import "dart:convert";
import "package:http/http.dart" as http;

import "../models/cart.dart";
import "../models/menu_item.dart";
import "../models/restaurant.dart";
import "../models/service_point.dart";

class ApiRawResponse {
  final int statusCode;
  final String rawBody;
  final Map<String, dynamic>? json;

  const ApiRawResponse({
    required this.statusCode,
    required this.rawBody,
    required this.json,
  });
}

class LoginResponse {
  final int userId;
  final String userFirstName;
  final String token;

  const LoginResponse({
    required this.userId,
    required this.userFirstName,
    required this.token,
  });

  factory LoginResponse.fromJson(Map<String, dynamic> json) {
    return LoginResponse(
      userId: (json["UserID"] as num).toInt(),
      userFirstName: (json["UserFirstName"] as String?) ?? "",
      token: (json["Token"] as String?) ?? "",
    );
  }
}

class Api {
  static String? _userToken;

  // MVP hardcode
  static int _mvpBusinessId = 17;

  static void setAuthToken(String? token) => _userToken = token;

  static void setBusinessId(int? businessId) {
    if (businessId != null && businessId > 0) {
      _mvpBusinessId = businessId;
    }
  }

  static void clearCookies() {
    // no-op
  }

  static String get baseUrl {
    const v = String.fromEnvironment("AALISTS_API_BASE_URL");
    if (v.isEmpty) {
      throw StateError(
        "AALISTS_API_BASE_URL is not set. Example (Android emulator): "
        "--dart-define=AALISTS_API_BASE_URL=http://10.0.2.2:8888/biz.payfrit.com/api",
      );
    }
    return v;
  }

  static Uri _u(String path) {
    final b = baseUrl.endsWith("/") ? baseUrl.substring(0, baseUrl.length - 1) : baseUrl;
    final p = path.startsWith("/") ? path : "/$path";
    return Uri.parse("$b$p");
  }

  static Map<String, String> _headers({required bool json, int? businessIdOverride}) {
    final h = <String, String>{};
    if (json) h["Content-Type"] = "application/json; charset=utf-8";

    final tok = _userToken;
    if (tok != null && tok.isNotEmpty) {
      h["X-User-Token"] = tok;
    }

    final int bid = (businessIdOverride != null && businessIdOverride > 0) ? businessIdOverride : _mvpBusinessId;
    h["X-Business-ID"] = bid.toString();

    return h;
  }

  static Map<String, dynamic>? _tryDecodeJsonMap(String body) {
    try {
      final decoded = jsonDecode(body);
      if (decoded is Map<String, dynamic>) return decoded;
    } catch (_) {}
    return null;
  }

  static Future<ApiRawResponse> _getRaw(String path, {int? businessIdOverride}) async {
    final url = _u(path);
    final resp = await http.get(url, headers: _headers(json: false, businessIdOverride: businessIdOverride));

    final body = resp.body;
    final j = _tryDecodeJsonMap(body);

    // ignore: avoid_print
    print("API GET  => $url");
    // ignore: avoid_print
    print("STATUS   => ${resp.statusCode}");
    // ignore: avoid_print
    print("BODY     => ${body.length > 2000 ? body.substring(0, 2000) : body}");

    return ApiRawResponse(statusCode: resp.statusCode, rawBody: body, json: j);
  }

  static Future<ApiRawResponse> _postRaw(
    String path,
    Map<String, dynamic> payload, {
    int? businessIdOverride,
  }) async {
    final url = _u(path);
    final resp = await http.post(
      url,
      headers: _headers(json: true, businessIdOverride: businessIdOverride),
      body: jsonEncode(payload),
    );

    final body = resp.body;
    final j = _tryDecodeJsonMap(body);

    // ignore: avoid_print
    print("API POST => $url");
    // ignore: avoid_print
    print("BODY IN  => ${jsonEncode(payload)}");
    // ignore: avoid_print
    print("STATUS   => ${resp.statusCode}");
    // ignore: avoid_print
    print("BODY OUT => ${body.length > 2000 ? body.substring(0, 2000) : body}");

    return ApiRawResponse(statusCode: resp.statusCode, rawBody: body, json: j);
  }

  static bool _ok(Map<String, dynamic> j) => j["OK"] == true || j["ok"] == true;

  static String _err(Map<String, dynamic> j) => (j["ERROR"] ?? j["error"] ?? "").toString();

  static List<dynamic>? _pickArray(Map<String, dynamic> j, List<String> keys) {
    for (final k in keys) {
      final v = j[k];
      if (v is List) return v;
    }
    return null;
  }

  static Map<String, dynamic> _requireJson(ApiRawResponse raw, String label) {
    final j = raw.json;
    if (j == null) {
      throw StateError("$label request failed: ${raw.statusCode}\nNon-JSON response.");
    }
    return j;
  }

