import type { ExtensionContext, Uri } from 'vscode'
import type { CodeReaderApi, RuleLocation, RuleReference } from './contract'
import type { IndexedName } from './nameResolution'
import { commands, window, workspace } from 'vscode'
import { logger } from '../logging/logger'
import { BlockFilter } from './editor/blockFilter'
import { NEXT_OCCURRENCE, PREVIOUS_OCCURRENCE } from './editor/occurrenceNavigation'
import { PREVIEW_VIEW_TYPE, PreviewEditorProvider } from './editor/previewEditor'
import { showPreview, showSource } from './editor/switchEditor'
import { registerCopyCommands } from './explorer/copyCommands'
import { FileTreeProvider } from './explorer/fileTree'
import { createPythonAdapter } from './languages/python'
import { createTypeScriptAdapter } from './languages/typescript'
import { resolveReference } from './libraryRules'
import { indexedNames } from './nameResolution'
import { registerNoteCommands } from './notes/commands'
import { FileNotes } from './notes/fileNotes'
import { CodeQa } from './qa/codeQa'
import { CodeReaderRegistry } from './registry'
import { celeryRule } from './rules/celery'
import { dataclassRule } from './rules/dataclass'
import { enumRule } from './rules/enum'
import { sqlalchemyRule } from './rules/sqlalchemy'
import { bundledWasmDir, TreeSitterRuntime } from './runtime'
import { pythonZhTranslator } from './translators/pythonZh'
import { typescriptZhTranslator } from './translators/typescriptZh'
import { workspaceIndexHost } from './workspaceFiles'
import { WorkspaceIndexes } from './workspaceIndex'

/** 当前语言插件覆盖的 languageId，给 editor/title 的 when 子句判断要不要显示「预览」。 */
const LANGUAGE_IDS_CONTEXT = 'superpowers.codeReader.languageIds'
const FILES_VIEW = 'superpowers.codeReader.files'
const OPEN_COMMAND = 'superpowers.codeReader.open'

/** 按 VS Code 的判断（含 files.associations）取文件的 languageId；图片等二进制文件打不开成文本，返回 undefined。 */
async function languageOf(uri: Uri): Promise<string | undefined> {
  try {
    return (await workspace.openTextDocument(uri)).languageId
  }
  catch {
    return undefined
  }
}

/** 侧栏点文件：语言受支持就用预览打开，否则用普通编辑器。 */
async function openFile(uri: Uri, registry: CodeReaderRegistry): Promise<void> {
  const languageId = await languageOf(uri)
  if (languageId !== undefined && registry.languageFor(languageId))
    // 和 vscode.open 一样按「预览标签」打开（用户关了 workbench.editor.enablePreview 时 VS Code 自会固定）
    await commands.executeCommand('vscode.openWith', uri, PREVIEW_VIEW_TYPE, { preview: true })
  else
    await commands.executeCommand('vscode.open', uri)
}

/**
 * 接入代码阅读：注册表、侧栏文件树（复制、文件注释）、预览编辑器（含问 AI）、编辑器右上角的「预览 / 编辑」切换。
 * 内置的语言插件、翻译插件和库规则与其他扩展一样通过返回的 API 注册。
 */
export function registerCodeReader(context: ExtensionContext): CodeReaderApi {
  const registry = new CodeReaderRegistry(context.globalState)
  const runtime = new TreeSitterRuntime(bundledWasmDir())
  const report = (message: string): void => logger.add({ level: 'warn', source: 'codeReader', message })
  const indexes = new WorkspaceIndexes(workspaceIndexHost(async (languageId, source) => {
    const adapter = registry.languageFor(languageId)
    if (!adapter)
      throw new Error(`没有「${languageId}」的语言插件`)
    return runtime.parse(adapter, languageId, source)
  }, report))
  const resolve = (reference: RuleReference): Promise<RuleLocation[]> => resolveReference(reference, registry.libraryRules(), indexes, report)
  const qa = new CodeQa(context.globalState)
  const namesIn = async (languageId: string, name: string): Promise<IndexedName[]> => {
    const adapter = registry.languageFor(languageId)
    return adapter ? indexedNames((index, key) => indexes.find(index, key), adapter, name) : []
  }
  const previews = new PreviewEditorProvider(context.extensionUri, registry, runtime, new BlockFilter(context.workspaceState), resolve, qa, namesIn)
  const notes = new FileNotes()
  const files = new FileTreeProvider(OPEN_COMMAND, notes)

  context.subscriptions.push(
    qa,
    notes,
    indexes,
    registerNoteCommands(notes),
    registerCopyCommands(),
    registry.onDidChange(() => {
      void commands.executeCommand('setContext', LANGUAGE_IDS_CONTEXT, registry.languageIds())
      previews.refresh()
    }),
    window.registerCustomEditorProvider(PREVIEW_VIEW_TYPE, previews),
    files,
    window.createTreeView(FILES_VIEW, { treeDataProvider: files, showCollapseAll: true }),
    commands.registerCommand('superpowers.codeReader.refresh', () => files.refresh()),
    commands.registerCommand(OPEN_COMMAND, (uri: Uri) => openFile(uri, registry)),
    // 标题栏按钮传来的是 (文件 Uri, { groupId })，原样转给 VS Code 定位是哪一组的哪个标签
    commands.registerCommand('superpowers.codeReader.showPreview', (...args: unknown[]) => showPreview(previews, args)),
    commands.registerCommand('superpowers.codeReader.showSource', (...args: unknown[]) => showSource(previews, args)),
    commands.registerCommand(NEXT_OCCURRENCE, () => previews.moveOccurrence(1)),
    commands.registerCommand(PREVIOUS_OCCURRENCE, () => previews.moveOccurrence(-1)),
  )

  const api: CodeReaderApi = registry
  const wasmDir = bundledWasmDir()
  context.subscriptions.push(
    api.registerLanguage(createTypeScriptAdapter(wasmDir)),
    api.registerLanguage(createPythonAdapter(wasmDir)),
    api.registerTranslator(typescriptZhTranslator),
    api.registerTranslator(pythonZhTranslator),
    api.registerLibraryRule(sqlalchemyRule),
    api.registerLibraryRule(celeryRule),
    api.registerLibraryRule(enumRule),
    api.registerLibraryRule(dataclassRule),
  )
  return api
}