// Copyright (C) 2018 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 '../tracks/all_controller';

import * as uuidv4 from 'uuid/v4';

import {assertExists, assertTrue} from '../base/logging';
import {
  Actions,
  AddTrackArgs,
  DeferredAction,
} from '../common/actions';
import {Engine} from '../common/engine';
import {NUM, NUM_NULL, rawQueryToRows, STR_NULL} from '../common/protos';
import {SCROLLING_TRACK_GROUP} from '../common/state';
import {TimeSpan} from '../common/time';
import {QuantizedLoad, ThreadDesc} from '../frontend/globals';
import {ANDROID_LOGS_TRACK_KIND} from '../tracks/android_log/common';
import {SLICE_TRACK_KIND} from '../tracks/chrome_slices/common';
import {CPU_FREQ_TRACK_KIND} from '../tracks/cpu_freq/common';
import {CPU_SLICE_TRACK_KIND} from '../tracks/cpu_slices/common';
import {
  PROCESS_SCHEDULING_TRACK_KIND
} from '../tracks/process_scheduling/common';
import {PROCESS_SUMMARY_TRACK} from '../tracks/process_summary/common';
import {THREAD_STATE_TRACK_KIND} from '../tracks/thread_state/common';

import {Child, Children, Controller} from './controller';
import {globals} from './globals';
import {LogsController} from './logs_controller';
import {QueryController, QueryControllerArgs} from './query_controller';
import {
  SelectionController,
  SelectionControllerArgs
} from './selection_controller';
import {TrackControllerArgs, trackControllerRegistry} from './track_controller';

type States = 'init'|'loading_trace'|'ready';

declare interface FileReaderSync { readAsArrayBuffer(blob: Blob): ArrayBuffer; }

declare var FileReaderSync:
    {prototype: FileReaderSync; new (): FileReaderSync;};

// TraceController handles handshakes with the frontend for everything that
// concerns a single trace. It owns the WASM trace processor engine, handles
// tracks data and SQL queries. There is one TraceController instance for each
// trace opened in the UI (for now only one trace is supported).
export class TraceController extends Controller<States> {
  private readonly engineId: string;
  private engine?: Engine;

  constructor(engineId: string) {
    super('init');
    this.engineId = engineId;
  }

  onDestroy() {
    if (this.engine !== undefined) globals.destroyEngine(this.engine.id);
  }

  run() {
    const engineCfg = assertExists(globals.state.engines[this.engineId]);
    switch (this.state) {
      case 'init':
        globals.dispatch(Actions.setEngineReady({
          engineId: this.engineId,
          ready: false,
        }));
        this.loadTrace().then(() => {
          globals.dispatch(Actions.setEngineReady({
            engineId: this.engineId,
            ready: true,
          }));
        });
        this.updateStatus('Opening trace');
        this.setState('loading_trace');
        break;

      case 'loading_trace':
        // Stay in this state until loadTrace() returns and marks the engine as
        // ready.
        if (this.engine === undefined || !engineCfg.ready) return;
        this.setState('ready');
        break;

      case 'ready':
        // At this point we are ready to serve queries and handle tracks.
        const engine = assertExists(this.engine);
        assertTrue(engineCfg.ready);
        const childControllers: Children = [];

        // Create a TrackController for each track.
        for (const trackId of Object.keys(globals.state.tracks)) {
          const trackCfg = globals.state.tracks[trackId];
          if (trackCfg.engineId !== this.engineId) continue;
          if (!trackControllerRegistry.has(trackCfg.kind)) continue;
          const trackCtlFactory = trackControllerRegistry.get(trackCfg.kind);
          const trackArgs: TrackControllerArgs = {trackId, engine};
          childControllers.push(Child(trackId, trackCtlFactory, trackArgs));
        }

