// Dashcam page: scan for a USB dashcam, then trigger importing its videos.
// Uses plain fetch() (not socket.io / yaris.js) since this is a one-shot
// request/response flow, not a live data stream, and yaris.js assumes DOM
// elements (#map, #speedGraph) that don't exist on this page.

const deviceStatus = document.getElementById('dash-device-status');
const importStatus = document.getElementById('dash-import-status');
const scanBtn = document.getElementById('dash-scan-btn');
const importBtn = document.getElementById('dash-import-btn');

function describeDevice(device) {
    const label = device.label ? ` "${device.label}"` : '';
    return `${device.path}${label} (${device.size}, ${device.fstype || 'unknown fs'})`;
}

function scanForDashcam() {
    deviceStatus.textContent = 'Scanning...';
    importBtn.disabled = true;

    fetch('/api/dash/devices')
        .then(response => response.json())
        .then(data => {
            const devices = data.devices || [];
            if (devices.length === 0) {
                deviceStatus.textContent = 'No USB dashcam/storage device detected. Plug it in and scan again.';
                return;
            }
            deviceStatus.textContent = 'Detected: ' + devices.map(describeDevice).join(', ');
            importBtn.disabled = false;
        })
        .catch(err => {
            deviceStatus.textContent = 'Error while scanning: ' + err;
        });
}

function importDashcam() {
    importStatus.textContent = 'Importing... this can take a while for large videos.';
    importBtn.disabled = true;

    fetch('/api/dash/import', { method: 'POST' })
        .then(response => response.json())
        .then(summary => {
            if (summary.status !== 'ok') {
                importStatus.textContent = summary.message || ('Import failed: ' + summary.status);
                return;
            }
            let text = `Found ${summary.found} video(s), copied ${summary.copied}, skipped ${summary.skipped} (already imported).`;
            if (summary.errors && summary.errors.length > 0) {
                text += ` Errors: ${summary.errors.join('; ')}`;
            }
            importStatus.textContent = text;
        })
        .catch(err => {
            importStatus.textContent = 'Error while importing: ' + err;
        })
        .finally(() => {
            importBtn.disabled = false;
        });
}

scanBtn.addEventListener('click', scanForDashcam);
importBtn.addEventListener('click', importDashcam);

// Auto-scan once when the page loads.
scanForDashcam();

// --- Remote server upload status/toggle ---

const uploadStatusEl = document.getElementById('upload-status');
const dashcamToggle = document.getElementById('dashcam-upload-toggle');

function describeUploadStatus(status) {
    if (!status.configured) {
        return 'Remote server not configured on this device (see db/upload_creds.env).';
    }
    let text = `Pending trip-log rows to upload: ${status.pending_tracking_rows}.`;
    if (status.last_success_at) {
        text += ` Last successful upload: ${status.last_success_at}`;
        if (status.last_network_path) {
            text += ` (via ${status.last_network_path === 'cellular' ? 'cellular fallback' : 'WiFi/Ethernet'})`;
        }
        text += '.';
    }
    if (status.cellular_fallback_configured) {
        text += ' Cellular (SIM868) fallback is enabled for trip logs if WiFi/Ethernet is unreachable.';
    }
    if (status.last_error) {
        text += ` Last error: ${status.last_error}.`;
    }
    return text;
}

function refreshUploadStatus() {
    fetch('/api/upload/status')
        .then(response => response.json())
        .then(status => {
            uploadStatusEl.textContent = describeUploadStatus(status);
            dashcamToggle.checked = status.dashcam_upload_enabled;
            dashcamToggle.disabled = !status.configured;
        })
        .catch(err => {
            uploadStatusEl.textContent = 'Error while checking upload status: ' + err;
        });
}

dashcamToggle.addEventListener('change', () => {
    fetch('/api/upload/dashcam_toggle', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ enabled: dashcamToggle.checked }),
    })
        .then(response => response.json())
        .then(status => {
            uploadStatusEl.textContent = describeUploadStatus(status);
            dashcamToggle.checked = status.dashcam_upload_enabled;
        })
        .catch(err => {
            uploadStatusEl.textContent = 'Error while updating toggle: ' + err;
        });
});

refreshUploadStatus();
setInterval(refreshUploadStatus, 15000);

// --- Relay via phone ---
// Lets a phone (open on this same page, over the Pi's hotspot/LAN) download
// pending dashcam files from the Pi and re-upload them directly to the
// remote server using its own network, reusing the exact same chunked
// upload wire protocol the Pi's own background uploader uses
// (/api/v1/dashcam/upload/status + /chunk) - just orchestrated by this
// browser instead of the Pi's Python client. Downloads are pulled in the
// same chunk size and immediately re-uploaded, one at a time, so the phone
// never has to hold a whole (300+MB) file in memory at once.

