opencode/packages/opencode/src/snapshot/index.ts

import { App } from "../app/app"
import { $ } from "bun"
import path from "path"
import fs from "fs/promises"
import { Ripgrep } from "../file/ripgrep"
import { Log } from "../util/log"

export namespace Snapshot {
  const log = Log.create({ service: "snapshot" })

  export async function create(sessionID: string) {
    log.info("creating snapshot")
    const app = App.info()
    const git = gitdir(sessionID)

    // not a git repo, check if too big to snapshot
    if (!app.git) {
      const files = await Ripgrep.files({
        cwd: app.path.cwd,
        limit: 1000,
      })
      log.info("found files", { count: files.length })
      if (files.length > 1000) return
    }

    if (await fs.mkdir(git, { recursive: true })) {
      await $`git init`
        .env({
          ...process.env,
          GIT_DIR: git,
          GIT_WORK_TREE: app.path.root,
        })
        .quiet()
        .nothrow()
      log.info("initialized")
    }

    await $`git --git-dir ${git} add .`.quiet().cwd(app.path.cwd).nothrow()
    log.info("added files")

    const result =
      await $`git --git-dir ${git} commit --allow-empty -m "snapshot" --author="opencode <mail@opencode.ai>"`
        .quiet()
        .cwd(app.path.cwd)
        .nothrow()
    log.info("commit")

    // Extract commit hash from output like "[main abc1234] snapshot"
    const match = result.stdout.toString().match(/\[.+ ([a-f0-9]+)\]/)
    if (!match) throw new Error("Failed to extract commit hash")
    return match[1]
  }

  export async function restore(sessionID: string, commit: string) {
    log.info("restore", { commit })
    const app = App.info()
    const git = gitdir(sessionID)
    await $`git --git-dir=${git} checkout ${commit} --force`
      .quiet()
      .cwd(app.path.root)
  }

  function gitdir(sessionID: string) {
    const app = App.info()
    return path.join(app.path.data, "snapshot", sessionID)
  }
}