// Global State
let currentDate = new Date();
let currentFilter = 'all';
let isSidebarCollapsed = false;

// Sample Appointment Data
const appointments = [
    { id: 1, patient: "John Smith", time: "09:00 AM", type: "general", color: "bg-blue-500", date: 15 },
    { id: 2, patient: "Emma Wilson", time: "10:30 AM", type: "emergency", color: "bg-red-500", date: 15 },
    { id: 3, patient: "Michael Brown", time: "02:00 PM", type: "followup", color: "bg-green-500", date: 15 },
    { id: 4, patient: "Sarah Davis", time: "11:00 AM", type: "consultation", color: "bg-yellow-500", date: 16 },
    { id: 5, patient: "James Miller", time: "03:30 PM", type: "general", color: "bg-blue-500", date: 16 },
    { id: 6, patient: "Linda Garcia", time: "09:30 AM", type: "emergency", color: "bg-red-500", date: 17 },
    { id: 7, patient: "Robert Taylor", time: "01:00 PM", type: "followup", color: "bg-green-500", date: 18 },
    { id: 8, patient: "Patricia Martinez", time: "10:00 AM", type: "general", color: "bg-blue-500", date: 19 },
    { id: 9, patient: "William Anderson", time: "04:00 PM", type: "consultation", color: "bg-yellow-500", date: 20 },
    { id: 10, patient: "Elizabeth Thomas", time: "11:30 AM", type: "followup", color: "bg-green-500", date: 21 },
    { id: 11, patient: "David Jackson", time: "02:30 PM", type: "general", color: "bg-blue-500", date: 22 },
    { id: 12, patient: "Jennifer White", time: "09:00 AM", type: "emergency", color: "bg-red-500", date: 23 }
];

// Initialize
document.addEventListener('DOMContentLoaded', () => {
    renderCalendar();
    updateCurrentDate();
    
    // Check window size for responsive sidebar
    window.addEventListener('resize', handleResize);
    handleResize();
});

// Sidebar Toggle
function toggleSidebar() {
    const sidebar = document.getElementById('sidebar');
    const mobileOverlay = document.getElementById('mobileOverlay');
    const sidebarTexts = document.querySelectorAll('.sidebar-text');
    
    if (window.innerWidth >= 1024) {
        // Desktop behavior
        isSidebarCollapsed = !isSidebarCollapsed;
        
        if (isSidebarCollapsed) {
            sidebar.classList.remove('w-64');
            sidebar.classList.add('w-20');
            sidebarTexts.forEach(text => {
                text.style.opacity = '0';
                text.style.width = '0';
                text.style.overflow = 'hidden';
            });
        } else {
            sidebar.classList.remove('w-20');
            sidebar.classList.add('w-64');
            sidebarTexts.forEach(text => {
                text.style.opacity = '1';
                text.style.width = 'auto';
                text.style.overflow = 'visible';
            });
        }
    } else {
        // Mobile behavior
        if (sidebar.classList.contains('-translate-x-full')) {
            sidebar.classList.remove('-translate-x-full');
            mobileOverlay.classList.remove('hidden');
        } else {
            sidebar.classList.add('-translate-x-full');
            mobileOverlay.classList.add('hidden');
        }
    }
}

function handleResize() {
    const sidebar = document.getElementById('sidebar');
    const mobileOverlay = document.getElementById('mobileOverlay');
    
    if (window.innerWidth >= 1024) {
        mobileOverlay.classList.add('hidden');
        if (!isSidebarCollapsed) {
            sidebar.classList.remove('-translate-x-full');
            sidebar.classList.add('w-64');
            sidebar.classList.remove('w-20');
        }
    } else {
        sidebar.classList.add('-translate-x-full');
        sidebar.classList.remove('w-20');
        sidebar.classList.add('w-64');
    }
}

// Calendar Functions
function renderCalendar() {
    const year = currentDate.getFullYear();
    const month = currentDate.getMonth();
    
