import 'dart:convert';

import 'package:flutter/foundation.dart';

import '../http_client.dart';
import '../http_util.dart';
import '../models.dart';
import 'base_provider.dart';
import 'webview_base_provider.dart';

class PhindAi extends BaseProvider {
  @override
  String get name => 'PhindAi';

  @override
  String get label => 'PhindAi';

  @override
  String get url => 'https://phindai.org';

  @override
  bool get working => true;

  @override
  bool get supportsStream => false;

  @override
  Duration get requestTimeout => const Duration(seconds: 90);

  @override
  String get defaultModel => 'deepseek-v3';

  @override
  List<String> get models => ['deepseek-v3', 'deepseek'];

  @override
  Stream<String> createAsyncGenerator(
    String model,
    List<Message> messages, {
    bool stream = false,
  }) async* {
    try {
      yield await _rest(messages);
      return;
    } catch (e) {
      debugPrint('Phind REST failed, trying origin WebView: $e');
    }
    yield await _viaWebView(messages);
  }

  Future<String> _rest(List<Message> messages) async {
    final prompt = messages.last.content;
    final headers = {
      'Accept':
          'text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8',
      'User-Agent': kDesktopUserAgent,
    };

    final mainPageResponse = await g4fHttp.get(Uri.parse(url), headers: headers);
    if (mainPageResponse.statusCode != 200) {
      throw Exception('Failed to fetch PhindAi main page: ${mainPageResponse.statusCode}');
    }

    final html = mainPageResponse.body;
    final match = RegExp(r'"nonce":"([a-f0-9]+)"').firstMatch(html) ??
        RegExp(r"'nonce':'([a-f0-9]+)'").firstMatch(html);
    if (match == null) {
      throw Exception('Failed to extract nonce from PhindAi response');
    }
    final nonce = match.group(1)!;

    final response = await g4fHttp.post(
      Uri.parse('$url/wp-admin/admin-ajax.php'),
      headers: headers,
      body: {
        'action': 'phind_ai_send',
        'nonce': nonce,
        'message': prompt,
      },
    );

    if (response.statusCode != 200) {
      throw Exception('PhindAi API returned status: ${response.statusCode}');
    }

    final data = jsonDecode(response.body);
    if (data is! Map || data['success'] != true) {
      throw Exception('PhindAi API returned success=False: $data');
    }
    final responseText = (data['data'] is Map ? data['data']['response'] : null) ?? '';
    final text = responseText.toString().trim();
    if (!looksLikeModelOutput(text)) {
      throw Exception('Phind REST unusable');
    }
    return text;
  }

  Future<String> _viaWebView(List<Message> messages) async {
    final promptJson = jsonEncode(messages.last.content);
    final raw = await runOriginWebView(
      originUrl: url,
      timeout: requestTimeout,
      functionBody: '''
        const prompt = $promptJson;
        const html = document.documentElement.innerHTML;
        const m = html.match(/"nonce":"([a-f0-9]+)"/) || html.match(/'nonce':'([a-f0-9]+)'/);
        if (!m) throw new Error('no nonce in page');
        const body = new URLSearchParams();
        body.set('action', 'phind_ai_send');
        body.set('nonce', m[1]);
        body.set('message', prompt);
        const r = await fetch('/wp-admin/admin-ajax.php', {
          method: 'POST',
          headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
          credentials: 'same-origin',
          body
        });
        const data = await r.json();
        if (!data || data.success !== true) {
          throw new Error('phind success=false ' + JSON.stringify(data).slice(0, 180));
        }
        return String((data.data && data.data.response) || '');
      ''',
    );
    final text = raw.trim();
    if (!looksLikeModelOutput(text)) {
      throw Exception('Phind WebView unusable: ${text.substring(0, text.length.clamp(0, 180))}');
    }
    return text;
  }
}