/*
 * Copyright (c) 2016-present Invertase Limited & Contributors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this library except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

import type { DocumentData, DocumentReference } from '../types/firestore';
import type { Timestamp } from '../FirestoreTimestamp';
import type { FieldPath } from '../FieldPath';
import type { Field } from './expressions';

/**
 * @beta
 * Result of running a pipeline. One per document (or per group with aggregation, or single for global aggregation).
 */
export interface PipelineResult<T = DocumentData> {
  data(): T;
  get(fieldPath: string | FieldPath | Field): unknown;
  readonly ref?: DocumentReference;
  readonly id?: string;
  readonly createTime?: Timestamp;
  readonly updateTime?: Timestamp;
}

/**
 * @beta
 * Snapshot returned from `execute(pipeline)`.
 */
export interface PipelineSnapshot<T = DocumentData> {
  readonly results: PipelineResult<T>[];
  readonly executionTime: Timestamp;
}

/**
 * @beta
 * Compares two pipeline results for equality.
 */
export function pipelineResultEqual(left: PipelineResult, right: PipelineResult): boolean {
  if (left === right) {
    return true;
  }

  const leftRefPath = left.ref?.path;
  const rightRefPath = right.ref?.path;

  if (leftRefPath !== rightRefPath) {
    return false;
  }

  if (left.id !== right.id) {
    return false;
  }

  const leftCreateTime = left.createTime?.toMillis();
  const rightCreateTime = right.createTime?.toMillis();
  if (leftCreateTime !== rightCreateTime) {
    return false;
  }

  const leftUpdateTime = left.updateTime?.toMillis();
  const rightUpdateTime = right.updateTime?.toMillis();
  if (leftUpdateTime !== rightUpdateTime) {
    return false;
  }

  return JSON.stringify(left.data()) === JSON.stringify(right.data());
}