import * as git from "../git.ts"
import { requireSession } from "./helpers.ts"

export async function action(branch: string) {
  const { session } = await requireSession(branch)

  if (session.prompt) {
    process.stderr.write(`PROMPT: ${session.prompt}\n\n`)
  }

  const main = await git.mainBranch(session.worktree)

  // Run git diff with inherited stdio so external diff tools (e.g. difftastic)
  // see a real TTY and git can use its own pager
  const proc = Bun.spawn(["git", "-C", session.worktree, "diff", `${main}...${branch}`], {
    stdin: "inherit",
    stdout: "inherit",
    stderr: "inherit",
  })
  const exitCode = await proc.exited
  if (exitCode !== 0) {
    process.exit(exitCode)
  }
}