// Demo Patient Data
const patients = [
    {
        id: 1,
        firstName: "John",
        lastName: "Smith",
        mrn: "839214",
        status: "active",
        insurance: "BlueCross",
        insuranceProvider: "BlueCross",
        nextAppointment: "2026-04-02",
        expirationDate: "2026-05-12",
        clinic: "Los Angeles",
        lastVisit: "2026-03-01",
        phoneVerified: true,
        emailVerified: true,
        provider: "Dr. Smith",
        tags: ["new"]
    },
    {
        id: 2,
        firstName: "Maria",
        lastName: "Gonzalez",
        mrn: "481992",
        status: "pending",
        insurance: "UnitedHealth",
        insuranceProvider: "UnitedHealth",
        nextAppointment: "2026-03-18",
        expirationDate: "2026-04-10",
        clinic: "San Diego",
        lastVisit: "2026-02-15",
        phoneVerified: true,
        emailVerified: false,
        provider: "Dr. Johnson",
        tags: ["followup"]
    },
    {
        id: 3,
        firstName: "David",
        lastName: "Chen",
        mrn: "673204",
        status: "active",
        insurance: "Aetna",
        insuranceProvider: "Aetna",
        nextAppointment: "2026-04-06",
        expirationDate: "2026-06-02",
        clinic: "San Francisco",
        lastVisit: "2026-03-05",
        phoneVerified: true,
        emailVerified: true,
        provider: "Dr. Smith",
        tags: ["telehealth"]
    },
    {
        id: 4,
        firstName: "Sarah",
        lastName: "Johnson",
        mrn: "904211",
        status: "approved",
        insurance: "Kaiser Permanente",
        insuranceProvider: "Kaiser",
        nextAppointment: "2026-04-01",
        expirationDate: "2026-05-20",
        clinic: "Los Angeles",
        lastVisit: "2026-03-10",
        phoneVerified: true,
        emailVerified: true,
        provider: "Dr. Williams",
        tags: []
    },
    {
        id: 5,
        firstName: "Michael",
        lastName: "Patel",
        mrn: "510992",
        status: "expired",
        insurance: "Medicare",
        insuranceProvider: "Medicare",
        nextAppointment: null,
        expirationDate: "2026-02-10",
        clinic: "San Jose",
        lastVisit: "2026-01-20",
        phoneVerified: false,
        emailVerified: true,
        provider: "Dr. Brown",
        tags: ["billing"]
    },
    {
        id: 6,
        firstName: "Lisa",
        lastName: "Nguyen",
        mrn: "482311",
        status: "active",
        insurance: "BlueShield",
        insuranceProvider: "BlueShield",
        nextAppointment: "2026-03-29",
        expirationDate: "2026-07-08",
        clinic: "Sacramento",
        lastVisit: "2026-02-28",
        phoneVerified: true,
        emailVerified: true,
        provider: "Dr. Johnson",
        tags: []
    },
    {
        id: 7,
        firstName: "Robert",
        lastName: "Walker",
        mrn: "881420",
        status: "active",
        insurance: "UnitedHealth",
        insuranceProvider: "UnitedHealth",
        nextAppointment: "2026-04-05",
        expirationDate: "2026-06-14",
        clinic: "Los Angeles",
        lastVisit: "2026-03-08",
        phoneVerified: true,
        emailVerified: false,
        provider: "Dr. Smith",
        tags: ["allergy"]
    },
    {
        id: 8,
        firstName: "Emily",
        lastName: "Carter",
        mrn: "640199",
        status: "pending",
        insurance: "Aetna",
        insuranceProvider: "Aetna",
        nextAppointment: "2026-03-20",
        expirationDate: "2026-04-22",
        clinic: "San Diego",
        lastVisit: "2026-02-25",
        phoneVerified: true,
        emailVerified: true,
        provider: "Dr. Williams",
        tags: ["new"]
    },
    {
        id: 9,
        firstName: "Daniel",
        lastName: "Kim",
        mrn: "777200",
        status: "approved",
        insurance: "BlueCross",
        insuranceProvider: "BlueCross",
        nextAppointment: "2026-04-03",
        expirationDate: "2026-05-30",
        clinic: "San Francisco",
        lastVisit: "2026-03-12",
        phoneVerified: true,
        emailVerified: true,
        provider: "Dr. Brown",
        tags: ["telehealth"]
    },
    {
        id: 10,
        firstName: "Jessica",
        lastName: "Brown",
        mrn: "223901",
        status: "archived",
        insurance: "Kaiser Permanente",
        insuranceProvider: "Kaiser",
        nextAppointment: null,
        expirationDate: null,
        clinic: "Fresno",
        lastVisit: "2025-12-15",
        phoneVerified: false,
        emailVerified: false,
        provider: "Dr. Johnson",
        tags: []
    },
    {
        id: 11,
        firstName: "Carlos",
        lastName: "Ramirez",
        mrn: "100239",
        status: "active",
        insurance: "Medicare",
        insuranceProvider: "Medicare",
        nextAppointment: "2026-03-25",
        expirationDate: "2026-05-05",
        clinic: "San Jose",
        lastVisit: "2026-02-20",
        phoneVerified: true,
        emailVerified: true,
        provider: "Dr. Smith",
        tags: []
    },
    {
        id: 12,
        firstName: "Olivia",
        lastName: "Taylor",
        mrn: "564009",
        status: "active",
        insurance: "BlueShield",
        insuranceProvider: "BlueShield",
        nextAppointment: "2026-04-04",
        expirationDate: "2026-06-18",
        clinic: "Los Angeles",
        lastVisit: "2026-03-15",
        phoneVerified: true,
        emailVerified: true,
        provider: "Dr. Williams",
        tags: ["new", "telehealth"]
    }
];