const relayStatusEl = document.getElementById('relay-status');
const relayRefreshBtn = document.getElementById('relay-refresh-btn');
const relayAllBtn = document.getElementById('relay-all-btn');
const relayStopBtn = document.getElementById('relay-stop-btn');
const relayFileList = document.getElementById('relay-file-list');

let relayConfig = null;
let pendingFiles = [];
const relayRowEls = new Map(); // relative_path -> { statusSpan, btn }
let heartbeatTimer = null;
let activeRelayCount = 0;
let relayStopRequested = false;

function humanSize(bytes) {
    if (bytes >= 1024 * 1024 * 1024) return (bytes / (1024 * 1024 * 1024)).toFixed(2) + ' GB';
    if (bytes >= 1024 * 1024) return (bytes / (1024 * 1024)).toFixed(1) + ' MB';
    if (bytes >= 1024) return (bytes / 1024).toFixed(1) + ' KB';
    return bytes + ' B';
}

function getRelayConfig() {
    if (relayConfig) return Promise.resolve(relayConfig);
    return fetch('/api/dash/relay/config')
        .then(response => response.json())
        .then(config => {
            relayConfig = config;
            return config;
        });
}

function startHeartbeat() {
    activeRelayCount++;
    relayStopBtn.disabled = false;
    if (heartbeatTimer) return;
    fetch('/api/dash/relay/heartbeat', { method: 'POST' }).catch(() => {});
    heartbeatTimer = setInterval(() => {
        fetch('/api/dash/relay/heartbeat', { method: 'POST' }).catch(() => {});
    }, 15000);
}

function stopHeartbeatIfIdle() {
    activeRelayCount = Math.max(0, activeRelayCount - 1);
    if (activeRelayCount > 0) return;
    if (heartbeatTimer) {
        clearInterval(heartbeatTimer);
        heartbeatTimer = null;
    }
    relayStopBtn.disabled = true;
    fetch('/api/dash/relay/stop', { method: 'POST' }).catch(() => {});
}

relayStopBtn.addEventListener('click', () => {
    relayStopRequested = true;
    activeRelayCount = 0;
    if (heartbeatTimer) {
        clearInterval(heartbeatTimer);
        heartbeatTimer = null;
    }
    fetch('/api/dash/relay/stop', { method: 'POST' }).catch(() => {});
    relayStatusEl.textContent = 'Relay stopped - the Pi will resume its own uploads shortly.';
    relayStopBtn.disabled = true;
});

// Best-effort: try to release the pause lease immediately if the page is
// closed mid-relay (it also self-expires after ~45s either way).
window.addEventListener('beforeunload', () => {
    if (heartbeatTimer && navigator.sendBeacon) {
        navigator.sendBeacon('/api/dash/relay/stop');
    }
});

async function fetchChunkWithRetry(relativePath, start, end, attempts = 3) {
    let lastErr;
    for (let attempt = 1; attempt <= attempts; attempt++) {
        try {
            const response = await fetch(`/api/dash/file/${encodeURIComponent(relativePath)}`, {
                headers: { Range: `bytes=${start}-${end}` },
            });
            if (!response.ok && response.status !== 206) {
                throw new Error(`download HTTP ${response.status}`);
            }
            return await response.blob();
        } catch (err) {
            lastErr = err;
            await new Promise(r => setTimeout(r, 1000 * attempt));
        }
    }
    throw lastErr;
}

async function uploadChunkWithRetry(config, relativePath, sha256, chunkIndex, totalChunks, blob, attempts = 3) {
    let lastErr;
    for (let attempt = 1; attempt <= attempts; attempt++) {
        try {
            const form = new FormData();
            form.append('relative_path', relativePath);
            form.append('sha256', sha256);
            form.append('chunk_index', String(chunkIndex));
            form.append('total_chunks', String(totalChunks));
            form.append('file', blob, `chunk_${chunkIndex}`);
            const response = await fetch(`${config.server_url}/api/v1/dashcam/upload/chunk`, {
                method: 'POST',
                headers: { 'X-Device-Name': config.device_name, 'X-Api-Key': config.api_key },
                body: form,
            });
            if (!response.ok) {
                throw new Error(`upload HTTP ${response.status}`);
            }
            return await response.json();
        } catch (err) {
            lastErr = err;
            await new Promise(r => setTimeout(r, 1000 * attempt));
        }
    }
    throw lastErr;
}

