import { escapeHtml, inferEnhancementClass, inferEnhancementLabel } from '../common.js';

// 侧栏数据源树。数据源当作"盘符"，可展开显示一层根目录快捷入口。
// 事件通过回调向编排器上报：onOpenSource / onOpenPath / onContextMenu。

export function createSidebar(rootElement, { onOpenSource, onContextMenu }) {
  let sources = [];
  let activeSourceId = null;

  function statusDotClass(source) {
    // 复用增强状态的语义色：ready/busy/error/idle
    switch (inferEnhancementClass(source)) {
      case 'status-ready':
        return 'ready';
      case 'status-busy':
        return 'busy';
      case 'status-error':
        return 'error';
      default:
        return 'idle';
    }
  }

  function render() {
    if (sources.length === 0) {
      rootElement.innerHTML = '<div class="explorer-tree-empty">暂无数据源，请从「上传任务库」添加。</div>';
      return;
    }

    rootElement.innerHTML = sources
      .map((source) => {
        const active = source.id === activeSourceId;
        const label = source.displayName || source.originalFilename || source.id;
        const dot = statusDotClass(source);
        const title = `${label} · ${inferEnhancementLabel(source)}`;
        return `
          <div class="explorer-tree-item${active ? ' active' : ''}"
               data-source-id="${escapeHtml(source.id)}"
               title="${escapeHtml(title)}"
               role="button" tabindex="0">
            <span class="explorer-drive-ico" aria-hidden="true">💽</span>
            <span class="explorer-tree-name">${escapeHtml(label)}</span>
            <span class="explorer-dot ${dot}" title="${escapeHtml(inferEnhancementLabel(source))}"></span>
          </div>
        `;
      })
      .join('');
  }

  function findSource(sourceId) {
    return sources.find((source) => source.id === sourceId) ?? null;
  }

  rootElement.addEventListener('click', (event) => {
    const item = event.target.closest('.explorer-tree-item');
    if (!(item instanceof HTMLElement)) {
      return;
    }
    onOpenSource?.(item.dataset.sourceId);
  });

  rootElement.addEventListener('keydown', (event) => {
    if (event.key !== 'Enter' && event.key !== ' ') {
      return;
    }
    const item = event.target.closest('.explorer-tree-item');
    if (!(item instanceof HTMLElement)) {
      return;
    }
    event.preventDefault();
    onOpenSource?.(item.dataset.sourceId);
  });

  rootElement.addEventListener('contextmenu', (event) => {
    const item = event.target.closest('.explorer-tree-item');
    if (!(item instanceof HTMLElement)) {
      return;
    }
    event.preventDefault();
    onContextMenu?.(item.dataset.sourceId, { x: event.clientX, y: event.clientY });
  });

  return {
    setSources(nextSources) {
      sources = Array.isArray(nextSources) ? nextSources : [];
      render();
    },
    setActive(sourceId) {
      activeSourceId = sourceId;
      render();
    },
    getSource: findSource,
    getSources() {
      return sources;
    }
  };
}