// State Management
let currentPage = 1;
let pageSize = 12;
let selectedRows = new Set();
let filteredPatients = [...patients];
let currentFilters = {
    search: '',
    status: 'all',
    tag: 'all',
    insurance: 'all',
    provider: 'all',
    date: 'all'
};

// Avatar Color Generator
function getAvatarColor(id) {
    const colors = [
        { bg: '#DBEAFE', text: '#1D4ED8' },
        { bg: '#EDE9FE', text: '#6D28D9' },
        { bg: '#FCE7F3', text: '#BE185D' },
        { bg: '#D1FAE5', text: '#047857' },
        { bg: '#FEF3C7', text: '#B45309' },
        { bg: '#E0E7FF', text: '#4338CA' }
    ];
    return colors[id % colors.length];
}

// Date Formatting
function formatDate(dateString) {
    if (!dateString) return '—';
    const date = new Date(dateString);
    return date.toLocaleDateString('en-US', { month: 'short', day: 'numeric', year: 'numeric' });
}

// Check if date is within 30 days or past due
function getExpirationClass(dateString) {
    if (!dateString) return '';
    const expDate = new Date(dateString);
    const today = new Date();
    const diffTime = expDate - today;
    const diffDays = Math.ceil(diffTime / (1000 * 60 * 60 * 24));
    
    if (diffDays < 0) return 'expiration-danger';
    if (diffDays <= 30) return 'expiration-warning';
    return '';
}

function getExpirationText(dateString) {
    if (!dateString) return '—';
    const expDate = new Date(dateString);
    const today = new Date();
    const diffTime = expDate - today;
    const diffDays = Math.ceil(diffTime / (1000 * 60 * 60 * 24));
    
    if (diffDays < 0) return 'Expired';
    return formatDate(dateString);
}

// Render Patient Row
function renderPatientRow(patient) {
    const avatarColors = getAvatarColor(patient.id);
    const initials = `${patient.firstName[0]}${patient.lastName[0]}`;
    const isSelected = selectedRows.has(patient.id);
    const expirationClass = getExpirationClass(patient.expirationDate);
    const expirationText = getExpirationText(patient.expirationDate);
    
    return `
        <div class="patient-row grid grid-cols-12 gap-4 px-6 py-4 items-center bg-white border-l-3 border-transparent cursor-pointer ${isSelected ? 'selected' : ''}" 
             onclick="handleRowClick(event, ${patient.id})" 
             data-id="${patient.id}">
            
