const yaml = require('js-yaml');
const moment = require('moment-timezone');
const {
    ValidationError, HomeworkNotLiveError, ProblemNotFoundError,
    HomeworkNotAttendedError,
} = require('../error');
const {
    PERM_VIEW_HOMEWORK, PERM_ATTEND_HOMEWORK, PERM_VIEW_PROBLEM,
    PERM_SUBMIT_PROBLEM, PERM_CREATE_HOMEWORK, PERM_EDIT_HOMEWORK,
    PERM_VIEW_HOMEWORK_SCOREBOARD,
} = require('../permission');
const { Route, Handler } = require('../service/server');
const system = require('../model/system');
const user = require('../model/user');
const contest = require('../model/contest');
const discussion = require('../model/discussion');
const problem = require('../model/problem');
const record = require('../model/record');
const document = require('../model/document');
const paginate = require('../lib/paginate');
const misc = require('../lib/misc');
const ranked = require('../lib/rank');

const HomeworkHandler = contest.ContestHandlerMixin(Handler);

class HomeworkMainHandler extends HomeworkHandler {
    async get({ domainId }) {
        const tdocs = await contest.getMulti(domainId, {}, document.TYPE_HOMEWORK).toArray();
        const calendar = [];
        for (const tdoc of tdocs) {
            const cal = { ...tdoc, url: `/homework/${tdoc.docId}` };
            if (contest.isHomeworkExtended(tdoc) || contest.isDone(tdoc)) {
                cal.endAt = tdoc.endAt;
                cal.penaltySince = tdoc.penaltySince;
            } else {
                cal.endAt = tdoc.penaltySince;
            }
            calendar.push(cal);
        }
        const path = [
            ['Hydro', 'homepage'],
            ['homework_main', null],
        ];
        this.response.body = { tdocs, calendar, path };
        this.response.template = 'homework_main.html';
    }
}

class HomeworkDetailHandler extends HomeworkHandler {
    async get({ domainId, tid, page = 1 }) {
        const tdoc = await contest.get(domainId, tid, document.TYPE_HOMEWORK);
        const [tsdoc, pdict] = await Promise.all([
            contest.getStatus(domainId, tdoc.docId, this.user._id, document.TYPE_HOMEWORK),
            problem.getList(domainId, tdoc.pids),
        ]);
        const psdict = {};
        let rdict = {};
        let attended = false;
        if (tsdoc) {
            attended = tsdoc.attend === 1;
            for (const pdetail of tsdoc.journal || []) {
                psdict[pdetail.pid] = pdetail;
                rdict[pdetail.rid] = { _id: pdetail.rid };
            }
            if (this.canShowRecord(tdoc) && tsdoc.journal) {
                rdict = await record.getList(
                    domainId,
                    tsdoc.journal.map((pdetail) => pdetail.rid),
                    true,
                );
            }
        }
        // discussion
        const [ddocs, dpcount, dcount] = await paginate(
            discussion.getMulti(domainId, { parentType: tdoc.docType, parentId: tdoc.docId }),
            page,
            await system.get('DISCUSSION_PER_PAGE'),
        );
        const uids = ddocs.map((ddoc) => ddoc.owner);
        uids.push(tdoc.owner);
        const udict = await user.getList(domainId, uids);
        const path = [
            ['Hydro', 'homepage'],
            ['homework_main', 'homework_main'],
            [tdoc.title, null, null, true],
        ];
        this.response.template = 'homework_detail.html';
        this.response.body = {
            tdoc, tsdoc, attended, udict, pdict, psdict, rdict, ddocs, page, dpcount, dcount, path,
        };
    }

    async postAttend({ domainId, tid }) {
        this.checkPerm(PERM_ATTEND_HOMEWORK);
        const tdoc = await contest.get(domainId, tid, document.TYPE_HOMEWORK);
        if (contest.isDone(tdoc)) throw new HomeworkNotLiveError(tdoc.docId);
        await contest.attend(domainId, tdoc.docId, this.user._id, document.TYPE_HOMEWORK);
        this.back();
    }
}

class HomeworkDetailProblemHandler extends HomeworkHandler {
    async prepare({ domainId, tid, pid }) {
        this.checkPerm(PERM_VIEW_PROBLEM);
        [this.tdoc, this.pdoc, this.tsdoc] = await Promise.all([
            contest.get(domainId, tid, document.TYPE_HOMEWORK),
            problem.get(domainId, pid, this.user._id),
            contest.getStatus(domainId, tid, this.user._id, document.TYPE_HOMEWORK),
        ]);
    }

