if global.Window
    return

const
    ion = import '../'
    fs = import 'fs'
    np = import 'path'
    utility = import './utility'

export class File
    constructor: (path) ->
        if path?.constructor is File
            return path
        if @constructor isnt File
            return new File(path)
        if typeof path isnt 'string'
            throw new Error("path string is required")
        Object.defineProperties(
            @
            {}
                path:
                    value: path
                    enumerable: true
                    writable: false
        )
        # set modified immediately
        @modified = utility.getModified(path)
        # make us reactive to observers.  Specifically we will just update our modified value as needed.
        ion.makeReactive(
            @
            =>
                let watcher
                if fs.existsSync(@path)
                    watcher = fs.watch(
                        @path
                        =>
                            let modified = utility.getModified(@path)
                            @modified = modified
                            if modified isnt @modified
                                # explicit check is only because current
                                # nodejs versions don't have Object.observe yet.
                                ion.checkForChanges()
                    )
                return -> watcher?.close()
        )
    properties:
        isFile:
            get: -> not @isDirectory
        isDirectory:
            get: -> fs.statSync(@path).isDirectory()
        directoryName:
            get: -> np.dirname(@path)
        exists:
            get: -> fs.existsSync(@path)
        copyFrom: (file) ->
            file = File(file)
            @write(file.read(null), null)
            console.log("Copied: {{np.normalize(@path)}}")
        read: do ->
            # we store changes here, not in File, otherwise
            # reading will cause file to change which causes
            let _lastModified = {}
            let _content = {}            
            return (encoding) ->
                if fs.existsSync(@path)
                    # cache file content as long as the file remains unmodified
                    let modified = utility.getModified(@path)
                    let content
                    if modified is _lastModified[@path]
                        content = _content[@path]
                    else
                        _content[@path] = content = utility.read(@path, encoding)
                        _lastModified[@path] = modified
                    return content
                else
                    return null
        getExtension: ->
            let index = @path.lastIndexOf('.')
            return index < 0 ? "" : @path.substring(index)
        write: (content, encoding) ->
            if content? and content isnt @read(encoding)
                utility.write(@path, content, encoding)
        delete: -> utility.write(@path, null)
        toString: -> @path
        valueOf: -> @path