            <!-- Patient Column -->
            <div class="col-span-4 flex items-center gap-3">
                <input type="checkbox" 
                       class="row-checkbox w-4 h-4 rounded border-gray-300 text-brand-600 focus:ring-brand-600 cursor-pointer"
                       ${isSelected ? 'checked' : ''} 
                       onclick="event.stopPropagation(); toggleRowSelection(${patient.id})">
                
                <div class="relative flex-shrink-0">
                    <div class="w-10 h-10 rounded-full flex items-center justify-center text-sm font-semibold"
                         style="background-color: ${avatarColors.bg}; color: ${avatarColors.text};">
                        ${initials}
                    </div>
                    <div class="avatar-status ${patient.status}"></div>
                </div>
                
                <div class="min-w-0 flex-1">
                    <div class="flex items-center gap-2">
                        <span class="text-sm font-semibold text-gray-900 truncate">
                            ${patient.firstName} ${patient.lastName}
                        </span>
                        ${patient.phoneVerified ? '<i data-lucide="phone" class="w-3 h-3 text-green-500"></i>' : ''}
                        ${patient.emailVerified ? '<i data-lucide="mail" class="w-3 h-3 text-blue-500"></i>' : ''}
                    </div>
                    <div class="text-xs text-gray-500 mt-0.5">MRN ${patient.mrn}</div>
                    <div class="text-xs text-gray-400 mt-0.5 truncate">
                        Last visit ${formatDate(patient.lastVisit)} • ${patient.clinic} Clinic
                    </div>
                </div>
            </div>

            <!-- Status Column -->
            <div class="col-span-1">
                <span class="status-chip ${patient.status}">
                    ${patient.status.charAt(0).toUpperCase() + patient.status.slice(1)}
                </span>
            </div>

            <!-- Insurance Column -->
            <div class="col-span-2 flex items-center gap-2 text-sm text-gray-700">
                <i data-lucide="shield" class="w-4 h-4 text-gray-400"></i>
                <span class="truncate">${patient.insurance}</span>
            </div>

            <!-- Next Appointment Column -->
            <div class="col-span-2 text-sm text-gray-700">
                ${formatDate(patient.nextAppointment)}
            </div>

            <!-- Expires Column -->
            <div class="col-span-1 text-sm ${expirationClass}">
                ${expirationText}
            </div>

            <!-- Clinic Column -->
            <div class="col-span-1 text-sm text-gray-700">
                ${patient.clinic}
            </div>

            <!-- Actions Column -->
            <div class="col-span-1 flex justify-end relative">
                <button onclick="event.stopPropagation(); toggleDropdown(event, ${patient.id})" 
                        class="p-2 hover:bg-gray-100 rounded-lg transition-colors">
                    <i data-lucide="more-vertical" class="w-4 h-4 text-gray-500"></i>
                </button>
            </div>
        </div>
    `;
}

// Filter Logic
function applyFilters() {
    filteredPatients = patients.filter(patient => {
        // Search filter
        if (currentFilters.search) {
            const searchLower = currentFilters.search.toLowerCase();
            const fullName = `${patient.firstName} ${patient.lastName}`.toLowerCase();
            const match = fullName.includes(searchLower) || 
                         patient.mrn.includes(searchLower) ||
                         patient.clinic.toLowerCase().includes(searchLower);
            if (!match) return false;
        }

        // Status filter
        if (currentFilters.status !== 'all' && patient.status !== currentFilters.status) {
            return false;
        }

        // Insurance filter
        if (currentFilters.insurance !== 'all' && patient.insuranceProvider !== currentFilters.insurance) {
            return false;
        }

        // Provider filter
        if (currentFilters.provider !== 'all' && patient.provider !== currentFilters.provider) {
            return false;
        }

