import { apiGet } from '../api.js';
import { showToast } from '../app.js';

let sortCol = null;
let sortDir = 'asc';
let allClients = [];
let questionsDef = [];
let questionnaireMeta = null;
let filterCoach = '';
let filterStatus = '';

export async function resultsPage(params) {
    const app = document.getElementById('app');
    sortCol = null;
    sortDir = 'asc';
    filterCoach = '';
    filterStatus = '';

    app.innerHTML = `
        <div class="page-header">
            <h1 id="resultsTitle">Results</h1>
            <div class="actions">
                <a href="#/questionnaire/${params.id}" class="btn">&larr; Back to Editor</a>
                <a href="#/" class="btn">Dashboard</a>
            </div>
        </div>
        <div id="resultsContent"><div class="spinner"></div></div>
    `;

    try {
        const data = await apiGet(`results.php?questionnaireID=${encodeURIComponent(params.id)}`);
        questionnaireMeta = data.questionnaire;
        questionsDef = data.questions || [];
        allClients = data.clients || [];
        document.getElementById('resultsTitle').textContent = `Results: ${questionnaireMeta.name} v${questionnaireMeta.version}`;
        renderResults();
    } catch (e) {
        showToast(e.message, 'error');
        document.getElementById('resultsContent').innerHTML = `<p class="error-text">${esc(e.message)}</p>`;
    }
}

function renderResults() {
    const container = document.getElementById('resultsContent');

    // Collect unique coaches and statuses for filters
    const coaches = [...new Set(allClients.map(c => c.coachID))].sort();
    const statuses = [...new Set(allClients.map(c => c.status))].filter(Boolean).sort();

    container.innerHTML = `
        <div class="card" style="margin-bottom:16px">
            <div class="filter-bar">
                <label style="font-size:.85rem;font-weight:500">Filter:</label>
                <select id="filterCoach">
                    <option value="">All coaches</option>
                    ${coaches.map(c => `<option value="${esc(c)}" ${filterCoach === c ? 'selected' : ''}>${esc(c)}</option>`).join('')}
                </select>
                <select id="filterStatus">
                    <option value="">All statuses</option>
                    ${statuses.map(s => `<option value="${esc(s)}" ${filterStatus === s ? 'selected' : ''}>${esc(s)}</option>`).join('')}
                </select>
                <span style="margin-left:auto;font-size:.85rem;color:var(--text-secondary)" id="resultCount"></span>
                <a id="exportCsvLink" class="btn btn-sm" href="#">Export CSV</a>
            </div>
        </div>
        <div class="card">
            <div class="table-wrapper">
                <table class="data-table" id="resultsTable">
                    <thead><tr id="resultsHead"></tr></thead>
                    <tbody id="resultsBody"></tbody>
                </table>
            </div>
        </div>
    `;

    document.getElementById('filterCoach').addEventListener('change', (e) => {
        filterCoach = e.target.value;
        renderTableRows();
    });
    document.getElementById('filterStatus').addEventListener('change', (e) => {
        filterStatus = e.target.value;
        renderTableRows();
    });
    document.getElementById('exportCsvLink').addEventListener('click', (e) => {
        e.preventDefault();
        exportCSV();
    });

    renderTableHead();
    renderTableRows();
}

function renderTableHead() {
    const head = document.getElementById('resultsHead');
    const fixedCols = [
        { key: 'clientCode', label: 'Client' },
        { key: 'coachID', label: 'Coach' },
        { key: 'status', label: 'Status' },
        { key: 'sumPoints', label: 'Score' },
        { key: 'completedAt', label: 'Completed' },
    ];
    const questionCols = questionsDef.map(q => ({
        key: `q_${q.questionID}`,
        label: q.defaultText,
        questionID: q.questionID,
    }));
    const allCols = [...fixedCols, ...questionCols];

    head.innerHTML = allCols.map(col => {
        let cls = 'sortable';
        if (sortCol === col.key) cls += sortDir === 'asc' ? ' sort-asc' : ' sort-desc';
        return `<th class="${cls}" data-key="${col.key}" title="${esc(col.label)}">${esc(col.label)}</th>`;
    }).join('');

    head.querySelectorAll('th.sortable').forEach(th => {
        th.addEventListener('click', () => {
            const key = th.dataset.key;
            if (sortCol === key) sortDir = sortDir === 'asc' ? 'desc' : 'asc';
            else { sortCol = key; sortDir = 'asc'; }
            renderTableHead();
            renderTableRows();
        });
    });
}

function getFilteredClients() {
    let clients = allClients;
    if (filterCoach) clients = clients.filter(c => c.coachID === filterCoach);
    if (filterStatus) clients = clients.filter(c => c.status === filterStatus);
    return clients;
}

function renderTableRows() {
    const body = document.getElementById('resultsBody');
    let clients = getFilteredClients();

