/*
MIT License

Copyright (c) 2018 Stephen Kamenar

WHAT: SublimeText-like Fuzzy Search

USAGE:
  fuzzysort.single('fs', 'Fuzzy Search') // {score: -16}
  fuzzysort.single('test', 'test') // {score: 0}
  fuzzysort.single('doesnt exist', 'target') // null

  fuzzysort.go('mr', ['Monitor.cpp', 'MeshRenderer.cpp'])
  // [{score: -18, target: "MeshRenderer.cpp"}, {score: -6009, target: "Monitor.cpp"}]

  fuzzysort.highlight(fuzzysort.single('fs', 'Fuzzy Search'), '<b>', '</b>')
  // <b>F</b>uzzy <b>S</b>earch
*/

// UMD (Universal Module Definition) for fuzzysort
;(function(root, UMD) {
  if(typeof define === 'function' && define.amd) define([], UMD)
  else if(typeof module === 'object' && module.exports) module.exports = UMD()
  else root.fuzzysort = UMD()
})(this, function UMD() { function fuzzysortNew(instanceOptions) {

  var fuzzysort = {

    single: function(search, target, options) {
      if(!search) return null
      if(!isObj(search)) search = fuzzysort.getPreparedSearch(search)

      if(!target) return null
      if(!isObj(target)) target = fuzzysort.getPrepared(target)

      var allowTypo = options && options.allowTypo!==undefined ? options.allowTypo
        : instanceOptions && instanceOptions.allowTypo!==undefined ? instanceOptions.allowTypo
        : true
      var algorithm = allowTypo ? fuzzysort.algorithm : fuzzysort.algorithmNoTypo
      return algorithm(search, target, search[0])
      // var threshold = options && options.threshold || instanceOptions && instanceOptions.threshold || -9007199254740991
      // var result = algorithm(search, target, search[0])
      // if(result === null) return null
      // if(result.score < threshold) return null
      // return result
    },

    go: function(search, targets, options) {
      if(!search) return noResults
      search = fuzzysort.prepareSearch(search)
      var searchLowerCode = search[0]

      var threshold = options && options.threshold || instanceOptions && instanceOptions.threshold || -9007199254740991
      var limit = options && options.limit || instanceOptions && instanceOptions.limit || 9007199254740991
      var allowTypo = options && options.allowTypo!==undefined ? options.allowTypo
        : instanceOptions && instanceOptions.allowTypo!==undefined ? instanceOptions.allowTypo
        : true
      var algorithm = allowTypo ? fuzzysort.algorithm : fuzzysort.algorithmNoTypo
      var resultsLen = 0; var limitedCount = 0
      var targetsLen = targets.length

      // This code is copy/pasted 3 times for performance reasons [options.keys, options.key, no keys]

      // options.keys
      if(options && options.keys) {
        var scoreFn = options.scoreFn || defaultScoreFn
        var keys = options.keys
        var keysLen = keys.length
        for(var i = targetsLen - 1; i >= 0; --i) { var obj = targets[i]
          var objResults = new Array(keysLen)
          for (var keyI = keysLen - 1; keyI >= 0; --keyI) {
            var key = keys[keyI]
            var target = getValue(obj, key)
            if(!target) { objResults[keyI] = null; continue }
            if(!isObj(target)) target = fuzzysort.getPrepared(target)

            objResults[keyI] = algorithm(search, target, searchLowerCode)
          }
          objResults.obj = obj // before scoreFn so scoreFn can use it
          var score = scoreFn(objResults)
          if(score === null) continue
          if(score < threshold) continue
          objResults.score = score
          if(resultsLen < limit) { q.add(objResults); ++resultsLen }
          else {
            ++limitedCount
            if(score > q.peek().score) q.replaceTop(objResults)
          }
        }

      // options.key
      } else if(options && options.key) {
        var key = options.key
        for(var i = targetsLen - 1; i >= 0; --i) { var obj = targets[i]
          var target = getValue(obj, key)
          if(!target) continue
          if(!isObj(target)) target = fuzzysort.getPrepared(target)

          var result = algorithm(search, target, searchLowerCode)
          if(result === null) continue
          if(result.score < threshold) continue

