// ============================================
// Bewerbungs-Tracker - Client-side JavaScript
// ============================================

// DOM Elements
const body = document.getElementById('body');
const darkModeToggle = document.getElementById('darkModeToggle');
const sunIcon = document.getElementById('sunIcon');
const moonIcon = document.getElementById('moonIcon');

// Modal Elements
const settingsModal = document.getElementById('settingsModal');
const applicationModal = document.getElementById('applicationModal');
const deleteModal = document.getElementById('deleteModal');
const pdfExportModal = document.getElementById('pdfExportModal');

// Form Elements
const settingsForm = document.getElementById('settingsForm');
const applicationForm = document.getElementById('applicationForm');
const pdfExportForm = document.getElementById('pdfExportForm');
const filterForm = document.getElementById('filterForm');

// Button Elements
const settingsBtn = document.getElementById('settingsBtn');
const addApplicationBtn = document.getElementById('addApplicationBtn');
const exportPdfBtn = document.getElementById('exportPdfBtn');

// Close Modal Buttons
const closeSettingsModal = document.getElementById('closeSettingsModal');
const closeApplicationModal = document.getElementById('closeApplicationModal');
const closeDeleteModal = document.getElementById('closeDeleteModal');
const closePdfModal = document.getElementById('closePdfModal');

const cancelSettings = document.getElementById('cancelSettings');
const cancelApplication = document.getElementById('cancelApplication');
const cancelDelete = document.getElementById('cancelDelete');
const cancelPdfExport = document.getElementById('cancelPdfExport');
const confirmDelete = document.getElementById('confirmDelete');

// Global variables
let currentApplicationId = null;
let currentDeleteId = null;
let pdfLibrariesLoaded = false;

// ============================================
// Dark Mode
// ============================================

function initializeDarkMode() {
    // Check localStorage for dark mode preference
    const darkMode = localStorage.getItem('darkMode');
    
    if (darkMode === 'enabled' || (!darkMode && window.matchMedia('(prefers-color-scheme: dark)').matches)) {
        body.classList.add('dark');
        sunIcon.classList.add('hidden');
        moonIcon.classList.remove('hidden');
    } else {
        body.classList.remove('dark');
        sunIcon.classList.remove('hidden');
        moonIcon.classList.add('hidden');
    }
}

function toggleDarkMode() {
    body.classList.toggle('dark');
    sunIcon.classList.toggle('hidden');
    moonIcon.classList.toggle('hidden');
    
    // Save preference to localStorage
    if (body.classList.contains('dark')) {
        localStorage.setItem('darkMode', 'enabled');
    } else {
        localStorage.setItem('darkMode', 'disabled');
    }
}

// ============================================
// Modal Functions
// ============================================

function showModal(modal) {
    modal.classList.remove('hidden');
    body.style.overflow = 'hidden';
}

function hideModal(modal) {
    modal.classList.add('hidden');
    body.style.overflow = '';
}

function resetApplicationForm() {
    applicationForm.reset();
    document.getElementById('modalTitle').textContent = 'Bewerbung hinzufügen';
    currentApplicationId = null;
}

// ============================================
// Settings Management
// ============================================

function loadSettings() {
    fetch('/api/settings')
        .then(response => response.json())
        .then(settings => {
            if (settings) {
                document.getElementById('userName').value = settings.name || '';
                document.getElementById('userAddress').value = settings.adresse || '';
                document.getElementById('customerNumber').value = settings.kundennummer || '';
            }
        })
        .catch(error => console.error('Error loading settings:', error));
}

function saveSettings(event) {
    event.preventDefault();
    
    const formData = new FormData(settingsForm);
    const settings = {
        name: formData.get('name'),
        adresse: formData.get('adresse'),
        kundennummer: formData.get('kundennummer')
    };
    
    fetch('/api/settings', {
        method: 'POST',
        headers: {
            'Content-Type': 'application/json'
        },
        body: JSON.stringify(settings)
    })
    .then(response => response.json())
    .then(data => {
        if (data.success) {
            hideModal(settingsModal);
            // Refresh page to update settings in header
            location.reload();
        }
    })
    .catch(error => console.error('Error saving settings:', error));
}