  // -------------------------
  // Authentication
  // -------------------------

  static Future<LoginResponse> login({
    required String username,
    required String password,
  }) async {
    final raw = await _postRaw(
      "/auth/login.cfm",
      {
        "username": username,
        "password": password,
      },
    );

    final j = _requireJson(raw, "Login");

    if (!_ok(j)) {
      final err = _err(j);
      if (err == "bad_credentials") {
        throw StateError("Invalid email/phone or password");
      } else if (err == "missing_fields") {
        throw StateError("Username and password are required");
      } else {
        throw StateError("Login failed: $err");
      }
    }

    final response = LoginResponse.fromJson(j);

    // Store token for future requests
    setAuthToken(response.token);

    return response;
  }

  static void logout() {
    setAuthToken(null);
    clearCookies();
  }

  // -------------------------
  // Businesses (legacy model name: Restaurant)
  // -------------------------

  static Future<ApiRawResponse> listRestaurantsRaw() async {
    return _getRaw("/businesses/list.cfm", businessIdOverride: _mvpBusinessId);
  }

  static Future<List<Restaurant>> listRestaurants() async {
    final raw = await listRestaurantsRaw();
    final j = _requireJson(raw, "Businesses");

    if (!_ok(j)) {
      throw StateError(
        "Businesses API returned OK=false\nERROR: ${_err(j)}\nDETAIL: ${(j["DETAIL"] ?? "").toString()}\nHTTP Status: ${raw.statusCode}",
      );
    }

    final arr = _pickArray(j, const ["Businesses", "BUSINESSES"]);
    if (arr == null) {
      throw StateError("Businesses JSON missing Businesses array.\nRaw: ${raw.rawBody}");
    }

    final out = <Restaurant>[];
    for (final e in arr) {
      if (e is Map<String, dynamic>) {
        out.add(Restaurant.fromJson(e));
      } else if (e is Map) {
        out.add(Restaurant.fromJson(e.cast<String, dynamic>()));
      }
    }
    return out;
  }

  // -------------------------
  // Service Points
  // -------------------------

  static Future<List<ServicePoint>> listServicePoints({required int businessId}) async {
    // CRITICAL: endpoint is behaving like it reads JSON body, not query/header.
    final raw = await _postRaw(
      "/servicepoints/list.cfm",
      {"BusinessID": businessId},
      businessIdOverride: businessId,
    );

    final j = _requireJson(raw, "ServicePoints");

    if (!_ok(j)) {
      throw StateError(
        "ServicePoints API returned OK=false\nERROR: ${_err(j)}\nDETAIL: ${(j["DETAIL"] ?? "").toString()}\nHTTP Status: ${raw.statusCode}",
      );
    }

    final arr = _pickArray(j, const ["ServicePoints", "SERVICEPOINTS"]);
    if (arr == null) {
      throw StateError("ServicePoints JSON missing ServicePoints array.\nRaw: ${raw.rawBody}");
    }

    final out = <ServicePoint>[];
    for (final e in arr) {
      if (e is Map<String, dynamic>) {
        out.add(ServicePoint.fromJson(e));
      } else if (e is Map) {
        out.add(ServicePoint.fromJson(e.cast<String, dynamic>()));
      }
    }
    return out;
  }

  // -------------------------
  // Menu Items
  // -------------------------

  static Future<List<MenuItem>> listMenuItems({required int businessId}) async {
    final raw = await _postRaw(
      "/menu/items.cfm",
      {"BusinessID": businessId},
      businessIdOverride: businessId,
    );

    final j = _requireJson(raw, "MenuItems");

    if (!_ok(j)) {
      throw StateError(
        "MenuItems API returned OK=false\nERROR: ${_err(j)}\nDETAIL: ${(j["DETAIL"] ?? "").toString()}\nHTTP Status: ${raw.statusCode}",
      );
    }

    final arr = _pickArray(j, const ["Items", "ITEMS"]);
    if (arr == null) {
      throw StateError("MenuItems JSON missing Items array.\nRaw: ${raw.rawBody}");
    }

    final out = <MenuItem>[];
    for (final e in arr) {
      if (e is Map<String, dynamic>) {
        out.add(MenuItem.fromJson(e));
      } else if (e is Map) {
        out.add(MenuItem.fromJson(e.cast<String, dynamic>()));
      }
    }
    return out;
  }

  // -------------------------
  // Cart & Orders
  // -------------------------

  static Future<Cart> getOrCreateCart({
    required int userId,
    required int businessId,
    required int servicePointId,
    required int orderTypeId,
  }) async {
    final raw = await _postRaw(
      "/orders/getOrCreateCart.cfm",
      {
        "OrderUserID": userId,
        "BusinessID": businessId,
        "OrderServicePointID": servicePointId,
        "OrderTypeID": orderTypeId,
      },
      businessIdOverride: businessId,
    );

    final j = _requireJson(raw, "GetOrCreateCart");

    if (!_ok(j)) {
      throw StateError(
        "GetOrCreateCart API returned OK=false\nERROR: ${_err(j)}\nDETAIL: ${(j["MESSAGE"] ?? "").toString()}\nHTTP Status: ${raw.statusCode}",
      );
    }

