// Editor View

import { api } from '../api.js';

export async function renderEditor(app) {
  const { id, libraryId } = app.state.params;
  let doc = null;
  let libraries = [];
  
  if (id) {
    try {
      doc = await api.getDocument(id);
    } catch (e) {
      app.showToast('Failed to load document', 'error');
      app.navigate('dashboard');
      return;
    }
  }

  try {
    libraries = await api.getLibraries();
  } catch (e) {}

  const isNew = !id;
  const appEl = document.getElementById('app');
  
  let formData = {
    title: doc?.title || '',
    content: doc?.content || '',
    tags: doc?.tags?.join(', ') || '',
    type: doc?.type || 'general',
    priority: doc?.priority || 'medium',
    status: doc?.status || 'draft',
    libraryId: doc?.libraryId || libraryId || ''
  };

  let showPreview = false;
  let hasChanges = false;

  function render() {
    appEl.innerHTML = `
      <header class="app-header">
        <button class="btn btn-ghost" onclick="handleCancel()">Cancel</button>
        <span style="flex:1;margin-left:16px">${isNew ? 'New Document' : 'Editing: ' + escapeHtml(formData.title)}</span>
        <button class="btn btn-primary" onclick="handleSave()">Save</button>
      </header>
      <main class="main-content">
        <div class="editor-container">
          <form class="editor-form" id="editor-form">
            <div class="form-row">
              <div class="form-group" style="flex:2">
                <label for="title">Title</label>
                <input type="text" id="title" value="${escapeHtml(formData.title)}" required>
              </div>
              <div class="form-group">
                <label for="libraryId">Library</label>
                <select id="libraryId">
                  <option value="">None</option>
                  ${libraries.map(l => `<option value="${l.id}" ${formData.libraryId === l.id ? 'selected' : ''}>${escapeHtml(l.name)}</option>`).join('')}
                </select>
              </div>
            </div>
            <div class="form-row">
              <div class="form-group">
                <label for="type">Type</label>
                <select id="type">
                  <option value="requirement" ${formData.type === 'requirement' ? 'selected' : ''}>Requirement</option>
                  <option value="note" ${formData.type === 'note' ? 'selected' : ''}>Note</option>
                  <option value="spec" ${formData.type === 'spec' ? 'selected' : ''}>Specification</option>
                  <option value="general" ${formData.type === 'general' ? 'selected' : ''}>General</option>
                </select>
              </div>
              <div class="form-group">
                <label for="status">Status</label>
                <select id="status">
                  <option value="draft" ${formData.status === 'draft' ? 'selected' : ''}>Draft</option>
                  <option value="approved" ${formData.status === 'approved' ? 'selected' : ''}>Approved</option>
                  <option value="implemented" ${formData.status === 'implemented' ? 'selected' : ''}>Implemented</option>
                </select>
              </div>
              <div class="form-group">
                <label for="priority">Priority</label>
                <select id="priority">
                  <option value="high" ${formData.priority === 'high' ? 'selected' : ''}>🔴 High</option>
                  <option value="medium" ${formData.priority === 'medium' ? 'selected' : ''}>🟡 Medium</option>
                  <option value="low" ${formData.priority === 'low' ? 'selected' : ''}>🟢 Low</option>
                </select>
              </div>
            </div>
            <div class="form-group">
              <label for="tags">Tags (comma-separated)</label>
              <input type="text" id="tags" value="${escapeHtml(formData.tags)}" placeholder="backend, api, auth">
            </div>
            <div class="form-group full-width">
              <div class="editor-toolbar">
                <button type="button" class="toolbar-btn" onclick="insertFormat('**', '**')" title="Bold">B</button>
                <button type="button" class="toolbar-btn" onclick="insertFormat('*', '*')" title="Italic"><em>I</em></button>
                <span class="toolbar-separator"></span>
                <button type="button" class="toolbar-btn" onclick="insertLine('# ')" title="Heading 1">H1</button>
                <button type="button" class="toolbar-btn" onclick="insertLine('## ')" title="Heading 2">H2</button>
                <button type="button" class="toolbar-btn" onclick="insertLine('### ')" title="Heading 3">H3</button>
                <span class="toolbar-separator"></span>
                <button type="button" class="toolbar-btn" onclick="insertLine('- ')" title="List">•</button>
                <button type="button" class="toolbar-btn" onclick="insertLine('1. ')" title="Numbered List">1.</button>
                <button type="button" class="toolbar-btn" onclick="insertLine('- [ ] ')" title="Task">☐</button>
                <span class="toolbar-separator"></span>
                <button type="button" class="toolbar-btn" onclick="insertFormat('\`', '\`')" title="Code">&lt;/&gt;</button>
                <div class="toolbar-tabs">
                  <button type="button" class="tab-btn ${!showPreview ? 'active' : ''}" onclick="togglePreview(false)">Write</button>
                  <button type="button" class="tab-btn ${showPreview ? 'active' : ''}" onclick="togglePreview(true)">Preview</button>
                </div>
              </div>
              <div class="editor-content ${showPreview ? 'show-preview' : ''}" id="editor-content">
                <div class="editor-pane">
                  <textarea id="content" placeholder="Write your content in Markdown...">${escapeHtml(formData.content)}</textarea>
                </div>
                <div class="preview-pane prose">${renderMarkdown(formData.content)}</div>
              </div>
            </div>
          </form>
        </div>
      </main>
    `;

