/* ============================================================
   SoundCloud-Style Audio Recorder + Waveform Display + Analyzer
   ============================================================
*/

// Global variables
let audioContext;
let gumStream;
let rec;
let input;

// DOM Elements
const recordBtn = document.getElementById("recordButton");
const stopBtn = document.getElementById("stopButton");
const pauseBtn = document.getElementById("pauseButton");
const recordingsList = document.getElementById("recordingsList");
const uploadButton = document.getElementById("upload-button");
const uploadInput = document.getElementById("audio-file");
const responseBox = document.getElementById("response");
const metadataBox = document.getElementById("metadata-display");

// ==============================
// Recording Controls
// ==============================

recordBtn.addEventListener("click", startRecording);
stopBtn.addEventListener("click", stopRecording);
pauseBtn.addEventListener("click", pauseRecording);

// Start recording
function startRecording() {
    console.log("Recording started...");

    recordBtn.disabled = true;
    stopBtn.disabled = false;
    pauseBtn.disabled = false;

    navigator.mediaDevices.getUserMedia({ audio: true }).then(function (stream) {
        audioContext = new (window.AudioContext || window.webkitAudioContext)();
        document.getElementById("formats").innerText =
            "Sample rate: " + audioContext.sampleRate + " Hz";

        gumStream = stream;
        input = audioContext.createMediaStreamSource(stream);

        rec = new Recorder(input, { numChannels: 1 });
        rec.record();

    }).catch(function (e) {
        console.error("Could not start recording:", e);
        recordBtn.disabled = false;
        stopBtn.disabled = true;
        pauseBtn.disabled = true;
    });
}

// Pause recording
function pauseRecording() {
    if (rec.recording) {
        rec.stop();
        pauseBtn.innerText = "Resume";
    } else {
        rec.record();
        pauseBtn.innerText = "Pause";
    }
}

// Stop recording
function stopRecording() {
    console.log("Recording stopped.");

    stopBtn.disabled = true;
    recordBtn.disabled = false;
    pauseBtn.disabled = true;
    pauseBtn.innerText = "Pause";

    rec.stop();
    gumStream.getAudioTracks()[0].stop();

    rec.exportWAV(createWaveformItem);
}

// ==============================
// File Upload
// ==============================

uploadButton.addEventListener("click", () => {
    if (!uploadInput.files.length) {
        alert("Select at least one file.");
        return;
    }
    Array.from(uploadInput.files).forEach((file) => handleUploadedFile(file));
});

function handleUploadedFile(file) {
    const url = URL.createObjectURL(file);
    createWaveformItem(file, url);
}

// ==============================
// Create SoundCloud-like Waveform
// ==============================

function createWaveformItem(blob, forcedUrl = null) {
    const url = forcedUrl || URL.createObjectURL(blob);

    const li = document.createElement("li");
    li.className = "wave-item";

    const container = document.createElement("div");
    container.className = "wave-canvas";

    // Waveform and its temporal analysis share one column, so both use the same time axis
    const waveCol = document.createElement("div");
    waveCol.className = "wave-col";
    const timelineEl = document.createElement("div");
    timelineEl.className = "timeline";
    waveCol.appendChild(container);
    waveCol.appendChild(timelineEl);

    const meta = document.createElement("div");
    meta.className = "wave-meta";
    meta.innerHTML = `<div class="file-title">${blob.name || "recording.wav"}</div>`;

    // Play button
    const playBtn = document.createElement("button");
    playBtn.className = "btn btn-play btn-sm";
    playBtn.innerText = "Play";

    // Analyze button
    const analyzeBtn = document.createElement("button");
    analyzeBtn.className = "btn btn-outline-secondary btn-sm";
    analyzeBtn.innerText = "Analyze";

    const controls = document.createElement("div");
    controls.className = "wave-controls";
    controls.appendChild(analyzeBtn);
    controls.appendChild(playBtn);

    li.appendChild(controls);
    li.appendChild(waveCol);
    li.appendChild(meta);
    recordingsList.appendChild(li);

    // Create WaveSurfer
    const wavesurfer = WaveSurfer.create({
        container,
        autoCenter: true,
        waveColor: "#bbb",
        progressColor: "#ff5500",
        cursorColor: "#333",
        barWidth: 2,
        height: 70,
        responsive: true,
    });

    // Analyze
    const item = { blob, wavesurfer, timelineEl, abort: null, timeline: null };
    analyzeBtn.addEventListener("click", () => {
        analyzeAudio(item);
    });

