<?php
require_once __DIR__ . '/../db/config.php';
require_once __DIR__ . '/../includes/functions.php';
require_once __DIR__ . '/../includes/WablasService.php';

session_write_close();
header("Content-Type: application/json");

// Enable error logging for cron
ini_set('log_errors', 1);
ini_set('error_log', __DIR__ . '/../storage/cron_errors.log');

try {
    $settings = get_company_settings();
    
    if (empty($settings['whatsapp_report_enabled']) || empty($settings['whatsapp_report_number']) || empty($settings['whatsapp_report_time'])) {
        echo json_encode(['status' => 'skipped', 'reason' => 'Not enabled or missing settings']);
        exit;
    }

    $timezone = !empty($settings['timezone']) ? $settings['timezone'] : 'UTC';
    date_default_timezone_set($timezone);

    $reportTime = $settings['whatsapp_report_time']; // e.g. "23:59:00" or "23:59"

    $lastReportFile = __DIR__ . '/../storage/last_daily_report.txt';
    if (!is_dir(dirname($lastReportFile))) {
        mkdir(dirname($lastReportFile), 0775, true);
    }

    $lastReportDate = file_exists($lastReportFile) ? trim(file_get_contents($lastReportFile)) : '';

    $nowDt = new DateTime('now', new DateTimeZone($timezone));
    $todayDateStr = $nowDt->format('Y-m-d');
    
    $targetTodayDt = clone $nowDt;
    $timeParts = explode(':', $reportTime);
    // Ignore seconds from the configuration, start matching exactly at the given minute
    $targetTodayDt->setTime((int)$timeParts[0], (int)($timeParts[1] ?? 0), 0);
    
    $targetYesterdayDt = clone $targetTodayDt;
    $targetYesterdayDt->modify('-1 day');
    $yesterdayDateStr = $targetYesterdayDt->format('Y-m-d');

    // Calculate time difference in seconds between now and the target scheduled times
    $diffToday = $nowDt->getTimestamp() - $targetTodayDt->getTimestamp();
    $diffYesterday = $nowDt->getTimestamp() - $targetYesterdayDt->getTimestamp();

    $reportDateToRun = null;

    // We allow a strict 15-minute window (900 seconds) to catch delayed cron executions.
    // If the diff is negative, the target time hasn't happened yet.
    // If the diff is > 900, we missed it by a lot (e.g. system was deployed or turned on hours later),
    // so we simply ignore it and wait for the NEXT proper scheduled time.
    if ($diffToday >= 0 && $diffToday <= 900 && $lastReportDate !== $todayDateStr) {
        $reportDateToRun = $todayDateStr;
    } elseif ($diffYesterday >= 0 && $diffYesterday <= 900 && $lastReportDate !== $yesterdayDateStr && $lastReportDate !== $todayDateStr) {
        $reportDateToRun = $yesterdayDateStr;
    }

    // Optional: write a small heartbeat log so user/admin knows cron is checking correctly
    $hb = "Timezone: $timezone | Now: " . $nowDt->format('Y-m-d H:i:s') . " | TargetToday: " . $targetTodayDt->format('Y-m-d H:i:s') . " | TargetYest: " . $targetYesterdayDt->format('Y-m-d H:i:s') . " | DiffToday: $diffToday | DiffYest: $diffYesterday | LastSent: $lastReportDate\n";
    file_put_contents(__DIR__ . '/../storage/cron_heartbeat.log', $hb);

    if (!$reportDateToRun) {
        echo json_encode(['status' => 'skipped', 'reason' => 'No report due within the allowed window or already sent', 'now' => $nowDt->format('Y-m-d H:i:s')]);
        exit;
    }

    $currentDate = $reportDateToRun;

    // GENERATE REPORT
    $pdo = db();
    
    // Get all non-cancelled orders for the report date
    $stmt = $pdo->prepare(
        "SELECT 
            o.id, o.total_amount as total, o.payment_type_id, o.user_id, o.outlet_id,
            pt.name as payment_type_name,
            u.username, u.full_name,
            outl.name as outlet_name
        FROM orders o
        LEFT JOIN payment_types pt ON o.payment_type_id = pt.id
        LEFT JOIN users u ON o.user_id = u.id
        LEFT JOIN outlets outl ON o.outlet_id = outl.id
        WHERE DATE(o.created_at) = ? AND o.status != 'cancelled'"
    );
    $stmt->execute([$currentDate]);
    $orders = $stmt->fetchAll(PDO::FETCH_ASSOC);