        // Tag filter
        if (currentFilters.tag !== 'all' && !patient.tags.includes(currentFilters.tag)) {
            return false;
        }

        return true;
    });

    currentPage = 1;
    render();
}

// Render List
function render() {
    const container = document.getElementById('patientList');
    const start = (currentPage - 1) * pageSize;
    const end = start + pageSize;
    const pagePatients = filteredPatients.slice(start, end);

    if (pagePatients.length === 0) {
        container.innerHTML = '';
        document.getElementById('emptyState').classList.remove('hidden');
    } else {
        document.getElementById('emptyState').classList.add('hidden');
        container.innerHTML = pagePatients.map(p => renderPatientRow(p)).join('');
        lucide.createIcons();
    }

    updatePagination();
    updateBulkActions();
}

// Pagination
function updatePagination() {
    const total = filteredPatients.length;
    const start = (currentPage - 1) * pageSize + 1;
    const end = Math.min(currentPage * pageSize, total);

    document.getElementById('showingStart').textContent = total === 0 ? 0 : start;
    document.getElementById('showingEnd').textContent = end;
    document.getElementById('totalCount').textContent = total;

    document.getElementById('prevBtn').disabled = currentPage === 1;
    document.getElementById('nextBtn').disabled = end >= total;

    // Page numbers
    const totalPages = Math.ceil(total / pageSize);
    const pageContainer = document.getElementById('pageNumbers');
    let html = '';
    
    for (let i = 1; i <= totalPages; i++) {
        if (i === 1 || i === totalPages || (i >= currentPage - 1 && i <= currentPage + 1)) {
            html += `<button onclick="goToPage(${i})" class="w-8 h-8 flex items-center justify-center rounded-lg text-sm font-medium transition-colors ${i === currentPage ? 'bg-brand-600 text-white' : 'text-gray-700 hover:bg-gray-100'}">${i}</button>`;
        } else if (i === currentPage - 2 || i === currentPage + 2) {
            html += `<span class="px-1 text-gray-400">...</span>`;
        }
    }
    pageContainer.innerHTML = html;
}

function changePage(delta) {
    currentPage += delta;
    render();
    window.scrollTo({ top: 0, behavior: 'smooth' });
}

function goToPage(page) {
    currentPage = page;
    render();
    window.scrollTo({ top: 0, behavior: 'smooth' });
}

function changePageSize() {
    pageSize = parseInt(document.getElementById('pageSize').value);
    currentPage = 1;
    render();
}

// Row Selection
function toggleRowSelection(id) {
    if (selectedRows.has(id)) {
        selectedRows.delete(id);
    } else {
        selectedRows.add(id);
    }
    render();
}

function handleRowClick(event, id) {
    // Navigate to patient details
    showToast(`Navigating to /patients/${id}`, 'info');
    // Simulate navigation
    console.log(`Navigate to /patients/${id}`);
}

function toggleSelectAll() {
    const checkboxes = document.querySelectorAll('.row-checkbox');
    const allSelected = selectedRows.size === filteredPatients.length;
    
    if (allSelected) {
        selectedRows.clear();
    } else {
        filteredPatients.forEach(p => selectedRows.add(p.id));
    }
    render();
}

function clearSelection() {
    selectedRows.clear();
    render();
}

function updateBulkActions() {
    const bar = document.getElementById('bulkActionsBar');
    const count = document.getElementById('selectedCount');
    
    if (selectedRows.size > 0) {
        bar.classList.remove('hidden');
        count.textContent = selectedRows.size;
    } else {
        bar.classList.add('hidden');
    }

    // Update select all checkbox
    const selectAllCheckbox = document.getElementById('selectAll');
    if (filteredPatients.length > 0 && selectedRows.size === filteredPatients.length) {
        selectAllCheckbox.checked = true;
        selectAllCheckbox.indeterminate = false;
    } else if (selectedRows.size > 0) {
        selectAllCheckbox.checked = false;
        selectAllCheckbox.indeterminate = true;
    } else {
        selectAllCheckbox.checked = false;
        selectAllCheckbox.indeterminate = false;
    }
}

function bulkAction(action) {
    showToast(`${action.charAt(0).toUpperCase() + action.slice(1)} ${selectedRows.size} patients (demo)`, 'success');
    if (action === 'archive') {
        clearSelection();
    }
}

