var DateFormat = require('dateformatjs').DateFormat;
var df = new DateFormat("MM/dd/yyyy");
var dfW3C = new DateFormat(DateFormat.W3C);
var async = require("async");
var _ = require('underscore');
var repCmdty = {space:"ISO4217",id:"RUB"};
var safe = require('safe');

module.exports = function account(webapp) {
    var app = webapp.web;
    var cashapi = webapp.api;
    var prefix = webapp.prefix;
    var ctx = webapp.ctx;
    var reportSettingsVersion = 2;

    app.get(prefix + "/reports/barflow", webapp.layout(), function (req, res, next ) {
        report1(req, res, next, "barflow");
    });

    app.get(prefix + "/reports/pieflow", webapp.layout(), function (req, res, next ) {
        report1(req, res, next, "pieflow");
    });

    function report1(req, res, next, type) {
        if (!req.query || !req.query.name) {
            var ct = "Income statement";
            if (type == 'pieflow')
                ct = 'Pie flow chart';
            else if (type == 'barflow')
                ct = 'Bar flow chart';

            res.redirect(req.url + "?name=" +  ctx.i18n(req.session.apiToken, 'cash', ct));
            return;
        }

        var pid = "reports-" + type + "-" + req.query.name;
        var vtabs,data,reportSettings;
        async.waterfall([
            function (cb1) {
                async.series([
                    function(cb2) {
                        webapp.guessTab(req, {pid: pid, name:req.query.name, url:req.url}, cb2);
                    },
                    function(cb2) {
                        webapp.getTabSettings(req.session.apiToken, pid, cb2);
                    }
                ],
                function (err, results) {
                    cb1(null, results[0], results[1]);
                });
            },
            function (vtabs_, reportSettings_, cb1) {
                vtabs = vtabs_;
                reportSettings = reportSettings_;
                if (_.isEmpty(reportSettings) || !reportSettings.version || (reportSettings.version != reportSettingsVersion)){
                    reportSettings = getDefaultSettings(req.query.name);
                    webapp.saveTabSettings(req.session.apiToken, pid, reportSettings, function(err){
                        if (err) console.log(err);
                    });
                }
                calculateGraphData(req.session.apiToken,type,reportSettings,cb1);
            },
            function(data_,cb1){
                data = data_;
                cb1()
            },
            function(){
                data.tabs = vtabs;
                data.pmenu = {name:req.query.name,
                    items:[{name:webapp.ctx.i18n(req.session.apiToken, 'cash','Page settings'),id:"settings",href:"#"}]}
                data.reportSettings = reportSettings;

                res.render(__dirname+"/../res/views/report", data);
            }],
            next
        );
    };