    // Toggle play/pause
    playBtn.addEventListener("click", () => {
        wavesurfer.playPause();
        playBtn.innerText = wavesurfer.isPlaying() ? "Pause" : "Play";
    });
    wavesurfer.on("finish", () => { playBtn.innerText = "Play"; });

    // Keep the timeline's playback cursor in sync with the audio
    const syncCursor = () => item.timeline && item.timeline.setCursor(wavesurfer.getCurrentTime());
    wavesurfer.on("audioprocess", syncCursor);
    wavesurfer.on("seek", syncCursor);

    wavesurfer.load(url);


    // Metadata
    if (metadataBox) blob.arrayBuffer().then((buffer) => {
        const ctx = new AudioContext();
        ctx.decodeAudioData(buffer).then((decoded) => {
            metadataBox.innerHTML = `
                <strong>Channels:</strong> ${decoded.numberOfChannels}<br>
                <strong>Duration:</strong> ${decoded.duration.toFixed(2)}s<br>
                <strong>Sample Rate:</strong> ${decoded.sampleRate} Hz
            `;
        });
    });
}

// ==============================
// Audio Analysis API (placeholder)
// ==============================

async function analyzeAudio(item) {
    const blob = item.blob;
    // Check if the response element exists
    const responseBox = document.getElementById('response');
    if (!responseBox) return;

    responseBox.innerHTML = "<em>Analyzing...</em>";

    // Convert Blob to File
    const file = new File([blob], blob.name || "recording.wav", { type: blob.type });

    const formData = new FormData();
    formData.append("files", file);

    try {
        // Replace the URL with your real backend endpoint
        const res = await fetch("/predict/", {
            method: "POST",
            body: formData,
        });

        const data = await res.json();

        let message = "Prediction Failed!";
        if (data[0]?.status === "success") {
          const item = data[0];
          const confidencePercent = Math.round(item.confidence * 100);
          message = `${item.filename} is ${item.label} with confidence of ${confidencePercent}%`;
        }
        let messageVolume = "... ";
        if (data[0]?.volume === "silent") {
          messageVolume = "The audio appears to be silent or contains no detectable speech. Please record/select another file! ";
          message = ""
        }
        if (data[0]?.volume === "augmented") {
          messageVolume = "The detected speech volume was low, so a volume augmentation was applied before analysis. ";
        }
        const volumeColor = "orange";
      let predictionColor = message.includes("Genuine") ? "green" : "red";

      const silent = data[0]?.volume === "silent";
      responseBox.innerHTML = `
          <div style="font-size: 1.1rem; margin-bottom: 6px; color:${volumeColor};">
              ${messageVolume}
          </div>
          <div style="font-size: 1.25rem; font-weight:600; color:${predictionColor};">
              ${message}
          </div>
      `;
      // Temporal analysis runs after the global score (one CPU-heavy job at a time)
      if (data[0]?.status === "success" && !silent) {
          runTimeline(item, file);
      }
    } catch (err) {
        responseBox.innerHTML = `<div style="font-size: 1.25rem; font-weight:600; color:red;">/!\ Analysis failed.</div>`;
        console.error(err);
    }
}

// ==============================
// Temporal Analysis (sliding window)
// ==============================

const SVG_NS = "http://www.w3.org/2000/svg";
const TL = {
    height: 150,
    padTop: 10,
    padBottom: 22,      // room for the time axis labels
    ink: "#2b3a55",     // the P(genuine) line
    genuineTint: "rgba(12, 163, 12, 0.08)",
    spoofTint: "rgba(208, 59, 59, 0.08)",
    grid: "#e6e6e6",
    cursor: "#ff5500",  // same orange as the waveform progress
};

function svgEl(tag, attrs = {}, parent = null) {
    const el = document.createElementNS(SVG_NS, tag);
    for (const [k, v] of Object.entries(attrs)) el.setAttribute(k, v);
    if (parent) parent.appendChild(el);
    return el;
}

const fmtPct = (p) => `${(p * 100).toFixed(1)}%`;
const fmtSec = (t) => `${t.toFixed(t < 10 ? 2 : 1)} s`;

function niceTimeStep(duration, widthPx) {
    const maxTicks = Math.max(2, Math.floor(widthPx / 60));
    const steps = [0.25, 0.5, 1, 2, 5, 10, 15, 30, 60, 120];
    return steps.find((s) => duration / s <= maxTicks) || 300;
}

