#!/usr/bin/env bash

set -Eeuo pipefail

SCRIPT_DIR="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
ROOT_DIR="$(cd -- "${SCRIPT_DIR}/.." && pwd)"
PROD_COMPOSE="${ROOT_DIR}/compose.prod.yaml"
ENV_FILE="${MOONWELL_ENV_FILE:-${ROOT_DIR}/.env}"
BACKUP_WORK_DIR="${ROOT_DIR}/storage/app/private/database-backups"
LOCK_FILE="${BACKUP_WORK_DIR}/backup.lock"
RUN_DIR=''

log() {
    printf '[%s] %s\n' "$(date '+%Y-%m-%d %H:%M:%S %Z')" "$*"
}

fail() {
    log "ERROR: $*" >&2
    exit 1
}

env_value() {
    local key="$1"
    local value

    value="$(grep -E "^${key}=" "$ENV_FILE" | tail -n 1 | cut -d '=' -f 2-)"
    if [[ "$value" == \"*\" && "$value" == *\" ]]; then
        value="${value:1:${#value}-2}"
    elif [[ "$value" == \'*\' && "$value" == *\' ]]; then
        value="${value:1:${#value}-2}"
    fi

    printf '%s' "$value"
}

validate_database_name() {
    [[ "$1" =~ ^[A-Za-z0-9_-]+$ ]] || fail "Недопустимое имя базы: $1"
}

prod() {
    docker compose -f "$PROD_COMPOSE" "$@"
}

cleanup() {
    if [[ -n "$RUN_DIR" && -d "$RUN_DIR" && "$RUN_DIR" == "${BACKUP_WORK_DIR}/"* ]]; then
        find "$RUN_DIR" -maxdepth 1 -type f -delete
        rmdir "$RUN_DIR" 2>/dev/null || true
    fi
}

dump_web_database() {
    local database="$1"
    local output="$2"

    log "Создаю дамп локальной базы ${database}"
    prod exec -T mysql sh -c '
        export MYSQL_PWD="$MYSQL_ROOT_PASSWORD"
        exec mysqldump \
            --user=root \
            --single-transaction \
            --quick \
            --hex-blob \
            --triggers \
            --no-tablespaces \
            --set-gtid-purged=OFF \
            --databases "$1"
    ' sh "$database" | gzip > "$output"
}

dump_remote_database() {
    local database="$1"
    local output="$2"
    local host="$3"
    local port="$4"
    local username="$5"
    local password="$6"

    log "Создаю дамп AzerothCore ${database}"
    docker run --rm --network host \
        --env MYSQL_PWD="$password" \
        mysql:8.4 \
        mysqldump \
            --host="$host" \
            --port="$port" \
            --user="$username" \
            --single-transaction \
            --quick \
            --hex-blob \
            --triggers \
            --no-tablespaces \
            --set-gtid-purged=OFF \
            --databases "$database" | gzip > "$output"
}

upload_backup() {
    local source="$1"
    local destination="$2"
    local app_uid app_gid

    app_uid="$(env_value WWWUSER)"
    app_gid="$(env_value WWWGROUP)"
    app_uid="${app_uid:-1000}"
    app_gid="${app_gid:-1000}"

    chown "${app_uid}:${app_gid}" "$RUN_DIR" "$source"
    chmod 0750 "$RUN_DIR"
    chmod 0640 "$source"
    prod exec -T --user "${app_uid}:${app_gid}" app \
        php artisan backup:upload "/var/www/html/storage/app/private/database-backups/${RUN_DIR##*/}/${source##*/}" "$destination"
}

main() {
    command -v docker >/dev/null 2>&1 || fail 'Не найден Docker'
    command -v gzip >/dev/null 2>&1 || fail 'Не найден gzip'
    command -v flock >/dev/null 2>&1 || fail 'Не найден flock'
    docker compose version >/dev/null 2>&1 || fail 'Не найден Docker Compose Plugin'
    [[ -f "$ENV_FILE" ]] || fail "Не найден ${ENV_FILE}"
    [[ -f "$PROD_COMPOSE" ]] || fail "Не найден ${PROD_COMPOSE}"

    mkdir -p "$BACKUP_WORK_DIR"
    exec 9>"$LOCK_FILE"
    if ! flock -n 9; then
        log 'Предыдущий запуск ещё выполняется, новый запуск пропущен'
        return 0
    fi

    local timestamp object_prefix web_database
    local acore_host acore_port acore_username acore_password acore_databases
    local database filename
    local -a databases=() files=()

    timestamp="$(date -u '+%Y-%m-%dT%H-%M-%SZ')"
    object_prefix="$(env_value DATABASE_BACKUP_PREFIX)"
    object_prefix="${object_prefix:-backups/databases}"
    object_prefix="${object_prefix%/}/$(date -u '+%Y/%m/%d')/${timestamp}"
    web_database="$(env_value DB_DATABASE)"
    acore_host="$(env_value AZEROTHCORE_AUTH_DB_HOST)"
    acore_port="$(env_value AZEROTHCORE_AUTH_DB_PORT)"
    acore_username="$(env_value AZEROTHCORE_AUTH_DB_USERNAME)"
    acore_password="$(env_value AZEROTHCORE_AUTH_DB_PASSWORD)"
    acore_databases="$(env_value DATABASE_BACKUP_ACORE_DATABASES)"
    acore_databases="${acore_databases:-acore_auth acore_characters acore_world acore_playerbots store}"

    [[ -n "$web_database" ]] || fail 'DB_DATABASE не задан'
    [[ -n "$acore_host" && -n "$acore_port" && -n "$acore_username" ]] || fail 'Не настроено подключение к AzerothCore'
    validate_database_name "$web_database"

    RUN_DIR="${BACKUP_WORK_DIR}/${timestamp}"
    mkdir -m 0700 "$RUN_DIR"
    trap cleanup EXIT

    filename="${web_database}.sql.gz"
    dump_web_database "$web_database" "${RUN_DIR}/${filename}"
    databases+=("$web_database")
    files+=("$filename")

    for database in $acore_databases; do
        validate_database_name "$database"
        filename="${database}.sql.gz"
        dump_remote_database "$database" "${RUN_DIR}/${filename}" "$acore_host" "$acore_port" "$acore_username" "$acore_password"
        databases+=("$database")
        files+=("$filename")
    done

    log "Все дампы созданы, загружаю набор ${timestamp} в S3"
    for filename in "${files[@]}"; do
        [[ -s "${RUN_DIR}/${filename}" ]] || fail "Пустой файл дампа: ${filename}"
        upload_backup "${RUN_DIR}/${filename}" "${object_prefix}/${filename}"
    done

    log "Бэкап завершён: ${#databases[@]} баз, s3://${object_prefix}/"
}

main "$@"