    async get({ domainId, tid, pid }) {
        const udoc = await user.getById(domainId, this.tdoc.owner);
        const attended = this.tsdoc && this.tsdoc.attend === 1;
        if (!contest.isDone(this.tdoc)) {
            if (!attended) throw new HomeworkNotAttendedError(tid);
            if (!contest.isOngoing(this.tdoc)) throw new HomeworkNotLiveError(tid);
        }
        if (!this.tdoc.pids.includes(pid)) throw new ProblemNotFoundError(domainId, pid, tid);
        const path = [
            ['Hydro', 'homepage'],
            ['homework_main', '/homework'],
            [this.tdoc.title, 'homework_detail', { tid }, true],
            [this.pdoc.title, null, null, true],
        ];
        this.response.template = 'problem_detail.html';
        this.response.body = {
            tdoc: this.tdoc, pdoc: this.pdoc, tsdoc: this.tsdoc, udoc, attended, path,
        };
    }
}

class HomeworkDetailProblemSubmitHandler extends HomeworkDetailProblemHandler {
    async get({ domainId, tid, pid }) {
        const udoc = await user.getById(domainId, this.tdoc.owner);
        const attended = this.tsdoc && this.tsdoc.attend === 1;
        if (!attended) throw new HomeworkNotAttendedError(tid);
        if (!contest.isOngoing(this.tdoc)) throw new HomeworkNotLiveError(tid);
        if (!this.tdoc.pids.includes(pid)) throw new ProblemNotFoundError(domainId, pid, tid);
        const rdocs = this.canShowRecord(this.tdoc)
            ? await record.getUserInProblemMulti(domainId, this.user._id, pid, true)
                .sort('_id', -1).limit(10).toArray()
            : [];
        const path = [
            ['Hydro', 'homepage'],
            ['homework_main', 'homework_main'],
            [this.tdoc.title, 'homework_detail', { tid }, true],
            [this.pdoc.title, 'homework_detail_problem', { tid, pid }, true],
            ['homework_detail_problem_submit', null],
        ];
        this.response.template = 'problem_submit.html';
        this.response.body = {
            tdoc: this.tdoc, pdoc: this.pdoc, tsdoc: this.tsdoc, udoc, attended, path, rdocs,
        };
    }

    async post({
        domainId, tid, pid, code, lang,
    }) {
        this.limitRate('add_record', 60, 100);
        const tsdoc = await contest.getStatus(domainId, tid, this.user._id, document.TYPE_HOMEWORK);
        if (!tsdoc.attend) throw new HomeworkNotAttendedError(tid);
        if (!contest.isOngoing(this.tdoc)) throw new HomeworkNotLiveError(tid);
        if (!this.tdoc.pids.includes(pid)) throw new ProblemNotFoundError(domainId, pid);
        const rid = await record.add(domainId, {
            pid, lang, code, uid: this.user._id, tid, hidden: true, ttype: document.TYPE_HOMEWORK,
        });
        await contest.updateStatus(domainId, tid, this.user._id,
            rid, pid, false, 0, document.TYPE_HOMEWORK);
        this.response.body = { tid, rid };
        if (this.canShowRecord(this.tdoc)) this.response.redirect = `/record/${rid}`;
        else this.response.redirect = `/homework/${tid}`;
    }
}

class HomeworkCreateHandler extends HomeworkHandler {
    async get() {
        const beginAt = moment().add(1, 'day');
        const penaltySince = beginAt.add(7, 'days');
        const path = [
            ['Hydro', 'homepage'],
            ['homework_main', 'homework_main'],
            ['homework_create', null],
        ];
        this.response.template = 'homework_edit.html';
        this.response.body = {
            path,
            dateBeginText: beginAt.tz(this.user.timeZone).format('YYYY-M-D'),
            timeBeginText: '00:00',
            datePenaltyText: penaltySince.tz(this.user.timeZone).format('YYYY-M-D'),
            timePenaltyText: '23:59',
            pids: '1000, 1001',
            extensionDays: 1,
            page_name: 'homework_create',
        };
    }