// Read an NDJSON stream line by line
async function* readNdjson(response) {
    const reader = response.body.getReader();
    const decoder = new TextDecoder();
    let buffer = "";
    while (true) {
        const { value, done } = await reader.read();
        if (done) break;
        buffer += decoder.decode(value, { stream: true });
        let nl;
        while ((nl = buffer.indexOf("\n")) >= 0) {
            const line = buffer.slice(0, nl).trim();
            buffer = buffer.slice(nl + 1);
            if (line) yield JSON.parse(line);
        }
    }
    if (buffer.trim()) yield JSON.parse(buffer);
}

async function runTimeline(item, file) {
    // A new analysis of the same item replaces the running one
    if (item.abort) item.abort.abort();
    item.abort = new AbortController();

    const windowSec = document.getElementById("tl-window")?.value || "4";
    const hopSec = document.getElementById("tl-hop")?.value || "1";

    const chart = createTimelineChart(item);
    item.timeline = chart;
    chart.setStatus("Temporal analysis: uploading…");

    const formData = new FormData();
    formData.append("file", file);
    formData.append("window_sec", windowSec);
    formData.append("hop_sec", hopSec);

    try {
        const res = await fetch("/timeline/", {
            method: "POST",
            body: formData,
            signal: item.abort.signal,
        });
        if (!res.ok) {
            const err = await res.json().catch(() => ({}));
            throw new Error(err.detail || `HTTP ${res.status}`);
        }
        for await (const msg of readNdjson(res)) {
            if (msg.n_windows !== undefined) chart.setHeader(msg);
            else chart.addSegment(msg);
        }
        chart.finish();
    } catch (err) {
        if (err.name === "AbortError") return;
        console.error(err);
        chart.setStatus(`Temporal analysis failed: ${err.message}`);
    }
}

function createTimelineChart(item) {
    const root = item.timelineEl;
    root.replaceChildren();
    root.classList.add("active");

    const status = document.createElement("div");
    status.className = "timeline-status";
    const plot = document.createElement("div");
    plot.className = "timeline-plot";
    const svg = svgEl("svg", { height: TL.height, role: "img" }, plot);
    const tip = document.createElement("div");
    tip.className = "timeline-tip";
    plot.appendChild(tip);

    // Table view: the same numbers without hovering
    const details = document.createElement("details");
    const summary = document.createElement("summary");
    summary.textContent = "Segment values";
    const table = document.createElement("table");
    const thead = table.createTHead().insertRow();
    ["Start", "End", "P(genuine)", "Decision"].forEach((h) => {
        const th = document.createElement("th");
        th.textContent = h;
        thead.appendChild(th);
    });
    const tbody = table.createTBody();
    details.append(summary, table);

    root.append(status, plot, details);

    const state = { header: null, segments: [], cursor: null, hover: null, done: false };

    const duration = () => {
        const d = item.wavesurfer.getDuration();
        return d > 0 ? d : state.header?.duration || 1;
    };
    const geom = () => {
        const w = plot.clientWidth || 600;
        const h = TL.height;
        const y0 = TL.padTop, y1 = h - TL.padBottom;
        return {
            w, h, y0, y1,
            x: (t) => (t / duration()) * w,
            y: (p) => y1 - p * (y1 - y0),
            t: (px) => Math.min(Math.max(px / w, 0), 1) * duration(),
        };
    };
    const center = (s) => (s.start + s.end) / 2;

    function render() {
        const g = geom();
        svg.replaceChildren();
        svg.setAttribute("viewBox", `0 0 ${g.w} ${g.h}`);

        // Zones: above 50% = genuine, below = spoof
        svgEl("rect", { x: 0, y: g.y0, width: g.w, height: g.y(0.5) - g.y0, fill: TL.genuineTint }, svg);
        svgEl("rect", { x: 0, y: g.y(0.5), width: g.w, height: g.y1 - g.y(0.5), fill: TL.spoofTint }, svg);

        // Hovered window span
        if (state.hover !== null) {
            const s = state.segments[state.hover];
            svgEl("rect", {
                x: g.x(s.start), y: g.y0, width: Math.max(1, g.x(s.end) - g.x(s.start)),
                height: g.y1 - g.y0, fill: "rgba(43, 58, 85, 0.07)",
            }, svg);
        }

        // Grid at 0 / 50 / 100 %, decision threshold dashed
        [0, 0.5, 1].forEach((p) => {
            svgEl("line", {
                x1: 0, x2: g.w, y1: g.y(p), y2: g.y(p),
                stroke: p === 0.5 ? "#9aa0a6" : TL.grid,
                "stroke-width": 1, "stroke-dasharray": p === 0.5 ? "4 3" : "",
            }, svg);
        });
        const ylab = (txt, p, dy) => {
            const t = svgEl("text", { x: g.w - 4, y: g.y(p) + dy, "text-anchor": "end" }, svg);
            t.textContent = txt;
        };
        ylab("100%", 1, 11);
        ylab("50%", 0.5, -4);
        ylab("0%", 0, -4);
        const zlab = (txt, y) => {
            const t = svgEl("text", { x: 4, y, "font-weight": 600 }, svg);
            t.textContent = txt;
        };
        zlab("▲ Genuine", g.y0 + 12);
        zlab("▼ Spoof", g.y1 - 5);

