// Copyright (c) Cratis. All rights reserved.
// Licensed under the MIT license. See LICENSE file in the project root for full license information.

import type { TransactionalAppendOptions } from '../transactions/TransactionalAppendOptions.js';
import { mergeNamedTags } from '../events/mergeNamedTags.js';
import { IUnitOfWork } from '../transactions/IUnitOfWork.js';
import { IUnitOfWorkManager } from '../transactions/IUnitOfWorkManager.js';
import { IEventSequence } from './IEventSequence.js';
import { ITransactionalEventSequence } from './ITransactionalEventSequence.js';

/**
 * Implements {@link ITransactionalEventSequence} by delegating appends to the current unit of work.
 */
export class TransactionalEventSequence implements ITransactionalEventSequence {
    constructor(
        private readonly _eventSequence: IEventSequence,
        private readonly _unitOfWorkManager: IUnitOfWorkManager
    ) {}

    /** @inheritdoc */
    get unitOfWork(): IUnitOfWork {
        return this._unitOfWorkManager.current;
    }

    /** @inheritdoc */
    async append(eventSourceId: string, event: object, options?: TransactionalAppendOptions): Promise<void> {
        this.unitOfWork.addEvent(this._eventSequence.id, eventSourceId, event, options);
    }

    /** @inheritdoc */
    async appendMany(eventSourceId: string, events: object[], options?: TransactionalAppendOptions): Promise<void> {
        // Validate once up front so an invalid tag adds none of the events.
        const shared = options?.namedTags === undefined ? options : { ...options, namedTags: mergeNamedTags(options.namedTags) };
        for (const event of events) {
            this.unitOfWork.addEvent(this._eventSequence.id, eventSourceId, event, shared);
        }
    }
}