        // Create a QueryController for each query.
        for (const queryId of Object.keys(globals.state.queries)) {
          const queryArgs: QueryControllerArgs = {queryId, engine};
          childControllers.push(Child(queryId, QueryController, queryArgs));
        }

        const selectionArgs: SelectionControllerArgs = {engine};
        childControllers.push(
          Child('selection', SelectionController, selectionArgs));

        childControllers.push(Child('logs', LogsController, {
          engine,
          app: globals,
        }));

        return childControllers;

      default:
        throw new Error(`unknown state ${this.state}`);
    }
    return;
  }

  private async loadTrace() {
    this.updateStatus('Creating trace processor');
    const engineCfg = assertExists(globals.state.engines[this.engineId]);
    this.engine = globals.createEngine();

    const statusHeader = 'Opening trace';
    if (engineCfg.source instanceof File) {
      const blob = engineCfg.source as Blob;
      const reader = new FileReaderSync();
      const SLICE_SIZE = 1024 * 1024;
      for (let off = 0; off < blob.size; off += SLICE_SIZE) {
        const slice = blob.slice(off, off + SLICE_SIZE);
        const arrBuf = reader.readAsArrayBuffer(slice);
        await this.engine.parse(new Uint8Array(arrBuf));
        const progress = Math.round((off + slice.size) / blob.size * 100);
        this.updateStatus(`${statusHeader} ${progress} %`);
      }
    } else {
      const resp = await fetch(engineCfg.source);
      if (resp.status !== 200) {
        this.updateStatus(`HTTP error ${resp.status}`);
        throw new Error(`fetch() failed with HTTP error ${resp.status}`);
      }
      // tslint:disable-next-line no-any
      const rd = (resp.body as any).getReader() as ReadableStreamReader;
      const tStartMs = performance.now();
      let tLastUpdateMs = 0;
      for (let off = 0;;) {
        const readRes = await rd.read() as {value: Uint8Array, done: boolean};
        if (readRes.value !== undefined) {
          off += readRes.value.length;
          await this.engine.parse(readRes.value);
        }
        // For traces loaded from the network there doesn't seem to be a
        // reliable way to compute the %. The content-length exposed by GCS is
        // before compression (which is handled transparently by the browser).
        const nowMs = performance.now();
        if (nowMs - tLastUpdateMs > 100) {
          tLastUpdateMs = nowMs;
          const mb = off / 1e6;
          const tElapsed = (nowMs - tStartMs) / 1e3;
          let status = `${statusHeader} ${mb.toFixed(1)} MB `;
          status += `(${(mb / tElapsed).toFixed(1)} MB/s)`;
          this.updateStatus(status);
        }
        if (readRes.done) break;
      }
    }

    await this.engine.notifyEof();

    const traceTime = await this.engine.getTraceTimeBounds();
    const traceTimeState = {
      startSec: traceTime.start,
      endSec: traceTime.end,
    };
    const actions: DeferredAction[] = [
      Actions.setTraceTime(traceTimeState),
      Actions.navigate({route: '/viewer'}),
    ];

    if (globals.state.frontendLocalState.lastUpdate === 0) {
      actions.push(Actions.setVisibleTraceTime({
        time: traceTimeState,
        lastUpdate: Date.now() / 1000,
      }));
    }

    globals.dispatchMultiple(actions);

    {
      // When we reload from a permalink don't create extra tracks:
      const {pinnedTracks, scrollingTracks} = globals.state;
      if (!pinnedTracks.length && !scrollingTracks.length) {
        await this.listTracks();
      }
    }

    await this.listThreads();
    await this.loadTimelineOverview(traceTime);
  }

  private async listTracks() {
    this.updateStatus('Loading tracks');

    const engine = assertExists<Engine>(this.engine);
    const numCpus = await engine.getNumberOfCpus();
    const tracksToAdd: AddTrackArgs[] = [];

