#!/usr/bin/env bash

set -Eeuo pipefail

SCRIPT_DIR="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd -P)"
SCRIPT_PATH="${SCRIPT_DIR}/$(basename -- "${BASH_SOURCE[0]}")"

fail() {
	printf 'ERROR: %s\n' "$*" >&2
	exit 1
}

trap 'printf "ERROR: broker update failed at line %d.\n" "$LINENO" >&2' ERR

cd "$SCRIPT_DIR"

command -v git >/dev/null 2>&1 || fail "git is required"
command -v docker >/dev/null 2>&1 || fail "docker is required"
docker compose version >/dev/null 2>&1 || fail "Docker Compose v2 is required"
[[ -f compose.yaml ]] || fail "compose.yaml was not found in ${SCRIPT_DIR}"
[[ -f .env ]] || fail ".env was not found in ${SCRIPT_DIR}"

if [[ "${1:-}" != "--post-pull" ]]; then
	branch="$(git symbolic-ref --quiet --short HEAD)" ||
		fail "the repository is in detached HEAD state"
	git rev-parse --abbrev-ref --symbolic-full-name '@{upstream}' >/dev/null 2>&1 ||
		fail "branch ${branch} does not have an upstream branch"
	git diff --quiet && git diff --cached --quiet ||
		fail "tracked local changes must be committed or stashed before updating"

	printf 'Updating TAPM Deployment Broker from branch %s...\n' "$branch"
	git pull --ff-only

	# Restart from the newly pulled script so updates to this file take effect.
	exec "$SCRIPT_PATH" --post-pull
fi

printf 'Building broker image...\n'
docker compose build broker

printf 'Applying pending database migrations...\n'
docker compose run --rm migrate

printf 'Starting broker...\n'
docker compose up -d broker

container_id="$(docker compose ps -q broker)"
[[ -n "$container_id" ]] || fail "Docker Compose did not return a broker container"

printf 'Waiting for broker health check'
for ((attempt = 1; attempt <= 75; attempt++)); do
	status="$(docker inspect --format '{{if .State.Health}}{{.State.Health.Status}}{{else}}{{.State.Status}}{{end}}' "$container_id")"
	case "$status" in
		healthy)
			printf ' healthy.\n'
			docker compose ps broker
			printf 'TAPM Deployment Broker update completed successfully.\n'
			exit 0
			;;
		exited | dead | unhealthy)
			printf ' %s.\n' "$status"
			docker compose logs --tail=100 broker
			fail "broker failed its health check"
			;;
	esac
	printf '.'
	sleep 2
done

printf ' timed out.\n'
docker compose logs --tail=100 broker
fail "broker did not become healthy within 150 seconds"