    // Sort
    if (sortCol) {
        clients = [...clients].sort((a, b) => {
            let va = getCellValue(a, sortCol);
            let vb = getCellValue(b, sortCol);
            if (va == null) va = '';
            if (vb == null) vb = '';
            if (typeof va === 'number' && typeof vb === 'number') {
                return sortDir === 'asc' ? va - vb : vb - va;
            }
            const cmp = String(va).localeCompare(String(vb), undefined, { numeric: true });
            return sortDir === 'asc' ? cmp : -cmp;
        });
    }

    document.getElementById('resultCount').textContent = `${clients.length} client${clients.length === 1 ? '' : 's'}`;

    if (!clients.length) {
        body.innerHTML = `<tr><td colspan="99" style="text-align:center;color:var(--text-secondary);padding:30px">No results found</td></tr>`;
        return;
    }

    // Build option text lookup
    const optionMap = {};
    questionsDef.forEach(q => {
        (q.answerOptions || []).forEach(o => {
            optionMap[o.answerOptionID] = o.defaultText;
        });
    });

    body.innerHTML = clients.map(c => {
        const completedDate = c.completedAt ? new Date(c.completedAt * 1000).toLocaleDateString() : '—';
        const statusBadge = c.status ? `<span class="badge badge-${c.status.toLowerCase().replace(/\s+/g,'_')}">${esc(c.status)}</span>` : '—';

        const questionCells = questionsDef.map(q => {
            const ans = c.answers && c.answers[q.questionID];
            if (!ans) return '<td>—</td>';
            if (ans.answerOptionID && optionMap[ans.answerOptionID]) {
                return `<td>${esc(optionMap[ans.answerOptionID])}</td>`;
            }
            if (ans.freeTextValue) return `<td>${esc(ans.freeTextValue)}</td>`;
            if (ans.numericValue !== null && ans.numericValue !== undefined) return `<td>${ans.numericValue}</td>`;
            return '<td>—</td>';
        }).join('');

        return `<tr>
            <td>${esc(c.clientCode)}</td>
            <td>${esc(c.coachID)}</td>
            <td>${statusBadge}</td>
            <td>${c.sumPoints !== null ? c.sumPoints : '—'}</td>
            <td>${completedDate}</td>
            ${questionCells}
        </tr>`;
    }).join('');
}

function getCellValue(client, key) {
    if (key === 'clientCode') return client.clientCode;
    if (key === 'coachID') return client.coachID;
    if (key === 'status') return client.status;
    if (key === 'sumPoints') return client.sumPoints;
    if (key === 'completedAt') return client.completedAt;
    if (key.startsWith('q_')) {
        const qid = key.substring(2);
        const ans = client.answers && client.answers[qid];
        if (!ans) return null;
        if (ans.numericValue !== null && ans.numericValue !== undefined) return ans.numericValue;
        if (ans.freeTextValue) return ans.freeTextValue;
        return ans.answerOptionID || null;
    }
    return null;
}

function exportCSV() {
    const clients = getFilteredClients();
    const optionMap = {};
    questionsDef.forEach(q => {
        (q.answerOptions || []).forEach(o => {
            optionMap[o.answerOptionID] = o.defaultText;
        });
    });

    const headers = ['clientCode', 'coachID', 'status', 'sumPoints', 'completedAt',
        ...questionsDef.map(q => q.defaultText)];

    const rows = clients.map(c => {
        const base = [
            c.clientCode, c.coachID, c.status, c.sumPoints ?? '',
            c.completedAt ? new Date(c.completedAt * 1000).toISOString() : ''
        ];
        const answerCols = questionsDef.map(q => {
            const ans = c.answers && c.answers[q.questionID];
            if (!ans) return '';
            if (ans.answerOptionID && optionMap[ans.answerOptionID]) return optionMap[ans.answerOptionID];
            if (ans.freeTextValue) return ans.freeTextValue;
            if (ans.numericValue !== null && ans.numericValue !== undefined) return ans.numericValue;
            return '';
        });
        return [...base, ...answerCols];
    });

    let csv = '\uFEFF'; // BOM
    csv += headers.map(csvEsc).join(',') + '\n';
    rows.forEach(r => { csv += r.map(csvEsc).join(',') + '\n'; });

    const blob = new Blob([csv], { type: 'text/csv;charset=utf-8' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = `${questionnaireMeta.name}_v${questionnaireMeta.version}_results.csv`;
    a.click();
    URL.revokeObjectURL(url);
    showToast('CSV exported', 'success');
}

function csvEsc(val) {
    const s = String(val ?? '');
    if (s.includes(',') || s.includes('"') || s.includes('\n')) {
        return '"' + s.replace(/"/g, '""') + '"';
    }
    return s;
}

function esc(s) {
    const d = document.createElement('div');
    d.textContent = s ?? '';
    return d.innerHTML;
}