import { execFileSync } from 'node:child_process'
import { existsSync, promises as fsp, rmSync, writeFileSync } from 'node:fs'
import * as os from 'node:os'
import * as path from 'node:path'
import { afterEach, describe, expect, it } from 'vitest'
import { ensureWorktreeFromRemote } from '../../src/git/worktree'

const gitEnv: NodeJS.ProcessEnv = {
  ...process.env,
  GIT_CONFIG_NOSYSTEM: '1',
  GIT_CONFIG_GLOBAL: '/dev/null',
  GIT_TERMINAL_PROMPT: '0',
  GIT_AUTHOR_NAME: 'remote-test',
  GIT_AUTHOR_EMAIL: 'remote@test.local',
  GIT_COMMITTER_NAME: 'remote-test',
  GIT_COMMITTER_EMAIL: 'remote@test.local',
}

function git(cwd: string, args: string[]): string {
  return execFileSync('git', ['-C', cwd, ...args], { encoding: 'utf8', env: gitEnv }).trim()
}

interface Fixture { root: string, origin: string, repo: string, templatePath: string }

/** origin（bare）← 同事的 clone push feature 分支；repo 是接管方的 clone，只有 main。 */
async function setup(): Promise<Fixture> {
  const root = await fsp.mkdtemp(path.join(os.tmpdir(), 'sw-remote-'))
  const origin = path.join(root, 'origin.git')
  git(root, ['init', '--bare', '-b', 'main', origin])
  const peer = path.join(root, 'peer')
  git(root, ['clone', origin, peer])
  writeFileSync(path.join(peer, 'README.md'), 'hello\n')
  git(peer, ['add', 'README.md'])
  git(peer, ['commit', '-m', 'init'])
  git(peer, ['push', '-u', 'origin', 'main'])
  git(peer, ['checkout', '-b', 'feature/x'])
  writeFileSync(path.join(peer, 'x.txt'), 'x\n')
  git(peer, ['add', 'x.txt'])
  git(peer, ['commit', '-m', 'feat x'])
  git(peer, ['push', '-u', 'origin', 'feature/x'])
  const repo = path.join(root, 'repo')
  git(root, ['clone', origin, repo])
  const templatePath = path.join(root, 'wt', 'x')
  return { root, origin, repo, templatePath }
}

let fx: Fixture | undefined
afterEach(() => {
  if (fx)
    rmSync(fx.root, { recursive: true, force: true })
  fx = undefined
})

describe('ensureWorktreeFromRemote', () => {
  it('从 origin 分支建 worktree，本地分支跟踪远端', async () => {
    fx = await setup()
    const out = await ensureWorktreeFromRemote({ workspaceRoot: fx.repo, worktreePath: fx.templatePath, branch: 'feature/x' })
    expect(out).toBe(fx.templatePath)
    expect(existsSync(path.join(fx.templatePath, 'x.txt'))).toBe(true)
    expect(git(fx.templatePath, ['rev-parse', '--abbrev-ref', 'HEAD'])).toBe('feature/x')
    expect(git(fx.templatePath, ['rev-parse', '--abbrev-ref', '@{u}'])).toBe('origin/feature/x')
  })

  it('该分支已有 live worktree 时直接复用', async () => {
    fx = await setup()
    const first = await ensureWorktreeFromRemote({ workspaceRoot: fx.repo, worktreePath: fx.templatePath, branch: 'feature/x' })
    const other = path.join(fx.root, 'wt', 'other')
    const second = await ensureWorktreeFromRemote({ workspaceRoot: fx.repo, worktreePath: other, branch: 'feature/x' })
    expect(second).toBe(first)
    expect(existsSync(other)).toBe(false)
  })

  it('模板路径被非 worktree 目录占着 → 删掉重建', async () => {
    fx = await setup()
    await fsp.mkdir(fx.templatePath, { recursive: true })
    writeFileSync(path.join(fx.templatePath, 'junk'), '')
    await ensureWorktreeFromRemote({ workspaceRoot: fx.repo, worktreePath: fx.templatePath, branch: 'feature/x' })
    expect(existsSync(path.join(fx.templatePath, 'junk'))).toBe(false)
    expect(existsSync(path.join(fx.templatePath, 'x.txt'))).toBe(true)
  })

  it('远端没有该分支 → 抛错', async () => {
    fx = await setup()
    await expect(
      ensureWorktreeFromRemote({ workspaceRoot: fx.repo, worktreePath: fx.templatePath, branch: 'feature/none' }),
    ).rejects.toThrow(/feature\/none/)
  })
})