// ============================================
// Application Management (CRUD)
// ============================================

function openAddApplicationModal() {
    resetApplicationForm();
    // Set default date to today
    const today = new Date().toISOString().split('T')[0];
    document.getElementById('applicationDatum').value = today;
    showModal(applicationModal);
}

function openEditApplicationModal(id) {
    // Fetch application data
    fetch(`/api/bewerbungen/${id}`)
        .then(response => response.json())
        .then(application => {
            currentApplicationId = application.id;
            document.getElementById('modalTitle').textContent = 'Bewerbung bearbeiten';
            document.getElementById('applicationId').value = application.id;
            document.getElementById('applicationDatum').value = application.datum;
            document.getElementById('applicationFirma').value = application.firma;
            document.getElementById('applicationStelle').value = application.stelle;
            document.getElementById('applicationArt').value = application.art || '';
            document.getElementById('applicationStatus').value = application.status || '';
            document.getElementById('applicationNotizen').value = application.notizen || '';
            showModal(applicationModal);
        })
        .catch(error => console.error('Error loading application:', error));
}

function saveApplication(event) {
    event.preventDefault();
    
    const formData = new FormData(applicationForm);
    const application = {
        datum: formData.get('datum'),
        firma: formData.get('firma'),
        stelle: formData.get('stelle'),
        art: formData.get('art'),
        status: formData.get('status'),
        notizen: formData.get('notizen'),
        interne_notizen: formData.get('interne_notizen'),
        kommentar: formData.get('kommentar')
    };
    
    let url = '/api/bewerbungen';
    let method = 'POST';
    
    if (currentApplicationId) {
        url = `/api/bewerbungen/${currentApplicationId}`;
        method = 'PUT';
    }
    
    fetch(url, {
        method: method,
        headers: {
            'Content-Type': 'application/json'
        },
        body: JSON.stringify(application)
    })
    .then(response => response.json())
    .then(data => {
        if (data.success) {
            hideModal(applicationModal);
            resetApplicationForm();
            // Refresh the page to show updated data
            location.reload();
        }
    })
    .catch(error => console.error('Error saving application:', error));
}

function openDeleteModal(id) {
    currentDeleteId = id;
    showModal(deleteModal);
}

function deleteApplication() {
    if (!currentDeleteId) return;
    
    fetch(`/api/bewerbungen/${currentDeleteId}`, {
        method: 'DELETE'
    })
    .then(response => response.json())
    .then(data => {
        if (data.success) {
            hideModal(deleteModal);
            currentDeleteId = null;
            // Refresh the page
            location.reload();
        }
    })
    .catch(error => console.error('Error deleting application:', error));
}

// ============================================
// PDF Export
// ============================================

function openPdfExportModal() {
    // Load PDF libraries if not already loaded
    loadPdfLibraries().then(() => {
        showModal(pdfExportModal);
    });
}

function generatePDF(event) {
    event.preventDefault();
    
    const month = document.getElementById('pdfMonth').value;
    const year = document.getElementById('pdfYear').value;
    
    // Fetch data for PDF
    let url = '/api/export?';
    const params = [];
    if (month) params.push(`month=${month}`);
    if (year) params.push(`year=${year}`);
    
    if (params.length > 0) {
        url += params.join('&') + '&';
    }
    
    Promise.all([
        fetch('/api/settings').then(res => res.json()),
        fetch(url).then(res => res.json())
    ])
    .then(([settings, applications]) => {
        generatePdfDocument(settings, applications, month, year);
        hideModal(pdfExportModal);
    })
    .catch(error => console.error('Error generating PDF:', error));
}