    async post({
        domainId, title, content, beginAtDate, beginAtTime,
        penaltySinceDate, penaltySinceTime, extensionDays,
        penaltyRules, pids, rated = false,
    }) {
        let beginAt;
        let penaltySince;
        try {
            beginAt = moment.tz(`${beginAtDate} ${beginAtTime}`, this.user.timeZone);
        } catch (e) {
            throw new ValidationError('beginAtDate', 'beginAtTime');
        }
        try {
            penaltySince = moment.tz(`${penaltySinceDate} ${penaltySinceTime}`, this.user.timeZone);
        } catch (e) {
            throw new ValidationError('endAtDate', 'endAtTime');
        }
        const endAt = penaltySince.add(extensionDays, 'days');
        if (beginAt.isSameOrAfter(penaltySince)) throw new ValidationError('endAtDate', 'endAtTime');
        if (penaltySince.isAfter(endAt)) throw new ValidationError('extensionDays');
        penaltySince = penaltySince.toDate();
        await this.verifyProblems(domainId, pids);
        const tid = await contest.add(domainId, title, content, this.user._id,
            'homework', beginAt.toDate(), endAt.toDate(), pids, rated,
            { penaltySince, penaltyRules }, document.TYPE_HOMEWORK);
        this.response.body = { tid };
        this.response.redirect = `/homework/${tid}`;
    }
}

class HomeworkEditHandler extends HomeworkHandler {
    async get({ domainId, tid }) {
        const tdoc = await contest.get(domainId, tid, document.TYPE_HOMEWORK);
        if (tdoc.owner !== this.user._id) this.checkPerm(PERM_EDIT_HOMEWORK);
        const extensionDays = Math.round(
            (tdoc.endAt.getTime() - tdoc.penaltySince.getTime()) / 36000 / 24,
        ) / 100;
        const path = [
            ['Hydro', 'homepage'],
            ['homework_main', 'homework_main'],
            [tdoc.title, 'homework_detail', { tid }, true],
            ['homework_edit', null],
        ];
        const beginAt = moment(tdoc.beginAt).tz(this.user.timeZone);
        const penaltySince = moment(tdoc.penaltySince).tz(this.user.timeZone);
        this.response.template = 'homework_edit.html';
        this.response.body = {
            tdoc,
            dateBeginText: beginAt.format('YYYY-M-D'),
            timeBeginText: beginAt.format('hh:mm'),
            datePenaltyText: penaltySince.format('YYYY-M-D'),
            timePenaltyText: penaltySince.format('hh:mm'),
            extensionDays,
            penaltyRules: yaml.safeDump(tdoc.penaltyRules),
            pids: tdoc.pids.join(','),
            path,
        };
    }

    async post({
        domainId, title, content, beginAtDate, beginAtTime,
        penaltySinceDate, penaltySinceTime, extensionDays,
        penaltyRules, pids, tid,
    }) {
        const tdoc = await contest.get(domainId, tid, document.TYPE_HOMEWORK);
        if (tdoc.owner !== this.user._id) this.checkPerm(PERM_EDIT_HOMEWORK);
        let beginAt;
        let penaltySince;
        try {
            beginAt = moment.tz(`${beginAtDate} ${beginAtTime}`, this.user.timeZone);
        } catch (e) {
            throw new ValidationError('beginAtDate', 'beginAtTime');
        }
        try {
            penaltySince = moment.tz(`${penaltySinceDate} ${penaltySinceTime}`, this.user.timeZone);
        } catch (e) {
            throw new ValidationError('endAtDate', 'endAtTime');
        }
        let endAt = penaltySince.add(extensionDays, 'days');
        if (beginAt.isSameOrAfter(penaltySince)) throw new ValidationError('endAtDate', 'endAtTime');
        await this.verifyProblems(domainId, pids);
        beginAt = beginAt.toDate();
        endAt = endAt.toDate();
        penaltySince = penaltySince.toDate();
        await contest.edit(domainId, tid, {
            title, content, beginAt, endAt, pids, penaltySince, penaltyRules,
        }, document.TYPE_HOMEWORK);
        if (tdoc.beginAt !== beginAt
            || tdoc.endAt !== endAt
            || tdoc.penaltySince !== penaltySince
            || new Set(tdoc.pids) !== new Set(pids)) {
            await contest.recalcStatus(domainId, document.TYPE_HOMEWORK, tdoc.docId);
        }
        this.response.body = { tid };
        this.response.redirect = `/homework/${tid}`;
    }
}

