/**
 * Enhanced Chat Interface - Similar to chat.z.ai
 * Features: Better input, chat history, session resumption, smooth animations
 */

// ============================================
// Enhanced Chat Input Experience
// ============================================

// Auto-focus chat input when switching to chat view
function focusChatInput() {
  setTimeout(() => {
    const input = document.getElementById('chat-input');
    if (input) {
      input.focus();
      // Move cursor to end
      input.setSelectionRange(input.value.length, input.value.length);
    }
  }, 100);
}

// Smooth textarea resize with animation
function enhanceChatInput() {
  const input = document.getElementById('chat-input');
  if (!input) return;

  // Auto-resize with smooth transition
  input.style.transition = 'height 0.2s ease';
  input.addEventListener('input', function() {
    this.style.height = 'auto';
    const newHeight = Math.min(this.scrollHeight, 200);
    this.style.height = newHeight + 'px';
  });

  // Focus animation
  input.addEventListener('focus', function() {
    this.parentElement.classList.add('input-focused');
  });

  input.addEventListener('blur', function() {
    this.parentElement.classList.remove('input-focused');
  });
}

// ============================================
// Chat History & Session Management
// ============================================

// Auto-load chat history when page loads
(async function loadChatHistoryOnLoad() {
  try {
    const res = await fetch('/claude/api/claude/sessions');
    const data = await res.json();

    const historyList = document.getElementById('chat-history-list');
    if (!historyList) return;

    // Combine active and historical sessions
    const allSessions = [
      ...(data.active || []).map(s => ({...s, status: 'active'})),
      ...(data.historical || []).map(s => ({...s, status: 'historical'}))
    ];

    // Sort by creation date (newest first)
    allSessions.sort((a, b) => new Date(b.createdAt || b.created_at) - new Date(a.createdAt || a.created_at));

    if (allSessions.length === 0) {
      historyList.innerHTML = '<div class="chat-history-empty">No chat history yet</div>';
      return;
    }

    historyList.innerHTML = allSessions.map(session => {
      const title = session.metadata?.project ||
                   session.project ||
                   session.id.substring(0, 12) + '...';
      const date = new Date(session.createdAt || session.created_at).toLocaleDateString();
      const isActive = session.id === (window.attachedSessionId || null);

      return `
        <div class="chat-history-item ${isActive ? 'active' : ''} ${session.status === 'historical' ? 'historical' : ''}"
             onclick="${session.status === 'historical' ? `resumeSession('${session.id}')` : `attachToSession('${session.id}')`}">
          <div class="chat-history-icon">
            ${session.status === 'historical' ? '📁' : '💬'}
          </div>
          <div class="chat-history-content">
            <div class="chat-history-title">${title}</div>
            <div class="chat-history-meta">
              <span class="chat-history-date">${date}</span>
              <span class="chat-history-status ${session.status}">
                ${session.status === 'historical' ? 'Historical' : 'Active'}
              </span>
            </div>
          </div>
          ${session.status === 'historical' ? '<span class="resume-badge">Resume</span>' : ''}
        </div>
      `;
    }).join('');

  } catch (error) {
    console.error('[loadChatHistoryOnLoad] Error loading chat history:', error);
  }
})();

// Resume historical session
async function resumeSession(sessionId) {
  console.log('Resuming historical session:', sessionId);

  // Show loading message
  if (typeof appendSystemMessage === 'function') {
    appendSystemMessage('📂 Loading historical session...');
  }

  try {
    // Load the historical session
    const res = await fetch('/claude/api/claude/sessions/' + sessionId);

    // Check if response is OK
    if (!res.ok) {
      const errorText = await res.text();
      console.error('Session fetch error:', res.status, errorText);

      // Handle 404 - session not found
      if (res.status === 404) {
        if (typeof appendSystemMessage === 'function') {
          appendSystemMessage('❌ Session not found. It may have been deleted or the ID is incorrect.');
        }
        return;
      }

      throw new Error(`HTTP ${res.status}: ${errorText}`);
    }

    // Parse JSON with error handling
    let data;
    try {
      data = await res.json();
    } catch (jsonError) {
      const responseText = await res.text();
      console.error('JSON parse error:', jsonError);
      console.error('Response text:', responseText);
      throw new Error('Invalid JSON response from server');
    }

    if (data.session) {
      if (typeof attachToSession === 'function') {
        attachToSession(sessionId);
      }

      // Update UI
      const sessionIdEl = document.getElementById('current-session-id');
      if (sessionIdEl) sessionIdEl.textContent = sessionId;

