import 'dart:convert';
import '../http_util.dart';
import '../models.dart';
import 'webview_base_provider.dart';

/// Cloudflare Workers AI playground via an in-page WebSocket.
class CloudflareAi extends WebViewBaseProvider {
  @override
  String get name => 'CloudflareAI';

  @override
  bool get working => true;

  @override
  List<String> get models => [
        '@cf/meta/llama-3.3-70b-instruct-fp8-fast',
        '@cf/meta/llama-3.1-8b-instruct-fp8',
        '@cf/google/gemma-3-12b-it',
      ];

  @override
  String get defaultModel => '@cf/meta/llama-3.3-70b-instruct-fp8-fast';

  @override
  String get baseUrl => 'https://playground.ai.cloudflare.com';

  @override
  String get apiEndpoint => 'wss://playground.ai.cloudflare.com/agents/playground';

  @override
  String buildJsFetchCode(String model, List<Message> messages, bool stream) {
    final cfMessages = [
      for (var i = 0; i < messages.length; i++)
        {
          'role': messages[i].role.name,
          'parts': [
            {'type': 'text', 'text': messages[i].content}
          ],
          'id': 'msg_$i',
        }
    ];
    final messagesJson = jsonEncode(cfMessages);
    final modelJson = jsonEncode(models.contains(model) ? model : defaultModel);
    return '''
      (async function() {
        const modelStr = $modelJson;
        const pk = crypto.randomUUID();
        const agentId = 'playground-' + Math.random().toString(36).slice(2, 15);
        const wsUrl = 'wss://playground.ai.cloudflare.com/agents/playground/' + agentId
          + '?_pk=' + pk + '&model=' + encodeURIComponent(modelStr);
        return await new Promise((resolve, reject) => {
          const ws = new WebSocket(wsUrl);
          let text = '';
          const timer = setTimeout(() => {
            try { ws.close(); } catch (e) {}
            if (text) resolve(text); else reject('Cloudflare timeout');
          }, 28000);
          ws.onopen = () => {
            ws.send(JSON.stringify({type:'cf_agent_stream_resume_request'}));
            ws.send(JSON.stringify({name:agentId, agent:'playground', type:'cf_agent_identity'}));
            ws.send(JSON.stringify({state:{model:modelStr, temperature:1, stream:true, system:'You are a helpful assistant.', useExternalProvider:false, externalProvider:'openai', generativeUI:false}, type:'cf_agent_state'}));
            ws.send(JSON.stringify({mcp:{prompts:[], resources:[], servers:{}, tools:[]}, type:'cf_agent_mcp_servers'}));
            ws.send(JSON.stringify({type:'cf_agent_stream_resume_none'}));
            setTimeout(() => {
              ws.send(JSON.stringify({
                id: 'req_' + Math.random().toString(36).slice(2, 10),
                init: { method: 'POST', body: JSON.stringify({ messages: $messagesJson, trigger: 'submit-message' }) },
                type: 'cf_agent_use_chat_request'
              }));
            }, 800);
          };
          ws.onmessage = (event) => {
            try {
              const data = JSON.parse(event.data);
              if (data.type === 'cf_agent_use_chat_response') {
                const body = JSON.parse(data.body);
                if (body.type === 'text-delta' && body.delta) text += body.delta;
                if (body.type === 'finish' || body.type === 'finish-step') {
                  clearTimeout(timer);
                  ws.close();
                  resolve(text);
                }
              }
            } catch (e) {}
          };
          ws.onerror = () => { clearTimeout(timer); reject('Cloudflare WS error'); };
        });
      })();
    ''';
  }

  @override
  String parseResponse(String rawResponse) {
    final text = rawResponse.trim();
    if (text.startsWith('{')) {
      try {
        final json = jsonDecode(text);
        if (json is Map && json['error'] != null) {
          throw Exception(json['error']);
        }
      } catch (e) {
        if (e.toString().contains('Exception:')) rethrow;
      }
    }
    if (!looksLikeModelOutput(text)) {
      throw Exception('Cloudflare empty: ${text.substring(0, text.length.clamp(0, 160))}');
    }
    return text;
  }
}