    // Update header
    const monthNames = ["January", "February", "March", "April", "May", "June",
        "July", "August", "September", "October", "November", "December"
    ];
    document.getElementById('calendarMonth').textContent = `${monthNames[month]} ${year}`;
    
    const firstDay = new Date(year, month, 1).getDay();
    const daysInMonth = new Date(year, month + 1, 0).getDate();
    const daysInPrevMonth = new Date(year, month, 0).getDate();
    
    const grid = document.getElementById('calendarGrid');
    grid.innerHTML = '';
    
    // Previous month days
    for (let i = firstDay - 1; i >= 0; i--) {
        const dayDiv = document.createElement('div');
        dayDiv.className = 'calendar-day bg-gray-50 p-2 border-b border-r border-gray-200 min-h-[120px] text-gray-400';
        dayDiv.innerHTML = `<span class="text-sm font-medium">${daysInPrevMonth - i}</span>`;
        grid.appendChild(dayDiv);
    }
    
    // Current month days
    const today = new Date();
    for (let day = 1; day <= daysInMonth; day++) {
        const dayDiv = document.createElement('div');
        const isToday = today.getDate() === day && today.getMonth() === month && today.getFullYear() === year;
        
        dayDiv.className = `calendar-day bg-white p-2 border-b border-r border-gray-200 min-h-[120px] hover:bg-gray-50 transition-colors cursor-pointer ${isToday ? 'bg-blue-50/30' : ''}`;
        
        let dayContent = `<div class="flex justify-between items-start mb-1">
            <span class="text-sm font-semibold ${isToday ? 'bg-blue-600 text-white w-7 h-7 flex items-center justify-center rounded-full' : 'text-gray-700'}">${day}</span>
        </div>`;
        
        // Add appointments for this day
        const dayAppointments = appointments.filter(apt => apt.date === day);
        if (currentFilter !== 'all') {
            const filteredApts = dayAppointments.filter(apt => apt.type === currentFilter);
            dayContent += generateAppointmentHTML(filteredApts);
        } else {
            dayContent += generateAppointmentHTML(dayAppointments);
        }
        
        dayDiv.innerHTML = dayContent;
        dayDiv.onclick = () => openAddAppointment(day);
        grid.appendChild(dayDiv);
    }
    
    // Next month days to fill grid
    const remainingCells = 42 - (firstDay + daysInMonth);
    for (let i = 1; i <= remainingCells; i++) {
        const dayDiv = document.createElement('div');
        dayDiv.className = 'calendar-day bg-gray-50 p-2 border-b border-r border-gray-200 min-h-[120px] text-gray-400';
        dayDiv.innerHTML = `<span class="text-sm font-medium">${i}</span>`;
        grid.appendChild(dayDiv);
    }
}

function generateAppointmentHTML(appointments) {
    if (appointments.length === 0) return '';
    
    let html = '<div class="space-y-1 mt-1">';
    appointments.slice(0, 3).forEach(apt => {
        html += `
            <div class="${apt.color} bg-opacity-10 border-l-2 ${apt.color.replace('bg-', 'border-')} px-2 py-1 rounded text-xs cursor-pointer hover:opacity-80 transition-opacity">
                <p class="font-semibold text-gray-900 truncate">${apt.time}</p>
                <p class="text-gray-600 truncate">${apt.patient}</p>
            </div>
        `;
    });
    
    if (appointments.length > 3) {
        html += `<div class="text-xs text-gray-500 text-center mt-1">+${appointments.length - 3} more</div>`;
    }
    
    html += '</div>';
    return html;
}

function changeMonth(direction) {
    currentDate.setMonth(currentDate.getMonth() + direction);
    renderCalendar();
}

function goToToday() {
    currentDate = new Date();
    renderCalendar();
}

function changeDateRange(value) {
    if (value === 'today') {
        // Filter to show only today's appointments in a list view (simplified for demo)
        alert('Switched to Today view - showing today\'s schedule');
    } else if (value === 'week') {
        alert('Switched to Week view - showing weekly schedule');
    }
    // Month view is default
}

