<?php
require_once __DIR__ . '/../../helpers.php';
require_once __DIR__ . '/_cronUtils.php';
runAuth();

/**
 * Create or update a scheduled task definition.
 * POST: { BusinessID, ScheduledTaskID? (for update), Name, Title, Details, CategoryID,
 *          CronExpression, IsActive, ScheduleType ('cron'|'interval'|'interval_after_completion'),
 *          IntervalMinutes (for interval types) }
 */

$data = readJsonBody();
$businessID      = (int) ($data['BusinessID'] ?? headerValue('X-Business-ID') ?? 0);
$taskID          = (int) ($data['ScheduledTaskID'] ?? 0);
$taskName        = trim($data['Name'] ?? '');
$taskTitle       = trim($data['Title'] ?? '');
$taskDetails     = trim($data['Details'] ?? '');
$categoryID      = (isset($data['CategoryID']) && is_numeric($data['CategoryID']) && $data['CategoryID'] > 0) ? (int) $data['CategoryID'] : null;
$cronExpression  = trim($data['CronExpression'] ?? '');
$isActive        = isset($data['IsActive']) ? ($data['IsActive'] ? 1 : 0) : 1;
$scheduleType    = trim($data['ScheduleType'] ?? 'cron');
$intervalMinutes = (isset($data['IntervalMinutes']) && is_numeric($data['IntervalMinutes'])) ? (int) $data['IntervalMinutes'] : null;

if ($businessID <= 0) {
    apiAbort(['OK' => false, 'ERROR' => 'missing_params', 'MESSAGE' => 'BusinessID is required']);
}
if ($taskName === '') {
    apiAbort(['OK' => false, 'ERROR' => 'missing_params', 'MESSAGE' => 'Name is required']);
}
if ($taskTitle === '') {
    apiAbort(['OK' => false, 'ERROR' => 'missing_params', 'MESSAGE' => 'Title is required']);
}

try {
    // Determine next run based on schedule type
    if ($scheduleType === 'interval' || $scheduleType === 'interval_after_completion') {
        if ($intervalMinutes === null || $intervalMinutes < 1) {
            apiAbort(['OK' => false, 'ERROR' => 'missing_params', 'MESSAGE' => 'IntervalMinutes is required for interval scheduling (minimum 1)']);
        }
        if ($cronExpression === '') {
            $cronExpression = '* * * * *';
        }
        $nextRunOn = ($taskID === 0)
            ? new DateTime('now', new DateTimeZone('UTC'))
            : new DateTime("+{$intervalMinutes} minutes", new DateTimeZone('UTC'));
    } else {
        if ($cronExpression === '') {
            apiAbort(['OK' => false, 'ERROR' => 'missing_params', 'MESSAGE' => 'CronExpression is required']);
        }
        $cronParts = preg_split('/\s+/', $cronExpression);
        if (count($cronParts) !== 5) {
            apiAbort(['OK' => false, 'ERROR' => 'invalid_cron', 'MESSAGE' => 'Cron expression must have 5 parts: minute hour day month weekday']);
        }
        $nextRunOn = calculateNextRun($cronExpression);
    }

    $nextRunStr = $nextRunOn->format('Y-m-d H:i:s');

    if ($taskID > 0) {
        // UPDATE
        $existing = queryOne("SELECT ID FROM ScheduledTaskDefinitions WHERE ID = ? AND BusinessID = ?", [$taskID, $businessID]);
        if (!$existing) {
            apiAbort(['OK' => false, 'ERROR' => 'not_found', 'MESSAGE' => 'Scheduled task not found']);
        }

        queryTimed("
            UPDATE ScheduledTaskDefinitions SET
                Name = ?, Title = ?, Details = ?, TaskCategoryID = ?,
                CronExpression = ?, ScheduleType = ?, IntervalMinutes = ?,
                IsActive = ?, NextRunOn = ?
            WHERE ID = ?
        ", [$taskName, $taskTitle, $taskDetails ?: null, $categoryID, $cronExpression, $scheduleType, $intervalMinutes, $isActive, $nextRunStr, $taskID]);

        jsonResponse([
            'OK'                => true,
            'SCHEDULED_TASK_ID' => $taskID,
            'NEXT_RUN'          => $nextRunStr,
            'MESSAGE'           => 'Scheduled task updated',
        ]);
    } else {
        // INSERT
        queryTimed("
            INSERT INTO ScheduledTaskDefinitions (
                BusinessID, Name, Title, Details, TaskCategoryID,
                CronExpression, ScheduleType, IntervalMinutes, IsActive, NextRunOn
            ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
        ", [$businessID, $taskName, $taskTitle, $taskDetails ?: null, $categoryID, $cronExpression, $scheduleType, $intervalMinutes, $isActive, $nextRunStr]);

        $newScheduledTaskID = (int) lastInsertId();

        // Create the first task immediately
        queryTimed("
            INSERT INTO Tasks (BusinessID, CategoryID, TaskTypeID, Title, Details, CreatedOn, ClaimedByUserID)
            VALUES (?, ?, 0, ?, ?, NOW(), 0)
        ", [$businessID, $categoryID, $taskTitle, $taskDetails ?: null]);

        $firstTaskID = (int) lastInsertId();

        // Calculate actual next run (after the immediate one)
        if ($scheduleType === 'interval_after_completion') {
            $actualNextRunStr = null; // Don't schedule until task completion
        } elseif ($scheduleType === 'interval') {
            $actualNextRun = new DateTime("+{$intervalMinutes} minutes", new DateTimeZone('UTC'));
            $actualNextRunStr = $actualNextRun->format('Y-m-d H:i:s');
        } else {
            $actualNextRun = calculateNextRun($cronExpression);
            $actualNextRunStr = $actualNextRun->format('Y-m-d H:i:s');
        }

        queryTimed("
            UPDATE ScheduledTaskDefinitions SET LastRunOn = NOW(), NextRunOn = ?
            WHERE ID = ?
        ", [$actualNextRunStr, $newScheduledTaskID]);

        jsonResponse([
            'OK'                => true,
            'SCHEDULED_TASK_ID' => $newScheduledTaskID,
            'TASK_ID'           => $firstTaskID,
            'NEXT_RUN'          => $actualNextRunStr ?? '',
            'MESSAGE'           => 'Scheduled task created and first task added',
        ]);
    }

} catch (Exception $e) {
    jsonResponse(['OK' => false, 'ERROR' => 'server_error', 'MESSAGE' => $e->getMessage()]);
}