// 文档查看器（4.4 → 预览能力收敛）：格式渲染统一交给 @ui FilePreview
// （md/图片/pdf/代码/数据/docx/xlsx/pptx/URL 一套分派），这里只保留 OverlayHost
// 容器、工具栏与文本族的在线编辑保存。
import { useEffect, useState } from 'react'
import { api } from '../api'
import { store } from '../store'
import { OverlayHost, Icon, Btn, FilePreview } from '@ui'
import type { Artifact } from '../contracts'
import { humanSize } from '../messageparts'

export function DocViewer({ artifact }: { artifact: Artifact }) {
  const [content, setContent] = useState<string | null>(null)
  const [editing, setEditing] = useState(false)
  const [dirty, setDirty] = useState(false)

  const textKind = isTextKind(artifact)
  useEffect(() => {
    if (!textKind) return
    setContent(null)
    fetch(api.artifactContentUrl(artifact.id)).then(r => r.text()).then(setContent).catch(() => setContent('（读取失败）'))
  }, [artifact.id])

  const source = {
    kind: 'artifact' as const,
    id: artifact.id,
    name: artifact.name,
    mime: artifact.mime,
    contentUrl: api.artifactContentUrl(artifact.id),
    downloadUrl: api.artifactDownloadUrl(artifact.id),
  }

  return (
    <OverlayHost title={artifact.name} icon="📄" onClose={() => store.viewArtifact(null)}>
      <div className="docv">
        <div className="docv-toolbar">
          <span className="docv-meta">{artifact.kind}{humanSize(artifact.size) ? ` · ${humanSize(artifact.size)}` : ''}</span>
          <span className="spacer" />
          {dirty && <span className="docv-dirty">未保存</span>}
          {textKind && (
            <>
              <Btn variant="ghost" icon={editing ? 'eye' : 'list'} onClick={() => setEditing(e => !e)}>{editing ? '预览' : '编辑'}</Btn>
              {editing && <Btn variant="primary" icon="check" disabled={!dirty} onClick={async () => {
                await api.saveArtifactContent(artifact.id, content ?? '')
                setDirty(false)
                store.toast('已保存')
              }}>保存</Btn>}
            </>
          )}
          <a className="btn v-ghost docv-dl" href={api.artifactDownloadUrl(artifact.id)} download={artifact.name}>
            <Icon name="download" size={14} /> 下载
          </a>
        </div>
        <div className="docv-body">
          {editing && textKind ? (
            <textarea className="search-input docv-editor" value={content ?? ''}
              onChange={e => { setContent(e.target.value); setDirty(true) }} />
          ) : (
            <FilePreview source={source} />
          )}
        </div>
      </div>
    </OverlayHost>
  )
}

function isTextKind(a: Artifact): boolean {
  return a.kind === 'document' && /\.(md|txt|csv|log|json)$/i.test(a.name)
}