// Category Filter
function filterCategory(category) {
    currentFilter = category;
    
    // Update UI
    document.querySelectorAll('.category-btn').forEach(btn => {
        if (btn.dataset.category === category) {
            btn.classList.remove('bg-white', 'text-gray-700', 'border', 'border-gray-200');
            btn.classList.add('bg-gray-900', 'text-white');
            btn.querySelector('span').classList.remove('category-dot');
            if (category !== 'all') {
                btn.querySelector('span').className = 'w-2 h-2 rounded-full bg-white';
            }
        } else {
            btn.classList.add('bg-white', 'text-gray-700', 'border', 'border-gray-200');
            btn.classList.remove('bg-gray-900', 'text-white');
            const colors = {
                'general': 'bg-blue-500 text-blue-500',
                'emergency': 'bg-red-500 text-red-500',
                'followup': 'bg-green-500 text-green-500',
                'consultation': 'bg-yellow-500 text-yellow-500'
            };
            if (btn.dataset.category !== 'all') {
                btn.querySelector('span').className = `w-2 h-2 rounded-full ${colors[btn.dataset.category]} category-dot`;
            } else {
                btn.querySelector('span').className = 'w-2 h-2 rounded-full bg-gray-900';
            }
        }
    });
    
    renderCalendar();
}

// Modal Functions
function openAddAppointment(day = null) {
    const modal = document.getElementById('addModal');
    modal.classList.remove('hidden');
    lucide.createIcons();
}

function closeAddAppointment() {
    document.getElementById('addModal').classList.add('hidden');
}

function saveAppointment() {
    closeAddAppointment();
    // Show success notification (simplified)
    const notification = document.createElement('div');
    notification.className = 'fixed bottom-4 right-4 bg-green-600 text-white px-6 py-3 rounded-lg shadow-lg z-50 fade-in flex items-center gap-2';
    notification.innerHTML = '<i data-lucide="check-circle" class="w-5 h-5"></i> Appointment saved successfully!';
    document.body.appendChild(notification);
    lucide.createIcons();
    
    setTimeout(() => {
        notification.remove();
    }, 3000);
}

// Export and Reports
function exportData() {
    const notification = document.createElement('div');
    notification.className = 'fixed bottom-4 right-4 bg-blue-600 text-white px-6 py-3 rounded-lg shadow-lg z-50 fade-in flex items-center gap-2';
    notification.innerHTML = '<i data-lucide="download" class="w-5 h-5"></i> Exporting calendar data...';
    document.body.appendChild(notification);
    lucide.createIcons();
    
    setTimeout(() => {
        notification.innerHTML = '<i data-lucide="check-circle" class="w-5 h-5"></i> Export complete!';
        setTimeout(() => notification.remove(), 2000);
    }, 1500);
}

function generateReports() {
    const notification = document.createElement('div');
    notification.className = 'fixed bottom-4 right-4 bg-purple-600 text-white px-6 py-3 rounded-lg shadow-lg z-50 fade-in flex items-center gap-2';
    notification.innerHTML = '<i data-lucide="file-text" class="w-5 h-5"></i> Generating report...';
    document.body.appendChild(notification);
    lucide.createIcons();
    
    setTimeout(() => {
        notification.innerHTML = '<i data-lucide="check-circle" class="w-5 h-5"></i> Report generated!';
        setTimeout(() => notification.remove(), 2000);
    }, 1500);
}

// Utility
function updateCurrentDate() {
    const options = { weekday: 'long', year: 'numeric', month: 'long', day: 'numeric' };
    document.getElementById('currentDateDisplay').textContent = new Date().toLocaleDateString('en-US', options);
}

// Close modal on outside click
document.getElementById('addModal').addEventListener('click', (e) => {
    if (e.target === document.getElementById('addModal')) {
        closeAddAppointment();
    }
});