class HomeworkScoreboardHandler extends HomeworkHandler {
    async get({ domainId, tid }) {
        const [tdoc, rows, udict] = await this.getScoreboard(
            domainId, tid, false, document.TYPE_HOMEWORK,
        );
        const path = [
            ['Hydro', 'homepage'],
            ['homework_main', 'homework_main'],
            [tdoc.title, 'homework_detail', { tid }, true],
            ['homework_scoreboard', null],
        ];
        this.response.template = 'contest_scoreboard.html';
        this.response.body = {
            tdoc, rows, path, udict,
        };
    }
}

class HomeworkScoreboardDownloadHandler extends HomeworkHandler {
    async get({ domainId, tid, ext }) {
        const getContent = {
            csv: async (rows) => `\uFEFF${rows.map((c) => (c.map((i) => i.value).join(','))).join('\n')}`,
            html: (rows) => this.renderHTML('contest_scoreboard_download_html.html', { rows }),
        };
        if (!getContent[ext]) throw new ValidationError('ext');
        const [, rows] = await this.getScoreboard(domainId, tid, true, document.TYPE_CONTEST);
        this.binary(await getContent[ext](rows), `${this.tdoc.title}.${ext}`);
    }
}

async function apply() {
    contest.isHomeworkExtended = (tdoc) => {
        const now = new Date().getTime();
        return tdoc.penaltySince.getTime() <= now && now < tdoc.endAt.getTime();
    };
    contest.RULES.homework = {
        TEXT: 'Assignment',
        check: () => { },
        stat: (tdoc, journal) => {
            const effective = {};
            for (const j of journal) {
                if (tdoc.pids.includes(j.pid)
                    && !effective.includes(j.pid)
                    && effective[j.pid].accept) {
                    effective[j.pid] = j;
                }
            }
            function time(jdoc) {
                const real = jdoc.rid.generationTime - tdoc.beginAt.getTime() / 1000;
                return Math.floor(real);
            }
            function penaltyScore(jdoc) {
                const { score } = jdoc;
                const exceedSeconds = Math.floor(
                    jdoc.rid.generationTime - tdoc.penaltySince.getTime() / 1000,
                );
                if (exceedSeconds < 0) return score;
                let coefficient = 1;
                const keys = Object.keys(tdoc.penaltyRules)
                    .map((k) => parseFloat(k)).sort((a, b) => a - b);
                for (const i of keys) {
                    if (i * 3600 <= exceedSeconds) coefficient = tdoc.penaltyRules[i];
                    else break;
                }
                return score * coefficient;
            }
            const detail = [];
            for (const j of effective) {
                detail.push({ ...j, penaltyScore: penaltyScore(j), time: time(j) });
            }
            return {
                score: Math.sum(detail.map((d) => d.score)),
                penaltyScore: Math.sum(detail.map((d) => d.penaltySince)),
                time: Math.sum(detail.map((d) => d.time)),
                detail,
            };
        },
        showScoreboard: () => true,
        showRecord: () => true,
        scoreboard(isExport, _, tdoc, rankedTsdocs, udict, pdict) {
            const columns = [
                { type: 'rank', value: _('Rank') },
                { type: 'user', value: _('User') },
                { type: 'total_score', value: _('Score') },
            ];
            if (isExport) {
                columns.push(
                    { type: 'total_original_score', value: _('Original Score') },
                    { type: 'total_time', value: _('Total Time (Seconds)') },
                );
            }
            columns.push({ type: 'total_time_str', value: _('Total Time') });
            for (const index in tdoc.pids) {
                const pid = tdoc.pids[index];
                if (isExport) {
                    columns.push(
                        {
                            type: 'problem_score',
                            value: '#{0} {1}'.format(index + 1, pdict[pid].title),
                        },
                        {
                            type: 'problem_original_score',
                            value: '#{0} {1}'.format(index + 1, _('Original Score')),
                        },
                        {
                            type: 'problem_time',
                            value: '#{0} {1}'.format(index + 1, _('Time (Seconds)')),
                        },
                        {
                            type: 'problem_time_str',
                            value: '#{0} {1}'.format(index + 1, _('Time')),
                        },
                    );
                } else {
                    columns.push({
                        type: 'problem_detail',
                        value: '#{0}'.format(index + 1),
                        raw: pdict[pid],
                    });
                }
            }
            const rows = [columns];
            for (const [rank, tsdoc] of rankedTsdocs) {
                const tsddict = {};
                for (const item of tsdoc.journal || []) {
                    tsddict[item.pid] = item;
                }
                const row = [
                    { type: 'string', value: rank },
                    {
                        type: 'user',
                        value: udict[tsdoc.uid].uname,
                        raw: udict[tsdoc.uid],
                    },
                    {
                        type: 'string',
                        value: tsdoc.penaltyScore || 0,
                    },
                ];
                if (isExport) {
                    row.push({ type: 'string', value: tsdoc.score || 0 });
                    row.push({ type: 'string', value: tsdoc.time || 0.0 });
                }
                row.push({ type: 'string', value: misc.formatSeconds(tsdoc.time || 0) });
                for (const pid of tdoc.pids) {
                    const rdoc = (tsddict[pid] || {}).rid;
                    const colScore = (tsddict[pid] || {}).penaltyScore || '-';
                    const colOriginalScore = (tsddict[pid] || {}).score || '-';
                    const colTime = (tsddict[pid] || {}).time || '-';
                    const colTimeStr = colTime !== '-' ? misc.formatSeconds(colTime || 0) : '-';
                    if (isExport) {
                        row.push(
                            { type: 'string', value: colScore },
                            { type: 'string', value: colOriginalScore },
                            { type: 'string', value: colTime },
                            { type: 'string', value: colTimeStr },
                        );
                    } else {
                        row.push({
                            type: 'record',
                            value: '{0} / {1}\n{2}'.format(colScore, colOriginalScore, colTimeStr),
                            raw: rdoc,
                        });
                    }
                }
                rows.push(row);
            }
            return rows;
        },
        rank: (tsdocs) => ranked(tsdocs, (a, b) => a.score === b.score),
    };
    Route('homework_main', '/homework', HomeworkMainHandler, PERM_VIEW_HOMEWORK);
    Route('homework_create', '/homework/create', HomeworkCreateHandler, PERM_CREATE_HOMEWORK);
    Route('homework_detail', '/homework/:tid', HomeworkDetailHandler, PERM_VIEW_HOMEWORK);
    Route('homework_scoreboard', '/homework/:tid/scoreboard', HomeworkScoreboardHandler, PERM_VIEW_HOMEWORK_SCOREBOARD);
    Route('homework_scoreboard', '/homework/:tid/scoreboard/download/:ext', HomeworkScoreboardDownloadHandler, PERM_VIEW_HOMEWORK_SCOREBOARD);
    Route('homework_detail_problem', '/homework/:tid/p/:pid', HomeworkDetailProblemHandler, PERM_VIEW_HOMEWORK);
    Route('homework_detail_problem_submit', '/homework/:tid/p/:pid/submit', HomeworkDetailProblemSubmitHandler, PERM_SUBMIT_PROBLEM);
    Route('homework_edit', '/homework/:tid/edit', HomeworkEditHandler);
}