// PDF Generation with jsPDF
function generatePdfDocument(settings, applications, month, year) {
    // Check if jsPDF is loaded
    if (typeof jsPDF === 'undefined') {
        console.error('jsPDF not loaded, please wait for libraries to load');
        alert('Bitte warten Sie einen Moment und versuchen Sie es erneut.');
        return;
    }
    
    const doc = new jsPDF({
        orientation: 'portrait',
        unit: 'mm',
        format: 'a4'
    });
    
    const monthNames = ['Januar', 'Februar', 'März', 'April', 'Mai', 'Juni',
                       'Juli', 'August', 'September', 'Oktober', 'November', 'Dezember'];
    
    const monthName = month ? monthNames[parseInt(month) - 1] : 'alle';
    const title = `Bewerbungsaktivitäten - ${monthName} ${year || 'Jahre'}`;
    const dateStr = new Date().toLocaleDateString('de-DE');
    
    // Page geometry
    const pageWidth = doc.internal.pageSize.getWidth();    // 210 mm
    const pageHeight = doc.internal.pageSize.getHeight();   // 297 mm
    const margin = 15;
    const contentWidth = pageWidth - margin * 2;            // 180 mm
    const bottomLimit = pageHeight - margin;

    let yPos = 20;

    // Start a new page if the next block would not fit
    function ensureSpace(needed) {
        if (yPos + needed > bottomLimit) {
            doc.addPage();
            yPos = margin;
        }
    }

    // Header with user data
    doc.setFont('helvetica', 'bold');
    doc.setFontSize(16);
    doc.text(title, pageWidth / 2, yPos, { align: 'center' });
    yPos += 12;

    // User information
    doc.setFontSize(12);
    doc.setFont('helvetica', 'normal');
    if (settings && settings.name) {
        doc.text(`Name: ${settings.name}`, margin, yPos);
        yPos += 7;
    }
    if (settings && settings.adresse) {
        doc.text(`Adresse: ${settings.adresse}`, margin, yPos);
        yPos += 7;
    }
    if (settings && settings.kundennummer) {
        doc.text(`Kundennummer: ${settings.kundennummer}`, margin, yPos);
        yPos += 7;
    }

    yPos += 5;

    // Summary text
    const totalApplications = applications.length;
    const summaryText = year
        ? `Im Monat ${monthName} ${year} habe ich mich insgesamt auf ${totalApplications} Stellen beworben.`
        : `Insgesamt habe ich mich auf ${totalApplications} Stellen beworben.`;

    doc.setFont('helvetica', 'bold');
    doc.text(summaryText, pageWidth / 2, yPos, { align: 'center' });

    yPos += 12;

    // Group entries by status (keep this order in sync with views/index.ejs)
    const statusOrder = ['Gesendet', 'Eingangsbestätigung', 'Vorstellungsgespräch',
                         'Einstellung', 'Absage', 'Keine Rückmeldung'];
    const groups = {};
    applications.forEach((app) => {
        const key = (app.status && app.status.trim()) ? app.status.trim() : 'Ohne Status';
        (groups[key] = groups[key] || []).push(app);
    });
    const orderedKeys = [
        ...statusOrder.filter((s) => groups[s]),
        ...Object.keys(groups).filter((k) => !statusOrder.includes(k))
    ];

    // One block per application — no table, so the note (which documents the
    // full Verlauf) gets the entire page width and is shown completely.
    orderedKeys.forEach((statusKey) => {
        const group = groups[statusKey];

        // Status group heading (dark bar), kept together with its first entry
        ensureSpace(40);
        doc.setFillColor(55, 65, 81);
        doc.rect(margin, yPos, contentWidth, 10, 'F');
        doc.setFont('helvetica', 'bold');
        doc.setFontSize(12);
        doc.setTextColor(255, 255, 255);
        doc.text(`${statusKey}  (${group.length})`, margin + 3, yPos + 6.8);
        yPos += 14;
        doc.setTextColor(0, 0, 0);

        group.forEach((app) => {
            const datum = new Date(app.datum).toLocaleDateString('de-DE');
            const firma = app.firma || '—';
            const stelle = app.stelle || '—';
            const art = app.art || '—';
            const notizen = (app.notizen || '').trim();

            // Keep the heading together with the start of its content
            ensureSpace(28);