          // have to clone result so duplicate targets from different obj can each reference the correct obj
          result = {target:result.target, _targetLowerCodes:null, _nextBeginningIndexes:null, score:result.score, indexes:result.indexes, obj:obj} // hidden

          if(resultsLen < limit) { q.add(result); ++resultsLen }
          else {
            ++limitedCount
            if(result.score > q.peek().score) q.replaceTop(result)
          }
        }

      // no keys
      } else {
        for(var i = targetsLen - 1; i >= 0; --i) { var target = targets[i]
          if(!target) continue
          if(!isObj(target)) target = fuzzysort.getPrepared(target)

          var result = algorithm(search, target, searchLowerCode)
          if(result === null) continue
          if(result.score < threshold) continue
          if(resultsLen < limit) { q.add(result); ++resultsLen }
          else {
            ++limitedCount
            if(result.score > q.peek().score) q.replaceTop(result)
          }
        }
      }

      if(resultsLen === 0) return noResults
      var results = new Array(resultsLen)
      for(var i = resultsLen - 1; i >= 0; --i) results[i] = q.poll()
      results.total = resultsLen + limitedCount
      return results
    },

    goAsync: function(search, targets, options) {
      var canceled = false
      var p = new Promise(function(resolve, reject) {
        if(!search) return resolve(noResults)
        search = fuzzysort.prepareSearch(search)
        var searchLowerCode = search[0]

        var q = fastpriorityqueue()
        var iCurrent = targets.length - 1
        var threshold = options && options.threshold || instanceOptions && instanceOptions.threshold || -9007199254740991
        var limit = options && options.limit || instanceOptions && instanceOptions.limit || 9007199254740991
        var allowTypo = options && options.allowTypo!==undefined ? options.allowTypo
          : instanceOptions && instanceOptions.allowTypo!==undefined ? instanceOptions.allowTypo
          : true
        var algorithm = allowTypo ? fuzzysort.algorithm : fuzzysort.algorithmNoTypo
        var resultsLen = 0; var limitedCount = 0
        function step() {
          if(canceled) return reject('canceled')

          var startMs = Date.now()

          // This code is copy/pasted 3 times for performance reasons [options.keys, options.key, no keys]

          // options.keys
          if(options && options.keys) {
            var scoreFn = options.scoreFn || defaultScoreFn
            var keys = options.keys
            var keysLen = keys.length
            for(; iCurrent >= 0; --iCurrent) { var obj = targets[iCurrent]
              var objResults = new Array(keysLen)
              for (var keyI = keysLen - 1; keyI >= 0; --keyI) {
                var key = keys[keyI]
                var target = getValue(obj, key)
                if(!target) { objResults[keyI] = null; continue }
                if(!isObj(target)) target = fuzzysort.getPrepared(target)

                objResults[keyI] = algorithm(search, target, searchLowerCode)
              }
              objResults.obj = obj // before scoreFn so scoreFn can use it
              var score = scoreFn(objResults)
              if(score === null) continue
              if(score < threshold) continue
              objResults.score = score
              if(resultsLen < limit) { q.add(objResults); ++resultsLen }
              else {
                ++limitedCount
                if(score > q.peek().score) q.replaceTop(objResults)
              }

              if(iCurrent%1000/*itemsPerCheck*/ === 0) {
                if(Date.now() - startMs >= 10/*asyncInterval*/) {
                  isNode?setImmediate(step):setTimeout(step)
                  return
                }
              }
            }

          // options.key
          } else if(options && options.key) {
            var key = options.key
            for(; iCurrent >= 0; --iCurrent) { var obj = targets[iCurrent]
              var target = getValue(obj, key)
              if(!target) continue
              if(!isObj(target)) target = fuzzysort.getPrepared(target)

              var result = algorithm(search, target, searchLowerCode)
              if(result === null) continue
              if(result.score < threshold) continue

