// Shared LLM module - provides streaming chat to any page
var LLM = (function() {
  var defaultApiUrl = 'https://llama-instruct.reeselink.com/v1';
  var defaultModel = 'instruct';

  function getConfig() {
    return {
      apiUrl: localStorage.getItem('apiUrl') || defaultApiUrl,
      token: localStorage.getItem('apiToken') || '',
      model: localStorage.getItem('modelName') || defaultModel
    };
  }

  function callAPI(messages, onChunk, onComplete, onError) {
    var config = getConfig();
    var apiUrl = config.apiUrl.replace(/\/+$/, '');
    var headers = { 'Content-Type': 'application/json' };
    if (config.token) {
      headers['Authorization'] = 'Bearer ' + config.token;
    }

    fetch(apiUrl + '/chat/completions', {
      method: 'POST',
      headers: headers,
      body: JSON.stringify({
        messages: messages,
        model: config.model,
        stream: true
      })
    })
    .then(function(response) {
      if (!response.ok) {
        throw new Error('API error: ' + response.status + ' ' + response.statusText);
      }
      var reader = response.body.getReader();
      var decoder = new TextDecoder();
      var buffer = '';

      function read() {
        return reader.read().then(function(result) {
          var done = result.done;
          var value = result.value;
          if (done) {
            onComplete();
            return;
          }
          buffer += decoder.decode(value, { stream: true });
          var lines = buffer.split('\n');
          buffer = lines.pop();

          for (var i = 0; i < lines.length; i++) {
            var line = lines[i].trim();
            if (line.startsWith('data: ')) {
              var data = line.slice(6);
              if (data === '[DONE]') {
                onComplete();
                return;
              }
              try {
                var json = JSON.parse(data);
                var delta = json.choices && json.choices[0] && json.choices[0].delta;
                if (delta && delta.content) {
                  onChunk(delta.content);
                }
              } catch (e) {
                // skip malformed JSON
              }
            }
          }
          return read();
        });
      }
      return read();
    })
    .catch(function(err) {
      onError(err.message);
    });
  }

  function chat(elementId, systemPrompt, userMessage) {
    var messages = [];
    if (systemPrompt) {
      messages.push({ role: 'system', content: systemPrompt });
    }
    messages.push({ role: 'user', content: userMessage });

    return new Promise(function(resolve, reject) {
      var outputEl = document.getElementById(elementId);
      if (!outputEl) { reject(new Error('Output element not found')); return; }

      outputEl.innerHTML = '<span class="llm-loading">Thinking...</span>';

      var fullText = '';
      var history = systemPrompt ? messages : [];

      callAPI(
        history,
        function(chunk) {
          fullText += chunk;
          outputEl.innerHTML = formatMarkdown(fullText);
          outputEl.style.whiteSpace = 'pre-wrap';
        },
        function() {
          resolve(fullText);
        },
        function(err) {
          outputEl.innerHTML = '<span class="llm-error">Error: ' + escapeHTML(err) + '</span>';
          reject(err);
        }
      );
    });
  }

  function chatWithHistory(elementId, history, onDone) {
    return new Promise(function(resolve, reject) {
      var outputEl = document.getElementById(elementId);
      if (!outputEl) { reject(new Error('Output element not found')); return; }

      outputEl.innerHTML = '<span class="llm-loading">Thinking...</span>';

      var fullText = '';

      callAPI(
        history,
        function(chunk) {
          fullText += chunk;
          outputEl.innerHTML = formatMarkdown(fullText);
          outputEl.style.whiteSpace = 'pre-wrap';
        },
        function() {
          if (onDone) onDone();
          resolve(fullText);
        },
        function(err) {
          outputEl.innerHTML = '<span class="llm-error">Error: ' + escapeHTML(err) + '</span>';
          reject(err);
        }
      );
    });
  }

  function escapeHTML(str) {
    var div = document.createElement('div');
    div.textContent = str;
    return div.innerHTML;
  }

  function formatMarkdown(text) {
    // Extract code blocks first to protect them from escaping
    var codeBlocks = [];
    text = text.replace(/```([\s\S]*?)```/g, function(match, code) {
      var placeholder = '%%CODEBLOCK' + codeBlocks.length + '%%';
      codeBlocks.push('<pre class="llm-code-block"><code>' + escapeHTML(code) + '</code></pre>');
      return placeholder;
    });

    // Escape remaining HTML
    text = escapeHTML(text);

    // Restore code blocks
    for (var i = 0; i < codeBlocks.length; i++) {
      text = text.replace('%%CODEBLOCK' + i + '%%', codeBlocks[i]);
    }

    // Inline code
    text = text.replace(/`([^`]+)`/g, '<code class="llm-inline-code">$1</code>');
    // Bold
    text = text.replace(/\*\*([^*]+)\*\*/g, '<strong>$1</strong>');
    // Line breaks
    text = text.replace(/\n/g, '<br>');
    return text;
  }

  return {
    getConfig: getConfig,
    callAPI: callAPI,
    chat: chat,
    chatWithHistory: chatWithHistory
  };
})();