    return Cart.fromJson(j);
  }

  static Future<Cart> getCart({required int orderId}) async {
    final raw = await _postRaw(
      "/orders/getCart.cfm",
      {"OrderID": orderId},
    );

    final j = _requireJson(raw, "GetCart");

    if (!_ok(j)) {
      throw StateError(
        "GetCart API returned OK=false\nERROR: ${_err(j)}\nHTTP Status: ${raw.statusCode}",
      );
    }

    return Cart.fromJson(j);
  }

  static Future<Cart> setLineItem({
    required int orderId,
    required int parentOrderLineItemId,
    required int itemId,
    required bool isSelected,
    int quantity = 1,
    String? remark,
  }) async {
    final raw = await _postRaw(
      "/orders/setLineItem.cfm",
      {
        "OrderID": orderId,
        "ParentOrderLineItemID": parentOrderLineItemId,
        "ItemID": itemId,
        "IsSelected": isSelected,
        "Quantity": quantity,
        if (remark != null && remark.isNotEmpty) "Remark": remark,
      },
    );

    final j = _requireJson(raw, "SetLineItem");

    if (!_ok(j)) {
      throw StateError(
        "SetLineItem API returned OK=false\nERROR: ${_err(j)}\nDETAIL: ${(j["MESSAGE"] ?? "").toString()}\nHTTP Status: ${raw.statusCode}",
      );
    }

    return Cart.fromJson(j);
  }

  static Future<void> submitOrder({required int orderId}) async {
    final raw = await _postRaw(
      "/orders/submit.cfm",
      {"OrderID": orderId},
    );

    final j = _requireJson(raw, "SubmitOrder");

    if (!_ok(j)) {
      throw StateError(
        "SubmitOrder API returned OK=false\nERROR: ${_err(j)}\nHTTP Status: ${raw.statusCode}",
      );
    }
  }

  // -------------------------
  // Beacons
  // -------------------------

  static Future<Map<String, int>> listAllBeacons() async {
    final raw = await _getRaw("/beacons/list_all.cfm");
    final j = _requireJson(raw, "ListAllBeacons");

    if (!_ok(j)) {
      throw StateError(
        "ListAllBeacons API returned OK=false\nERROR: ${_err(j)}\nHTTP Status: ${raw.statusCode}",
      );
    }

    final arr = _pickArray(j, const ["items", "ITEMS"]);
    if (arr == null) return {};

    final Map<String, int> uuidToBeaconId = {};

    for (final e in arr) {
      if (e is! Map) continue;
      final item = e is Map<String, dynamic> ? e : e.cast<String, dynamic>();

      final uuid = (item["BeaconUUID"] ?? item["BEACONUUID"] ?? "").toString().trim();
      final beaconId = item["BeaconID"] ?? item["BEACONID"];

      if (uuid.isNotEmpty && beaconId is num) {
        uuidToBeaconId[uuid] = beaconId.toInt();
      }
    }

    return uuidToBeaconId;
  }

  static Future<BeaconBusinessMapping> getBusinessFromBeacon({
    required int beaconId,
  }) async {
    final raw = await _postRaw(
      "/beacons/getBusinessFromBeacon.cfm",
      {"BeaconID": beaconId},
    );
    final j = _requireJson(raw, "GetBusinessFromBeacon");

    if (!_ok(j)) {
      throw StateError(
        "GetBusinessFromBeacon API returned OK=false\nERROR: ${_err(j)}\nHTTP Status: ${raw.statusCode}",
      );
    }

    final beacon = j["BEACON"] as Map<String, dynamic>? ?? {};
    final business = j["BUSINESS"] as Map<String, dynamic>? ?? {};
    final servicePoint = j["SERVICEPOINT"] as Map<String, dynamic>? ?? {};

    return BeaconBusinessMapping(
      beaconId: _parseInt(beacon["BeaconID"]) ?? 0,
      beaconName: (beacon["BeaconName"] as String?) ?? "",
      businessId: _parseInt(business["BusinessID"]) ?? 0,
      businessName: (business["BusinessName"] as String?) ?? "",
      servicePointId: _parseInt(servicePoint["ServicePointID"]) ?? 0,
      servicePointName: (servicePoint["ServicePointName"] as String?) ?? "",
    );
  }

  static int? _parseInt(dynamic value) {
    if (value == null) return null;
    if (value is int) return value;
    if (value is num) return value.toInt();
    if (value is String) {
      if (value.isEmpty) return null;
      return int.tryParse(value);
    }
    return null;
  }
}

class BeaconBusinessMapping {
  final int beaconId;
  final String beaconName;
  final int businessId;
  final String businessName;
  final int servicePointId;
  final String servicePointName;

  const BeaconBusinessMapping({
    required this.beaconId,
    required this.beaconName,
    required this.businessId,
    required this.businessName,
    required this.servicePointId,
    required this.servicePointName,
  });
}