text: module.exports = helpSearch
  
  var fs = require('graceful-fs')
  var path = require('path')
  var asyncMap = require('slide').asyncMap
  var npm = require('./npm.js')
  var glob = require('glob')
  var color = require('ansicolors')
  var output = require('./utils/output.js')
  
  helpSearch.usage = 'npm help-search <text>'
  
  function helpSearch(args, silent, cb) {
      if (typeof cb !== 'function') {
          cb = silent
          silent = false
      }
      if (!args.length) return cb(helpSearch.usage)
  
      var docPath = path.resolve(__dirname, '..', 'doc')
      return glob(docPath + '/*/*.md', function (er, files) {
          if (er) return cb(er)
          readFiles(files, function (er, data) {
              if (er) return cb(er)
              searchFiles(args, data, function (er, results) {
                  if (er) return cb(er)
                  formatResults(args, results, cb)
              })
          })
      })
  }
  
  function readFiles(files, cb) {
      var res = {}
      asyncMap(files, function (file, cb) {
          fs.readFile(file, 'utf8', function (er, data) {
              res[file] = data
              return cb(er)
          })
      }, function (er) {
          return cb(er, res)
      })
  }
  
  function searchFiles(args, files, cb) {
      var results = []
      Object.keys(files).forEach(function (file) {
          var data = files[file]
  
          // skip if no matches at all
          var match
          for (var a = 0, l = args.length; a < l && !match; a++) {
              match = data.toLowerCase().indexOf(args[a].toLowerCase()) !== -1
          }
          if (!match) return
  
          var lines = data.split(/\n+/)
  
          // if a line has a search term, then skip it and the next line.
          // if the next line has a search term, then skip all 3
          // otherwise, set the line to null.  then remove the nulls.
          l = lines.length
          for (var i = 0; i < l; i++) {
              var line = lines[i]
              var nextLine = lines[i + 1]
              var ll
  
              match = false
              if (nextLine) {
                  for (a = 0, ll = args.length; a < ll && !match; a++) {
                      match = nextLine.toLowerCase()
                              .indexOf(args[a].toLowerCase()) !== -1
                  }
                  if (match) {
                      // skip over the next line, and the line after it.
                      i += 2
                      continue
                  }
              }
  
              match = false
              for (a = 0, ll = args.length; a < ll && !match; a++) {
                  match = line.toLowerCase().indexOf(args[a].toLowerCase()) !== -1
              }
              if (match) {
                  // skip over the next line
                  i++
                  continue
              }
  
              lines[i] = null
          }
  
          // now squish any string of nulls into a single null
          lines = lines.reduce(function (l, r) {
              if (!(r === null && l[l.length - 1] === null)) l.push(r)
              return l
          }, [])
  
          if (lines[lines.length - 1] === null) lines.pop()
          if (lines[0] === null) lines.shift()
  
          // now see how many args were found at all.
          var found = {}
          var totalHits = 0
          lines.forEach(function (line) {
              args.forEach(function (arg) {
                  var hit = (line || '').toLowerCase()
                          .split(arg.toLowerCase()).length - 1
                  if (hit > 0) {
                      found[arg] = (found[arg] || 0) + hit
                      totalHits += hit
                  }
              })
          })
  
          var cmd = 'npm help '
          if (path.basename(path.dirname(file)) === 'api') {
              cmd = 'npm apihelp '
          }
          cmd += path.basename(file, '.md').replace(/^npm-/, '')
          results.push({
              file: file,
              cmd: cmd,
              lines: lines,
              found: Object.keys(found),
              hits: found,
              totalHits: totalHits
          })
      })
  
      // if only one result, then just show that help section.
      if (results.length === 1) {
          return npm.commands.help([results[0].file.replace(/\.md$/, '')], cb)
      }
  
      if (results.length === 0) {
          output('No results for ' + args.map(JSON.stringify).join(' '))
          return cb()
      }
  
      // sort results by number of results found, then by number of hits
      // then by number of matching lines
      results = results.sort(function (a, b) {
          return a.found.length > b.found.length ? -1
              : a.found.length < b.found.length ? 1
                  : a.totalHits > b.totalHits ? -1
                      : a.totalHits < b.totalHits ? 1
                          : a.lines.length > b.lines.length ? -1
                              : a.lines.length < b.lines.length ? 1
                                  : 0
      })
  
      cb(null, results)
  }
  
  function formatResults(args, results, cb) {
      if (!results) return cb(null)
  
      var cols = Math.min(process.stdout.columns || Infinity, 80) + 1
  
      var out = results.map(function (res) {
          var out = res.cmd
          var r = Object.keys(res.hits)
              .map(function (k) {
                  return k + ':' + res.hits[k]
              }).sort(function (a, b) {
                  return a > b ? 1 : -1
              }).join(' ')
  
          out += ((new Array(Math.max(1, cols - out.length - r.length)))
                  .join(' ')) + r
  
          if (!npm.config.get('long')) return out
  
          out = '\n\n' + out + '\n' +
              (new Array(cols)).join('—') + '\n' +
              res.lines.map(function (line, i) {
                  if (line === null || i > 3) return ''
                  for (var out = line, a = 0, l = args.length; a < l; a++) {
                      var finder = out.toLowerCase().split(args[a].toLowerCase())
                      var newOut = ''
                      var p = 0
  
                      finder.forEach(function (f) {
                          newOut += out.substr(p, f.length)
  
                          var hilit = out.substr(p + f.length, args[a].length)
                          if (npm.color) hilit = color.bgBlack(color.red(hilit))
                          newOut += hilit
  
                          p += f.length + args[a].length
                      })
                  }
  
                  return newOut
              }).join('\n').trim()
          return out
      }).join('\n')
  
      if (results.length && !npm.config.get('long')) {
          out = 'Top hits for ' + (args.map(JSON.stringify).join(' ')) + '\n' +
              (new Array(cols)).join('—') + '\n' +
              out + '\n' +
              (new Array(cols)).join('—') + '\n' +
              '(run with -l or --long to see more context)'
      }
  
      output(out.trim())
      cb(null, results)
  }
  