mempool/frontend/src/app/lightning/nodes-map/nodes-map.component.ts

import { ChangeDetectionStrategy, Component, Inject, Input, Output, EventEmitter, LOCALE_ID, NgZone, OnDestroy, OnInit, OnChanges } from '@angular/core';
import { SeoService } from '../../services/seo.service';
import { ApiService } from '../../services/api.service';
import { Observable, BehaviorSubject, switchMap, tap, combineLatest } from 'rxjs';
import { AssetsService } from '../../services/assets.service';
import { EChartsOption, registerMap } from 'echarts';
import { lerpColor } from '../../shared/graphs.utils';
import { Router } from '@angular/router';
import { RelativeUrlPipe } from '../../shared/pipes/relative-url/relative-url.pipe';
import { StateService } from '../../services/state.service';
import { AmountShortenerPipe } from '../../shared/pipes/amount-shortener.pipe';
import { getFlagEmoji } from '../../shared/common.utils';

@Component({
  selector: 'app-nodes-map',
  templateUrl: './nodes-map.component.html',
  styleUrls: ['./nodes-map.component.scss'],
  changeDetection: ChangeDetectionStrategy.OnPush,
})
export class NodesMap implements OnInit, OnChanges {
  @Input() widget: boolean = false;
  @Input() nodes: any[] | undefined = undefined;
  @Input() type: 'none' | 'isp' | 'country' = 'none';
  @Input() fitContainer = false;
  @Output() readyEvent = new EventEmitter();
  inputNodes$: BehaviorSubject<any>;
  nodes$: Observable<any>;
  observable$: Observable<any>;

  chartInstance = undefined;
  chartOptions: EChartsOption = {};
  chartInitOptions = {
    renderer: 'svg',
  };

  constructor(
    @Inject(LOCALE_ID) public locale: string,
    private seoService: SeoService,
    private apiService: ApiService,
    private stateService: StateService,
    private assetsService: AssetsService,
    private router: Router,
    private zone: NgZone,
    private amountShortenerPipe: AmountShortenerPipe
  ) {
  }

  ngOnInit(): void {
    if (!this.widget) {
      this.seoService.setTitle($localize`:@@af8560ca50882114be16c951650f83bca73161a7:Lightning Nodes World Map`);
      this.seoService.setDescription($localize`:@@meta.description.lightning.node-channel-map:See the locations of non-Tor Lightning network nodes visualized on a world map. Hover/tap on points on the map for node names and details.`);
    }

    if (!this.inputNodes$) {
      this.inputNodes$ = new BehaviorSubject(this.nodes);
    }

    this.nodes$ = this.inputNodes$.pipe(
      switchMap((nodes) =>  nodes ? [nodes] : this.apiService.getWorldNodes$())
    );

    this.observable$ = combineLatest(
      this.assetsService.getWorldMapJson$,
      this.nodes$
    ).pipe(tap((data) => {
      registerMap('world', data[0]);

      let maxLiquidity = data[1].maxLiquidity;
      let inputNodes: any[] = data[1].nodes;
      let mapCenter: number[] = [0, 5];
      if (this.type === 'country') {
        mapCenter = [0, 0];
      } else if (this.type === 'isp') {
        mapCenter = [0, 10];
      }

      let mapZoom = 1.3;
      if (!inputNodes) {
        inputNodes = [];
        for (const node of data[1]) {
          if (this.type === 'country') {
            mapCenter[0] += node.longitude;
            mapCenter[1] += node.latitude;
          }
          inputNodes.push([
            node.longitude,
            node.latitude,
            node.public_key,
            node.alias,
            node.capacity,
            node.channels,
            node.country,
            node.iso_code,
          ]);
          maxLiquidity = Math.max(maxLiquidity ?? 0, node.capacity);
        }
        if (this.type === 'country') {
          mapCenter[0] /= data[1].length;
          mapCenter[1] /= data[1].length;
          mapZoom = 6;
        }
      }