      // Load session messages
      if (typeof clearChatDisplay === 'function') {
        clearChatDisplay();
      }

      // Add historical messages
      if (data.session.outputBuffer && data.session.outputBuffer.length > 0) {
        data.session.outputBuffer.forEach(entry => {
          if (typeof appendMessage === 'function') {
            appendMessage('assistant', entry.content, false);
          }
        });
      }

      // Show resume message
      const sessionDate = new Date(data.session.createdAt || data.session.created_at);
      if (typeof appendSystemMessage === 'function') {
        appendSystemMessage('✅ Resumed historical session from ' + sessionDate.toLocaleString());
        appendSystemMessage('ℹ️ This is a read-only historical session. Start a new chat to continue working.');
      }

      // Update active state in sidebar
      if (typeof loadChatHistory === 'function') {
        loadChatHistory();
      }

      // Subscribe to session (for any future updates)
      if (typeof subscribeToSession === 'function') {
        subscribeToSession(sessionId);
      }
    } else {
      throw new Error('No session data in response');
    }
  } catch (error) {
    console.error('Error resuming session:', error);
    if (typeof appendSystemMessage === 'function') {
      appendSystemMessage('❌ Failed to resume session: ' + error.message);

      // Remove the loading message
      const messagesContainer = document.getElementById('chat-messages');
      if (messagesContainer) {
        const loadingMessages = messagesContainer.querySelectorAll('.chat-system');
        loadingMessages.forEach(msg => {
          if (msg.textContent.includes('Loading historical session')) {
            msg.remove();
          }
        });
      }
    }
  }
}

// ============================================
// Enhanced Message Rendering
// ============================================

// Enhanced append with animations
function appendMessageWithAnimation(role, content, animate = true) {
  const messagesContainer = document.getElementById('chat-messages');
  if (!messagesContainer) return;

  const messageDiv = document.createElement('div');
  messageDiv.className = `chat-message chat-message-${role} ${animate ? 'message-appear' : ''}`;

  const avatar = role === 'user' ? '👤' : '🤖';
  const label = role === 'user' ? 'You' : 'Claude';

  // Strip dyad tags for display
  const displayContent = stripDyadTags(content);

  messageDiv.innerHTML = `
    <div class="message-avatar">${avatar}</div>
    <div class="message-content">
      <div class="message-header">
        <span class="message-label">${label}</span>
        <span class="message-time">${new Date().toLocaleTimeString()}</span>
      </div>
      <div class="message-text">${formatMessageText(displayContent)}</div>
    </div>
  `;

  messagesContainer.appendChild(messageDiv);

  // Scroll to bottom
  messagesContainer.scrollTop = messagesContainer.scrollHeight;

  // Update token usage
  if (typeof updateTokenUsage === 'function') {
    updateTokenUsage(content.length);
  }
}

// Strip dyad tags from message for display
function stripDyadTags(content) {
  let stripped = content;

  // Remove dyad-write tags and replace with placeholder
  stripped = stripped.replace(/<dyad-write\s+path="[^"]+">([\s\S]*?)<\/dyad-write>/g, (match, content) => {
    return `
      <div class="code-operation">
        <div class="operation-header">
          <span class="operation-icon">📄</span>
          <span class="operation-label">Code generated</span>
        </div>
        <pre class="operation-code"><code>${escapeHtml(content.trim())}</code></pre>
      </div>
    `;
  });

  // Remove other dyad tags
  stripped = stripped.replace(/<dyad-[^>]+>/g, (match) => {
    const tagType = match.match(/dyad-(\w+)/)?.[1] || 'operation';
    const icons = {
      'rename': '✏️',
      'delete': '🗑️',
      'add-dependency': '📦',
      'command': '⚡'
    };
    return `<span class="tag-placeholder">${icons[tagType] || '⚙️'} ${tagType}</span>`;
  });

  return stripped;
}

// Format message text with markdown-like rendering
function formatMessageText(text) {
  // Basic markdown-like formatting
  let formatted = escapeHtml(text);

  // Code blocks
  formatted = formatted.replace(/```(\w+)?\n([\s\S]*?)```/g, (match, lang, code) => {
    return `<pre><code class="language-${lang || 'text'}">${escapeHtml(code.trim())}</code></pre>`;
  });

  // Inline code
  formatted = formatted.replace(/`([^`]+)`/g, '<code>$1</code>');

  // Bold
  formatted = formatted.replace(/\*\*([^*]+)\*\*/g, '<strong>$1</strong>');

  // Links
  formatted = formatted.replace(/https?:\/\/[^\s]+/g, '<a href="$&" target="_blank">$&</a>');

