const uploadZone = document.getElementById('uploadZone');
const fileInput = document.getElementById('fileInput');
const fileList = document.getElementById('fileList');
const startBtn = document.getElementById('startBtn');
const requirementInput = document.getElementById('requirementInput');
const statusDot = document.getElementById('statusDot');
const statusText = document.getElementById('statusText');
const logOutput = document.getElementById('logOutput');
const reportContainer = document.getElementById('reportContainer');
const galleryContainer = document.getElementById('galleryContainer');

let isRunning = false;
let pollingInterval = null;
let currentSessionId = null;

// --- Upload Logic ---
if (uploadZone) {
    uploadZone.addEventListener('dragover', (e) => {
        e.preventDefault();
        uploadZone.classList.add('dragover');
    });
    uploadZone.addEventListener('dragleave', () => uploadZone.classList.remove('dragover'));
    uploadZone.addEventListener('drop', (e) => {
        e.preventDefault();
        uploadZone.classList.remove('dragover');
        handleFiles(e.dataTransfer.files);
    });
}
if (fileInput) {
    fileInput.addEventListener('change', (e) => handleFiles(e.target.files));
}

async function handleFiles(files) {
    if (files.length === 0) return;

    fileList.innerHTML = '';
    const formData = new FormData();

    for (const file of files) {
        formData.append('files', file);
        const fileItem = document.createElement('div');
        fileItem.innerText = `📄 ${file.name}`;
        fileItem.style.fontSize = '0.8rem';
        fileItem.style.color = '#fff';
        fileList.appendChild(fileItem);
    }

    try {
        const res = await fetch('/api/upload', {
            method: 'POST',
            body: formData
        });
        if (res.ok) {
            const data = await res.json();
            console.log('Upload success:', data);
        } else {
            alert('Upload failed');
        }
    } catch (e) {
        console.error(e);
        alert('Upload failed');
    }
}

// --- Start Analysis ---
if (startBtn) {
    startBtn.addEventListener('click', async () => {
        if (isRunning) return;

        const requirement = requirementInput.value.trim();
        if (!requirement) {
            alert('Please enter analysis requirement');
            return;
        }

        setRunningState(true);

        try {
            const res = await fetch('/api/start', {
                method: 'POST',
                headers: { 'Content-Type': 'application/json' },
                body: JSON.stringify({ requirement })
            });

            if (res.ok) {
                const data = await res.json();
                currentSessionId = data.session_id; // Store Session ID
                console.log("Started Session:", currentSessionId);

                startPolling();
                switchTab('logs');
            } else {
                const err = await res.json();
                alert('Failed to start: ' + err.detail);
                setRunningState(false);
            }
        } catch (e) {
            console.error(e);
            alert('Error starting analysis');
            setRunningState(false);
        }
    });
}

function setRunningState(running) {
    isRunning = running;
    startBtn.disabled = running;
    startBtn.innerHTML = running ? '<i class="fa-solid fa-spinner fa-spin"></i> Running...' : '<i class="fa-solid fa-play"></i> Start Analysis';

    if (running) {
        statusDot.className = 'dot running';
        statusText.innerText = 'Analysis in Progress';
    } else {
        statusDot.className = 'dot done';
        statusText.innerText = 'Completed';
    }
}

// --- Status Polling ---
function startPolling() {
    if (pollingInterval) clearInterval(pollingInterval);
    if (!currentSessionId) return;

    pollingInterval = setInterval(async () => {
        try {
            const res = await fetch(`/api/status?session_id=${currentSessionId}`);
            if (!res.ok) return;
            const data = await res.json();

            // Update Logs
            logOutput.innerText = data.log || "Waiting for logs...";
            // Auto scroll to bottom
            const term = document.querySelector('.terminal-window');
            if (term) term.scrollTop = term.scrollHeight;

            if (!data.is_running && isRunning) {
                // Just finished
                setRunningState(false);
                clearInterval(pollingInterval);

                if (data.has_report) {
                    loadReport();
                    loadGallery(); // Load images when done
                    switchTab('report');
                }
            }
        } catch (e) {
            console.error('Polling error', e);
        }
    }, 2000);
}

async function loadReport() {
    if (!currentSessionId) return;
    try {
        const res = await fetch(`/api/report?session_id=${currentSessionId}`);
        const data = await res.json();

        // Render Markdown
        reportContainer.innerHTML = marked.parse(data.content);

        // Fix images relative path for display if needed
        // The backend should return a base_path or we handle it here
        if (data.base_path) {
            // Backend already handled replacement? 
            // The backend returns content with updated paths.
        }

    } catch (e) {
        reportContainer.innerHTML = '<p class="error">Failed to load report.</p>';
        console.error(e);
    }
}

async function loadGallery() {
    if (!currentSessionId) return;

    // Switch to gallery view logic if we were already there
    // But this is just data loading
    try {
        const res = await fetch(`/api/figures?session_id=${currentSessionId}`);
        const data = await res.json();

        const galleryGrid = document.getElementById('galleryContainer');
        if (!data.figures || data.figures.length === 0) {
            galleryGrid.innerHTML = `
                <div class="empty-state">
                    <i class="fa-solid fa-images"></i>
                    <p>No images generated in this session.</p>
                </div>
            `;
            return;
        }

        let html = '';
        data.figures.forEach(fig => {
            html += `
                <div class="gallery-card">
                    <div class="img-wrapper">
                        <img src="${fig.web_url}" alt="${fig.filename}" onclick="window.open('${fig.web_url}', '_blank')">
                    </div>
                    <div class="card-content">
                        <h4>${fig.filename}</h4>
                        <p class="desc">${fig.description || 'No description'}</p>
                        ${fig.analysis ? `<div class="analysis-box"><i class="fa-solid fa-magnifying-glass"></i> ${fig.analysis}</div>` : ''}
                    </div>
                </div>
            `;
        });
        galleryGrid.innerHTML = html;

