<?php
// api.php - RESTful API handlers for ShahrNegar

require_once __DIR__ . '/db.php';

// Set response headers
header('Content-Type: application/json; charset=utf-8');
header('Access-Control-Allow-Origin: *');
header('Access-Control-Allow-Methods: GET, POST, PATCH, PUT, DELETE, OPTIONS');
header('Access-Control-Allow-Headers: Content-Type, Authorization, X-Requested-With');

if ($_SERVER['REQUEST_METHOD'] === 'OPTIONS') {
    http_response_code(200);
    exit;
}

initDB();
$pdo = getDB();

$requestUri = parse_url($_SERVER['REQUEST_URI'], PHP_URL_PATH);
$method = $_SERVER['REQUEST_METHOD'];

// Helper JSON response
function jsonResponse($data, int $statusCode = 200) {
    http_response_code($statusCode);
    echo json_encode($data, JSON_UNESCAPED_UNICODE | JSON_PRETTY_PRINT);
    exit;
}

function getJsonInput(): array {
    $input = file_get_contents('php://input');
    return json_decode($input, true) ?? [];
}

// 1. GET /api/stats
if ($requestUri === '/api/stats' && $method === 'GET') {
    $total = (int)$pdo->query("SELECT COUNT(*) FROM issues")->fetchColumn();
    $pending = (int)$pdo->query("SELECT COUNT(*) FROM issues WHERE status = 'pending'")->fetchColumn();
    $reviewing = (int)$pdo->query("SELECT COUNT(*) FROM issues WHERE status = 'reviewing'")->fetchColumn();
    $inProgress = (int)$pdo->query("SELECT COUNT(*) FROM issues WHERE status = 'in_progress'")->fetchColumn();
    $resolved = (int)$pdo->query("SELECT COUNT(*) FROM issues WHERE status = 'resolved'")->fetchColumn();
    $upvotes = (int)$pdo->query("SELECT COALESCE(SUM(upvotes), 0) FROM issues")->fetchColumn();

    $catStmt = $pdo->query("SELECT category, COUNT(*) as count FROM issues GROUP BY category ORDER BY count DESC");
    $categories = $catStmt->fetchAll();

    $distStmt = $pdo->query("SELECT district, COUNT(*) as count FROM issues GROUP BY district ORDER BY district ASC");
    $districts = $distStmt->fetchAll();

    $prioStmt = $pdo->query("SELECT priority, COUNT(*) as count FROM issues GROUP BY priority");
    $priorities = [];
    foreach ($prioStmt->fetchAll() as $row) {
        $priorities[$row['priority']] = (int)$row['count'];
    }

    $resolutionRate = $total > 0 ? round(($resolved / $total) * 100, 1) : 0;

    jsonResponse([
        'total' => $total,
        'pending' => $pending,
        'reviewing' => $reviewing,
        'in_progress' => $inProgress,
        'resolved' => $resolved,
        'total_upvotes' => $upvotes,
        'categories' => $categories,
        'districts' => $districts,
        'priorities' => $priorities,
        'resolution_rate' => $resolutionRate
    ]);
}

// 2. GET /api/issues
if ($requestUri === '/api/issues' && $method === 'GET') {
    $category = $_GET['category'] ?? null;
    $status = $_GET['status'] ?? null;
    $district = isset($_GET['district']) ? (int)$_GET['district'] : 0;
    $priority = $_GET['priority'] ?? null;
    $search = $_GET['search'] ?? null;
    $sortBy = $_GET['sort_by'] ?? 'newest';

    $sql = "SELECT * FROM issues WHERE 1=1";
    $params = [];

    if ($category && $category !== 'all') {
        $sql .= " AND category = ?";
        $params[] = $category;
    }

    if ($status && $status !== 'all') {
        $sql .= " AND status = ?";
        $params[] = $status;
    }

    if ($district > 0) {
        $sql .= " AND district = ?";
        $params[] = $district;
    }

    if ($priority && $priority !== 'all') {
        $sql .= " AND priority = ?";
        $params[] = $priority;
    }

    if ($search) {
        $sql .= " AND (title LIKE ? OR description LIKE ? OR address LIKE ? OR tracking_code LIKE ?)";
        $searchParam = "%{$search}%";
        $params[] = $searchParam;
        $params[] = $searchParam;
        $params[] = $searchParam;
        $params[] = $searchParam;
    }

    if ($sortBy === 'upvotes') {
        $sql .= " ORDER BY upvotes DESC, id DESC";
    } elseif ($sortBy === 'oldest') {
        $sql .= " ORDER BY id ASC";
    } elseif ($sortBy === 'emergency') {
        $sql .= " ORDER BY CASE priority WHEN 'emergency' THEN 1 WHEN 'high' THEN 2 WHEN 'medium' THEN 3 ELSE 4 END, id DESC";
    } else {
        $sql .= " ORDER BY id DESC";
    }

    $stmt = $pdo->prepare($sql);
    $stmt->execute($params);
    $rows = $stmt->fetchAll();

