#!/usr/bin/env bash
# Aligns only origin/test, origin/pprod, origin/prod to current branch SHA. main is not aligned.
set -euo pipefail

if ! git rev-parse --is-inside-work-tree >/dev/null 2>&1; then
	echo "[branch-align][ERROR] Not in a git repository" >&2
	exit 1
fi

PROJECT_ROOT="$(git rev-parse --show-toplevel)"
DEPLOY_DIR="$(cd "$(dirname "${BASH_SOURCE[0]:-$0}")" && pwd)"
if [[ "$(pwd)" != "$PROJECT_ROOT" ]]; then
	cd "$PROJECT_ROOT" && exec "${DEPLOY_DIR}/$(basename "${BASH_SOURCE[0]:-$0}")" "$@"
fi

env_branch="${1:-}"
if [[ -z "$env_branch" ]]; then
	echo "[branch-align][ERROR] Missing <env> argument (expected: main|test|pprod|prod)" >&2
	echo "Usage: ./deploy/branch-align.sh <env>" >&2
	exit 1
fi
if [[ ! "$env_branch" =~ ^(main|test|pprod|prod)$ ]]; then
	echo "[branch-align][ERROR] Invalid <env>: must be main, test, pprod or prod (got: '${env_branch}')" >&2
	echo "Usage: ./deploy/branch-align.sh <env>" >&2
	exit 1
fi

current_branch="$(git rev-parse --abbrev-ref HEAD)"
if [[ "$current_branch" != "$env_branch" ]]; then
	echo "[branch-align][ERROR] Must be on branch '${env_branch}' (current: '${current_branch}')" >&2
	exit 1
fi

# Fetch latest refs

git fetch origin

target_sha="$(git rev-parse "$env_branch")"
origin_env_sha="$(git rev-parse "origin/${env_branch}")"

if [[ "$target_sha" != "$origin_env_sha" ]]; then
	echo "[branch-align] origin/${env_branch} differs from local ${env_branch}. Updating remote to local (env priority)."
	git push --force-with-lease origin "${target_sha}:${env_branch}"
	git fetch origin
fi

# Align all three branches to env SHA
for br in test pprod prod; do
	if [[ "$br" == "$env_branch" ]]; then
		# Ensure tracking exists
		git branch --set-upstream-to="origin/${br}" "$br" >/dev/null 2>&1 || true
		continue
	fi

	git branch -f "$br" "$target_sha"	
	git push --force-with-lease origin "${target_sha}:${br}"	
	git branch --set-upstream-to="origin/${br}" "$br" >/dev/null 2>&1 || true

done

# Also ensure env branch tracks its remote

git branch --set-upstream-to="origin/${env_branch}" "$env_branch" >/dev/null 2>&1 || true

# Verify last 30 commits are identical

tmp1="$(mktemp -t branch-align-test.XXXXXX)"
tmp2="$(mktemp -t branch-align-pprod.XXXXXX)"
tmp3="$(mktemp -t branch-align-prod.XXXXXX)"
cleanup() {
	rm -f "$tmp1" "$tmp2" "$tmp3"
}
trap cleanup EXIT

git log -30 --format=%H origin/test > "$tmp1"
git log -30 --format=%H origin/pprod > "$tmp2"
git log -30 --format=%H origin/prod > "$tmp3"

if ! diff -u "$tmp1" "$tmp2" >/dev/null; then
	echo "[branch-align][ERROR] Last 30 commits differ: origin/test vs origin/pprod" >&2
	exit 1
fi
if ! diff -u "$tmp1" "$tmp3" >/dev/null; then
	echo "[branch-align][ERROR] Last 30 commits differ: origin/test vs origin/prod" >&2
	exit 1
fi

# Final assertions

if [[ "$(git rev-parse --abbrev-ref HEAD)" != "$env_branch" ]]; then
	echo "[branch-align][ERROR] Branch changed unexpectedly" >&2
	exit 1
fi

sha_test="$(git rev-parse origin/test)"
sha_pprod="$(git rev-parse origin/pprod)"
sha_prod="$(git rev-parse origin/prod)"

if [[ "$sha_test" != "$sha_pprod" ]] || [[ "$sha_test" != "$sha_prod" ]]; then
	echo "[branch-align][ERROR] Remote branches are not aligned" >&2
	echo "origin/test=$sha_test" >&2
	echo "origin/pprod=$sha_pprod" >&2
	echo "origin/prod=$sha_prod" >&2
	exit 1
fi

echo "[branch-align] OK: origin/test, origin/pprod, origin/prod aligned to ${sha_test}"