    } catch (e) {
        console.error("Gallery load failed", e);
    }
}

// --- Export Report ---
window.triggerExport = async function () {
    if (!currentSessionId) {
        alert("No active session to export.");
        return;
    }

    const btn = document.getElementById('exportBtn');
    const originalText = btn.innerHTML;
    btn.innerHTML = '<i class="fa-solid fa-spinner fa-spin"></i> Zipping...';
    btn.disabled = true;

    try {
        // Trigger download
        // We can't use fetch for file download easily if we want browser to handle save dialog
        // So we create a link approach or check status first

        // Check if download is possible
        const url = `/api/export?session_id=${currentSessionId}`;
        const res = await fetch(url, { method: 'HEAD' });
        if (res.ok) {
            window.location.href = url;
        } else {
            alert("Export failed: No data available.");
        }
    } catch (e) {
        alert("Export failed: " + e.message);
    } finally {
        btn.innerHTML = originalText;
        btn.disabled = false;
    }
}


// --- Tabs (Inner) ---
window.switchTab = function (tabName) {
    document.querySelectorAll('.tab-btn').forEach(b => b.classList.remove('active'));
    document.querySelectorAll('.tab-content').forEach(c => c.classList.remove('active'));

    const btn = document.querySelector(`button[onclick="switchTab('${tabName}')"]`);
    if (btn) btn.classList.add('active');

    const tab = document.getElementById(`${tabName}Tab`);
    if (tab) tab.classList.add('active');
}

// --- View Navigation (Outer Sidebar) ---
window.switchView = function (viewName) {
    // 1. Update Sidebar Buttons
    document.querySelectorAll('.nav-btn').forEach(b => b.classList.remove('active'));
    const navBtn = document.querySelector(`button[onclick="switchView('${viewName}')"]`);
    if (navBtn) navBtn.classList.add('active');

    // 2. Switch Main Content Sections
    const viewId = 'view' + viewName.charAt(0).toUpperCase() + viewName.slice(1);

    document.querySelectorAll('.view-section').forEach(v => {
        // Hide all
        v.style.display = 'none';
        v.classList.remove('active');
    });

    const activeView = document.getElementById(viewId);
    if (activeView) {
        // Analysis view uses flex for layout (logs scrolling), others use block
        if (viewName === 'analysis') {
            activeView.style.display = 'flex';
            activeView.style.flexDirection = 'column';
        } else {
            activeView.style.display = 'block';
            // If switching to gallery, reload it if session exists
            if (viewName === 'gallery' && currentSessionId) {
                loadGallery();
            }
        }
        activeView.classList.add('active');
    }

    // 3. Toggle Sidebar Controls (only show Analysis Controls in analysis view)
    const analysisControls = document.getElementById('analysisControls');
    if (analysisControls) {
        analysisControls.style.display = (viewName === 'analysis') ? 'block' : 'none';
    }
}

// --- Tool Functions ---
window.triggerMerge = async function () {
    const sourceDir = document.getElementById('mergeSource').value;
    const resultDiv = document.getElementById('mergeResult');

    resultDiv.innerHTML = '<i class="fa-solid fa-spinner fa-spin"></i> Merging...';

    try {
        const res = await fetch('/api/tools/merge', {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({ source_dir: sourceDir, output_filename: 'merged_output.csv' })
        });
        const data = await res.json();
        if (data.status === 'success') {
            resultDiv.innerHTML = `<span style="color:var(--success)"><i class="fa-solid fa-check"></i> ${data.message}</span>`;
        } else {
            resultDiv.innerHTML = `<span style="color:var(--warning)">${data.message}</span>`;
        }
    } catch (e) {
        resultDiv.innerHTML = `<span style="color:red">Error: ${e.message}</span>`;
    }
}

window.triggerSort = async function () {
    const targetFile = document.getElementById('sortTarget').value;
    const resultDiv = document.getElementById('sortResult');

    resultDiv.innerHTML = '<i class="fa-solid fa-spinner fa-spin"></i> Sorting...';

    try {
        const res = await fetch('/api/tools/sort', {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({ target_file: targetFile })
        });
        const data = await res.json();
        if (data.status === 'success') {
            resultDiv.innerHTML = `<span style="color:var(--success)"><i class="fa-solid fa-check"></i> ${data.message}</span>`;
        } else {
            resultDiv.innerHTML = `<span style="color:var(--warning)">${data.message}</span>`;
        }
    } catch (e) {
        resultDiv.innerHTML = `<span style="color:red">Error: ${e.message}</span>`;
    }
}

// --- Help Functions ---
window.fetchHelp = async function () {
    const container = document.getElementById('helpContainer');
    container.innerHTML = 'Loading...';

    try {
        const res = await fetch('/api/help/troubleshooting');
        const data = await res.json();
        container.innerHTML = marked.parse(data.content);
    } catch (e) {
        container.innerHTML = 'Failed to load guide.';
    }
}