<?php
/**
 * AJAX API voor Dagplanning & Taken
 */

require_once __DIR__ . '/../includes/auth.php';
require_once __DIR__ . '/../includes/integrations/microsoft.php';
$user = require_auth();
$db = get_db_connection();

header('Content-Type: application/json');

$action = $_GET['action'] ?? ($_POST['action'] ?? '');
$today = date('Y-m-d');

try {
    // 1. Dagdoel of notities opslaan
    if ($action === 'save_goal') {
        $data = json_decode(file_get_contents('php://input'), true);
        $date = $data['date'] ?? $today;
        $focusGoal = $data['focus_goal'] ?? '';
        $notes = $data['notes'] ?? '';

        $stmt = $db->prepare("
            INSERT INTO daily_plans (user_id, plan_date, focus_goal, notes)
            VALUES (?, ?, ?, ?)
            ON DUPLICATE KEY UPDATE focus_goal = VALUES(focus_goal), notes = VALUES(notes)
        ");
        $stmt->execute([$user['id'], $date, $focusGoal, $notes]);

        echo json_encode(['success' => true]);
        exit;
    }

    // 2. Taak toevoegen
    if ($action === 'add_task') {
        $data = json_decode(file_get_contents('php://input'), true);
        $title = trim($data['title'] ?? '');
        $priority = in_array($data['priority'] ?? '', ['P1', 'P2', 'P3']) ? $data['priority'] : 'P2';
        $timeBlockStart = !empty($data['time_block_start']) ? trim($data['time_block_start']) : null;
        $durationMinutes = (int)($data['duration_minutes'] ?? 30);
        if ($durationMinutes <= 0) $durationMinutes = 30;
        $date = !empty($data['date']) ? trim($data['date']) : $today;
        $syncOutlook = !empty($data['sync_to_outlook']);

        if (empty($title)) {
            echo json_encode(['error' => 'Titel is verplicht']);
            exit;
        }

        // Haal of maak daily plan op
        $stmtPlan = $db->prepare("
            INSERT INTO daily_plans (user_id, plan_date)
            VALUES (?, ?)
            ON DUPLICATE KEY UPDATE id=LAST_INSERT_ID(id)
        ");
        $stmtPlan->execute([$user['id'], $date]);
        $planId = $db->lastInsertId();

        $source = !empty($data['source']) ? substr(trim($data['source']), 0, 50) : 'FOCIZ';
        $externalId = !empty($data['external_id']) ? substr(trim($data['external_id']), 0, 255) : null;
        $externalUrl = !empty($data['external_url']) ? trim($data['external_url']) : null;
        $timeBlockEnd = null;

        // Als er een tijdblok is en de gebruiker heeft synchronisatie naar Outlook gekozen (of source is OUTLOOK)
        if (($syncOutlook || $source === 'OUTLOOK') && !empty($timeBlockStart) && empty($externalId)) {
            $msResult = microsoft_create_event($user['id'], [
                'subject'          => $title,
                'description'      => "Gepland via Fociz Dagplanning ({$priority})",
                'date'             => $date,
                'start_time'       => $timeBlockStart,
                'duration_minutes' => $durationMinutes,
            ]);

            if (!empty($msResult['success']) && !empty($msResult['event_id'])) {
                $source = 'OUTLOOK';
                $externalId = $msResult['event_id'];
                $externalUrl = $msResult['web_link'] ?? 'https://outlook.office.com';
                $timeBlockEnd = $msResult['end_time'] ?? null;
            }
        }

        // Bereken timeBlockEnd indien nog niet gezet maar wel starttijd bekend
        if (!empty($timeBlockStart) && empty($timeBlockEnd)) {
            try {
                $dtEnd = new DateTime("{$date} {$timeBlockStart}:00", new DateTimeZone('Europe/Amsterdam'));
                $dtEnd->modify("+{$durationMinutes} minutes");
                $timeBlockEnd = $dtEnd->format('H:i');
            } catch (Throwable $e) {
                // negeer
            }
        }

        $stmt = $db->prepare("
            INSERT INTO tasks (user_id, daily_plan_id, title, priority, time_block_start, time_block_end, duration_minutes, status, source, external_id, external_url)
            VALUES (?, ?, ?, ?, ?, ?, ?, 'TODO', ?, ?, ?)
        ");
        $stmt->execute([$user['id'], $planId, $title, $priority, $timeBlockStart, $timeBlockEnd, $durationMinutes, $source, $externalId, $externalUrl]);
        $taskId = (int)$db->lastInsertId();

        echo json_encode([
            'success' => true,
            'task' => [
                'id' => $taskId,
                'title' => $title,
                'priority' => $priority,
                'time_block_start' => $timeBlockStart,
                'time_block_end' => $timeBlockEnd,
                'duration_minutes' => $durationMinutes,
                'is_completed' => 0,
                'status' => 'TODO',
                'source' => $source,
                'external_id' => $externalId,
                'external_url' => $externalUrl,
            ],
            'outlook_synced' => ($source === 'OUTLOOK' && !empty($externalId)),
        ]);
        exit;
    }