    $commentCountStmt = $pdo->prepare("SELECT COUNT(*) FROM comments WHERE issue_id = ?");

    $issues = [];
    foreach ($rows as $row) {
        $commentCountStmt->execute([$row['id']]);
        $row['comment_count'] = (int)$commentCountStmt->fetchColumn();
        $issues[] = $row;
    }

    jsonResponse($issues);
}

// 3. POST /api/issues (Create new issue)
if ($requestUri === '/api/issues' && $method === 'POST') {
    $data = getJsonInput();

    if (empty($data['title']) || empty($data['category']) || empty($data['address'])) {
        jsonResponse(['error' => 'اطلاعات ضروری تکمیل نشده است.'], 400);
    }

    $trackingCode = 'SHR-' . rand(10000, 99999);
    $now = date('Y-m-d H:i');

    $stmt = $pdo->prepare("INSERT INTO issues (
        tracking_code, title, category, description, address, district, priority, status,
        lat, lng, image_url, reporter_name, reporter_phone, upvotes, created_at
    ) VALUES (?, ?, ?, ?, ?, ?, ?, 'pending', ?, ?, ?, ?, ?, 1, ?)");

    $stmt->execute([
        $trackingCode,
        $data['title'],
        $data['category'],
        $data['description'] ?? '',
        $data['address'],
        (int)($data['district'] ?? 1),
        $data['priority'] ?? 'medium',
        (float)($data['lat'] ?? 35.7538),
        (float)($data['lng'] ?? 51.4172),
        $data['image_url'] ?? 'https://images.unsplash.com/photo-1515162816999-a0c47dc192f7?auto=format&fit=crop&w=800&q=80',
        $data['reporter_name'] ?? 'شهروند مسئول',
        $data['reporter_phone'] ?? '',
        $now
    ]);

    $issueId = $pdo->lastInsertId();

    // Timeline initial record
    $tlStmt = $pdo->prepare("INSERT INTO timeline (issue_id, status, title, description, created_at) VALUES (?, 'pending', 'ثبت اولیه گزارش در سامانه', 'گزارش شما با موفقیت در سامانه شهرنگار ثبت گردید و در نوبت بررسی کارشناسی قرار گرفت.', ?)");
    $tlStmt->execute([$issueId, $now]);

    $fetchStmt = $pdo->prepare("SELECT * FROM issues WHERE id = ?");
    $fetchStmt->execute([$issueId]);
    jsonResponse($fetchStmt->fetch(), 201);
}

// 4. GET /api/track/{code}
if (preg_match('#^/api/track/([^/]+)$#', $requestUri, $matches) && $method === 'GET') {
    $code = strtoupper(trim(urldecode($matches[1])));
    $stmt = $pdo->prepare("SELECT * FROM issues WHERE UPPER(tracking_code) = ?");
    $stmt->execute([$code]);
    $issue = $stmt->fetch();

    if (!$issue) {
        jsonResponse(['error' => "هیچ گزارشی با کد رهگیری «{$code}» یافت نشد."], 404);
    }

    $tlStmt = $pdo->prepare("SELECT * FROM timeline WHERE issue_id = ? ORDER BY id ASC");
    $tlStmt->execute([$issue['id']]);
    $issue['timeline'] = $tlStmt->fetchAll();

    $cmStmt = $pdo->prepare("SELECT * FROM comments WHERE issue_id = ? ORDER BY id DESC");
    $cmStmt->execute([$issue['id']]);
    $issue['comments'] = $cmStmt->fetchAll();

    jsonResponse($issue);
}

// 5. GET /api/issues/{id}
if (preg_match('#^/api/issues/(\d+)$#', $requestUri, $matches) && $method === 'GET') {
    $issueId = (int)$matches[1];
    $stmt = $pdo->prepare("SELECT * FROM issues WHERE id = ?");
    $stmt->execute([$issueId]);
    $issue = $stmt->fetch();

    if (!$issue) {
        jsonResponse(['error' => 'گزارش مورد نظر یافت نشد.'], 404);
    }

    $tlStmt = $pdo->prepare("SELECT * FROM timeline WHERE issue_id = ? ORDER BY id ASC");
    $tlStmt->execute([$issueId]);
    $issue['timeline'] = $tlStmt->fetchAll();

    $cmStmt = $pdo->prepare("SELECT * FROM comments WHERE issue_id = ? ORDER BY id DESC");
    $cmStmt->execute([$issueId]);
    $issue['comments'] = $cmStmt->fetchAll();

    jsonResponse($issue);
}

// 6. POST /api/issues/{id}/upvote
if (preg_match('#^/api/issues/(\d+)/upvote$#', $requestUri, $matches) && $method === 'POST') {
    $issueId = (int)$matches[1];
    $stmt = $pdo->prepare("UPDATE issues SET upvotes = upvotes + 1 WHERE id = ?");
    $stmt->execute([$issueId]);

    if ($stmt->rowCount() === 0) {
        jsonResponse(['error' => 'گزارش یافت نشد.'], 404);
    }

