zordius/webtasks

/*jslint node: true */
'use strict';

var request_id = 0,
    subtask = require('subtask'),
    locate = require('./locate'),
    render = require('./render'),
    REQ = require('request'),
    React = require('react'),
    CLIENT_ONLY = 2,

contextCached = function (task, args) {
    var taskKey = task.taskType + '_' + task.taskName + ':' + Array.prototype.slice.call(args).join(','),
        Task = this.taskPool[taskKey];

    if (!Task) {
        if (task && task.apply) {
            Task = task.apply(this, args);
            Task.taskType = task.taskType;
            Task.taskName = task.taskName;
            this.taskPool[taskKey] = Task;
        }
    }

    return Task;
},

webtaskContext = function (req, res) {
    this.request_id = ++request_id;
    this.taskPool = {
        errors: [],
        req: req,
        res: res,
        react_id: 0,
        react: {}
    };
},

webtaskContextProto = {
    cookie: function (name) {
        return subtask(this.taskPool.req.cookies[name]);
    },
    query: function (name) {
        return subtask(this.taskPool.req.query[name]);
    },
    param: function (name) {
        return subtask(this.taskPool.req.params[name]);
    },
    fetch: function (cfg) {
        return subtask(function (cb) {
            REQ(cfg, function (E, R, B) {
                cb({body: B, response: R, error: E});
            });
        });
    },
    input: function (name) {
        return locate.subtask(this, name, 'input').apply(this, []);
    },
    data: function (name) {
        return subtask.before(locate.subtask(this, name, 'data'), contextCached, this);
    },
    module: function (name) {
        return subtask.after(locate.subtask(this, name, 'module'), function (T) {
            return T.transform(function (R) {
                return {view: 'module_' + name, data: R};
            }).pipe(render);
        }, this);
    },
    page: function (name) {
        return subtask.after(locate.subtask(this, name, 'page'), function (T) {
            return T.transform(function (R) {
                return {view: 'page_' + name, data: R};
            }).pipe(render);
        }, this);
    },
    react: function (name, dynamic) {
        var CX = this;
        return function () {
            var component,
                componentFactory,
                id = 'react_' + (++CX.taskPool.react_id),
                task;

            if (dynamic) {
                CX.taskPool.react[id] = {
                    jsx: name,
                    props: arguments[0]
                };
            }

            try {
                component = locate(CX, name, 'react', '.jsx');
                componentFactory = component ? React.createFactory(component) : undefined;
                if (componentFactory) {
                    if (dynamic) {
                        task = subtask('<div class="reactContainer" id="' + id + '">' + ((dynamic === CLIENT_ONLY) ? '' : React.renderToString(componentFactory(arguments[0]))) + '</div>');
                    } else {
                        task = subtask(React.renderToStaticMarkup(componentFactory(arguments[0])));
                    }
                }
            } catch (E) {
                CX.taskPool.errors.push(E);
            }


            return task || subtask();
        };
    },
    dreact: function (name) {
        return this.react(name, true);
    },
    creact: function (name) {
        return this.react(name, CLIENT_ONLY);
    },
    reactBindStr: function () {
        var O = [],
            R = [],
            react,
            reacts = this.taskPool.react,
            I;

        for (I in reacts) {
            if (reacts.hasOwnProperty(I)) {
                react = reacts[I];
                O.push('("./react/' + react.jsx + '.jsx", ' + JSON.stringify(react.props) + ', document.getElementById("' + I + '"))');
            }
        }

        return O.length ? ('require("$R")' + O.join('') + ';') : null;
    },
    task: function () {
        var T = subtask.apply(this, arguments).quiet();
        T.errors = this.taskPool.errors;
        return T;
    }
};

webtaskContext.prototype = webtaskContextProto;

module.exports = webtaskContext;