              // have to clone result so duplicate targets from different obj can each reference the correct obj
              result = {target:result.target, _targetLowerCodes:null, _nextBeginningIndexes:null, score:result.score, indexes:result.indexes, obj:obj} // hidden

              if(resultsLen < limit) { q.add(result); ++resultsLen }
              else {
                ++limitedCount
                if(result.score > q.peek().score) q.replaceTop(result)
              }

              if(iCurrent%1000/*itemsPerCheck*/ === 0) {
                if(Date.now() - startMs >= 10/*asyncInterval*/) {
                  isNode?setImmediate(step):setTimeout(step)
                  return
                }
              }
            }

          // no keys
          } else {
            for(; iCurrent >= 0; --iCurrent) { var target = targets[iCurrent]
              if(!target) continue
              if(!isObj(target)) target = fuzzysort.getPrepared(target)

              var result = algorithm(search, target, searchLowerCode)
              if(result === null) continue
              if(result.score < threshold) continue
              if(resultsLen < limit) { q.add(result); ++resultsLen }
              else {
                ++limitedCount
                if(result.score > q.peek().score) q.replaceTop(result)
              }

              if(iCurrent%1000/*itemsPerCheck*/ === 0) {
                if(Date.now() - startMs >= 10/*asyncInterval*/) {
                  isNode?setImmediate(step):setTimeout(step)
                  return
                }
              }
            }
          }

          if(resultsLen === 0) return resolve(noResults)
          var results = new Array(resultsLen)
          for(var i = resultsLen - 1; i >= 0; --i) results[i] = q.poll()
          results.total = resultsLen + limitedCount
          resolve(results)
        }

        isNode?setImmediate(step):step()
      })
      p.cancel = function() { canceled = true }
      return p
    },

    highlight: function(result, hOpen, hClose) {
      if(result === null) return null
      if(hOpen === undefined) hOpen = '<b>'
      if(hClose === undefined) hClose = '</b>'
      var highlighted = ''
      var matchesIndex = 0
      var opened = false
      var target = result.target
      var targetLen = target.length
      var matchesBest = result.indexes
      for(var i = 0; i < targetLen; ++i) { var char = target[i]
        if(matchesBest[matchesIndex] === i) {
          ++matchesIndex
          if(!opened) { opened = true
            highlighted += hOpen
          }

          if(matchesIndex === matchesBest.length) {
            highlighted += char + hClose + target.substr(i+1)
            break
          }
        } else {
          if(opened) { opened = false
            highlighted += hClose
          }
        }
        highlighted += char
      }

      return highlighted
    },

    prepare: function(target) {
      if(!target) return
      return {target:target, _targetLowerCodes:fuzzysort.prepareLowerCodes(target), _nextBeginningIndexes:null, score:null, indexes:null, obj:null} // hidden
    },
    prepareSlow: function(target) {
      if(!target) return
      return {target:target, _targetLowerCodes:fuzzysort.prepareLowerCodes(target), _nextBeginningIndexes:fuzzysort.prepareNextBeginningIndexes(target), score:null, indexes:null, obj:null} // hidden
    },
    prepareSearch: function(search) {
      if(!search) return
      return fuzzysort.prepareLowerCodes(search)
    },



    // Below this point is only internal code
    // Below this point is only internal code
    // Below this point is only internal code
    // Below this point is only internal code



    getPrepared: function(target) {
      if(target.length > 999) return fuzzysort.prepare(target) // don't cache huge targets
      var targetPrepared = preparedCache.get(target)
      if(targetPrepared !== undefined) return targetPrepared
      targetPrepared = fuzzysort.prepare(target)
      preparedCache.set(target, targetPrepared)
      return targetPrepared
    },
    getPreparedSearch: function(search) {
      if(search.length > 999) return fuzzysort.prepareSearch(search) // don't cache huge searches
      var searchPrepared = preparedSearchCache.get(search)
      if(searchPrepared !== undefined) return searchPrepared
      searchPrepared = fuzzysort.prepareSearch(search)
      preparedSearchCache.set(search, searchPrepared)
      return searchPrepared
    },

    algorithm: function(searchLowerCodes, prepared, searchLowerCode) {
      var targetLowerCodes = prepared._targetLowerCodes
      var searchLen = searchLowerCodes.length
      var targetLen = targetLowerCodes.length
      var searchI = 0 // where we at
      var targetI = 0 // where you at
      var typoSimpleI = 0
      var matchesSimpleLen = 0

