#!/bin/sh
set -eu

usage() {
    cat <<EOF
Usage: $(basename "$0") BACKUP_ID [DB_NAME] [DB_USER]

Restore the Gitea data volume and database from a backup run identified by BACKUP_ID.
BACKUP_ID should match the directory name under ./backups (e.g. 2025-11-17_12-30).
DB_NAME and DB_USER default to environment variables GITEA_DB / GITEA_DB_USER,
falling back to "gitea" / "gitea" if unset.
EOF
}

if [ "${1:-}" = "--help" ] || [ "${1:-}" = "-h" ]; then
    usage
    exit 0
fi

if [ $# -lt 1 ] || [ $# -gt 3 ]; then
    usage >&2
    exit 1
fi

BACKUP_ID=$1
ROOT_DIR=$(cd "$(dirname "$0")/../.." && pwd)
BACKUPS_DIR="$ROOT_DIR/backups/$BACKUP_ID"

load_env_file() {
    local file=$1
    if [ -f "$file" ]; then
        # shellcheck disable=SC1090
        set -a
        . "$file"
        set +a
    fi
}

# Load shared or service-specific environment files if present
load_env_file "$ROOT_DIR/.env"

DB_NAME=${GITEA_DB:-${GITEA_DB_NAME:-gitea}}
DB_USER=${GITEA_DB_USER:-gitea}
DB_PASSWORD=${GITEA_DB_PASSWORD:-${GITEA_DB_PASS:-}}

DB_NAME=${2:-$DB_NAME}
DB_USER=${3:-$DB_USER}

if [ ! -d "$BACKUPS_DIR" ]; then
    printf 'Backup directory not found: %s\n' "$BACKUPS_DIR" >&2
    exit 1
fi

COMPOSE_CMD="docker compose"
cd "$ROOT_DIR"

printf 'Stopping Gitea service before restore...\n'
if ! $COMPOSE_CMD stop gitea >/dev/null 2>&1; then
    printf 'Warning: could not stop Gitea service (it may already be stopped).\n' >&2
fi

ARCHIVE="gitea_data_${BACKUP_ID}.tar.gz"
HOST_FILE="$BACKUPS_DIR/$ARCHIVE"
CONTAINER_PATH="/backups/$BACKUP_ID/$ARCHIVE"

if [ ! -f "$HOST_FILE" ]; then
    printf 'Archive missing: %s\n' "$HOST_FILE" >&2
    exit 1
fi

printf 'Restoring gitea_data from %s\n' "$HOST_FILE"
$COMPOSE_CMD run --rm restore restore-volume gitea_data "$CONTAINER_PATH"

DB_DUMP_DIR="$BACKUPS_DIR"
DB_DUMP_FILE="$DB_DUMP_DIR/${DB_NAME}_${BACKUP_ID}.sql"
DB_DUMP_GZ="$DB_DUMP_FILE.gz"

if [ -f "$DB_DUMP_GZ" ]; then
    DB_SOURCE="$DB_DUMP_GZ"
elif [ -f "$DB_DUMP_FILE" ]; then
    DB_SOURCE="$DB_DUMP_FILE"
else
    DB_SOURCE=""
fi

if [ -n "$DB_SOURCE" ]; then
    if [ -z "$DB_PASSWORD" ]; then
        printf 'Database dump found (%s) but GITEA_DB_PASSWORD not set; skipping DB restore.\n' "$DB_SOURCE" >&2
    else
        printf 'Restoring database %s from %s\n' "$DB_NAME" "$DB_SOURCE"
        DROP_FLAG=${GITEA_DROP_EXISTING_DB:-${DROP_EXISTING_DB:-1}}
        RESTORE_ENV_ARGS="-e PGPASSWORD=$DB_PASSWORD -e DROP_EXISTING_DB=$DROP_FLAG"
        if [ -n "${POSTGRES_ADMIN_USER:-}" ] && [ -n "${POSTGRES_ADMIN_PASSWORD:-}" ]; then
            RESTORE_ENV_ARGS="$RESTORE_ENV_ARGS -e POSTGRES_ADMIN_USER=$POSTGRES_ADMIN_USER -e POSTGRES_ADMIN_PASSWORD=$POSTGRES_ADMIN_PASSWORD"
        fi
        if [ -n "${POSTGRES_ADMIN_DB:-}" ]; then
            RESTORE_ENV_ARGS="$RESTORE_ENV_ARGS -e POSTGRES_ADMIN_DB=$POSTGRES_ADMIN_DB"
        fi
        if [ -n "${GITEA_DB_HOST:-}" ]; then
            RESTORE_ENV_ARGS="$RESTORE_ENV_ARGS -e POSTGRES_HOST=$GITEA_DB_HOST"
        elif [ -n "${POSTGRES_HOST:-}" ]; then
            RESTORE_ENV_ARGS="$RESTORE_ENV_ARGS -e POSTGRES_HOST=$POSTGRES_HOST"
        fi
        # shellcheck disable=SC2086
        $COMPOSE_CMD run --rm $RESTORE_ENV_ARGS restore \
            restore-db "/backups/$BACKUP_ID/$(basename "$DB_SOURCE")" "$DB_NAME" "$DB_USER" "$DB_PASSWORD"
    fi
else
    printf 'No database dump found for %s in %s\n' "$DB_NAME" "$DB_DUMP_DIR" >&2
fi

printf '\nRestore command completed. Restart Gitea when ready.\n'

printf 'Starting Gitea service...\n'
if ! $COMPOSE_CMD up -d gitea; then
    printf 'Warning: failed to start Gitea service. Please start it manually.\n' >&2
fi