    // Event listeners
    const titleInput = document.getElementById('title');
    const contentInput = document.getElementById('content');
    const tagsInput = document.getElementById('tags');
    const typeInput = document.getElementById('type');
    const statusInput = document.getElementById('status');
    const priorityInput = document.getElementById('priority');
    const libraryInput = document.getElementById('libraryId');

    const inputs = [titleInput, contentInput, tagsInput, typeInput, statusInput, priorityInput, libraryInput];
    inputs.forEach(input => {
      if (input) {
        input.addEventListener('input', () => {
          hasChanges = true;
          updateFormData();
          if (showPreview) {
            document.querySelector('.preview-pane').innerHTML = renderMarkdown(formData.content);
          }
        });
      }
    });

    window.insertFormat = (before, after) => {
      const textarea = document.getElementById('content');
      const start = textarea.selectionStart;
      const end = textarea.selectionEnd;
      const text = textarea.value;
      const selected = text.substring(start, end);
      textarea.value = text.substring(0, start) + before + selected + after + text.substring(end);
      textarea.focus();
      textarea.selectionStart = start + before.length;
      textarea.selectionEnd = end + before.length;
      hasChanges = true;
    };

    window.insertLine = (prefix) => {
      const textarea = document.getElementById('content');
      const start = textarea.selectionStart;
      const text = textarea.value;
      // Find start of current line
      let lineStart = start;
      while (lineStart > 0 && text[lineStart - 1] !== '\n') lineStart--;
      textarea.value = text.substring(0, lineStart) + prefix + text.substring(lineStart);
      textarea.focus();
      textarea.selectionStart = textarea.selectionEnd = lineStart + prefix.length;
      hasChanges = true;
    };

    window.togglePreview = (show) => {
      showPreview = show;
      const content = document.getElementById('editor-content');
      if (show) {
        content.classList.add('show-preview');
      } else {
        content.classList.remove('show-preview');
      }
    };

    window.handleCancel = async () => {
      if (hasChanges) {
        const confirmed = await app.confirmDelete('You have unsaved changes. Discard?');
        if (!confirmed) return;
      }
      app.navigate('dashboard');
    };

    window.handleSave = async () => {
      updateFormData();
      
      const data = {
        title: formData.title,
        content: formData.content,
        tags: formData.tags.split(',').map(t => t.trim()).filter(t => t),
        type: formData.type,
        priority: formData.priority,
        status: formData.status,
        libraryId: formData.libraryId || null
      };

      try {
        if (isNew) {
          await api.createDocument(data);
        } else {
          await api.updateDocument(id, data);
        }
        app.showToast('Document saved', 'success');
        app.navigate('dashboard');
      } catch (e) {
        app.showToast('Failed to save: ' + e.message, 'error');
      }
    };

    function updateFormData() {
      formData = {
        title: titleInput.value,
        content: contentInput.value,
        tags: tagsInput.value,
        type: typeInput.value,
        priority: priorityInput.value,
        status: statusInput.value,
        libraryId: libraryInput.value
      };
    }
  }

  render();
}

function escapeHtml(str) {
  if (!str) return '';
  const div = document.createElement('div');
  div.textContent = str;
  return div.innerHTML;
}

function renderMarkdown(content) {
  if (!content) return '<p style="color:var(--color-text-muted)">Nothing to preview</p>';
  
  if (typeof marked !== 'undefined') {
    return marked.parse(content);
  }
  
  // Fallback
  return content
    .replace(/&/g, '&amp;')
    .replace(/</g, '&lt;')
    .replace(/>/g, '&gt;')
    .replace(/^### (.+)$/gm, '<h3>$1</h3>')
    .replace(/^## (.+)$/gm, '<h2>$1</h2>')
    .replace(/^# (.+)$/gm, '<h1>$1</h1>')
    .replace(/\*\*(.+?)\*\*/g, '<strong>$1</strong>')
    .replace(/\*(.+?)\*/g, '<em>$1</em>')
    .replace(/`(.+?)`/g, '<code>$1</code>')
    .replace(/\n\n/g, '</p><p>');
}