    function calculateGraphData(token, type, params, cb){
        var periods=categories=null;
        var accountsTree,accKeys;
        switch(type){
            case 'barflow':
                periods = getPeriods(new Date(params.startDate), new Date(params.endDate));
                categories = _.map(periods, function (p) { return (p.start.getMonth()+1)+"."+p.start.getFullYear();});
            break;
            case 'pieflow':
            break;
        }
        async.waterfall([
            function (cb1) {
                cashapi.getAllAccounts(token, cb1);
            },
            function (accounts, cb1) {
                //here not filter accounts yet
                accKeys = _(accounts).reduce(function (memo, acc) {
                    memo[acc._id] = {name:acc.name, _id:acc._id, parentId:acc.parentId,summ:0,type:acc.type};
                    if(periods)
                        memo[acc._id].periods = _(periods).map(function (p) { return _.clone(p); });
                    return memo;
                }, {});
                cashapi.getTransactionsInDateRange(token,[params.startDate,params.endDate,true,false],cb1);
            },
            function(trns,cb1){
                (function (cb) {
                async.forEach(trns, function (tr,cb) {
                    cashapi.getCmdtyPrice(token,tr.currency,{space:"ISO4217",id:params.reportCurrency},null,'safe',function(err,rate){
                        if(err && !(err.skilap && err.skilap.subject == "UnknownRate"))
                            return cb(err);
                        if (!err && rate!=0)
                            var irate = rate;
                        _.forEach(tr.splits, function(split) {
                            var acs = accKeys[split.accountId];
                            if (acs) {
                                var val = split.value*irate;
                                if (params.accType!=acs.type){
                                    acs.summ  = 0;
                                    val = 0;
                                }
                                if (params.accType == "INCOME")
                                    val *= -1;
                                acs.summ += val;
                                if (periods) {
                                    var d = tr.datePosted.valueOf();
                                    _.forEach(acs.periods, function (p) {
                                        if (d > p.start.valueOf() && d <= p.end.valueOf()) {
                                            p.summ += val;
                                        }
                                    });
                                }
                            }
                        });
                        cb();
                    })
                },cb);
            })(safe.sure(cb1, function () {
                //collapse accounts to accLevel
                if(params.accLevel != 'All'){
                    async.series([
                        function(cb2){
                            async.forEachSeries(_.keys(accKeys), function(key,cb3){
                                cashapi.getAccountInfo(token,key,['level'],function(err,res){
                                    if (err) return cb3(err);
                                    accKeys[key].level = res.level;
                                    cb3();
                                });
                            },cb2);
                        },
                        function(cb2){
                            do {
                                // get current ids
                                var ids = _.reduce(_.values(accKeys), function (memo, item) {
                                    memo[item._id] = 1;
                                    return memo;
                                }, {})
                                // remove accounts that can't be reduced now
                                // accounts that have child or with level
                                // not covered by collapse
                                _.each(accKeys, function (item, id) {
                                    delete ids[item.parentId];
                                    if (item.level<=params.accLevel)
                                        delete ids[id];
                                    if (item.type!=params.accType)
                                        delete ids[id];
                                })
                                // reduce
                                _.each(ids, function (v,id) {
                                    var child = accKeys[id];
                                    var parent = accKeys[child.parentId];
                                    parent.summ+=child.summ;
                                    parent.expand = 1;
                                    if (child.periods) {
                                        for (var i = 0 ; i<child.periods.length; i++) {
                                            parent.periods[i].summ+=child.periods[i].summ;
                                        }
                                    }
                                    delete accKeys[id];
                                })
                            } while (_.size(ids)!=0);
                            //filter by id and type
                            if(_.isArray(params.accIds) && _.size(accKeys) != params.accIds.length){
                                accKeys = _.filter(accKeys, function(elem){
                                    if (elem.expand)
                                        return true;
                                    return _.find(params.accIds, function(item){return _.isEqual(elem._id.toString(),item.toString())}
                                )});
                            }
                            accKeys = _(accKeys).reduce(function (memo, acc) {
                                if (acc.type == params.accType || acc.expand)
                                    memo[acc._id] = acc;
                                return memo;
                            }, {});
                            cb2();
                        }
                    ],function(err){
                        if(err) return cb1(err);
                        cb1();
                    });
                }
                else{
                    //filter by id and type;
                    if(_.isArray(params.accIds) && _.size(accKeys) != params.accIds.length){
                        accKeys = _.filter(accKeys, function(elem){ return _.find(params.accIds, function(item){return _.isEqual(elem._id.toString(),item.toString())})});
                    }
                    accKeys = _(accKeys).reduce(function (memo, acc) {
                        if (acc.type == params.accType)
                            memo[acc._id] = acc;
                        return memo;
                    }, {});
                    cb1();
                }
                }))
            },
            function(cb1){
                var total = 0;
                // find important accounts (with biggest summ over entire period)
                var iacs = _(accKeys).chain().map(function (acs) { return {_id:acs._id, summ:acs.summ}})
                    .sortBy(function (acs) {return acs.summ}).last(params.maxAcc)
                    .reduce(function (memo, acs) { memo[acs._id]=1; return memo; }, {}).value();
                // colapse non important
                var final = _(accKeys).reduce( function (memo, accKey) {
                    total += accKey.summ;
                    if (_(iacs).has(accKey._id))
                        memo[accKey._id] = accKey;
                    else {
                        var other = memo['other'];
                        if (other==null) {
                            accKey.name = "Other";
                            accKey._id = 'other';
                            memo['other'] = accKey;
                        } else {
                            other.summ+=accKey.summ;
                            if (periods)
                                for(var i =0; i<other.periods.length; i++) {
                                    other.periods[i].summ+=accKey.periods[i].summ;
                                }
                        }
                    }
                    return memo;
                }, {});
                // transform into report form
                var report = _(final).reduce( function (memo,accKey) {
                    var obj = {};
                    if (periods){
                        var obj = {name:accKey.name, data:_(accKey.periods).pluck('summ')}
                    } else {
                        obj = [accKey.name, accKey.summ];
                    }
                    memo.push(obj);
                    return memo;
                }, [])
                cb1(null,report);

            }
        ], function (err, series) {
            if(err) return cb(err);
            if(type == 'pieflow')
                series = {type:'pie', data: series};

            var data = {categories:JSON.stringify(categories), series:JSON.stringify(series)};
            data[type] = 1;
            cb(null, data);
        });
    }

    // split date range into periods
    function getPeriods (sd, ed) {
        var ret = [];
        var start = new Date(sd.valueOf());
        var end = new Date(sd.valueOf());
        while (end.valueOf() < ed.valueOf()) {
            end = new Date(start.getFullYear(),start.getMonth()+1,1);
            if (ed.valueOf()<end.valueOf())
                end = ed;
            ret.push({start:start, end:end, summ:0});
            start = end;
        }
        return ret;
    }

    function getDefaultSettings(reportName) {
        var defaultSettings = {
                startDate:dfW3C.format(new Date(new Date().getFullYear(), 0, 1)),
                endDate:dfW3C.format(new Date(new Date().getFullYear(), 11, 31)),
                accIsVisible:1,
                accType:"EXPENSE",
                maxAcc:10,
                reportName:reportName,
                accIds:null,
                accLevel:2,
                accLevelOptions:[{name:'All'},{name:1},{name:2},{name:3},{name:4},{name:5},{name:6}],
                version: reportSettingsVersion,
                reportCurrency:repCmdty.id
            };
        return defaultSettings;
    }
}