var db = require('../db')
var bdb = require('./bdb')('search')
var STOPWORDS = require('./stopwords')

var wordRegexp = new RegExp("[^a-z0-9]+", 'g');
function parse_terms (s) {
  return s.toLowerCase().split(wordRegexp).filter((term) => !!term)
}
function cmp (a,b){ return (a<b)?-1:(a===b)?0:1 }

function find_term(term) {
  var res = bdb.get(term).toString()
  // console.log(res)
  if (! res.length) return []
  var matches = res.split(",").map((s) => {
    if (! s.length) return;
    var partz = s.split(" ")
    return {
      thread: parseInt(partz[0]),
      comment: parseInt(partz[1]),
      file: parseInt(partz[2]),
      strength: parseInt(partz[3]) || 1,
    }
  })
  // console.log(matches)
  return matches
}

function search (query, start, limit) {
  if (!query) return
	start = parseInt(start) || 0;
	limit = parseInt(limit) || 10;
	var scores = {};
	var terms = parse_terms(query);
  var total
  var to_display = limit
  var threads = {}
  var thread_ids = []
  var comment_ids = []
  var file_ids = []
  var results = []

  terms.forEach((term) => {
    if (STOPWORDS.has(term)) return;
    var results = find_term(term);
    if (!results) return;
    results.forEach((result) => {
      var score = scores[result.thread] = scores[result.thread] || { count: 0, strength: 0 }
      score.thread = score.thread || parseInt(result.thread)
      score.comment = score.comment || parseInt(result.comment)
      score.file = score.file || parseInt(result.file)
      score.strength += parseFloat(result.strength)
      score.count += 1
    })
  })
  total = Object.keys(scores).length
  Object.values(scores).sort((b,a) => {
    // if (a.count !== b.count) {
    //   return cmp(a.count, b.count)
    // }
    return cmp(a.strength, b.strength)
  }).some((match, i) => {
    if (i < start) return false
    if (to_display-- === 0) return true
    results.push(match)
    // console.log(match)
    thread_ids.push(match.thread)
    if (match.comment) comment_ids.push(match.comment)
    if (match.file) file_ids.push(match.file)
    return false
  })

  return {
    meta: {
      query: query,
      terms: terms,
      start: start,
      next: start + limit,
      limit: limit,
      total: total,
    },
    results: results,
		thread_ids: thread_ids,
		comment_ids: comment_ids,
		file_ids: file_ids,
  };
}

module.exports = { search: search }