async function relayOneFile(file, statusEl) {
    const config = await getRelayConfig();
    if (!config.configured) {
        statusEl.textContent = 'Remote server not configured on this device.';
        return;
    }

    relayStopRequested = false;
    startHeartbeat();
    try {
        const statusResp = await fetch(
            `${config.server_url}/api/v1/dashcam/upload/status?relative_path=${encodeURIComponent(file.relative_path)}&sha256=${file.sha256}`,
            { headers: { 'X-Device-Name': config.device_name, 'X-Api-Key': config.api_key } }
        );
        if (!statusResp.ok) throw new Error(`status check HTTP ${statusResp.status}`);
        const status = await statusResp.json();

        if (status.status !== 'already_uploaded') {
            const received = new Set(status.received_chunk_indices || []);
            const totalChunks = Math.max(1, Math.ceil(file.size / config.chunk_size));

            for (let idx = 0; idx < totalChunks; idx++) {
                if (relayStopRequested) {
                    statusEl.textContent = 'Stopped.';
                    return;
                }
                if (received.has(idx)) continue;

                const start = idx * config.chunk_size;
                const end = Math.min(start + config.chunk_size, file.size) - 1;
                statusEl.textContent = `Relaying... chunk ${idx + 1}/${totalChunks}`;

                const blob = await fetchChunkWithRetry(file.relative_path, start, end);
                await uploadChunkWithRetry(config, file.relative_path, file.sha256, idx, totalChunks, blob);
            }
        }

        // Update the Pi's own local dedupe table right away so the pending
        // list (and its own background uploader) reflect this immediately,
        // instead of waiting for its next full backlog scan.
        await fetch('/api/dash/relay/mark_uploaded', {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({ relative_path: file.relative_path, sha256: file.sha256 }),
        }).catch(() => {});

        statusEl.textContent = 'Done.';
        pendingFiles = pendingFiles.filter(f => f.relative_path !== file.relative_path);
    } catch (err) {
        statusEl.textContent = 'Error: ' + err;
        throw err;
    } finally {
        stopHeartbeatIfIdle();
    }
}

function renderPendingFiles() {
    relayFileList.innerHTML = '';
    relayRowEls.clear();

    if (pendingFiles.length === 0) {
        relayStatusEl.textContent = 'No pending dashcam files to relay.';
        relayAllBtn.disabled = true;
        return;
    }

    relayStatusEl.textContent = `${pendingFiles.length} file(s) pending upload.`;
    relayAllBtn.disabled = false;

    pendingFiles.forEach(file => {
        const li = document.createElement('li');
        li.className = 'list-group-item d-flex justify-content-between align-items-center flex-wrap gap-2';

        const label = document.createElement('span');
        label.textContent = `${file.relative_path} (${humanSize(file.size)})`;

        const statusSpan = document.createElement('span');
        statusSpan.className = 'text-muted small';

        const btn = document.createElement('button');
        btn.className = 'btn btn-sm btn-outline-primary';
        btn.type = 'button';
        btn.textContent = 'Relay';
        btn.addEventListener('click', () => {
            btn.disabled = true;
            relayOneFile(file, statusSpan).finally(() => {
                btn.disabled = false;
            });
        });

        li.appendChild(label);
        li.appendChild(statusSpan);
        li.appendChild(btn);
        relayFileList.appendChild(li);
        relayRowEls.set(file.relative_path, { statusSpan, btn });
    });
}

function refreshPendingFiles() {
    relayStatusEl.textContent = 'Checking pending files...';
    fetch('/api/dash/pending')
        .then(response => response.json())
        .then(data => {
            pendingFiles = data.files || [];
            renderPendingFiles();
        })
        .catch(err => {
            relayStatusEl.textContent = 'Error while checking pending files: ' + err;
        });
}

relayRefreshBtn.addEventListener('click', refreshPendingFiles);

relayAllBtn.addEventListener('click', async () => {
    relayStopRequested = false;
    relayAllBtn.disabled = true;
    for (const file of pendingFiles.slice()) {
        if (relayStopRequested) break;
        const row = relayRowEls.get(file.relative_path);
        const statusSpan = row ? row.statusSpan : relayStatusEl;
        if (row) row.btn.disabled = true;
        try {
            await relayOneFile(file, statusSpan);
        } catch (err) {
            // Keep going with the remaining files even if one fails.
        }
    }
    relayAllBtn.disabled = pendingFiles.length === 0;
});

refreshPendingFiles();