'use strict'

utils = require 'src/utils'

module.exports = (Networking) ->
    impl = {}

    Request: require('./request.coffee') Networking
    Response: require('./response.coffee') Networking, impl

    init: (networking) ->
        isReady = false

        # Send internal request to change the page based on the URI
        impl.changePage = (uri) ->
            # send internal request
            res = networking.createLocalRequest
                method: Networking.Request.GET
                type: Networking.Request.HTML_TYPE
                uri: uri

        # synchronize with browser page changing
        window.addEventListener 'popstate', ->
            if isReady
                impl.changePage location.pathname + location.search

        # don't refresh page on click anchor
        document.addEventListener 'click', (e) ->
            {target} = e

            # consider only anchors
            # omit anchors with the `target` attribute
            return if target.nodeName isnt 'A' or target.getAttribute('target')

            if target.href.indexOf(networking.url) is 0 and not ///^\/static\////.test(target.pathname)
                # avoid browser to refresh page
                e.preventDefault()

                # change page to the anchor pathname
                impl.changePage target.pathname + target.search

        # change page to the current one
        onLoaded = ->
            if document.readyState is 'complete'
                setTimeout ->
                    isReady = true
                    impl.changePage location.pathname + location.search
            return

        if document.readyState is 'complete'
            onLoaded()
        else
            document.addEventListener 'readystatechange', onLoaded

        return

    ###
    Send a XHR request and call `callback` on response.
    ###
    sendRequest: (req, res, callback) ->
        {Request} = Networking

        xhr = new XMLHttpRequest

        # prevent caching
        uri = req.uri.toString()
        if utils.has(uri, '?')
            uri = "#{uri}&now=#{Date.now()}"
        else
            uri = "#{uri}?now=#{Date.now()}"

        xhr.open req.method, uri, true

        for name, val of req.headers
            xhr.setRequestHeader name, val
        xhr.setRequestHeader 'X-Expected-Type', req.type

        if cookies = utils.tryFunction(JSON.stringify, null, [req.cookies], null)
            xhr.setRequestHeader 'X-Cookies', cookies

        xhr.onload = ->
            {response} = xhr

            if req.type is Request.JSON_TYPE and typeof response is 'string'
                response = utils.tryFunction JSON.parse, null, [response], response

            if cookies = xhr.getResponseHeader('X-Cookies')
                cookies = utils.tryFunction JSON.parse, null, [cookies], null

            callback
                status: xhr.status
                data: response
                cookies: cookies

        xhr.onerror = ->
            callback
                status: xhr.status
                data: xhr.response

        if utils.isObject(req.data)
            data = utils.tryFunction JSON.stringify, null, [req.data], req.data
        else
            data = req.data
        xhr.send data