            // Heading bar: Firma – Stelle (left), Datum (right)
            doc.setFillColor(225, 232, 240);
            doc.rect(margin, yPos, contentWidth, 9, 'F');
            doc.setFont('helvetica', 'bold');
            doc.setFontSize(11);
            doc.setTextColor(20, 20, 20);
            const heading = doc.splitTextToSize(`${firma}  –  ${stelle}`, contentWidth - 40)[0];
            doc.text(heading, margin + 2, yPos + 6);
            doc.text(datum, pageWidth - margin - 2, yPos + 6, { align: 'right' });
            yPos += 9;

            // Meta line: Art
            doc.setFont('helvetica', 'normal');
            doc.setFontSize(9);
            doc.setTextColor(90, 90, 90);
            doc.text(`Art: ${art}`, margin + 2, yPos + 5);
            yPos += 9;

            // Status-Verlauf timeline (chronological status changes with comments)
            const verlauf = Array.isArray(app.verlauf) ? app.verlauf : [];
            if (verlauf.length) {
                doc.setFont('helvetica', 'bold');
                doc.setFontSize(10);
                doc.setTextColor(20, 20, 20);
                ensureSpace(6);
                doc.text('Status-Verlauf:', margin + 2, yPos + 4);
                yPos += 6;

                doc.setFontSize(9);
                verlauf.forEach((v) => {
                    const vDatum = new Date(v.datum).toLocaleDateString('de-DE');
                    doc.setFont('helvetica', 'bold');
                    doc.setTextColor(50, 50, 50);
                    ensureSpace(5);
                    doc.text(`${vDatum}  —  ${v.status || ''}`, margin + 5, yPos + 4);
                    yPos += 5;

                    const kommentar = (v.kommentar || '').trim();
                    if (kommentar) {
                        doc.setFont('helvetica', 'normal');
                        doc.setTextColor(0, 0, 0);
                        kommentar.split(/\r?\n/).forEach((paragraph) => {
                            const lines = doc.splitTextToSize(paragraph.length ? paragraph : ' ', contentWidth - 12);
                            lines.forEach((line) => {
                                ensureSpace(4.5);
                                doc.text(line, margin + 9, yPos + 3.5);
                                yPos += 4.5;
                            });
                        });
                    }
                });
                yPos += 3;
            }

            // Notizen label
            doc.setFont('helvetica', 'bold');
            doc.setFontSize(10);
            doc.setTextColor(20, 20, 20);
            doc.text('Notizen:', margin + 2, yPos + 4);
            yPos += 6;

            // Notizen body — full width, complete, with page breaks line by line
            doc.setFont('helvetica', 'normal');
            doc.setFontSize(10);
            doc.setTextColor(0, 0, 0);
            const lineHeight = 5;
            const noteText = notizen || '(keine Notizen)';
            noteText.split(/\r?\n/).forEach((paragraph) => {
                const lines = doc.splitTextToSize(paragraph.length ? paragraph : ' ', contentWidth - 4);
                lines.forEach((line) => {
                    ensureSpace(lineHeight);
                    doc.text(line, margin + 2, yPos + 4);
                    yPos += lineHeight;
                });
            });

            // Separator before the next entry
            yPos += 4;
            ensureSpace(6);
            doc.setDrawColor(210, 210, 210);
            doc.line(margin, yPos, pageWidth - margin, yPos);
            yPos += 8;
        });

        // Extra spacing after a status group
        yPos += 4;
    });

    // Footer with confirmation
    ensureSpace(20);
    yPos += 6;
    doc.setFont('helvetica', 'italic');
    doc.setFontSize(10);
    doc.setTextColor(0, 0, 0);
    doc.text('Ich versichere, dass die oben genannten Angaben der Wahrheit entsprechen.', pageWidth / 2, yPos, { align: 'center' });
    yPos += 7;
    doc.text(`Datum: ${dateStr}`, pageWidth / 2, yPos, { align: 'center' });
    
    // Save the PDF
    const fileName = `Bewerbungsaktivitaeten_${monthName}_${year || 'alle'}.pdf`;
    doc.save(fileName);
}

// Load PDF libraries dynamically
function loadPdfLibraries() {
    return new Promise((resolve) => {
        if (pdfLibrariesLoaded) {
            resolve();
            return;
        }
        