    $fetch = $pdo->prepare("SELECT upvotes FROM issues WHERE id = ?");
    $fetch->execute([$issueId]);
    $newUpvotes = (int)$fetch->fetchColumn();

    jsonResponse(['id' => $issueId, 'upvotes' => $newUpvotes]);
}

// 7. POST /api/issues/{id}/comment
if (preg_match('#^/api/issues/(\d+)/comment$#', $requestUri, $matches) && $method === 'POST') {
    $issueId = (int)$matches[1];
    $data = getJsonInput();

    if (empty($data['content'])) {
        jsonResponse(['error' => 'متن نظر نمی‌تواند خالی باشد.'], 400);
    }

    $check = $pdo->prepare("SELECT id FROM issues WHERE id = ?");
    $check->execute([$issueId]);
    if (!$check->fetch()) {
        jsonResponse(['error' => 'گزارش یافت نشد.'], 404);
    }

    $now = date('Y-m-d H:i');
    $author = !empty($data['author_name']) ? trim($data['author_name']) : 'شهروند محترم';

    $stmt = $pdo->prepare("INSERT INTO comments (issue_id, author_name, content, created_at) VALUES (?, ?, ?, ?)");
    $stmt->execute([$issueId, $author, trim($data['content']), $now]);
    $commentId = $pdo->lastInsertId();

    $cm = $pdo->prepare("SELECT * FROM comments WHERE id = ?");
    $cm->execute([$commentId]);
    jsonResponse($cm->fetch(), 201);
}

// 8. PATCH / POST /api/issues/{id}/status (Admin Status Update)
if (preg_match('#^/api/issues/(\d+)/status$#', $requestUri, $matches) && in_array($method, ['PATCH', 'POST'])) {
    $issueId = (int)$matches[1];
    $data = getJsonInput();

    $check = $pdo->prepare("SELECT * FROM issues WHERE id = ?");
    $check->execute([$issueId]);
    $current = $check->fetch();
    if (!$current) {
        jsonResponse(['error' => 'گزارش یافت نشد.'], 404);
    }

    $newStatus = $data['status'] ?? $current['status'];
    $officialResponse = $data['official_response'] ?? $current['official_response'];
    $resolvedImageUrl = $data['resolved_image_url'] ?? $current['resolved_image_url'];

    $now = date('Y-m-d H:i');
    $resolvedAt = ($newStatus === 'resolved') ? $now : $current['resolved_at'];

    $upd = $pdo->prepare("UPDATE issues SET status = ?, official_response = ?, resolved_image_url = ?, resolved_at = ? WHERE id = ?");
    $upd->execute([$newStatus, $officialResponse, $resolvedImageUrl, $resolvedAt, $issueId]);

    $statusTitles = [
        'pending' => 'در صف بررسی مجدد',
        'reviewing' => 'بررسی کارشناسی و ارجاع به معاونت مربوطه',
        'in_progress' => 'اعزام اکیپ اجرایی و آغاز عملیات میدانی',
        'resolved' => 'اتمام عملیات و رفع کامل مسئله',
        'rejected' => 'عدم احراز یا خارج از حیطه اختیارات شهرداری'
    ];

    $tlTitle = !empty($data['timeline_title']) ? $data['timeline_title'] : ($statusTitles[$newStatus] ?? "تغییر وضعیت به {$newStatus}");
    $tlDesc = !empty($data['timeline_desc']) ? $data['timeline_desc'] : ($officialResponse ?: 'وضعیت پرونده توسط مدیریت سامانه به‌روزرسانی شد.');

    $tlStmt = $pdo->prepare("INSERT INTO timeline (issue_id, status, title, description, created_at) VALUES (?, ?, ?, ?, ?)");
    $tlStmt->execute([$issueId, $newStatus, $tlTitle, $tlDesc, $now]);

    $updated = $pdo->prepare("SELECT * FROM issues WHERE id = ?");
    $updated->execute([$issueId]);
    jsonResponse($updated->fetch());
}

// 9. POST /api/upload
if ($requestUri === '/api/upload' && $method === 'POST') {
    if (!isset($_FILES['file'])) {
        jsonResponse(['error' => 'فایلی ارسال نشده است.'], 400);
    }

    $uploadDir = __DIR__ . '/static/uploads/';
    if (!is_dir($uploadDir)) {
        mkdir($uploadDir, 0777, true);
    }

    $ext = pathinfo($_FILES['file']['name'], PATHINFO_EXTENSION);
    $filename = uniqid('img_', true) . '.' . $ext;
    $target = $uploadDir . $filename;

    if (move_uploaded_file($_FILES['file']['tmp_name'], $target)) {
        jsonResponse(['url' => '/static/uploads/' . $filename]);
    } else {
        jsonResponse(['error' => 'خطا در ذخیره‌سازی فایل.'], 500);
    }
}

// Default 404 for API
jsonResponse(['error' => 'مسیر مورد نظر در API یافت نشد.'], 404);