#!/usr/bin/env bash
# Refresh the development database (personal_dev) from a fresh production dump.
#
# Prod is the source of truth for data; dev is a disposable copy of it.
#
# Required env (put them in .env.dev-refresh or export them; never commit real values):
#   PROD_DB_URL    read access to prod, e.g. postgresql://personal:...@127.0.0.1:5440/personal
#   DEV_ADMIN_URL  superuser on the dev cluster, maintenance DB, e.g. postgresql://postgres:...@127.0.0.1:5440/postgres
#                  (not needed with PG_CONTAINER, which uses the container's local superuser)
# Optional:
#   DEV_DB_NAME    target database (default personal_dev)
#   DEV_OWNER      role that owns every object in the dev DB (default personal_dev). It is the
#                  role the dev site logs in as, so it can also run migrations there. It must not
#                  be a member of any prod role; prod's CONNECT is not granted to it.
#   PG_DOCKER=1    use the postgres:17-alpine image instead of local pg_dump/pg_restore
#   PG_CONTAINER   name of the Postgres container (e.g. postgres-db-1): run every tool inside it
#                  via `docker exec` as the local superuser. URLs are then as seen from inside
#                  the container, e.g. PROD_DB_URL=postgresql://personal:...@127.0.0.1:5432/personal
#   DOCKER         docker command (default "docker"; e.g. "sudo -n docker")
#
# What it does: dump prod (custom format) -> drop + recreate DEV_DB_NAME owned by DEV_OWNER ->
# restore without prod ownership/grants, every object owned by DEV_OWNER -> clear sessions and
# verification tokens so prod logins can't be reused in dev. It never writes to prod.
set -euo pipefail

cd "$(dirname "$0")/.."
if [[ -f .env.dev-refresh ]]; then set -a; . ./.env.dev-refresh; set +a; fi

: "${PROD_DB_URL:?set PROD_DB_URL (source, read-only use)}"
DEV_DB_NAME="${DEV_DB_NAME:-personal_dev}"
DEV_OWNER="${DEV_OWNER:-personal_dev}"
DOCKER="${DOCKER:-docker}"
if [[ -n "${PG_CONTAINER:-}" ]]; then
	DEV_ADMIN_URL="${DEV_ADMIN_URL:-postgresql://postgres@localhost/postgres}"
fi
: "${DEV_ADMIN_URL:?set DEV_ADMIN_URL (superuser URL to the dev cluster maintenance DB)}"

for ident in "$DEV_DB_NAME" "$DEV_OWNER"; do
	if [[ ! "$ident" =~ ^[a-z_][a-z0-9_]*$ ]]; then
		echo "DEV_DB_NAME / DEV_OWNER must be plain lowercase identifiers" >&2
		exit 1
	fi
done
case "$DEV_DB_NAME" in
personal | personal_prod | postgres | template0 | template1)
	echo "Refusing to overwrite '$DEV_DB_NAME'" >&2
	exit 1
	;;
esac
case "$DEV_OWNER" in
personal | personal_app | personal_ddl | personal_ro | postgres)
	echo "Refusing: DEV_OWNER '$DEV_OWNER' is a prod/superuser role" >&2
	exit 1
	;;
esac

# host:port/db of a URL (no credentials), for the "same database" guard.
endpoint() { bun -e 'const u=new URL(process.argv[1]); console.log(`${u.hostname}:${u.port||5432}${u.pathname}`)' "$1"; }
with_db() { bun -e 'const u=new URL(process.argv[1]); u.pathname="/"+process.argv[2]; console.log(u.toString())' "$1" "$2"; }

prod_endpoint="$(endpoint "$PROD_DB_URL")"
dev_url="$(with_db "$DEV_ADMIN_URL" "$DEV_DB_NAME")"
if [[ "$(endpoint "$dev_url")" == "$prod_endpoint" ]]; then
	echo "Refusing: target $DEV_DB_NAME is the prod source database ($prod_endpoint)" >&2
	exit 1
fi

# Dump goes to stdout and restore reads stdin, so the same commands work locally,
# in a throwaway postgres image, or inside the Postgres container.
if [[ -n "${PG_CONTAINER:-}" ]]; then
	pg() { $DOCKER exec -i -u postgres "$PG_CONTAINER" "$@"; }
elif [[ "${PG_DOCKER:-0}" == 1 ]]; then
	pg() { $DOCKER run --rm -i --network host postgres:17-alpine "$@"; }
else
	pg() { "$@"; }
fi

work="$(mktemp -d)"
trap 'rm -rf "$work"' EXIT
dump="$work/prod.dump"

echo "Dumping prod ($prod_endpoint)..."
pg pg_dump --format=custom --no-password "$PROD_DB_URL" >"$dump"
[[ -s "$dump" ]] || { echo "Empty dump; aborting before touching $DEV_DB_NAME" >&2; exit 1; }
pg pg_restore --list <"$dump" >/dev/null

echo "Recreating $DEV_DB_NAME (owner $DEV_OWNER)..."
pg psql -v ON_ERROR_STOP=1 -q "$DEV_ADMIN_URL" <<SQL
SELECT count(pg_terminate_backend(pid)) AS terminated_sessions FROM pg_stat_activity WHERE datname = '$DEV_DB_NAME' AND pid <> pg_backend_pid();
DROP DATABASE IF EXISTS "$DEV_DB_NAME";
DO \$\$
BEGIN
  IF NOT EXISTS (SELECT 1 FROM pg_roles WHERE rolname = '$DEV_OWNER') THEN
    EXECUTE format('CREATE ROLE %I NOLOGIN', '$DEV_OWNER');
    RAISE NOTICE 'created role $DEV_OWNER (NOLOGIN; give it a password + LOGIN for dev use)';
  END IF;
END \$\$;
CREATE DATABASE "$DEV_DB_NAME" OWNER "$DEV_OWNER";
REVOKE CONNECT, TEMPORARY ON DATABASE "$DEV_DB_NAME" FROM PUBLIC;
SQL

echo "Restoring into $DEV_DB_NAME..."
# --no-owner/--no-privileges + --role: everything ends up owned by DEV_OWNER and none of
# prod's grants (personal_app, personal_ro, ...) are copied into dev.
pg pg_restore --no-password --exit-on-error --no-owner --no-privileges --role="$DEV_OWNER" \
	--dbname="$dev_url" <"$dump"

echo "Clearing sessions and verification tokens..."
pg psql -v ON_ERROR_STOP=1 -q "$dev_url" -c 'TRUNCATE auth.session, auth.verification'

pg psql -qAt "$dev_url" -c "SELECT 'drizzle migrations recorded: ' || count(*) FROM drizzle.__drizzle_migrations"
echo "Done. Apply pending migrations from your branch with: bun run db:migrate"