const fs = require('fs');
const path = require('path');
const { JSDOM } = require('jsdom');
const { stringify } = require('csv-stringify/sync');

function parseArgs(argv) {
    const args = {
        input: './calendarData.html',
        format: 'json',
        out: ''
    };

    for (let i = 0; i < argv.length; i += 1) {
        const a = argv[i];
        if (a === '--in' && argv[i + 1]) {
            args.input = String(argv[i + 1]);
            i += 1;
            continue;
        }
        if (a === '--csv') {
            args.format = 'csv';
            continue;
        }
        if (a === '--html') {
            args.format = 'html';
            continue;
        }
        if (a === '--json') {
            args.format = 'json';
            continue;
        }
        if (a === '--out' && argv[i + 1]) {
            args.out = String(argv[i + 1]);
            i += 1;
            continue;
        }
        if (a === '--help' || a === '-h') {
            args.help = true;
        }
    }

    return args;
}

function printHelp() {
    console.log('設備予約HTML(calendarData.html)を解析して JSON/CSV を出力します');
    console.log('');
    console.log('使い方:');
    console.log('  node analyzeCalendar.js --json                 # JSON出力 (default)');
    console.log('  node analyzeCalendar.js --csv                  # CSV出力 (設備名,開始時間,終了時間,内容,登録者)');
    console.log('  node analyzeCalendar.js --html                 # HTML出力 (table)');
    console.log('  node analyzeCalendar.js --csv --out out.csv    # CSVをファイル保存');
    console.log('  node analyzeCalendar.js --html --out out.html  # HTMLをファイル保存');
    console.log('  node analyzeCalendar.js --in calendarData.html # 入力HTML指定');
}

function parseTimeRange(text) {
    const normalized = String(text || '').trim();
    const m = normalized.match(/(\d{1,2}:\d{2})\s*[~〜]\s*(\d{1,2}:\d{2})/);
    if (!m) {
        return { start: '', end: '' };
    }
    return { start: m[1], end: m[2] };
}

function toCsv(result) {
    const records = [];
    records.push(['設備名', '開始時間', '終了時間', '内容', '登録者']);

    for (const facilityName of Object.keys(result)) {
        const items = Array.isArray(result[facilityName]) ? result[facilityName] : [];
        for (const item of items) {
            const timeRange = item?.[0] || '';
            const content = item?.[1] || '';
            const registrant = item?.[2] || '';
            const { start, end } = parseTimeRange(timeRange);
            records.push([facilityName, start, end, content, registrant]);
        }
    }

    return stringify(records, { header: false });
}

function escapeHtml(text) {
    return String(text ?? '')
        .replace(/&/g, '&amp;')
        .replace(/</g, '&lt;')
        .replace(/>/g, '&gt;')
        .replace(/"/g, '&quot;')
        .replace(/'/g, '&#39;');
}

function timeToMinutes(hhmm) {
    const m = String(hhmm || '').trim().match(/^(\d{1,2}):(\d{2})$/);
    if (!m) return NaN;
    const h = Number(m[1]);
    const mm = Number(m[2]);
    if (h < 0 || h > 23 || mm < 0 || mm > 59) return NaN;
    return h * 60 + mm;
}

function buildTimeSlots(startHHMM, endHHMM, stepMinutes) {
    const start = timeToMinutes(startHHMM);
    const end = timeToMinutes(endHHMM);
    if (!Number.isFinite(start) || !Number.isFinite(end) || start >= end) {
        throw new Error(`時間枠の指定が不正です: ${startHHMM} - ${endHHMM}`);
    }
    const slots = [];
    for (let t = start; t < end; t += stepMinutes) {
        const h = Math.floor(t / 60);
        const m = t % 60;
        slots.push(`${String(h).padStart(2, '0')}:${String(m).padStart(2, '0')}`);
    }
    return { startMinutes: start, endMinutes: end, slots };
}

function toScheduleTableHtml(facilities, result, options) {
    const startHHMM = options?.startHHMM || '07:00';
    const endHHMM = options?.endHHMM || '21:00';
    const stepMinutes = options?.stepMinutes || 30;

    const { startMinutes, endMinutes, slots } = buildTimeSlots(startHHMM, endHHMM, stepMinutes);
    const slotCount = slots.length;

    const facilityList = Array.isArray(facilities) ? facilities : [];

    const rowsHtml = [];
    for (const facilityName of facilityList) {
        const items = Array.isArray(result[facilityName]) ? result[facilityName] : [];

        // startIndex -> { span, html }
        const cells = new Map();
        for (const item of items) {
            const timeRange = item?.[0] || '';
            const content = item?.[1] || '';
            const registrant = item?.[2] || '';
            const { start, end } = parseTimeRange(timeRange);

            const sMin = timeToMinutes(start);
            const eMin = timeToMinutes(end);
            if (!Number.isFinite(sMin) || !Number.isFinite(eMin) || sMin >= eMin) {
                continue;
            }

            const clippedStart = Math.max(sMin, startMinutes);
            const clippedEnd = Math.min(eMin, endMinutes);
            if (clippedStart >= clippedEnd) {
                continue;
            }

            const startIndex = Math.floor((clippedStart - startMinutes) / stepMinutes);
            const endIndex = Math.ceil((clippedEnd - startMinutes) / stepMinutes);
            const span = Math.max(1, Math.min(slotCount, endIndex) - Math.max(0, startIndex));

            const key = Math.max(0, startIndex);
            if (cells.has(key)) {
                // 予定が重複している場合は後勝ちにせず、先勝ちで維持
                continue;
            }

            const cellHtml = `${escapeHtml(content)}<br/>${escapeHtml(registrant)}`;
            cells.set(key, { span, html: cellHtml });
        }

