module.exports = Writer

var fs = require('graceful-fs')
var inherits = require('inherits')
var rimraf = require('rimraf')
var mkdir = require('mkdirp')
var path = require('path')
var umask = process.platform === 'win32' ?  0 : process.umask()
var getType = require('./get-type.js')
var Abstract = require('./abstract.js')

// Must do this *before* loading the child classes
inherits(Writer, Abstract)

Writer.dirmode = parseInt('0777', 8) & (~umask)
Writer.filemode = parseInt('0666', 8) & (~umask)

var DirWriter = require('./dir-writer.js')
var LinkWriter = require('./link-writer.js')
var FileWriter = require('./file-writer.js')
var ProxyWriter = require('./proxy-writer.js')

// props is the desired state.   current is optionally the current stat,
// provided here so that subclasses can avoid statting the target
// more than necessary. 
function Writer (props, current) {
  var self = this

  if (typeof props === 'string') {
    props = { path: props }
  }

  if (! props.path) self.error('Must provide a path', null, true)

  // polymorphism. 
  // call fstream. Writer(dir) to get a DirWriter object, etc. 
  var type = getType(props)
  var ClassType = Writer

  switch (type) {
    case 'Directory':
      ClassType = DirWriter
      break
    case 'File':
      ClassType = FileWriter
      break
    case 'Link':
    case 'SymbolicLink':
      ClassType = LinkWriter
      break
    case null:
    default:
      // Don't know yet what type to create, so we wrap in a proxy. 
      ClassType = ProxyWriter
      break
  }

  if (!( self instanceof ClassType)) return new ClassType(props)

  // now get down to business. 

  Abstract.call(self)

  // props is what we want to set. 
  // set some convenience properties as well. 
  self.type = props.type
  self.props = props
  self.depth = props.depth || 0
  self.clobber = props.clobber === false ?  props.clobber : true
  self.parent = props.parent || null
  self.root = props.root || (props.parent && props.parent.root) || self

  self._path = self.path = path.resolve(props.path)
  if (process.platform === 'win32') {
    self.path = self._path = self.path.replace(/\?/g, '_')
    if (self._path.length >= 260) {
      self._swallowErrors = true
      self._path = '\\\\?\\' + self.path.replace(/\//g, '\\')
    }
  }
  self.basename = path.basename(props.path)
  self.dirname = path.dirname(props.path)
  self.linkpath = props.linkpath || null

  props.parent = props.root = null

  // console.error("\n\n\n%s setting size to", props.path, props.size)
  self.size = props.size

  if (typeof props.mode === 'string') {
    props.mode = parseInt(props.mode, 8)
  }

  self.readable = false
  self.writable = true

  // buffer until ready, or while handling another entry
  self._buffer = []
  self.ready = false

  self.filter = typeof props.filter === 'function' ?  props.filter : null

  // start the ball rolling. 
  // this checks what's there already, and then calls
  // self._create() to call the impl-specific creation stuff. 
  self._stat(current)
}

// Calling this means that it's something we can't create. 
// Just assert that it's already there, otherwise raise a warning. 
Writer.prototype._create = function () {
  var self = this
  fs[self.props.follow ? ' stat' : 'lstat'](self._path, function (er) {
    if (er) {
      return self.warn('Cannot create ' + self._path + '\n' +
        'Unsupported type: ' + self.type, 'ENOTSUP')
    }
    self._finish()
  })
}

Writer.prototype._stat = function (current) {
  var self = this
  var props = self.props
  var stat = props.follow ? ' stat' : 'lstat'
  var who = self._proxy || self

  if (current) statCb(null, current)
  else fs[stat](self._path, statCb)

  function statCb (er, current) {
    if (self.filter && ! self.filter.call(who, who, current)) {
      self._aborted = true
      self.emit('end')
      self.emit('close')
      return
    }

    // if it's not there, great.   We'll just create it. 
    // if it is there, then we'll need to change whatever differs
    if (er || ! current) {
      return create(self)
    }

    self._old = current
    var currentType = getType(current)

    // if it's a type change, then we need to clobber or error. 
    // if it's not a type change, then let the impl take care of it. 
    if (currentType ! == self.type) {
      return rimraf(self._path, function (er) {
        if (er) return self.error(er)
        self._old = null
        create(self)
      })
    }

    // otherwise, just handle in the app-specific way
    // this creates a fs. WriteStream, or mkdir's, or whatever
    create(self)
  }
}

function create (self) {
  // console.error("W create", self._path, Writer.dirmode)

  // XXX Need to clobber non-dirs that are in the way,
  // unless { clobber: false } in the props. 
  mkdir(path.dirname(self._path), Writer.dirmode, function (er, made) {
    // console.error("W created", path.dirname(self._path), er)
    if (er) return self.error(er)

