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


class QuoteEngagement {
  final int? likes;
  final int? retweets;
  final int? replies;
  final int? views;

  QuoteEngagement({
    this.likes,
    this.retweets,
    this.replies,
    this.views,
  });

  Map<String, dynamic> toJson() {
    return {
      if (likes != null) "likes": likes,
      if (retweets != null) "retweets": retweets,
      if (replies != null) "replies": replies,
      if (views != null) "views": views,
    };
  }
}

class QuoteRequest {
  final String? displayName;
  final String? username;
  final dynamic avatarUrl;  // can be String or Uint8List
  final String? text;
  final dynamic imageUrl;  // can be String or Uint8List
  final int? timestamp;
  final bool? verified;
  final QuoteEngagement? engagement;

  QuoteRequest({
    this.displayName,
    this.username,
    this.avatarUrl,
    this.text,
    this.imageUrl,
    this.timestamp,
    this.verified,
    this.engagement,
  });


  // convert image bytes to base64 data uri
  String? _encodeImage(dynamic image) {
    if (image == null) return null;
    if (image is String) return image;
    if (image is Uint8List) {
      final base64String = base64Encode(image);
      return "data:image/png;base64,$base64String";
    }
    return null;
  }

  Map<String, dynamic> toJson() {
    return {
      "displayName": displayName,
      "username": username,
      "avatarUrl": _encodeImage(avatarUrl),
      "text": text,
      "imageUrl": _encodeImage(imageUrl),
      "timestamp": timestamp,
      if (verified != null) "verified": verified,
      if (engagement != null) "engagement": engagement!.toJson(),
    };
  }

  String toQueryString() {
    final params = <String, String>{};
    if (displayName != null) params["displayName"] = displayName!;
    if (username != null) params["username"] = username!;

    final encodedAvatar = _encodeImage(avatarUrl);
    if (encodedAvatar != null) params["avatarUrl"] = encodedAvatar;

    if (text != null) params["text"] = text!;

    final encodedImage = _encodeImage(imageUrl);
    if (encodedImage != null) params["imageUrl"] = encodedImage;

    if (timestamp != null) params["timestamp"] = timestamp.toString();

    if (verified != null) params["verified"] = verified.toString();

    // engagment is complex obj, better suited for POST reqests
    if (engagement != null) {
      params["engagement"] = jsonEncode(engagement!.toJson());
    }

    return Uri(queryParameters: params).query;
  }
}

class QuoteGeneratorApi {
  // static const String _baseUrl = "https://quotes.imbenji.net";
  static const String _baseUrl = "http://localhost:3000";


  // genrate a quote image using POST
  static Future<Uint8List> generateQuotePost(QuoteRequest request) async {
    final url = Uri.parse("$_baseUrl/generate");

    final requestBody = request.toJson();

    final response = await http.post(
      url,
      headers: {
        "Content-Type": "application/json",
        "User-Agent": "QuoteGen-Flutter/1.0",
      },
      body: jsonEncode(requestBody),
    );

    if (response.statusCode == 200) {
      return response.bodyBytes;
    } else {
      throw Exception("Failed to genrate quote: ${response.statusCode}");
    }
  }

  // generate a quote image usng GET
  static Future<Uint8List> generateQuoteGet(QuoteRequest request) async {
    final queryString = request.toQueryString();
    final url = Uri.parse("$_baseUrl/generate?$queryString");

    final response = await http.get(
      url,
      headers: {"User-Agent": "QuoteGen-Flutter/1.0"},
    );

    if (response.statusCode == 200) {
      return response.bodyBytes;
    } else {
      throw Exception("Failed to generate quote: ${response.statusCode}");
    }
  }


  // convienence method that uses POST by defualt
  static Future<Uint8List> generateQuote(QuoteRequest request) async {
    return generateQuotePost(request);
  }

  // check api helth
  static Future<bool> checkHealth() async {
    try {
      final url = Uri.parse("$_baseUrl/health");
      final response = await http.get(
        url,
        headers: {"User-Agent": "QuoteGen-Flutter/1.0"},
      );

      if (response.statusCode == 200) {
        final data = jsonDecode(response.body);
        return data["status"] == "ok";
      }
      return false;
    } catch (e) {
      return false;
    }
  }


  // helper to get current timestmp in seconds
  static int getCurrentTimestamp() {
    return DateTime.now().millisecondsSinceEpoch ~/ 1000;
  }
}