/**
 * Main application logic for Scenar Creator SPA.
 */

window.currentDocument = null;
let typeCounter = 1;
let scheduleCounter = 1;

/* --- Tab switching --- */
function switchTab(event, tabId) {
    document.querySelectorAll('.tab').forEach(t => t.classList.remove('active'));
    document.querySelectorAll('.tab-content').forEach(c => c.classList.remove('active'));
    event.target.classList.add('active');
    document.getElementById(tabId).classList.add('active');
}

/* --- Status messages --- */
function showStatus(message, type) {
    const el = document.getElementById('statusMessage');
    el.textContent = message;
    el.className = 'status-message ' + type;
    el.style.display = 'block';
    setTimeout(() => { el.style.display = 'none'; }, 5000);
}

/* --- Type management --- */
function addTypeRow() {
    const container = document.getElementById('typesContainer');
    const idx = typeCounter++;
    const div = document.createElement('div');
    div.className = 'type-row';
    div.setAttribute('data-index', idx);
    div.innerHTML = `
        <input type="text" name="type_name_${idx}" placeholder="Kód typu" class="type-code">
        <input type="text" name="type_desc_${idx}" placeholder="Popis">
        <input type="color" name="type_color_${idx}" value="#0070C0">
        <button type="button" class="btn btn-danger btn-sm" onclick="removeTypeRow(${idx})">X</button>
    `;
    container.appendChild(div);
    updateTypeDatalist();
}

function removeTypeRow(idx) {
    const row = document.querySelector(`.type-row[data-index="${idx}"]`);
    if (row) row.remove();
    updateTypeDatalist();
}

function updateTypeDatalist() {
    const datalist = document.getElementById('availableTypes');
    datalist.innerHTML = '';
    document.querySelectorAll('#typesContainer .type-row').forEach(row => {
        const nameInput = row.querySelector('input[name^="type_name_"]');
        if (nameInput && nameInput.value.trim()) {
            const opt = document.createElement('option');
            opt.value = nameInput.value.trim();
            datalist.appendChild(opt);
        }
    });
}

// Update datalist on type name changes
document.getElementById('typesContainer').addEventListener('input', function (e) {
    if (e.target.name && e.target.name.startsWith('type_name_')) {
        updateTypeDatalist();
    }
});

/* --- Schedule management --- */
function addScheduleRow() {
    const tbody = document.getElementById('scheduleBody');
    const idx = scheduleCounter++;
    const tr = document.createElement('tr');
    tr.setAttribute('data-index', idx);
    tr.innerHTML = `
        <td><input type="date" name="datum_${idx}" required></td>
        <td><input type="time" name="zacatek_${idx}" required></td>
        <td><input type="time" name="konec_${idx}" required></td>
        <td><input type="text" name="program_${idx}" required placeholder="Název bloku"></td>
        <td><input type="text" name="typ_${idx}" list="availableTypes" required placeholder="Typ"></td>
        <td><input type="text" name="garant_${idx}" placeholder="Garant"></td>
        <td><input type="text" name="poznamka_${idx}" placeholder="Poznámka"></td>
        <td><button type="button" class="btn btn-danger btn-sm" onclick="removeScheduleRow(${idx})">X</button></td>
    `;
    tbody.appendChild(tr);
}

function removeScheduleRow(idx) {
    const row = document.querySelector(`#scheduleBody tr[data-index="${idx}"]`);
    if (row) row.remove();
}

/* --- Build ScenarioDocument from builder form --- */
function buildDocumentFromForm() {
    const title = document.getElementById('builderTitle').value.trim();
    const detail = document.getElementById('builderDetail').value.trim();

    if (!title || !detail) {
        throw new Error('Název akce a detail jsou povinné');
    }

    // Collect types
    const programTypes = [];
    document.querySelectorAll('#typesContainer .type-row').forEach(row => {
        const code = row.querySelector('input[name^="type_name_"]').value.trim();
        const desc = row.querySelector('input[name^="type_desc_"]').value.trim();
        const color = row.querySelector('input[name^="type_color_"]').value;
        if (code) {
            programTypes.push({ code, description: desc, color });
        }
    });

    // Collect blocks
    const blocks = [];
    document.querySelectorAll('#scheduleBody tr').forEach(tr => {
        const inputs = tr.querySelectorAll('input');
        const datum = inputs[0].value;
        const zacatek = inputs[1].value;
        const konec = inputs[2].value;
        const program = inputs[3].value.trim();
        const typ = inputs[4].value.trim();
        const garant = inputs[5].value.trim() || null;
        const poznamka = inputs[6].value.trim() || null;

        if (datum && zacatek && konec && program && typ) {
            blocks.push({ datum, zacatek, konec, program, typ, garant, poznamka });
        }
    });

    if (blocks.length === 0) {
        throw new Error('Přidejte alespoň jeden blok');
    }

    return {
        version: "1.0",
        event: { title, detail },
        program_types: programTypes,
        blocks
    };
}