    $totalOrders = count($orders);
    $totalAmount = 0;
    
    $outletsData = [];
    $stmtOut = $pdo->query("SELECT name FROM outlets WHERE is_deleted = 0");
    $allOutlets = $stmtOut->fetchAll(PDO::FETCH_ASSOC);
    foreach ($allOutlets as $o) {
        $outletsData[$o["name"]] = [
            "total" => 0,
            "staff" => [],
            "payments" => []
        ];
    }

    foreach ($orders as $order) {
        $totalAmount += $order['total'];
        
        $outletName = $order['outlet_name'] ?? 'Unknown Outlet';
        $staffName = !empty($order['full_name']) ? $order['full_name'] : ($order['username'] ?? 'Unknown Staff');
        $paymentType = $order['payment_type_name'] ?? 'Unknown Payment';
        $amount = (float)$order['total'];

        if (!isset($outletsData[$outletName])) {
            $outletsData[$outletName] = [
                'total' => 0,
                'staff' => [],
                'payments' => []
            ];
        }

        $outletsData[$outletName]['total'] += $amount;

        if (!isset($outletsData[$outletName]['staff'][$staffName])) {
            $outletsData[$outletName]['staff'][$staffName] = 0;
        }
        $outletsData[$outletName]['staff'][$staffName] += $amount;

        if (!isset($outletsData[$outletName]['payments'][$paymentType])) {
            $outletsData[$outletName]['payments'][$paymentType] = 0;
        }
        $outletsData[$outletName]['payments'][$paymentType] += $amount;
    }

    $companyName = $settings['company_name'] ?? 'Restaurant';
    $currency = $settings['currency_symbol'] ?? '$';

    $message = "📊 *Daily Summary Report* 📊\n";
    $message .= "🏢 *" . $companyName . "*\n";
    $message .= "📅 Date: " . $currentDate . "\n";
    $message .= "--------------------------------\n";
    $message .= "🛒 Total Orders: " . $totalOrders . "\n";
    $message .= "💰 Total Revenue: " . format_currency($totalAmount) . "\n\n";

    if (empty($outletsData)) {
        $message .= "No active branches found.\n";
    } else {
        foreach ($outletsData as $outletName => $data) {
            $message .= "🏪 *" . $outletName . "*\n";
            $message .= "  Total: " . format_currency($data['total']) . "\n";
            
            $message .= "  🧑‍🍳 *Staff Breakdown:*
";
            if (empty($data['staff'])) {
                $message .= "    - No staff sales\n";
            } else {
                foreach ($data['staff'] as $staff => $amt) {
                    $message .= "    - " . $staff . ": " . format_currency($amt) . "\n";
                }
            }
            
            $message .= "  💳 *Payment Breakdown:*
";
            if (empty($data['payments'])) {
                $message .= "    - No payments\n";
            } else {
                foreach ($data['payments'] as $pt => $amt) {
                    $message .= "    - " . $pt . ": " . format_currency($amt) . "\n";
                }
            }
            $message .= "\n";
        }
    }

    $message .= "--------------------------------\n";
    $message .= "Generated automatically at " . $nowDt->format('H:i:s');

    // Write immediately to prevent duplicate triggers
    file_put_contents($lastReportFile, $currentDate);
    
    // Send via Wablas
    $wablasService = new WablasService($pdo);
    
    $numbers = array_map('trim', explode(',', $settings['whatsapp_report_number']));
    $successCount = 0;
    $errors = [];
    
    foreach ($numbers as $number) {
        if (!empty($number)) {
            $result = $wablasService->sendMessage($number, $message);
            if ($result['success']) {
                $successCount++;
            } else {
                $errors[] = $number . ': ' . $result['message'];
            }
        }
    }

    if ($successCount > 0) {
        echo json_encode(['status' => 'success', 'message' => 'Report sent to ' . $successCount . ' number(s)']);
    } else {
        // Revert on failure so it tries again next minute
        if (file_exists($lastReportFile)) { unlink($lastReportFile); }
        echo json_encode(['status' => 'error', 'message' => implode(', ', $errors)]);
    }

} catch (Exception $e) {
    error_log("Daily Report Cron Error: " . $e->getMessage());
    echo json_encode(['status' => 'error', 'message' => $e->getMessage()]);
}