内部模块: Snapshot (快照系统)

export async function track() {
  if (Instance.project.vcs !== "git") return  // 仅 Git 项目
  
  const cfg = await Config.get()
  if (cfg.snapshot === false) return  // 用户可禁用
  
  const git = gitdir()  // ~/.opencode/data/snapshot/{projectID}
  
  // 初始化独立 Git 仓库
  if (await fs.mkdir(git, { recursive: true })) {
    await $`git init`.env({
      GIT_DIR: git,
      GIT_WORK_TREE: Instance.worktree,
    })
  }
  
  // 暂存所有文件
  await $`git --git-dir ${git} --work-tree ${worktree} add .`
  
  // 生成 tree hash (不创建 commit)
  const hash = await $`git --git-dir ${git} --work-tree ${worktree} write-tree`.text()
  
  return hash.trim()  // 例如: "abc123..."
}

export async function patch(hash: string): Promise<Patch> {
  const git = gitdir()
  
  // 暂存当前状态
  await $`git --git-dir ${git} --work-tree ${worktree} add .`
  
  // 比较 hash 和当前状态，获取变更文件列表
  const result = await $`git --git-dir ${git} --work-tree ${worktree} diff --name-only ${hash} -- .`.text()
 
  return {
    hash,
    files: result.split("\n").filter(Boolean).map(f => path.join(worktree, f)),
  }
}

export async function revert(patches: Patch[]) {
  const files = new Set<string>()
  const git = gitdir()
  
  for (const item of patches) {
    for (const file of item.files) {
      if (files.has(file)) continue
      
      // 恢复到快照版本
      const result = await $`git --git-dir ${git} --work-tree ${worktree} checkout ${item.hash} -- ${file}`
      
      if (result.exitCode !== 0) {
        // 检查文件是否存在于快照中
        const checkTree = await $`git ls-tree ${item.hash} -- ${relativePath}`
        
        if (!checkTree.text().trim()) {
          // 文件不存在于快照 = 新创建的文件 → 删除它
          await fs.unlink(file)
        }
      }
      
      files.add(file)
    }
  }
}

export async function diffFull(from: string, to: string): Promise<FileDiff[]> {
  const result: FileDiff[] = []
  
  // 获取变更统计
  for (const line of await $`git diff --numstat ${from} ${to}`.lines()) {
    const [additions, deletions, file] = line.split("\t")
    
    // 获取文件内容
    const before = await $`git show ${from}:${file}`.text()
    const after = await $`git show ${to}:${file}`.text()
    
    result.push({
      file,
      before,
      after,
      additions: parseInt(additions),
      deletions: parseInt(deletions),
    })
  }
  
  return result
}

// 1. 任务开始前创建快照
const before = await Snapshot.track()
 
// 2. Agent 执行修改...
 
// 3. 用户点击 "Revert All"
const changes = await Snapshot.patch(before)
await Snapshot.revert([changes])
 
// 所有文件恢复原状

// 只回滚特定文件
await Snapshot.revert([{
  hash: beforeHash,
  files: ["/path/to/specific/file.ts"]
}])

// opencode.json
{
  "snapshot": false  // 禁用快照 (默认 true)
}