      const nodes: any[] = [];
      for (const node of inputNodes) {
        // We add a bit of noise so nodes at the same location are not all
        // on top of each other
        const random = Math.random() * 2 * Math.PI;
        const random2 = Math.random() * 0.01;
        nodes.push([
          node[0] + random2 * Math.cos(random),
          node[1] + random2 * Math.sin(random),
          node[4], // Liquidity
          node[3], // Alias
          node[2], // Public key
          node[5], // Channels
          node[6].en, // Country
          node[7], // ISO Code
        ]);
      }

      maxLiquidity = Math.max(1, maxLiquidity);
      this.prepareChartOptions(nodes, maxLiquidity, mapCenter, mapZoom);
    }));
  }

  ngOnChanges(changes): void {
    if (changes.nodes) {
      if (!this.inputNodes$) {
        this.inputNodes$ = new BehaviorSubject(changes.nodes.currentValue);
      } else {
        this.inputNodes$.next(changes.nodes.currentValue);
      }
    }
  }

  prepareChartOptions(nodes, maxLiquidity, mapCenter, mapZoom) {
    let title: object;
    if (nodes.length === 0) {
      title = {
        textStyle: {
          color: 'grey',
          fontSize: 15
        },
        text: $localize`No data to display yet. Try again later.`,
        left: 'center',
        top: 'center'
      };
    }

    this.chartOptions = {
      silent: false,
      title: title ?? undefined,
      tooltip: {},
      geo: {
        animation: false,
        silent: true,
        center: mapCenter,
        zoom: mapZoom,
        tooltip: {
          show: false
        },
        map: 'world',
        roam: true,
        itemStyle: {
          borderColor: 'black',
          color: '#272b3f'
        },
        scaleLimit: {
          min: 1.3,
          max: 100000,
        },
        emphasis: {
          disabled: true,
        }
      },
      series: [
        {
          large: false,
          type: 'scatter',
          data: nodes,
          coordinateSystem: 'geo',
          geoIndex: 0,
          progressive: 500,
          symbolSize: function (params) {
            return 10 * Math.pow(params[2] / maxLiquidity, 0.2) + 3;
          },
          tooltip: {
            position: function(point, params, dom, rect, size) {
              return point;
            },
            trigger: 'item',
            show: true,
            backgroundColor: 'rgba(17, 19, 31, 1)',
            borderRadius: 0,
            shadowColor: 'rgba(0, 0, 0, 0.5)',
            textStyle: {
              color: '#b1b1b1',
              align: 'left',
            },
            borderColor: '#000',
            formatter: (value) => {
              const data = value.data;
              const alias = data[3].length > 0 ? data[3] : data[4].slice(0, 20);
              const liquidity = data[2] >= 100000000 ?
                `${this.amountShortenerPipe.transform(data[2] / 100000000)} BTC` :
                `${this.amountShortenerPipe.transform(data[2], 2)} sats`;

              return `
                <b style="color: white">${alias}</b><br>
                ${liquidity}<br>` +
                $localize`:@@205c1b86ac1cc419c4d0cca51fdde418c4ffdc20:${data[5]}:INTERPOLATION: channels` + `<br>
                ${getFlagEmoji(data[7])} ${data[6]}
              `;
            }
          },
          itemStyle: {
            color: function (params) {
              return `${lerpColor('#1E88E5', '#D81B60', Math.pow(params.data[2] / maxLiquidity, 0.2))}`;
            },
            opacity: 1,
            borderColor: 'black',
            borderWidth: 0,
          },
          zlevel: 2,
        },
      ]
    };
  }

  onChartInit(ec) {
    if (this.chartInstance !== undefined) {
      return;
    }

    this.chartInstance = ec;

    this.chartInstance.on('click', (e) => {
      if (e.data) {
        this.zone.run(() => {
          const url = new RelativeUrlPipe(this.stateService).transform(`/lightning/node/${e.data[4]}`);
          this.router.navigate([url]);
        });
      }
    });

    this.chartInstance.on('georoam', (e) => {
      this.chartInstance.resize();
    });
  }

  onChartFinished(e) {
    this.readyEvent.emit();
  }
}