// Copyright (C) 2020 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file 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 {ColumnDef, Sorting} from '../../public/aggregation';
import {AreaSelection} from '../../public/selection';
import {Engine} from '../../trace_processor/engine';
import {AreaSelectionAggregator} from '../../public/selection';
import {UnionDataset} from '../../trace_processor/dataset';
import {LONG, NUM, STR} from '../../trace_processor/query_result';

export class SliceSelectionAggregator implements AreaSelectionAggregator {
  readonly id = 'slice_aggregation';

  async createAggregateView(engine: Engine, area: AreaSelection) {
    const desiredSchema = {
      id: NUM,
      name: STR,
      ts: LONG,
      dur: LONG,
    };
    const validDatasets = area.tracks
      .map((track) => track.track.getDataset?.())
      .filter((ds) => ds !== undefined)
      .filter((ds) => ds.implements(desiredSchema));
    if (validDatasets.length === 0) {
      return false;
    }
    const unionDataset = new UnionDataset(validDatasets);
    await engine.query(`
      create or replace perfetto table ${this.id} as
      select
        name,
        sum(dur) AS total_dur,
        sum(dur)/count() as avg_dur,
        count() as occurrences
        from (${unionDataset.optimize().query()})
      where
        ts + dur > ${area.start}
        and ts < ${area.end}
      group by name
    `);

    return true;
  }

  getTabName() {
    return 'Slices';
  }

  async getExtra() {}

  getDefaultSorting(): Sorting {
    return {column: 'total_dur', direction: 'DESC'};
  }

  getColumnDefinitions(): ColumnDef[] {
    return [
      {
        title: 'Name',
        kind: 'STRING',
        columnConstructor: Uint32Array,
        columnId: 'name',
      },
      {
        title: 'Wall duration (ms)',
        kind: 'TIMESTAMP_NS',
        columnConstructor: Float64Array,
        columnId: 'total_dur',
        sum: true,
      },
      {
        title: 'Avg Wall duration (ms)',
        kind: 'TIMESTAMP_NS',
        columnConstructor: Float64Array,
        columnId: 'avg_dur',
      },
      {
        title: 'Occurrences',
        kind: 'NUMBER',
        columnConstructor: Uint32Array,
        columnId: 'occurrences',
        sum: true,
      },
    ];
  }
}