        const tds = [];
        tds.push(`<th class="facility">${escapeHtml(facilityName)}</th>`);

        for (let i = 0; i < slotCount; i += 1) {
            const cell = cells.get(i);
            if (cell) {
                tds.push(`<td class="booked" colspan="${cell.span}">${cell.html}</td>`);
                i += (cell.span - 1);
                continue;
            }
            tds.push('<td class="empty"></td>');
        }

        rowsHtml.push(`<tr>${tds.join('')}</tr>`);
    }

    const headerCells = ['<th class="facility">設備名</th>', ...slots.map(s => `<th class="time">${escapeHtml(s)}</th>`)].join('');
    const tableHtml = `
<table class="schedule">
  <thead>
    <tr>${headerCells}</tr>
  </thead>
  <tbody>
    ${rowsHtml.join('\n    ')}
  </tbody>
</table>`;

    const title = options?.title || '設備予約';
    const style = `
  <style>
    body { font-family: system-ui, -apple-system, Segoe UI, sans-serif; margin: 16px; }
    h1 { font-size: 18px; margin: 0 0 12px; }
    .note { font-size: 12px; color: #444; margin: 0 0 12px; }
    table.schedule { border-collapse: collapse; width: 100%; table-layout: fixed; }
    table.schedule th, table.schedule td { border: 1px solid #ccc; padding: 4px; vertical-align: top; }
    table.schedule th.facility { position: sticky; left: 0; background: #f7f7f7; width: 220px; min-width: 220px; max-width: 220px; }
    table.schedule th.time { font-size: 11px; background: #fafafa; }
    table.schedule td.empty { background: #fff; }
    table.schedule td.booked { background: #e8f0ff; font-size: 12px; white-space: normal; word-break: break-word; }
  </style>`;

    return `<!doctype html>
<html lang="ja">
<head>
  <meta charset="utf-8" />
  <meta name="viewport" content="width=device-width, initial-scale=1" />
  <title>${escapeHtml(title)}</title>${style}
</head>
<body>
  <h1>${escapeHtml(title)}</h1>
  <p class="note">時間枠: ${escapeHtml(startHHMM)}〜${escapeHtml(endHHMM)}（${stepMinutes}分刻み）</p>
  ${tableHtml}
</body>
</html>`;
}

function analyzeHtmlToResult(htmlText) {
    const dom = new JSDOM(htmlText);
    const document = dom.window.document;

    // 1. 設備名をすべて取得
    const timeGridTitle = document.querySelector('.time_grid_title');
    const facilityElements = timeGridTitle.querySelectorAll('.resource_cover a.name');
    const facilities = Array.from(facilityElements).map(el => el.textContent.trim()).filter(Boolean);

    // 2. スケジュールデータを取得
    const timeGridBody = document.querySelector('.time_grid_body');
    const facilityGrids = Array.from(timeGridBody.querySelectorAll(':scope > .grid'));

    // 3. 設備ごとに配列に格納
    const result = {};
    facilities.forEach((facility) => {
        result[facility] = [];
    });

    function splitScheduleText(text) {
        // 例: "10:00~11:30, 打合せ, 伊藤理奈"
        // 件名にカンマが入っても壊れにくいように、最後を登録者として扱う
        const parts = String(text || '').split(/\s*,\s*/).filter(p => p.length > 0);
        if (parts.length === 0) {
            return { time: '', title: '', registrant: '' };
        }
        if (parts.length === 1) {
            return { time: parts[0], title: '', registrant: '' };
        }
        if (parts.length === 2) {
            return { time: parts[0], title: parts[1], registrant: '' };
        }
        const time = parts[0];
        const registrant = parts[parts.length - 1];
        const title = parts.slice(1, parts.length - 1).join(', ');
        return { time, title, registrant };
    }

    // データを設備ごとに抽出
    const count = Math.min(facilities.length, facilityGrids.length);
    for (let facilityIndex = 0; facilityIndex < count; facilityIndex += 1) {
        const facilityName = facilities[facilityIndex];
        const grid = facilityGrids[facilityIndex];

        const disabledMsgs = Array.from(grid.querySelectorAll('.schedule.disabled .msg'));
        let previousText = '';

        for (const msg of disabledMsgs) {
            const text = (msg.textContent || '').trim();
            if (!text) {
                previousText = '';
                continue;
            }

            // 同一予定が複数枠(30分単位など)にまたがる場合、同じ文言が連続するので除外
            if (text === previousText) {
                continue;
            }
            previousText = text;

            const { time, title, registrant } = splitScheduleText(text);
            result[facilityName].push([time || '', title || '', registrant || '']);
        }
    }

    return { facilities, result };
}

function main() {
    const args = parseArgs(process.argv.slice(2));
    if (args.help) {
        printHelp();
        return;
    }

    const inputPath = path.resolve(args.input);
    const html = fs.readFileSync(inputPath, 'utf-8');
    const analyzed = analyzeHtmlToResult(html);
    const facilities = analyzed.facilities;
    const result = analyzed.result;

    if (args.format === 'csv') {
        const csv = toCsv(result);
        if (args.out) {
            const outPath = path.resolve(args.out);
            fs.writeFileSync(outPath, csv, 'utf-8');
        } else {
            process.stdout.write(csv);
        }
    } else if (args.format === 'html') {
        const outPath = path.resolve(args.out || './schedule_table.html');
        const htmlOut = toScheduleTableHtml(facilities, result, { title: '設備予約' });
        fs.writeFileSync(outPath, htmlOut, 'utf-8');
        console.log(`saved: ${outPath}`);
    } else {
        console.log(JSON.stringify(result, null, 2));
    }

    module.exports = result;
}

main();