/* --- Handle builder form submit (Excel) --- */
async function handleBuild(event) {
    event.preventDefault();
    try {
        const doc = buildDocumentFromForm();
        const blob = await API.postBlob('/api/generate-excel', doc);
        API.downloadBlob(blob, 'scenar_timetable.xlsx');
        showStatus('Excel vygenerován', 'success');
    } catch (err) {
        showStatus('Chyba: ' + err.message, 'error');
    }
    return false;
}

/* --- Handle builder PDF --- */
async function handleBuildPdf() {
    try {
        const doc = buildDocumentFromForm();
        const blob = await API.postBlob('/api/generate-pdf', doc);
        API.downloadBlob(blob, 'scenar_timetable.pdf');
        showStatus('PDF vygenerován', 'success');
    } catch (err) {
        showStatus('Chyba: ' + err.message, 'error');
    }
}

/* --- Handle Excel import --- */
async function handleImport(event) {
    event.preventDefault();
    const form = document.getElementById('importForm');
    const formData = new FormData(form);

    try {
        const result = await API.postFormData('/api/import-excel', formData);
        if (result.success && result.document) {
            window.currentDocument = result.document;
            showImportedDocument(result.document);
            if (result.warnings && result.warnings.length > 0) {
                showStatus('Import OK, warnings: ' + result.warnings.join('; '), 'success');
            } else {
                showStatus('Excel importován', 'success');
            }
        } else {
            showStatus('Import failed: ' + (result.errors || []).join('; '), 'error');
        }
    } catch (err) {
        showStatus('Chyba importu: ' + err.message, 'error');
    }
    return false;
}

/* --- Show imported document in editor --- */
function showImportedDocument(doc) {
    const area = document.getElementById('editorArea');
    area.style.display = 'block';

    // Info
    document.getElementById('importedInfo').innerHTML =
        `<strong>${doc.event.title}</strong> — ${doc.event.detail}`;

    // Types
    const typesHtml = doc.program_types.map((pt, i) => `
        <div class="imported-type-row">
            <input type="text" value="${pt.code}" data-field="code" data-idx="${i}">
            <input type="text" value="${pt.description}" data-field="description" data-idx="${i}">
            <input type="color" value="${pt.color}" data-field="color" data-idx="${i}">
        </div>
    `).join('');
    document.getElementById('importedTypesContainer').innerHTML = typesHtml;

    // Blocks
    const blocksHtml = doc.blocks.map(b =>
        `<div class="block-item">${b.datum} ${b.zacatek}–${b.konec} | <strong>${b.program}</strong> [${b.typ}] ${b.garant || ''}</div>`
    ).join('');
    document.getElementById('importedBlocksContainer').innerHTML = blocksHtml;
}

/* --- Get current document (with any edits from import editor) --- */
function getCurrentDocument() {
    if (!window.currentDocument) {
        throw new Error('No document loaded');
    }
    // Update types from editor
    const typeRows = document.querySelectorAll('#importedTypesContainer .imported-type-row');
    if (typeRows.length > 0) {
        window.currentDocument.program_types = Array.from(typeRows).map(row => ({
            code: row.querySelector('[data-field="code"]').value.trim(),
            description: row.querySelector('[data-field="description"]').value.trim(),
            color: row.querySelector('[data-field="color"]').value,
        }));
    }
    return window.currentDocument;
}

/* --- Generate Excel from imported data --- */
async function generateExcelFromImport() {
    try {
        const doc = getCurrentDocument();
        const blob = await API.postBlob('/api/generate-excel', doc);
        API.downloadBlob(blob, 'scenar_timetable.xlsx');
        showStatus('Excel vygenerován', 'success');
    } catch (err) {
        showStatus('Chyba: ' + err.message, 'error');
    }
}

/* --- Generate PDF from imported data --- */
async function generatePdfFromImport() {
    try {
        const doc = getCurrentDocument();
        const blob = await API.postBlob('/api/generate-pdf', doc);
        API.downloadBlob(blob, 'scenar_timetable.pdf');
        showStatus('PDF vygenerován', 'success');
    } catch (err) {
        showStatus('Chyba: ' + err.message, 'error');
    }
}