// API base URL
const API_BASE = '/api';

// Initialize
document.addEventListener('DOMContentLoaded', () => {
    loadBooks();
    loadSchedules();

    // Event listeners
    document.getElementById('send-btn').addEventListener('click', sendChatMessage);
    document.getElementById('chat-input').addEventListener('keypress', (e) => {
        if (e.key === 'Enter') sendChatMessage();
    });
    document.getElementById('upload-btn').addEventListener('click', uploadPDF);
    document.getElementById('add-schedule-btn').addEventListener('click', addSchedule);
});

async function sendChatMessage() {
    const input = document.getElementById('chat-input');
    const button = document.getElementById('send-btn');
    const message = input.value.trim();

    if (!message || button.disabled) return;
    button.disabled = true;

    // Add user message to chat
    addMessage(message, 'user');
    input.value = '';

    // Show loading
    showLoading();

    try {
        const response = await fetch(`${API_BASE}/chat`, {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({ message, top_k: 3 }),
        });

        const data = await response.json().catch(() => ({}));
        if (!response.ok) {
            const detail = typeof data.detail === 'string' ? data.detail : 'Erro ao enviar mensagem';
            throw new Error(detail);
        }

        hideLoading();
        addMessage(data.response, 'bot');

        if (data.sources && data.sources.length > 0) {
            const sourceText = data.sources.map((source) => {
                const meta = source.metadata || source;
                return `📖 ${meta.title || 'Desconhecido'} (trecho ${meta.chunk_id ?? '?'})`;
            }).join('\n');
            addMessage(`Fontes:\n${sourceText}`, 'bot');
        }
    } catch (error) {
        hideLoading();
        addMessage(`Erro: ${error.message}`, 'bot');
    } finally {
        button.disabled = false;
        input.focus();
    }
}

function addMessage(content, type) {
    const container = document.getElementById('chat-messages');
    const messageDiv = document.createElement('div');
    messageDiv.className = `message ${type}`;
    const body = document.createElement('div');
    body.className = 'message-content';
    body.textContent = content;
    messageDiv.appendChild(body);
    container.appendChild(messageDiv);
    container.scrollTop = container.scrollHeight;
}

function showLoading() {
    const container = document.getElementById('chat-messages');
    const loadingDiv = document.createElement('div');
    loadingDiv.id = 'chat-loading';
    loadingDiv.className = 'message bot';
    loadingDiv.innerHTML = '<div class="message-content">Carregando...</div>';
    container.appendChild(loadingDiv);
    container.scrollTop = container.scrollHeight;
}

function hideLoading() {
    const loading = document.getElementById('chat-loading');
    if (loading) loading.remove();
}

async function loadBooks() {
    try {
        const response = await fetch(`${API_BASE}/books`);
        const books = await response.json();

        const booksList = document.getElementById('books-list');
        booksList.innerHTML = '';

        if (books.length === 0) {
            booksList.innerHTML = '<p style="color: #666;">Nenhum livro encontrado.</p>';
            return;
        }

        books.forEach(book => {
            const bookDiv = document.createElement('div');
            bookDiv.className = 'book-item';
            const icon = document.createElement('div');
            icon.className = 'book-icon';
            icon.textContent = '📖';
            const name = document.createElement('div');
            name.className = 'book-name';
            name.textContent = book.title;
            bookDiv.append(icon, name);
            booksList.appendChild(bookDiv);
        });

        // Update book dropdown
        const select = document.getElementById('schedule-book');
        select.innerHTML = '<option value="">Todos os livros</option>';
        books.forEach(book => {
            const option = document.createElement('option');
            option.value = book.title;
            option.textContent = book.title;
            select.appendChild(option);
        });
    } catch (error) {
        console.error('Erro ao carregar livros:', error);
    }
}

async function uploadPDF() {
    const fileInput = document.getElementById('file-input');
    const file = fileInput.files[0];

    if (!file) {
        alert('Selecione um arquivo PDF primeiro');
        return;
    }

    const statusDiv = document.getElementById('upload-status');
    statusDiv.textContent = 'Enviando...';

    try {
        const formData = new FormData();
        formData.append('file', file);

        const response = await fetch(`${API_BASE}/upload`, {
            method: 'POST',
            body: formData,
        });

        if (!response.ok) {
            throw new Error('Erro ao fazer upload');
        }

        const data = await response.json();
        statusDiv.textContent = `✅ ${data.filename} enviado com sucesso!`;
        statusDiv.style.color = '#4caf50';

        setTimeout(() => {
            statusDiv.textContent = '';
            fileInput.value = '';
        }, 3000);

        // Reload books
        loadBooks();
    } catch (error) {
        statusDiv.textContent = `❌ Erro: ${error.message}`;
        statusDiv.style.color = '#f44336';
    }
}

async function loadSchedules() {
    try {
        const response = await fetch(`${API_BASE}/schedules`);
        const schedules = await response.json();

        renderSchedules(schedules);
    } catch (error) {
        console.error('Erro ao carregar agendamentos:', error);
    }
}

function renderSchedules(schedules) {
    const container = document.getElementById('schedules-list');
    container.innerHTML = '';

    if (schedules.length === 0) {
        container.innerHTML = '<p style="color: #666;">Nenhum agendamento.</p>';
        return;
    }

    schedules.forEach(schedule => {
        const div = document.createElement('div');
        div.className = 'schedule-item';
        const info = document.createElement('div');
        info.className = 'schedule-info';
        const time = document.createElement('span');
        time.className = 'schedule-time';
        time.textContent = formatDateTime(schedule.time);
        const book = document.createElement('span');
        book.className = 'schedule-book';
        book.textContent = schedule.book || 'Todos os livros';
        info.append(time, book);
        const remove = document.createElement('button');
        remove.className = 'schedule-delete';
        remove.type = 'button';
        remove.textContent = 'Excluir';
        remove.addEventListener('click', () => deleteSchedule(schedule.id));
        div.append(info, remove);
        container.appendChild(div);
    });
}

async function addSchedule() {
    const timeInput = document.getElementById('schedule-time');
    const bookSelect = document.getElementById('schedule-book');

    if (!timeInput.value) {
        alert('Selecione uma data e hora');
        return;
    }

    try {
        const response = await fetch(`${API_BASE}/schedules`, {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({
                time: timeInput.value,
                book: bookSelect.value || null,
                enabled: true,
            }),
        });

        if (!response.ok) {
            throw new Error('Erro ao criar agendamento');
        }

        const schedule = await response.json();
        loadSchedules();

        timeInput.value = '';
        bookSelect.value = '';
    } catch (error) {
        alert(`Erro: ${error.message}`);
    }
}

async function deleteSchedule(scheduleId) {
    if (!confirm('Tem certeza que deseja excluir este agendamento?')) {
        return;
    }

    try {
        const response = await fetch(`${API_BASE}/schedules/${scheduleId}`, {
            method: 'DELETE',
        });

        if (!response.ok) {
            throw new Error('Erro ao excluir agendamento');
        }

        loadSchedules();
    } catch (error) {
        alert(`Erro: ${error.message}`);
    }
}

function formatDateTime(dateString) {
    const date = new Date(dateString);
    return date.toLocaleString('pt-BR');
}