      // very basic fuzzy match; to remove non-matching targets ASAP!
      // walk through target. find sequential matches.
      // if all chars aren't found then exit
      for(;;) {
        var isMatch = searchLowerCode === targetLowerCodes[targetI]
        if(isMatch) {
          matchesSimple[matchesSimpleLen++] = targetI
          ++searchI; if(searchI === searchLen) break
          searchLowerCode = searchLowerCodes[typoSimpleI===0?searchI : (typoSimpleI===searchI?searchI+1 : (typoSimpleI===searchI-1?searchI-1 : searchI))]
        }

        ++targetI; if(targetI >= targetLen) { // Failed to find searchI
          // Check for typo or exit
          // we go as far as possible before trying to transpose
          // then we transpose backwards until we reach the beginning
          for(;;) {
            if(searchI <= 1) return null // not allowed to transpose first char
            if(typoSimpleI === 0) { // we haven't tried to transpose yet
              --searchI
              var searchLowerCodeNew = searchLowerCodes[searchI]
              if(searchLowerCode === searchLowerCodeNew) continue // doesn't make sense to transpose a repeat char
              typoSimpleI = searchI
            } else {
              if(typoSimpleI === 1) return null // reached the end of the line for transposing
              --typoSimpleI
              searchI = typoSimpleI
              searchLowerCode = searchLowerCodes[searchI + 1]
              var searchLowerCodeNew = searchLowerCodes[searchI]
              if(searchLowerCode === searchLowerCodeNew) continue // doesn't make sense to transpose a repeat char
            }
            matchesSimpleLen = searchI
            targetI = matchesSimple[matchesSimpleLen - 1] + 1
            break
          }
        }
      }

      var searchI = 0
      var typoStrictI = 0
      var successStrict = false
      var matchesStrictLen = 0

      var nextBeginningIndexes = prepared._nextBeginningIndexes
      if(nextBeginningIndexes === null) nextBeginningIndexes = prepared._nextBeginningIndexes = fuzzysort.prepareNextBeginningIndexes(prepared.target)
      var firstPossibleI = targetI = matchesSimple[0]===0 ? 0 : nextBeginningIndexes[matchesSimple[0]-1]

      // Our target string successfully matched all characters in sequence!
      // Let's try a more advanced and strict test to improve the score
      // only count it as a match if it's consecutive or a beginning character!
      if(targetI !== targetLen) for(;;) {
        if(targetI >= targetLen) {
          // We failed to find a good spot for this search char, go back to the previous search char and force it forward
          if(searchI <= 0) { // We failed to push chars forward for a better match
            // transpose, starting from the beginning
            ++typoStrictI; if(typoStrictI > searchLen-2) break
            if(searchLowerCodes[typoStrictI] === searchLowerCodes[typoStrictI+1]) continue // doesn't make sense to transpose a repeat char
            targetI = firstPossibleI
            continue
          }

          --searchI
          var lastMatch = matchesStrict[--matchesStrictLen]
          targetI = nextBeginningIndexes[lastMatch]

        } else {
          var isMatch = searchLowerCodes[typoStrictI===0?searchI : (typoStrictI===searchI?searchI+1 : (typoStrictI===searchI-1?searchI-1 : searchI))] === targetLowerCodes[targetI]
          if(isMatch) {
            matchesStrict[matchesStrictLen++] = targetI
            ++searchI; if(searchI === searchLen) { successStrict = true; break }
            ++targetI
          } else {
            targetI = nextBeginningIndexes[targetI]
          }
        }
      }

