note = ".($note !== '' ? "'".$db->escape($note)."'" : "NULL");
    }
    if (isset($in['rotation'])) {
        $rot = (int) $in['rotation'];
        $rot = (($rot % 360) + 360) % 360;
        $sets[] = "rotation = ".$rot;
    }
    if (empty($sets)) api_fail('Nichts zu aktualisieren');

    $sql = "UPDATE ".$db->prefix()."bericht_page SET ".implode(',', $sets)." WHERE rowid = ".$page_id;
    if (!$db->query($sql)) api_fail($db->lasterror(), 500);
    api_ok();
}

api_fail('Methode nicht unterstützt', 405);