global.Hydro.handler.homework = module.exports = apply;

/*
@app.route('/homework/{tid:\w{24}}/code', 'homework_code')
class HomeworkCodeHandler(base.OperationHandler):
  @base.limit_rate('homework_code', 3600, 60)
  @base.route_argument
  @base.require_perm(builtin.PERM_VIEW_HOMEWORK)
  @base.require_perm(builtin.PERM_READ_RECORD_CODE)
  @base.sanitize
  async def get(this, *, tid: objectid.ObjectId):
    tdoc, tsdocs = await contest.get_and_list_status(domainId, document.TYPE_HOMEWORK, tid)
    rnames = {}
    for tsdoc in tsdocs:
      for pdetail in tsdoc.get('detail', []):
        rnames[pdetail['rid']] = 'U{}_P{}_R{}'.format(tsdoc['uid'], pdetail['pid'], pdetail['rid'])
    output_buffer = io.BytesIO()
    zip_file = zipfile.ZipFile(output_buffer, 'a', zipfile.ZIP_DEFLATED)
    rdocs = record.get_multi(get_hidden=True, _id={'$in': list(rnames.keys())})
    async for rdoc in rdocs:
      zip_file.writestr(rnames[rdoc['_id']] + '.' + rdoc['lang'], rdoc['code'])
    # mark all files as created in Windows :p
    for zfile in zip_file.filelist:
      zfile.create_system = 0
    zip_file.close()

    await this.binary(output_buffer.getvalue(), 'application/zip',
                      file_name='{}.zip'.format(tdoc['title']))
*/