      { // tally up the score & keep track of matches for highlighting later
        if(successStrict) { var matchesBest = matchesStrict; var matchesBestLen = matchesStrictLen }
        else { var matchesBest = matchesSimple; var matchesBestLen = matchesSimpleLen }
        var score = 0
        var lastTargetI = -1
        for(var i = 0; i < searchLen; ++i) { var targetI = matchesBest[i]
          // score only goes down if they're not consecutive
          if(lastTargetI !== targetI - 1) score -= targetI
          lastTargetI = targetI
        }
        if(!successStrict) {
          score *= 1000
          if(typoSimpleI !== 0) score += -20/*typoPenalty*/
        } else {
          if(typoStrictI !== 0) score += -20/*typoPenalty*/
        }
        score -= targetLen - searchLen
        prepared.score = score
        prepared.indexes = new Array(matchesBestLen); for(var i = matchesBestLen - 1; i >= 0; --i) prepared.indexes[i] = matchesBest[i]

        return prepared
      }
    },

    algorithmNoTypo: function(searchLowerCodes, prepared, searchLowerCode) {
      var targetLowerCodes = prepared._targetLowerCodes
      var searchLen = searchLowerCodes.length
      var targetLen = targetLowerCodes.length
      var searchI = 0 // where we at
      var targetI = 0 // where you at
      var matchesSimpleLen = 0

      // very basic fuzzy match; to remove non-matching targets ASAP!
      // walk through target. find sequential matches.
      // if all chars aren't found then exit
      for(;;) {
        var isMatch = searchLowerCode === targetLowerCodes[targetI]
        if(isMatch) {
          matchesSimple[matchesSimpleLen++] = targetI
          ++searchI; if(searchI === searchLen) break
          searchLowerCode = searchLowerCodes[searchI]
        }
        ++targetI; if(targetI >= targetLen) return null // Failed to find searchI
      }

      var searchI = 0
      var successStrict = false
      var matchesStrictLen = 0

      var nextBeginningIndexes = prepared._nextBeginningIndexes
      if(nextBeginningIndexes === null) nextBeginningIndexes = prepared._nextBeginningIndexes = fuzzysort.prepareNextBeginningIndexes(prepared.target)
      var firstPossibleI = targetI = matchesSimple[0]===0 ? 0 : nextBeginningIndexes[matchesSimple[0]-1]

      // Our target string successfully matched all characters in sequence!
      // Let's try a more advanced and strict test to improve the score
      // only count it as a match if it's consecutive or a beginning character!
      if(targetI !== targetLen) for(;;) {
        if(targetI >= targetLen) {
          // We failed to find a good spot for this search char, go back to the previous search char and force it forward
          if(searchI <= 0) break // We failed to push chars forward for a better match

          --searchI
          var lastMatch = matchesStrict[--matchesStrictLen]
          targetI = nextBeginningIndexes[lastMatch]

        } else {
          var isMatch = searchLowerCodes[searchI] === targetLowerCodes[targetI]
          if(isMatch) {
            matchesStrict[matchesStrictLen++] = targetI
            ++searchI; if(searchI === searchLen) { successStrict = true; break }
            ++targetI
          } else {
            targetI = nextBeginningIndexes[targetI]
          }
        }
      }

      { // tally up the score & keep track of matches for highlighting later
        if(successStrict) { var matchesBest = matchesStrict; var matchesBestLen = matchesStrictLen }
        else { var matchesBest = matchesSimple; var matchesBestLen = matchesSimpleLen }
        var score = 0
        var lastTargetI = -1
        for(var i = 0; i < searchLen; ++i) { var targetI = matchesBest[i]
          // score only goes down if they're not consecutive
          if(lastTargetI !== targetI - 1) score -= targetI
          lastTargetI = targetI
        }
        if(!successStrict) score *= 1000
        score -= targetLen - searchLen
        prepared.score = score
        prepared.indexes = new Array(matchesBestLen); for(var i = matchesBestLen - 1; i >= 0; --i) prepared.indexes[i] = matchesBest[i]

