#!/usr/bin/env bash
# Regression: git_fetch_and_checkout must emit only two SHAs on stdout.
set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
TMP="$(mktemp -d)"
trap 'rm -rf "$TMP"' EXIT

git init -q "$TMP/repo"
git -C "$TMP/repo" config user.email "test@example.com"
git -C "$TMP/repo" config user.name "Test"
echo first >"$TMP/repo/file.txt"
git -C "$TMP/repo" add file.txt
git -C "$TMP/repo" commit -q -m "first"
FIRST_SHA="$(git -C "$TMP/repo" rev-parse HEAD)"
echo second >"$TMP/repo/file.txt"
git -C "$TMP/repo" commit -q -am "second"
SECOND_SHA="$(git -C "$TMP/repo" rev-parse HEAD)"

# Minimal reimplementation of the capture contract under test.
git_fetch_and_checkout() {
  local previous_sha target_sha deploy_dir="$1" ref="$2"
  previous_sha="$(git -C "$deploy_dir" rev-parse HEAD)"
  git -C "$deploy_dir" fetch origin --prune >&2 2>/dev/null || true
  target_sha="$(git -C "$deploy_dir" rev-parse "${ref}^{commit}")"
  git -C "$deploy_dir" reset --hard "$target_sha" >&2
  printf '%s %s\n' "$previous_sha" "$target_sha"
}

git -C "$TMP/repo" remote add origin "$TMP/repo"
git -C "$TMP/repo" checkout -q "$FIRST_SHA"

capture="$(git_fetch_and_checkout "$TMP/repo" "$SECOND_SHA")"
read -r got_previous got_target <<<"$capture"

[[ "$got_previous" == "$FIRST_SHA" ]] || { echo "expected previous $FIRST_SHA, got $got_previous"; exit 1; }
[[ "$got_target" == "$SECOND_SHA" ]] || { echo "expected target $SECOND_SHA, got $got_target"; exit 1; }
[[ "$capture" != *"HEAD is now at"* ]] || { echo "git reset output leaked into capture: $capture"; exit 1; }

echo "ok: deploy-sha-capture regression passed"