tileserver-gl/src/serve_style.js

'use strict';

import path from 'path';
import fs from 'node:fs';

import clone from 'clone';
import express from 'express';
import { validateStyleMin } from '@maplibre/maplibre-gl-style-spec';

import { getPublicUrl } from './utils.js';

const httpTester = /^(http(s)?:)?\/\//;

const fixUrl = (req, url, publicUrl) => {
  if (!url || typeof url !== 'string' || url.indexOf('local://') !== 0) {
    return url;
  }
  const queryParams = [];
  if (req.query.key) {
    queryParams.unshift(`key=${encodeURIComponent(req.query.key)}`);
  }
  let query = '';
  if (queryParams.length) {
    query = `?${queryParams.join('&')}`;
  }
  return url.replace('local://', getPublicUrl(publicUrl, req)) + query;
};

export const serve_style = {
  init: (options, repo) => {
    const app = express().disable('x-powered-by');

    app.get('/:id/style.json', (req, res, next) => {
      const item = repo[req.params.id];
      if (!item) {
        return res.sendStatus(404);
      }
      const styleJSON_ = clone(item.styleJSON);
      for (const name of Object.keys(styleJSON_.sources)) {
        const source = styleJSON_.sources[name];
        source.url = fixUrl(req, source.url, item.publicUrl);
      }
      // mapbox-gl-js viewer cannot handle sprite urls with query
      if (styleJSON_.sprite) {
        if (Array.isArray(styleJSON_.sprite)) {
          styleJSON_.sprite.forEach((spriteItem) => {
            spriteItem.url = fixUrl(req, spriteItem.url, item.publicUrl);
          });
        } else {
          styleJSON_.sprite = fixUrl(req, styleJSON_.sprite, item.publicUrl);
        }
      }
      if (styleJSON_.glyphs) {
        styleJSON_.glyphs = fixUrl(req, styleJSON_.glyphs, item.publicUrl);
      }
      return res.send(styleJSON_);
    });

    app.get('/:id/sprite(/:name)?:scale(@[23]x)?.:format([\\w]+)', (req, res, next) => {
      const item = repo[req.params.id];
      const spriteName = req.params.name || 'sprite';

      if (!item || !item.spritePaths) {
        return res.sendStatus(404);
      }

      let spritePath
      for (const sprite of item.spritePaths) {
        if (sprite.name === spriteName) {
          spritePath = sprite.path;
        }
      }

      if (!spritePath) {
        return res.sendStatus(404);
      }

      const scale = req.params.scale;
      const format = req.params.format;
      const filename = `${spritePath + (scale || '')}.${format}`;
      return fs.readFile(filename, (err, data) => {
        if (err) {
          console.log('Sprite load error:', filename);
          return res.sendStatus(404);
        } else {
          if (format === 'json') res.header('Content-type', 'application/json');
          if (format === 'png') res.header('Content-type', 'image/png');
          return res.send(data);
        }
      });
    });

    return app;
  },
  remove: (repo, id) => {
    delete repo[id];
  },
  add: (options, repo, params, id, publicUrl, reportTiles, reportFont) => {
    const styleFile = path.resolve(options.paths.styles, params.style);

    let styleFileData;
    try {
      styleFileData = fs.readFileSync(styleFile);
    } catch (e) {
      console.log('Error reading style file');
      return false;
    }

    const styleJSON = JSON.parse(styleFileData);
    const validationErrors = validateStyleMin(styleJSON);
    if (validationErrors.length > 0) {
      console.log(`The file "${params.style}" is not a valid style file:`);
      for (const err of validationErrors) {
        console.log(`${err.line}: ${err.message}`);
      }
      return false;
    }

    for (const name of Object.keys(styleJSON.sources)) {
      const source = styleJSON.sources[name];
      let url = source.url;
      if (
        url &&
        (url.startsWith('pmtiles://') || url.startsWith('mbtiles://'))
      ) {
        const protocol = url.split(':')[0];

        let dataId = url.replace('pmtiles://', '').replace('mbtiles://', '');
        if (dataId.startsWith('{') && dataId.endsWith('}')) {
          dataId = dataId.slice(1, -1);
        }

        const mapsTo = (params.mapping || {})[dataId];
        if (mapsTo) {
          dataId = mapsTo;
        }

        const identifier = reportTiles(dataId, protocol);
        if (!identifier) {
          return false;
        }
        source.url = `local://data/${identifier}.json`;
      }
    }

    for (const obj of styleJSON.layers) {
      if (obj['type'] === 'symbol') {
        const fonts = (obj['layout'] || {})['text-font'];
        if (fonts && fonts.length) {
          fonts.forEach(reportFont);
        } else {
          reportFont('Open Sans Regular');
          reportFont('Arial Unicode MS Regular');
        }
      }
    }

    let spritePaths = [];
    if (styleJSON.sprite && styleJSON.sprite) {
      if (Array.isArray(styleJSON.sprite)) {
        styleJSON.sprite.forEach((spriteItem) => {
          if (!httpTester.test(spriteItem.url)) {
            let spriteName = spriteItem.url.substring(spriteItem.url.lastIndexOf('/') + 1);
            let spritePath = path.join(
              options.paths.sprites,
              spriteItem.url
                .replace('{style}', path.basename(styleFile, '.json'))
                .replace(
                  '{styleJsonFolder}',
                  path.relative(options.paths.sprites, path.dirname(styleFile))
                )
            );
            spriteItem.url = `local://styles/${id}/sprite/` + spriteName;
            spritePaths.push({id: spriteItem.id, name: spriteName, path: spritePath});
          }
        });
      } else {
        if (!httpTester.test(styleJSON.sprite)) {
          let spritePath = path.join(
            options.paths.sprites,
            styleJSON.sprite
              .replace('{style}', path.basename(styleFile, '.json'))
              .replace(
                '{styleJsonFolder}',
                path.relative(options.paths.sprites, path.dirname(styleFile))
              )
          );
          styleJSON.sprite = `local://styles/${id}/sprite`;
          spritePaths.push({id: 'default', name: 'sprite', path: spritePath});
        }
      }
    }

    if (styleJSON.glyphs && !httpTester.test(styleJSON.glyphs)) {
      styleJSON.glyphs = 'local://fonts/{fontstack}/{range}.pbf';
    }

    repo[id] = {
      styleJSON,
      spritePaths,
      publicUrl,
      name: styleJSON.name,
    };

    return true;
  },
};