        return prepared
      }
    },

    prepareLowerCodes: function(str) {
      var strLen = str.length
      var lowerCodes = [] // new Array(strLen)    sparse array is too slow
      var lower = str.toLowerCase()
      for(var i = 0; i < strLen; ++i) lowerCodes[i] = lower.charCodeAt(i)
      return lowerCodes
    },
    prepareBeginningIndexes: function(target) {
      var targetLen = target.length
      var beginningIndexes = []; var beginningIndexesLen = 0
      var wasUpper = false
      var wasAlphanum = false
      for(var i = 0; i < targetLen; ++i) {
        var targetCode = target.charCodeAt(i)
        var isUpper = targetCode>=65&&targetCode<=90
        var isAlphanum = isUpper || targetCode>=97&&targetCode<=122 || targetCode>=48&&targetCode<=57
        var isBeginning = isUpper && !wasUpper || !wasAlphanum || !isAlphanum
        wasUpper = isUpper
        wasAlphanum = isAlphanum
        if(isBeginning) beginningIndexes[beginningIndexesLen++] = i
      }
      return beginningIndexes
    },
    prepareNextBeginningIndexes: function(target) {
      var targetLen = target.length
      var beginningIndexes = fuzzysort.prepareBeginningIndexes(target)
      var nextBeginningIndexes = [] // new Array(targetLen)     sparse array is too slow
      var lastIsBeginning = beginningIndexes[0]
      var lastIsBeginningI = 0
      for(var i = 0; i < targetLen; ++i) {
        if(lastIsBeginning > i) {
          nextBeginningIndexes[i] = lastIsBeginning
        } else {
          lastIsBeginning = beginningIndexes[++lastIsBeginningI]
          nextBeginningIndexes[i] = lastIsBeginning===undefined ? targetLen : lastIsBeginning
        }
      }
      return nextBeginningIndexes
    },

    cleanup: cleanup,
    new: fuzzysortNew,
  }
  return fuzzysort
} // fuzzysortNew

// This stuff is outside fuzzysortNew, because it's shared with instances of fuzzysort.new()
var isNode = typeof require !== 'undefined' && typeof window === 'undefined'
// var MAX_INT = Number.MAX_SAFE_INTEGER
// var MIN_INT = Number.MIN_VALUE
var preparedCache = new Map()
var preparedSearchCache = new Map()
var noResults = []; noResults.total = 0
var matchesSimple = []; var matchesStrict = []
function cleanup() { preparedCache.clear(); preparedSearchCache.clear(); matchesSimple = []; matchesStrict = [] }
function defaultScoreFn(a) {
  var max = -9007199254740991
  for (var i = a.length - 1; i >= 0; --i) {
    var result = a[i]; if(result === null) continue
    var score = result.score
    if(score > max) max = score
  }
  if(max === -9007199254740991) return null
  return max
}

// prop = 'key'              2.5ms optimized for this case, seems to be about as fast as direct obj[prop]
// prop = 'key1.key2'        10ms
// prop = ['key1', 'key2']   27ms
function getValue(obj, prop) {
  var tmp = obj[prop]; if(tmp !== undefined) return tmp
  var segs = prop
  if(!Array.isArray(prop)) segs = prop.split('.')
  var len = segs.length
  var i = -1
  while (obj && (++i < len)) obj = obj[segs[i]]
  return obj
}

function isObj(x) { return typeof x === 'object' } // faster as a function

// Hacked version of https://github.com/lemire/FastPriorityQueue.js
var fastpriorityqueue=function(){var r=[],o=0,e={};function n(){for(var e=0,n=r[e],c=1;c<o;){var f=c+1;e=c,f<o&&r[f].score<r[c].score&&(e=f),r[e-1>>1]=r[e],c=1+(e<<1)}for(var a=e-1>>1;e>0&&n.score<r[a].score;a=(e=a)-1>>1)r[e]=r[a];r[e]=n}return e.add=function(e){var n=o;r[o++]=e;for(var c=n-1>>1;n>0&&e.score<r[c].score;c=(n=c)-1>>1)r[n]=r[c];r[n]=e},e.poll=function(){if(0!==o){var e=r[0];return r[0]=r[--o],n(),e}},e.peek=function(e){if(0!==o)return r[0]},e.replaceTop=function(o){r[0]=o,n()},e};
var q = fastpriorityqueue() // reuse this, except for async, it needs to make its own

return fuzzysortNew()
}) // UMD

// TODO: (performance) wasm version!?

// TODO: (performance) layout memory in an optimal way to go fast by avoiding cache misses

// TODO: (performance) preparedCache is a memory leak

// TODO: (like sublime) backslash === forwardslash

// TODO: (performance) i have no idea how well optimized the allowing typos algorithm is