import LifecycleUnit from '../../lib/src/lifecycle/Unit.ts'
import Config from '../../lib/src/unit/Config.ts'
import {Unit} from '../../lib/src/lifecycle/decorators.ts'
import Database from './service/Database.ts'

/**
 * Lifecycle unit which loads and creates database connections from the database config files.
 * @extends LifecycleUnit
 */
@Unit()
export class DatabaseUnit extends LifecycleUnit {
    constructor(
        protected config: Config,
        protected db: Database,
    ) {
        super()
    }

    public async up() {
        const connections: { [key: string]: any } = this.config.get('db.connections')

        for ( const conn_name in connections ) {
            if ( !connections.hasOwnProperty(conn_name) ) continue
            const config = connections[conn_name]

            switch(config.type) {
                case 'postgres':
                    await this.db.postgres(conn_name, config)
                    break
                default:
                    throw new TypeError(`Invalid database driver type: ${config.type}`)
            }
        }
    }
}