document.addEventListener('DOMContentLoaded', () => {
    const uploadArea = document.getElementById('upload-area');
    const fileInput = document.getElementById('file-input');
    const imagePreview = document.getElementById('image-preview');
    const uploadContent = document.querySelector('.upload-content');
    const analyzeBtn = document.getElementById('analyze-btn');
    const btnText = document.querySelector('.btn-text');
    const loader = document.querySelector('.loader');

    const resultsPlaceholder = document.getElementById('results-placeholder');
    const resultsContent = document.getElementById('results-content');
    const mainDisease = document.getElementById('main-disease');
    const chartCanvas = document.getElementById('resultsChart');
    const cropsGallery = document.getElementById('crops-gallery');

    let selectedFile = null;
    let chartInstance = null;

    // Theming Colors for the Chart
    const chartColors = [
        '#2f855a', // Green
        '#8b5a2b', // Brown
        '#48bb78', // Light Green
        '#b7791f', // Yellow-Brown
        '#276749'  // Dark Green
    ];

    // Drag and Drop Events
    ['dragenter', 'dragover', 'dragleave', 'drop'].forEach(eventName => {
        uploadArea.addEventListener(eventName, preventDefaults, false);
    });

    function preventDefaults(e) {
        e.preventDefault();
        e.stopPropagation();
    }

    ['dragenter', 'dragover'].forEach(eventName => {
        uploadArea.addEventListener(eventName, () => uploadArea.classList.add('dragover'), false);
    });

    ['dragleave', 'drop'].forEach(eventName => {
        uploadArea.addEventListener(eventName, () => uploadArea.classList.remove('dragover'), false);
    });

    uploadArea.addEventListener('drop', handleDrop, false);
    uploadArea.addEventListener('click', () => fileInput.click());
    fileInput.addEventListener('change', handleFileSelect);

    function handleDrop(e) {
        const dt = e.dataTransfer;
        const file = dt.files[0];
        handleFile(file);
    }

    function handleFileSelect(e) {
        const file = e.target.files[0];
        handleFile(file);
    }

    function handleFile(file) {
        if (file && file.type.startsWith('image/')) {
            selectedFile = file;
            
            // Show preview
            const reader = new FileReader();
            reader.onload = (e) => {
                imagePreview.src = e.target.result;
                imagePreview.classList.remove('hidden');
                uploadContent.classList.add('hidden');
                analyzeBtn.disabled = false;
            }
            reader.readAsDataURL(file);
        } else {
            alert('Por favor, selecione um arquivo de imagem válido.');
        } 
    }

    analyzeBtn.addEventListener('click', async () => {
        if (!selectedFile) return;

        // UI Loading State
        analyzeBtn.disabled = true;
        btnText.innerHTML = '<i class="ph-bold ph-scan"></i> Analisando...';
        loader.classList.remove('hidden');
        resultsPlaceholder.querySelector('p').textContent = 'Processando IA (pode levar alguns segundos)...';
        resultsContent.classList.add('hidden');
        resultsPlaceholder.classList.remove('hidden');

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

        try {
            const response = await fetch('/predict', {
                method: 'POST',
                body: formData
            });

            if (!response.ok) {
                const errData = await response.json();
                throw new Error(errData.error || 'Erro na análise da imagem.');
            }

            const data = await response.json();
            updateResults(data);
        } catch (error) {
            alert(error.message);
            resultsPlaceholder.querySelector('p').textContent = 'Falha na análise. Tente novamente.';
        } finally {
            analyzeBtn.disabled = false;
            btnText.innerHTML = '<i class="ph-bold ph-scan"></i> Analisar Folha';
            loader.classList.add('hidden');
        }
    });

    function updateResults(data) {
        // Hide placeholder, show results
        resultsPlaceholder.classList.add('hidden');
        resultsContent.classList.remove('hidden');

        // Update Text
        mainDisease.textContent = data.mais_frequente;
        


        // Render Chart
        renderChart(data.contagem);

        // Render Crops
        renderCrops(data.imagens || []);
    }

    function renderCrops(imagens) {
        cropsGallery.innerHTML = '';
        if (imagens.length === 0) {
            cropsGallery.innerHTML = '<p style="color:var(--text-secondary); width: 100%;">Nenhum recorte gerado.</p>';
            return;
        }

        const timestamp = Date.now();
        imagens.forEach(imgData => {
            const card = document.createElement('div');
            card.className = 'crop-card';
            
            const img = document.createElement('img');
            // Cache buster for new analyses
            img.src = `${imgData.url}?t=${timestamp}`;
            img.alt = 'Recorte detectado';
            
            const label = document.createElement('div');
            label.className = 'crop-card-label';
            label.textContent = imgData.classe;

            card.appendChild(img);
            card.appendChild(label);
            cropsGallery.appendChild(card);
        });
    }

    function renderChart(counts) {
        const labels = Object.keys(counts);
        const data = Object.values(counts);

        if (chartInstance) {
            chartInstance.destroy();
        }

        chartInstance = new Chart(chartCanvas, {
            type: 'doughnut',
            data: {
                labels: labels,
                datasets: [{
                    data: data,
                    backgroundColor: chartColors,
                    borderWidth: 0,
                    hoverOffset: 4
                }]
            },
            options: {
                responsive: true,
                maintainAspectRatio: false,
                plugins: {
                    legend: {
                        position: 'right',
                        labels: {
                            color: '#4a5568',
                            font: { family: "'Outfit', sans-serif", size: 10 },
                            padding: 10,
                            boxWidth: 12
                        }
                    },
                    tooltip: {
                        backgroundColor: 'rgba(255, 255, 255, 0.95)',
                        titleColor: '#2d3748',
                        bodyColor: '#2d3748',
                        borderColor: 'rgba(47, 133, 90, 0.2)',
                        borderWidth: 1,
                        padding: 10,
                        titleFont: { family: "'Outfit', sans-serif", size: 12, weight: 'bold' },
                        bodyFont: { family: "'Outfit', sans-serif", size: 12 }
                    }
                },
                cutout: '70%'
            }
        });
    }
});