    // TODO(hjd): Renable Vsync tracks when fixed.
    //// TODO(hjd): Move this code out of TraceController.
    // for (const counterName of ['VSYNC-sf', 'VSYNC-app']) {
    //  const hasVsync =
    //      !!(await engine.query(
    //             `select ts from counters where name like "${
    //                                                         counterName
    //                                                       }" limit 1`))
    //            .numRecords;
    //  if (!hasVsync) continue;
    //  addToTrackActions.push(Actions.addTrack({
    //    engineId: this.engineId,
    //    kind: 'VsyncTrack',
    //    name: `${counterName}`,
    //    config: {
    //      counterName,
    //    }
    //  }));
    //}
    const maxFreq = await engine.query(`
     select max(value)
     from counters
     where name = 'cpufreq';
    `);

    for (let cpu = 0; cpu < numCpus; cpu++) {
      tracksToAdd.push({
        engineId: this.engineId,
        kind: CPU_SLICE_TRACK_KIND,
        name: `Cpu ${cpu}`,
        trackGroup: SCROLLING_TRACK_GROUP,
        config: {
          cpu,
        }
      });
    }

    for (let cpu = 0; cpu < numCpus; cpu++) {
      // Only add a cpu freq track if we have
      // cpu freq data.
      // TODO(taylori): Find a way to display cpu idle
      // events even if there are no cpu freq events.
      const freqExists = await engine.query(`
        select value
        from counters
        where name = 'cpufreq' and ref = ${cpu}
        limit 1;
      `);
      if (freqExists.numRecords > 0) {
        tracksToAdd.push({
          engineId: this.engineId,
          kind: CPU_FREQ_TRACK_KIND,
          name: `Cpu ${cpu} Frequency`,
          trackGroup: SCROLLING_TRACK_GROUP,
          config: {
            cpu,
            maximumValue: +maxFreq.columns[0].doubleValues![0],
          }
        });
      }
    }

    const counters = await engine.query(`
      select name, ref, ref_type
      from counter_definitions
      where ref is not null
      group by name, ref, ref_type
      order by ref_type desc
    `);

    interface CounterMap {
      [index: number]: string[];
    }

    const counterUpids: CounterMap = new Array();
    const counterUtids: CounterMap = new Array();
    for (let i = 0; i < counters.numRecords; i++) {
      const name = counters.columns[0].stringValues![i];
      const ref = +counters.columns[1].longValues![i];
      const refType = counters.columns[2].stringValues![i];
      if (refType === 'upid') {
        const el = counterUpids[ref];
        el === undefined ? counterUpids[ref] = [name] :
                           counterUpids[ref].push(name);
      } else if (refType === 'utid') {
        const el = counterUtids[ref];
        el === undefined ? counterUtids[ref] = [name] :
                           counterUtids[ref].push(name);
      } else if (refType === '[NULL]') {
        // Add global counter tracks that are not bound to any pid/tid.
        tracksToAdd.push({
          engineId: this.engineId,
          kind: 'CounterTrack',
          name,
          trackGroup: SCROLLING_TRACK_GROUP,
          config: {
            name,
            ref: 0,
          }
        });
      }
    }

    // Local experiments shows getting maxDepth separately is ~2x faster than
    // joining with threads and processes.
    const maxDepthQuery =
        await engine.query('select utid, max(depth) from slices group by utid');

    const utidToMaxDepth = new Map<number, number>();
    for (let i = 0; i < maxDepthQuery.numRecords; i++) {
      const utid = maxDepthQuery.columns[0].longValues![i] as number;
      const maxDepth = maxDepthQuery.columns[1].longValues![i] as number;
      utidToMaxDepth.set(utid, maxDepth);
    }