  // Line breaks
  formatted = formatted.replace(/\n/g, '<br>');

  return formatted;
}

// Escape HTML
function escapeHtml(text) {
  const div = document.createElement('div');
  div.textContent = text;
  return div.innerHTML;
}

// ============================================
// Quick Actions & Suggestions
// ============================================

// Show quick action suggestions
function showQuickActions() {
  const messagesContainer = document.getElementById('chat-messages');
  if (!messagesContainer) return;

  const quickActions = document.createElement('div');
  quickActions.className = 'quick-actions';
  quickActions.innerHTML = `
    <div class="quick-actions-title">💡 Quick Actions</div>
    <div class="quick-actions-grid">
      <button class="quick-action-btn" onclick="executeQuickAction('create-react')">
        <span class="action-icon">⚛️</span>
        <span class="action-label">Create React App</span>
      </button>
      <button class="quick-action-btn" onclick="executeQuickAction('create-nextjs')">
        <span class="action-icon">▲</span>
        <span class="action-label">Create Next.js App</span>
      </button>
      <button class="quick-action-btn" onclick="executeQuickAction('create-vue')">
        <span class="action-icon">💚</span>
        <span class="action-label">Create Vue App</span>
      </button>
      <button class="quick-action-btn" onclick="executeQuickAction('create-html')">
        <span class="action-icon">📄</span>
        <span class="action-label">Create HTML Page</span>
      </button>
      <button class="quick-action-btn" onclick="executeQuickAction('explain-code')">
        <span class="action-icon">📖</span>
        <span class="action-label">Explain Codebase</span>
      </button>
      <button class="quick-action-btn" onclick="executeQuickAction('fix-bug')">
        <span class="action-icon">🐛</span>
        <span class="action-label">Fix Bug</span>
      </button>
    </div>
  `;

  messagesContainer.appendChild(quickActions);
}

// Execute quick action
function executeQuickAction(action) {
  const actions = {
    'create-react': 'Create a React app with components and routing',
    'create-nextjs': 'Create a Next.js app with server-side rendering',
    'create-vue': 'Create a Vue 3 app with composition API',
    'create-html': 'Create a responsive HTML5 page with modern styling',
    'explain-code': 'Explain the codebase structure and main files',
    'fix-bug': 'Help me fix a bug in my code'
  };

  const prompt = actions[action];
  if (prompt) {
    const input = document.getElementById('chat-input');
    if (input) {
      input.value = prompt;
      input.focus();
      // Auto-send after short delay
      setTimeout(() => {
        if (typeof sendChatMessage === 'function') {
          sendChatMessage();
        }
      }, 300);
    }
  }
}

// ============================================
// Enhanced Chat View Loading
// ============================================

// Hook into loadChatView to add enhancements
document.addEventListener('DOMContentLoaded', () => {
  // Wait for chat-functions.js to load
  setTimeout(() => {
    // Override loadChatView to add enhancements
    if (typeof window.loadChatView === 'function') {
      const originalLoadChatView = window.loadChatView;
      window.loadChatView = async function() {
        // Call original function first
        await originalLoadChatView.call(this);

        // Add our enhancements
        setTimeout(() => {
          enhanceChatInput();
          focusChatInput();

          // Show quick actions on first load
          const messagesContainer = document.getElementById('chat-messages');
          if (messagesContainer && messagesContainer.querySelector('.chat-welcome')) {
            showQuickActions();
          }
        }, 100);
      };
    }
  }, 1000);
});

// Auto-start enhancements when chat view is active
const observer = new MutationObserver((mutations) => {
  mutations.forEach((mutation) => {
    if (mutation.target.id === 'chat-view' && mutation.target.classList.contains('active')) {
      enhanceChatInput();
      focusChatInput();
    }
  });
});

// Start observing after DOM loads
if (document.readyState === 'loading') {
  document.addEventListener('DOMContentLoaded', () => {
    setTimeout(() => {
      const chatView = document.getElementById('chat-view');
      if (chatView) observer.observe(chatView, { attributes: true });
    }, 1500);
  });
} else {
  setTimeout(() => {
    const chatView = document.getElementById('chat-view');
    if (chatView) observer.observe(chatView, { attributes: true });
  }, 1500);
}

// Export functions
if (typeof window !== 'undefined') {
  window.resumeSession = resumeSession;
  window.executeQuickAction = executeQuickAction;
  window.showQuickActions = showQuickActions;
  window.enhanceChatInput = enhanceChatInput;
  window.focusChatInput = focusChatInput;
  window.appendMessageWithAnimation = appendMessageWithAnimation;
}