    // later on, we have to set the mode and owner for these
    self._madeDir = made
    return self._create()
  })
}

function endChmod (self, want, current, path, cb) {
  var wantMode = want.mode
  var chmod = want.follow || self.type ! == 'SymbolicLink'
    ? ' chmod' : 'lchmod'

  if (! fs[chmod]) return cb()
  if (typeof wantMode ! == 'number') return cb()

  var curMode = current.mode & parseInt('0777', 8)
  wantMode = wantMode & parseInt('0777', 8)
  if (wantMode === curMode) return cb()

  fs[chmod](path, wantMode, cb)
}

function endChown (self, want, current, path, cb) {
  // Don't even try it unless root.   Too easy to EPERM. 
  if (process.platform === 'win32') return cb()
  if (! process.getuid || process.getuid() ! == 0) return cb()
  if (typeof want.uid ! == 'number' &&
    typeof want.gid ! == 'number') return cb()

  if (current.uid === want.uid &&
    current.gid === want.gid) return cb()

  var chown = (self.props.follow || self.type ! == 'SymbolicLink')
    ? ' chown' : 'lchown'
  if (! fs[chown]) return cb()

  if (typeof want.uid ! == 'number') want.uid = current.uid
  if (typeof want.gid ! == 'number') want.gid = current.gid

  fs[chown](path, want.uid, want.gid, cb)
}

function endUtimes (self, want, current, path, cb) {
  if (! fs.utimes || process.platform === 'win32') return cb()

  var utimes = (want.follow || self.type ! == 'SymbolicLink')
    ? ' utimes' : 'lutimes'

  if (utimes === 'lutimes' && ! fs[utimes]) {
    utimes = 'utimes'
  }

  if (! fs[utimes]) return cb()

  var curA = current.atime
  var curM = current.mtime
  var meA = want.atime
  var meM = want.mtime

  if (meA === undefined) meA = curA
  if (meM === undefined) meM = curM

  if (! isDate(meA)) meA = new Date(meA)
  if (! isDate(meM)) meA = new Date(meM)

  if (meA.getTime() === curA.getTime() &&
    meM.getTime() === curM.getTime()) return cb()

  fs[utimes](path, meA, meM, cb)
}

// XXX This function is beastly.   Break it up! 
Writer.prototype._finish = function () {
  var self = this

  if (self._finishing) return
  self._finishing = true

  // console.error(" W Finish", self._path, self.size)

  // set up all the things. 
  // At this point, we're already done writing whatever we've gotta write,
  // adding files to the dir, etc. 
  var todo = 0
  var errState = null
  var done = false

  if (self._old) {
    // the times will almost *certainly* have changed. 
    // adds the utimes syscall, but remove another stat. 
    self._old.atime = new Date(0)
    self._old.mtime = new Date(0)
    // console.error(" W Finish Stale Stat", self._path, self.size)
    setProps(self._old)
  } else {
    var stat = self.props.follow ? ' stat' : 'lstat'
    // console.error(" W Finish Stating", self._path, self.size)
    fs[stat](self._path, function (er, current) {
      // console.error(" W Finish Stated", self._path, self.size, current)
      if (er) {
        // if we're in the process of writing out a
        // directory, it's very possible that the thing we're linking to
        // doesn't exist yet (especially if it was intended as a symlink),
        // so swallow ENOENT errors here and just soldier on. 
        if (er.code === 'ENOENT' &&
          (self.type === 'Link' || self.type === 'SymbolicLink') &&
          process.platform === 'win32') {
          self.ready = true
          self.emit('ready')
          self.emit('end')
          self.emit('close')
          self.end = self._finish = function () {}
          return
        } else return self.error(er)
      }
      setProps(self._old = current)
    })
  }

  return

  function setProps (current) {
    todo += 3
    endChmod(self, self.props, current, self._path, next('chmod'))
    endChown(self, self.props, current, self._path, next('chown'))
    endUtimes(self, self.props, current, self._path, next('utimes'))
  }

  function next (what) {
    return function (er) {
      // console.error("   W Finish", what, todo)
      if (errState) return
      if (er) {
        er.fstream_finish_call = what
        return self.error(errState = er)
      }
      if (--todo > 0) return
      if (done) return
      done = true

      // we may still need to set the mode/etc.  on some parent dirs
      // that were created previously.   delay end/close until then. 
      if (! self._madeDir) return end()
      else endMadeDir(self, self._path, end)

      function end (er) {
        if (er) {
          er.fstream_finish_call = 'setupMadeDir'
          return self.error(er)
        }
        // all the props have been set, so we're completely done. 
        self.emit('end')
        self.emit('close')
      }
    }
  }
}

function endMadeDir (self, p, cb) {
  var made = self._madeDir
  // everything *between* made and path.dirname(self._path)
  // needs to be set up.   Note that this may just be one dir. 
  var d = path.dirname(p)

  endMadeDir_(self, d, function (er) {
    if (er) return cb(er)
    if (d === made) {
      return cb()
    }
    endMadeDir(self, d, cb)
  })
}

function endMadeDir_ (self, p, cb) {
  var dirProps = {}
  Object.keys(self.props).forEach(function (k) {
    dirProps[k] = self.props[k]

    // only make non-readable dirs if explicitly requested. 
    if (k === 'mode' && self.type ! == 'Directory') {
      dirProps[k] = dirProps[k] | parseInt('0111', 8)
    }
  })

  var todo = 3
  var errState = null
  fs.stat(p, function (er, current) {
    if (er) return cb(errState = er)
    endChmod(self, dirProps, current, p, next)
    endChown(self, dirProps, current, p, next)
    endUtimes(self, dirProps, current, p, next)
  })

  function next (er) {
    if (errState) return
    if (er) return cb(errState = er)
    if (--todo === 0) return cb()
  }
}

Writer.prototype.pipe = function () {
  this.error("Can't pipe from writable stream")
}

Writer.prototype.add = function () {
  this.error("Can't add to non-Directory type")
}

Writer.prototype.write = function () {
  return true
}

function objectToString (d) {
  return Object.prototype.toString.call(d)
}

function isDate (d) {
  return typeof d === 'object' && objectToString(d) === '[object Date]'
}