    // Return all threads
    // sorted by:
    //  total cpu time *for the whole parent process*
    //  upid
    //  utid
    const threadQuery = await engine.query(`
        select
          utid,
          tid,
          upid,
          pid,
          thread.name as threadName,
          process.name as processName,
          total_dur as totalDur
        from
          thread
          left join process using(upid)
          left join (select upid, sum(dur) as total_dur
              from sched join thread using(utid)
              group by upid
            ) using(upid) group by utid, upid
        order by total_dur desc, upid, utid`);

    const upidToUuid = new Map<number, string>();
    const utidToUuid = new Map<number, string>();
    const addTrackGroupActions: DeferredAction[] = [];

    for (const row of rawQueryToRows(threadQuery, {
           utid: NUM,
           upid: NUM_NULL,
           tid: NUM_NULL,
           pid: NUM_NULL,
           threadName: STR_NULL,
           processName: STR_NULL,
           totalDur: NUM_NULL,
         })) {
      const utid = row.utid;
      const tid = row.tid;
      const upid = row.upid;
      const pid = row.pid;
      const threadName = row.threadName;
      const processName = row.processName;
      const hasSchedEvents = !!row.totalDur;
      const threadSched =
          await engine.query(`select count(1) from sched where utid = ${utid}`);
      const threadHasSched = threadSched.columns[0].longValues![0] > 0;

      const maxDepth = utid === null ? undefined : utidToMaxDepth.get(utid);
      if (maxDepth === undefined &&
          (upid === null || counterUpids[upid] === undefined) &&
          counterUtids[utid] === undefined && !threadHasSched) {
        continue;
      }

      // Group by upid if present else by utid.
      let pUuid = upid === null ? utidToUuid.get(utid) : upidToUuid.get(upid);
      // These should only happen once for each track group.
      if (pUuid === undefined) {
        pUuid = uuidv4();
        const summaryTrackId = uuidv4();
        if (upid === null) {
          utidToUuid.set(utid, pUuid);
        } else {
          upidToUuid.set(upid, pUuid);
        }

        const pidForColor = pid || tid || upid || utid || 0;
        const kind = hasSchedEvents ? PROCESS_SCHEDULING_TRACK_KIND :
                                      PROCESS_SUMMARY_TRACK;

        tracksToAdd.push({
          id: summaryTrackId,
          engineId: this.engineId,
          kind,
          name: `${upid === null ? tid : pid} summary`,
          config: {pidForColor, upid, utid},
        });

        addTrackGroupActions.push(Actions.addTrackGroup({
          engineId: this.engineId,
          summaryTrackId,
          name: upid === null ? `${threadName} ${tid}` :
                                `${processName} ${pid}`,
          id: pUuid,
          collapsed: true,
        }));

        if (upid !== null) {
          const counterNames = counterUpids[upid];
          if (counterNames !== undefined) {
            counterNames.forEach(element => {
              tracksToAdd.push({
                engineId: this.engineId,
                kind: 'CounterTrack',
                name: element,
                trackGroup: pUuid,
                config: {
                  name: element,
                  ref: upid,
                }
              });
            });
          }
        }
      }
      const counterThreadNames = counterUtids[utid];
      if (counterThreadNames !== undefined) {
        counterThreadNames.forEach(element => {
          tracksToAdd.push({
            engineId: this.engineId,
            kind: 'CounterTrack',
            name: element,
            trackGroup: pUuid,
            config: {
              name: element,
              ref: utid,
            }
          });
        });
      }
      if (threadHasSched) {
        tracksToAdd.push({
          engineId: this.engineId,
          kind: THREAD_STATE_TRACK_KIND,
          name: `${threadName} [${tid}]`,
          trackGroup: pUuid,
          config: {utid}
        });
      }

      if (maxDepth !== undefined) {
        tracksToAdd.push({
          engineId: this.engineId,
          kind: SLICE_TRACK_KIND,
          name: `${threadName} [${tid}]`,
          trackGroup: pUuid,
          config: {upid, utid, maxDepth},
        });
      }
    }

    const logCount = await engine.query(`select count(1) from android_logs`);
    if (logCount.columns[0].longValues![0] > 0) {
      tracksToAdd.push({
        engineId: this.engineId,
        kind: ANDROID_LOGS_TRACK_KIND,
        name: 'Android logs',
        trackGroup: SCROLLING_TRACK_GROUP,
        config: {}
      });
    }