    // 3. Bestaande taak handmatig naar Microsoft Outlook synchroniseren
    if ($action === 'sync_task_to_outlook') {
        $data = json_decode(file_get_contents('php://input'), true);
        $taskId = (int)($data['task_id'] ?? 0);

        if (!$taskId) {
            echo json_encode(['error' => 'Geen taak-ID opgegeven']);
            exit;
        }

        // Haal taak inclusief plan datum op
        $stmtTask = $db->prepare("
            SELECT t.*, dp.plan_date
            FROM tasks t
            LEFT JOIN daily_plans dp ON t.daily_plan_id = dp.id
            WHERE t.id = ? AND t.user_id = ?
        ");
        $stmtTask->execute([$taskId, $user['id']]);
        $task = $stmtTask->fetch();

        if (!$task) {
            echo json_encode(['error' => 'Taak niet gevonden']);
            exit;
        }

        // Als al gesynchroniseerd
        if (!empty($task['external_id']) && $task['source'] === 'OUTLOOK') {
            echo json_encode([
                'success' => true,
                'already_synced' => true,
                'external_id' => $task['external_id'],
                'external_url' => $task['external_url']
            ]);
            exit;
        }

        $planDate = $task['plan_date'] ?: $today;
        $startTime = !empty($task['time_block_start']) ? $task['time_block_start'] : ($data['time_block_start'] ?? '09:00');
        $duration = (int)($task['duration_minutes'] ?: 30);

        $msResult = microsoft_create_event($user['id'], [
            'subject'          => $task['title'],
            'description'      => "Gepland via Fociz Dagplanning (" . $task['priority'] . ")",
            'date'             => $planDate,
            'start_time'       => $startTime,
            'duration_minutes' => $duration,
        ]);

        if (empty($msResult['success']) || empty($msResult['event_id'])) {
            echo json_encode(['error' => $msResult['error'] ?? 'Kon afspraak niet aanmaken in Microsoft Outlook']);
            exit;
        }

        // Sla Outlook ID en bron op in de taak
        $stmtUp = $db->prepare("
            UPDATE tasks 
            SET source = 'OUTLOOK', 
                external_id = ?, 
                external_url = ?, 
                time_block_start = COALESCE(time_block_start, ?),
                time_block_end = ?
            WHERE id = ? AND user_id = ?
        ");
        $stmtUp->execute([
            $msResult['event_id'],
            $msResult['web_link'] ?? 'https://outlook.office.com',
            $msResult['start_time'],
            $msResult['end_time'],
            $taskId,
            $user['id']
        ]);

        echo json_encode([
            'success' => true,
            'external_id' => $msResult['event_id'],
            'external_url' => $msResult['web_link'] ?? 'https://outlook.office.com',
            'start_time' => $msResult['start_time'],
            'end_time' => $msResult['end_time'],
        ]);
        exit;
    }

    // 4. Taak status toggelen (voltooid / open)
    if ($action === 'toggle_task') {
        $data = json_decode(file_get_contents('php://input'), true);
        $taskId = (int)($data['task_id'] ?? 0);
        $isCompleted = !empty($data['is_completed']) ? 1 : 0;
        $status = $isCompleted ? 'DONE' : 'TODO';

        $stmt = $db->prepare("
            UPDATE tasks SET is_completed = ?, status = ?
            WHERE id = ? AND user_id = ?
        ");
        $stmt->execute([$isCompleted, $status, $taskId, $user['id']]);

        echo json_encode(['success' => true]);
        exit;
    }

    // 5. Taak verwijderen (verwijder ook eventueel gekoppelde Outlook afspraak)
    if ($action === 'delete_task') {
        $data = json_decode(file_get_contents('php://input'), true);
        $taskId = (int)($data['task_id'] ?? 0);

        // Haal eerst op of deze taak aan Outlook was gekoppeld
        $stmtCheck = $db->prepare("SELECT external_id, source FROM tasks WHERE id = ? AND user_id = ?");
        $stmtCheck->execute([$taskId, $user['id']]);
        $taskToDelete = $stmtCheck->fetch();

        if ($taskToDelete && !empty($taskToDelete['external_id']) && $taskToDelete['source'] === 'OUTLOOK') {
            try {
                microsoft_delete_event($user['id'], $taskToDelete['external_id']);
            } catch (Throwable $t) {
                error_log("Fout bij verwijderen Outlook afspraak voor taak {$taskId}: " . $t->getMessage());
            }
        }

        $stmt = $db->prepare("DELETE FROM tasks WHERE id = ? AND user_id = ?");
        $stmt->execute([$taskId, $user['id']]);

        echo json_encode(['success' => true]);
        exit;
    }

    echo json_encode(['error' => 'Onbekende actie']);
} catch (Exception $e) {
    http_response_code(500);
    echo json_encode(['error' => $e->getMessage()]);
}