        // Check if already loading
        if (document.getElementById('jspdf-script')) {
            const checkLoaded = setInterval(() => {
                if (typeof jsPDF !== 'undefined') {
                    clearInterval(checkLoaded);
                    pdfLibrariesLoaded = true;
                    resolve();
                }
            }, 100);
            return;
        }
        
        // Load jsPDF from CDN
        const script1 = document.createElement('script');
        script1.id = 'jspdf-script';
        script1.src = 'https://cdnjs.cloudflare.com/ajax/libs/jspdf/2.5.1/jspdf.umd.min.js';
        script1.onload = () => {
            const script2 = document.createElement('script');
            script2.src = 'https://cdnjs.cloudflare.com/ajax/libs/jspdf-autotable/3.8.2/jspdf.plugin.autotable.min.js';
            script2.onload = () => {
                pdfLibrariesLoaded = true;
                resolve();
            };
            document.head.appendChild(script2);
        };
        document.head.appendChild(script1);
    });
}

// ============================================
// Event Listeners
// ============================================

// Dark Mode Toggle
darkModeToggle.addEventListener('click', toggleDarkMode);

// Settings Modal
settingsBtn.addEventListener('click', () => {
    loadSettings();
    showModal(settingsModal);
});
closeSettingsModal.addEventListener('click', () => hideModal(settingsModal));
cancelSettings.addEventListener('click', () => hideModal(settingsModal));
settingsForm.addEventListener('submit', saveSettings);

// Application Modal
addApplicationBtn.addEventListener('click', openAddApplicationModal);
closeApplicationModal.addEventListener('click', () => {
    hideModal(applicationModal);
    resetApplicationForm();
});
cancelApplication.addEventListener('click', () => {
    hideModal(applicationModal);
    resetApplicationForm();
});
applicationForm.addEventListener('submit', saveApplication);

// Delete Modal
closeDeleteModal.addEventListener('click', () => hideModal(deleteModal));
cancelDelete.addEventListener('click', () => hideModal(deleteModal));
confirmDelete.addEventListener('click', deleteApplication);

// PDF Export Modal
exportPdfBtn.addEventListener('click', openPdfExportModal);
closePdfModal.addEventListener('click', () => hideModal(pdfExportModal));
cancelPdfExport.addEventListener('click', () => hideModal(pdfExportModal));
pdfExportForm.addEventListener('submit', generatePDF);

// Filter Form
document.getElementById('filterForm').addEventListener('submit', function(e) {
    e.preventDefault();
    const month = document.getElementById('filterMonth').value;
    const year = document.getElementById('filterYear').value;
    let url = '/';
    if (month || year) {
        url += '?';
        if (month) url += `month=${month}&`;
        if (year) url += `year=${year}&`;
    }
    window.location.href = url;
});

// Delete buttons (event delegation). Editing opens its own page (/bewerbung/:id).
document.addEventListener('click', (e) => {
    if (e.target.closest('.delete-btn')) {
        const id = e.target.closest('.delete-btn').dataset.id;
        openDeleteModal(id);
    }
});

// Close modals when clicking outside
document.addEventListener('click', (e) => {
    if (e.target === settingsModal) hideModal(settingsModal);
    if (e.target === applicationModal) {
        hideModal(applicationModal);
        resetApplicationForm();
    }
    if (e.target === deleteModal) hideModal(deleteModal);
    if (e.target === pdfExportModal) hideModal(pdfExportModal);
});

// Close modals with Escape key
document.addEventListener('keydown', (e) => {
    if (e.key === 'Escape') {
        if (!settingsModal.classList.contains('hidden')) hideModal(settingsModal);
        if (!applicationModal.classList.contains('hidden')) {
            hideModal(applicationModal);
            resetApplicationForm();
        }
        if (!deleteModal.classList.contains('hidden')) hideModal(deleteModal);
        if (!pdfExportModal.classList.contains('hidden')) hideModal(pdfExportModal);
    }
});

// Set current year in footer
document.getElementById('currentYear').textContent = new Date().getFullYear();

// ============================================
// Initialize
// ============================================

// Initialize dark mode
initializeDarkMode();

console.log('Bewerbungs-Tracker initialized');