path = require 'path'

async = require 'async'
fs = require 'fs-plus'
request = require 'request'

module.exports = (grunt) ->
  {rm} = require('./task-helpers')(grunt)

  cmd = path.join('node_modules', '.bin', 'coffee')
  commonArgs = [path.join('build', 'node_modules', '.bin', 'biscotto'), '--']
  opts =
    stdio: 'inherit'

  grunt.registerTask 'build-docs', 'Builds the API docs in src', ->
    done = @async()

    downloadIncludes (error, includePaths) ->
      if error?
        done(error)
      else
        rm('docs/output/api')
        args = [
          commonArgs...
          '--title', 'Atom API Documentation'
          '-o', 'docs/output/api'
          '-r', 'docs/README.md'
          'src/'
          includePaths...
        ]
        grunt.util.spawn({cmd, args, opts}, done)

  grunt.registerTask 'lint-docs', 'Generate stats about the doc coverage', ->
    done = @async()
    downloadIncludes (error, includePaths) ->
      if error?
        done(error)
      else
        args = [
          commonArgs...
          '--noOutput'
          'src/'
          includePaths...
        ]
        grunt.util.spawn({cmd, args, opts}, done)

  grunt.registerTask 'missing-docs', 'Generate stats about the doc coverage', ->
    done = @async()
    downloadIncludes (error, includePaths) ->
      if error?
        done(error)
      else
        args = [
          commonArgs...
          '--noOutput'
          '--missing'
          'src/'
          includePaths...
        ]
        grunt.util.spawn({cmd, args, opts}, done)

  grunt.registerTask 'copy-docs', 'Copies over latest API docs to atom-docs', ->
    done = @async()

    fetchTag = (args..., callback) ->
      cmd = 'git'
      args = ['describe', '--abbrev=0', '--tags']
      grunt.util.spawn {cmd, args}, (error, result) ->
        if error?
          callback(error)
        else
          callback(null, String(result).trim())

    copyDocs = (tag, callback) ->
      cmd = 'cp'
      args = ['-r', 'docs/output/', "../atom.io/public/docs/api/#{tag}/"]

      fs.exists "../atom.io/public/docs/api/", (exists) ->
        if exists
          grunt.util.spawn {cmd, args}, (error, result) ->
            if error?
              callback(error)
            else
              callback(null, tag)
        else
          grunt.log.error "../atom.io/public/docs/api/ doesn't exist"
          return false

    grunt.util.async.waterfall [fetchTag, copyDocs], done

  grunt.registerTask 'deploy-docs', 'Publishes latest API docs to atom-docs.githubapp.com', ->
    done = @async()
    docsRepoArgs = ['--work-tree=../atom-docs/', '--git-dir=../atom-docs/.git/']

    fetchTag = (args..., callback) ->
      cmd = 'git'
      args = ['describe', '--abbrev=0', '--tags']
      grunt.util.spawn {cmd, args}, (error, result) ->
        if error?
          callback(error)
        else
          callback(null, String(result).trim().split('.')[0..1].join('.'))

    stageDocs = (tag, callback) ->
      cmd = 'git'
      args = [docsRepoArgs..., 'add', "public/#{tag}"]
      grunt.util.spawn({cmd, args, opts}, callback)

    fetchSha = (args..., callback) ->
      cmd = 'git'
      args = ['rev-parse', 'HEAD']
      grunt.util.spawn {cmd, args}, (error, result) ->
        if error?
          callback(error)
        else
          callback(null, String(result).trim())

    commitChanges = (sha, callback) ->
      cmd = 'git'
      args = [docsRepoArgs..., 'commit', "-m Update API docs to #{sha}"]
      grunt.util.spawn({cmd, args, opts}, callback)

    pushOrigin = (args..., callback) ->
      cmd = 'git'
      args = [docsRepoArgs..., 'push', 'origin', 'master']
      grunt.util.spawn({cmd, args, opts}, callback)

    pushHeroku = (args..., callback) ->
      cmd = 'git'
      args = [docsRepoArgs..., 'push', 'heroku', 'master']
      grunt.util.spawn({cmd, args, opts}, callback)

    grunt.util.async.waterfall [fetchTag, stageDocs, fetchSha, commitChanges, pushOrigin, pushHeroku], done

downloadFileFromRepo = ({repo, file}, callback) ->
  uri = "https://raw.github.com/atom/#{repo}/master/#{file}"
  request uri, (error, response, contents) ->
    return callback(error) if error?
    downloadPath = path.join('docs', 'includes', repo, file)
    fs.writeFile downloadPath, contents, (error) ->
      callback(error, downloadPath)

downloadIncludes = (callback) ->
  includes = [
    {repo: 'first-mate',  file: 'src/grammar.coffee'}
    {repo: 'first-mate',  file: 'src/grammar-registry.coffee'}
    {repo: 'space-pen',   file: 'src/space-pen.coffee'}
    {repo: 'text-buffer', file: 'src/marker.coffee'}
    {repo: 'text-buffer', file: 'src/point.coffee'}
    {repo: 'text-buffer', file: 'src/range.coffee'}
    {repo: 'theorist',    file: 'src/model.coffee'}
  ]

  async.map(includes, downloadFileFromRepo, callback)