'use strict'

utils = require 'src/utils'
assert = require 'src/assert'
log = require 'src/log'

module.exports = (File) -> class AttrsToSet
    @__name__ = 'AttrsToSet'
    @__path__ = 'File.AttrsToSet'

    JSON_CTOR_ID = @JSON_CTOR_ID = File.JSON_CTORS.push(AttrsToSet) - 1

    i = 1
    JSON_NODE = i++
    JSON_ATTRS = i++
    JSON_ARGS_LENGTH = @JSON_ARGS_LENGTH = i

    @_fromJSON = (file, arr, obj) ->
        unless obj
            node = file.node.getChildByAccessPath arr[JSON_NODE]
            obj = new AttrsToSet file, node, arr[JSON_ATTRS]
        obj

    constructor: (@file, @node, @attrs) ->
        assert.instanceOf @file, File
        assert.instanceOf @node, File.Element
        assert.isPlainObject @attrs

        # set current attributes
        for attr of @attrs
            if @node.attrs[attr]?
                this.setAttribute attr, null

        # listen on changes
        @node.onAttrsChange @setAttribute, this

        `//<development>`
        if @constructor is AttrsToSet
            Object.preventExtensions @
        `//</development>`

    setAttribute: (attr, oldValue) ->
        unless @attrs[attr]
            return

        val = @node.attrs[attr]
        if typeof @node[attr] is 'function' and @node[attr].connect
            if typeof oldValue is 'function'
                @node[attr].disconnect oldValue
            if typeof val is 'function'
                @node[attr] val
        else
            @node[attr] = val
        return

    clone: (original, file) ->
        node = original.node.getCopiedElement @node, file.node

        new AttrsToSet file, node, @attrs

    toJSON: (key, arr) ->
        unless arr
            arr = new Array JSON_ARGS_LENGTH
            arr[0] = JSON_CTOR_ID
        arr[JSON_NODE] = @node.getAccessPath @file.node
        arr[JSON_ATTRS] = @attrs
        arr