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

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 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("API_BASE_URL");
    if (v.isEmpty) {
      throw StateError(
        "API_BASE_URL is not set. Example (Android emulator): "
        "--dart-define=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;
  }

  // -------------------------
  // 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;
  }

  // -------------------------
  // Ordering API (stubs referenced by OrderHomeScreen)
  // -------------------------

  static Future<dynamic> listMenuItems({required int businessId}) async {
    throw StateError("endpoint_not_implemented: Api.listMenuItems");
  }

  static Future<dynamic> getOrCreateCart({
    required int userId,
    required int businessId,
    required int servicePointId,
    required int orderTypeId,
  }) async {
    throw StateError("endpoint_not_implemented: Api.getOrCreateCart");
  }

  static Future<dynamic> getCart({required int orderId}) async {
    throw StateError("endpoint_not_implemented: Api.getCart");
  }

  static Future<void> setLineItem({
    required int orderId,
    required int parentOrderLineItemId,
    required int itemId,
    required int qty,
    required List<int> selectedChildItemIds,
  }) async {
    throw StateError("endpoint_not_implemented: Api.setLineItem");
  }

  static Future<void> submitOrder({required int orderId}) async {
    throw StateError("endpoint_not_implemented: Api.submitOrder");
  }
}