    addTrackGroupActions.push(Actions.addTracks({tracks: tracksToAdd}));
    globals.dispatchMultiple(addTrackGroupActions);
  }

  private async listThreads() {
    this.updateStatus('Reading thread list');
    const sqlQuery = `select utid, tid, pid, thread.name,
        ifnull(
          case when length(process.name) > 0 then process.name else null end,
          thread.name)
        from (select * from thread order by upid) as thread
        left join (select * from process order by upid) as process
        using(upid)`;
    const threadRows = await assertExists(this.engine).query(sqlQuery);
    const threads: ThreadDesc[] = [];
    for (let i = 0; i < threadRows.numRecords; i++) {
      const utid = threadRows.columns[0].longValues![i] as number;
      const tid = threadRows.columns[1].longValues![i] as number;
      const pid = threadRows.columns[2].longValues![i] as number;
      const threadName = threadRows.columns[3].stringValues![i];
      const procName = threadRows.columns[4].stringValues![i];
      threads.push({utid, tid, threadName, pid, procName});
    }  // for (record ...)
    globals.publish('Threads', threads);
  }

  private async loadTimelineOverview(traceTime: TimeSpan) {
    const engine = assertExists<Engine>(this.engine);
    const numSteps = 100;
    const stepSec = traceTime.duration / numSteps;
    let hasSchedOverview = false;
    for (let step = 0; step < numSteps; step++) {
      this.updateStatus(
          'Loading overview ' +
          `${Math.round((step + 1) / numSteps * 1000) / 10}%`);
      const startSec = traceTime.start + step * stepSec;
      const startNs = Math.floor(startSec * 1e9);
      const endSec = startSec + stepSec;
      const endNs = Math.ceil(endSec * 1e9);

      // Sched overview.
      const schedRows = await engine.query(
          `select sum(dur)/${stepSec}/1e9, cpu from sched ` +
          `where ts >= ${startNs} and ts < ${endNs} and utid != 0 ` +
          'group by cpu order by cpu');
      const schedData: {[key: string]: QuantizedLoad} = {};
      for (let i = 0; i < schedRows.numRecords; i++) {
        const load = schedRows.columns[0].doubleValues![i];
        const cpu = schedRows.columns[1].longValues![i] as number;
        schedData[cpu] = {startSec, endSec, load};
        hasSchedOverview = true;
      }  // for (record ...)
      globals.publish('OverviewData', schedData);
    }  // for (step ...)

    if (hasSchedOverview) {
      return;
    }

    // Slices overview.
    const traceStartNs = traceTime.start * 1e9;
    const stepSecNs = stepSec * 1e9;
    const sliceSummaryQuery = await engine.query(
        `select bucket, upid, sum(utid_sum) / cast(${stepSecNs} as float) ` +
        `as upid_sum from thread inner join ` +
        `(select cast((ts - ${traceStartNs})/${stepSecNs} as int) as bucket, ` +
        `sum(dur) as utid_sum, utid from slices group by bucket, utid) ` +
        `using(utid) group by bucket, upid`);

    const slicesData: {[key: string]: QuantizedLoad[]} = {};
    for (let i = 0; i < sliceSummaryQuery.numRecords; i++) {
      const bucket = sliceSummaryQuery.columns[0].longValues![i] as number;
      const upid = sliceSummaryQuery.columns[1].longValues![i] as number;
      const load = sliceSummaryQuery.columns[2].doubleValues![i];

      const startSec = traceTime.start + stepSec * bucket;
      const endSec = startSec + stepSec;

      const upidStr = upid.toString();
      let loadArray = slicesData[upidStr];
      if (loadArray === undefined) {
        loadArray = slicesData[upidStr] = [];
      }
      loadArray.push({startSec, endSec, load});
    }
    globals.publish('OverviewData', slicesData);
  }

  private updateStatus(msg: string): void {
    globals.dispatch(Actions.updateStatus({
      msg,
      timestamp: Date.now() / 1000,
    }));
  }
}