/*
 * make-search-index.js
 *
 * This converts a "search data" file produced by the haskell site builder into
 * a lunr.js index and saves it in JSON. Metadata for rendering search output
 * (currently titles and tags) are stored separately in an extra file.
 *
 * Installing dependencies:
 * yarnpkg add lunr
 *
 * Usage:
 * site ....some args.... --search-data-output tmp/search-raw.json
 * node make-search-index.js tmp/search-raw.json _site/search-index.json _site/search-meta.json
 */

lunr = require("lunr")
fs = require("fs")

if(process.argv.length !== 5) {
  console.error('Needs exactly 3 arguments (input json, output index).');
  process.exit(1);
}

documents = JSON.parse(fs.readFileSync(process.argv[2], {encoding: 'utf8'}))

var idx = lunr(function () {
  this.ref('link')
  this.field('title', {boost: 10})
  this.field('text')
  documents.forEach(function (doc) {
    this.add(doc)
  }, this)
})

fs.writeFileSync(process.argv[3], JSON.stringify(idx), {encoding: 'utf8'})
fs.writeFileSync(process.argv[4], JSON.stringify(
    Object.fromEntries(documents.map(x => [x.link, {"title": x.title, "tags": x.tags}]))
  ), {encoding: 'utf8'})