// Dropdown Menu
let activeDropdown = null;

function toggleDropdown(event, patientId) {
    event.stopPropagation();
    
    // Close existing
    if (activeDropdown) {
        activeDropdown.remove();
        activeDropdown = null;
        return;
    }

    // Create new dropdown
    const template = document.getElementById('dropdownTemplate');
    const dropdown = template.cloneNode(true);
    dropdown.id = 'activeDropdown';
    dropdown.classList.remove('hidden');
    
    // Position
    const button = event.currentTarget;
    const rect = button.getBoundingClientRect();
    dropdown.style.position = 'fixed';
    dropdown.style.top = `${rect.bottom + 4}px`;
    dropdown.style.right = `${window.innerWidth - rect.right}px`;
    dropdown.style.zIndex = '100';
    
    document.body.appendChild(dropdown);
    activeDropdown = dropdown;
    lucide.createIcons();

    // Close on outside click
    setTimeout(() => {
        document.addEventListener('click', closeDropdown, { once: true });
    }, 0);
}

function closeDropdown() {
    if (activeDropdown) {
        activeDropdown.remove();
        activeDropdown = null;
    }
}

function handleAction(action) {
    closeDropdown();
    const messages = {
        view: 'Viewing patient details',
        edit: 'Opening patient editor',
        schedule: 'Opening scheduler',
        telehealth: 'Starting telehealth session',
        invoice: 'Invoice created (demo)',
        message: 'Message composer opened',
        upload: 'Document upload opened',
        archive: 'Patient archived (demo)'
    };
    showToast(messages[action] || 'Action completed', action === 'archive' ? 'warning' : 'success');
}

// More Filters Toggle
function toggleMoreFilters() {
    const panel = document.getElementById('moreFilters');
    panel.classList.toggle('hidden');
}

// Toast Notifications
function showToast(message, type = 'info') {
    const container = document.getElementById('toast-container');
    const toast = document.createElement('div');
    
    const colors = {
        success: 'bg-green-50 text-green-800 border-green-200',
        warning: 'bg-amber-50 text-amber-800 border-amber-200',
        error: 'bg-red-50 text-red-800 border-red-200',
        info: 'bg-blue-50 text-blue-800 border-blue-200'
    };

    const icons = {
        success: 'check-circle',
        warning: 'alert-triangle',
        error: 'x-circle',
        info: 'info'
    };
    
    toast.className = `${colors[type]} border rounded-lg px-4 py-3 shadow-lg flex items-center gap-3 min-w-[300px] animate-fade-up`;
    toast.innerHTML = `
        <i data-lucide="${icons[type]}" class="w-5 h-5"></i>
        <span class="text-sm font-medium">${message}</span>
    `;
    
    container.appendChild(toast);
    lucide.createIcons();
    
    setTimeout(() => {
        toast.style.opacity = '0';
        toast.style.transform = 'translateX(100%)';
        toast.style.transition = 'all 300ms ease';
        setTimeout(() => toast.remove(), 300);
    }, 3000);
}

// Event Listeners
document.getElementById('searchInput').addEventListener('input', (e) => {
    currentFilters.search = e.target.value;
    applyFilters();
});

document.getElementById('statusFilter').addEventListener('change', (e) => {
    currentFilters.status = e.target.value;
    applyFilters();
});

document.getElementById('insuranceFilter').addEventListener('change', (e) => {
    currentFilters.insurance = e.target.value;
    applyFilters();
});

document.getElementById('providerFilter').addEventListener('change', (e) => {
    currentFilters.provider = e.target.value;
    applyFilters();
});

document.getElementById('tagFilter').addEventListener('change', (e) => {
    currentFilters.tag = e.target.value;
    applyFilters();
});

document.getElementById('selectAll').addEventListener('change', toggleSelectAll);

// Initialize
document.addEventListener('DOMContentLoaded', () => {
    render();
    lucide.createIcons();
});