import type {
  Event,
  ExtensionContext,
  TreeDataProvider,
  TreeItem,
} from 'vscode'
import { commands, EventEmitter, window } from 'vscode'
import { initIdentity } from './auth/identity'
import { setProfilesDirOverride } from './cc/profiles'
import { KanbanWebviewPanel } from './panel/KanbanPanel'
import { getSettings } from './settings/store'
import { registerCreateSessionUriHandler } from './uri/createSessionUriHandler'
import { webhookCoordinator } from './webhook/coordinator'

/**
 * 侧边栏 TreeView 永远没有 item —— 它存在的唯一目的是接住活动栏图标
 * 点击事件，触发"开 Kanban panel + 切回 File Explorer"的自动跳转。
 */
class EmptyTreeProvider implements TreeDataProvider<never> {
  private readonly _onDidChangeTreeData = new EventEmitter<void>()
  readonly onDidChangeTreeData: Event<void> = this._onDidChangeTreeData.event

  getTreeItem(): TreeItem {
    throw new Error('unreachable')
  }

  getChildren(): never[] {
    return []
  }
}

export function activate(context: ExtensionContext): void {
  // Profiles 目录 override 在 panel 未打开时也要生效（list / launch 共用）。
  setProfilesDirOverride(getSettings(context).profilesDirectory || undefined)
  // Start the webhook server immediately so PR callbacks are received even
  // when the Kanban panel is closed. Disposed automatically via subscriptions.
  webhookCoordinator.init(context)
  context.subscriptions.push({
    dispose: () => { void webhookCoordinator.dispose() },
  })
  // 状态栏常驻展示当前 Gitea 身份;token 用错人(同步/复制)时第一眼能看出来。
  void initIdentity(context)

  // vscode://clurdra.superpowers-vscode-clurdra/create-session 外部触发开 cc 会话 tab。
  registerCreateSessionUriHandler(context)

  const treeView = window.createTreeView('superpowers.kanban', {
    treeDataProvider: new EmptyTreeProvider(),
    showCollapseAll: false,
  })

  let wasVisible = treeView.visible
  let isAutoOpening = false

  const autoOpenPanelFromActivityBar = async (): Promise<void> => {
    if (isAutoOpening)
      return
    isAutoOpening = true
    try {
      KanbanWebviewPanel.createOrShow(context)
      // 立刻把 sidebar 切回 File Explorer，让 superpowers 的空 sidebar 一闪而过
      try {
        await commands.executeCommand('workbench.view.explorer')
      }
      catch {
        // 不存在 explorer 视图时静默忽略
      }
    }
    finally {
      isAutoOpening = false
    }
  }

  treeView.onDidChangeVisibility(async (e) => {
    const isVisible = e.visible
    // 仅当从不可见变可见（即用户点击了活动栏图标）时触发
    if (isVisible && !wasVisible && !isAutoOpening)
      await autoOpenPanelFromActivityBar()
    wasVisible = isVisible
  })

  context.subscriptions.push(
    treeView,
    commands.registerCommand('superpowers.openKanban', () => {
      KanbanWebviewPanel.createOrShow(context)
    }),
    commands.registerCommand('superpowers.refresh', () => {
      KanbanWebviewPanel.refresh()
    }),
    commands.registerCommand('superpowers.setGiteaToken', () => {
      KanbanWebviewPanel.createOrShow(context)
      KanbanWebviewPanel.requestEditAuth()
    }),
  )
}

export function deactivate(): void {}