        // Time axis
        const step = niceTimeStep(duration(), g.w);
        for (let t = 0; t <= duration() + 1e-9; t += step) {
            const x = g.x(t);
            svgEl("line", { x1: x, x2: x, y1: g.y1, y2: g.y1 + 4, stroke: "#bbb" }, svg);
            const lbl = svgEl("text", {
                x, y: g.h - 6,
                "text-anchor": t === 0 ? "start" : x > g.w - 20 ? "end" : "middle",
            }, svg);
            lbl.textContent = `${+t.toFixed(2)}s`;
        }

        // P(genuine) line through window centres; silent windows break the line
        let d = "";
        let pen = false;
        state.segments.forEach((s) => {
            if (s.silent) { pen = false; return; }
            d += `${pen ? "L" : "M"}${g.x(center(s)).toFixed(1)},${g.y(s.bonafide_prob).toFixed(1)}`;
            pen = true;
        });
        if (d) {
            svgEl("path", {
                d, fill: "none", stroke: TL.ink, "stroke-width": 2,
                "stroke-linejoin": "round", "stroke-linecap": "round",
            }, svg);
        }

        // Markers (only when sparse enough to stay readable)
        const showDots = state.segments.length <= 60;
        state.segments.forEach((s, i) => {
            const cx = g.x(center(s));
            if (s.silent) {
                svgEl("line", {
                    x1: cx - 4, x2: cx + 4, y1: g.y1 - 3, y2: g.y1 - 3,
                    stroke: "#adb5bd", "stroke-width": 2, "stroke-linecap": "round",
                }, svg);
                return;
            }
            if (!showDots && i !== state.hover) return;
            svgEl("circle", {
                cx, cy: g.y(s.bonafide_prob), r: i === state.hover ? 5 : 3.5,
                fill: TL.ink, stroke: "#fff", "stroke-width": 2,
            }, svg);
        });

        // Crosshair on hover
        if (state.hover !== null) {
            const x = g.x(center(state.segments[state.hover]));
            svgEl("line", { x1: x, x2: x, y1: g.y0, y2: g.y1, stroke: TL.ink, "stroke-width": 1, opacity: 0.4 }, svg);
        }

        // Playback cursor
        if (state.cursor !== null) {
            const x = g.x(state.cursor);
            svgEl("line", { x1: x, x2: x, y1: 0, y2: g.y1, stroke: TL.cursor, "stroke-width": 2 }, svg);
        }

        svg.setAttribute("aria-label", ariaSummary());
    }

    function ariaSummary() {
        const scored = state.segments.filter((s) => !s.silent);
        if (!scored.length) return "Temporal analysis: no scored segments yet";
        const spoofed = scored.filter((s) => s.bonafide_prob < 0.5).length;
        return `Probability of genuine speech over time: ${spoofed} of ${scored.length} segments below 50%`;
    }

    function updateStatus() {
        const h = state.header;
        if (!h) return;
        const n = state.segments.length;
        const cfg = `window ${h.window_sec} s · hop ${h.hop_sec} s`;
        status.replaceChildren();
        const strong = document.createElement("strong");
        if (!state.done) {
            strong.textContent = `Temporal analysis: ${n} / ${h.n_windows} segments`;
            status.append(strong, ` · ${cfg} · computing…`);
            return;
        }
        const scored = state.segments.filter((s) => !s.silent);
        const spoofed = scored.filter((s) => s.bonafide_prob < 0.5).length;
        const silent = n - scored.length;
        strong.textContent = `${spoofed} of ${scored.length} segments look spoofed`;
        status.append(
            strong,
            ` · ${cfg}${silent ? ` · ${silent} silent segment${silent > 1 ? "s" : ""} not scored` : ""}`,
        );
    }

    function addRow(s) {
        const row = tbody.insertRow();
        [
            fmtSec(s.start),
            fmtSec(s.end),
            s.silent ? "—" : fmtPct(s.bonafide_prob),
            s.silent ? "silent" : s.bonafide_prob >= 0.5 ? "Genuine" : "Spoof",
        ].forEach((v) => { row.insertCell().textContent = v; });
    }

    // Hover: snap to the nearest window centre
    function showTip(i) {
        const s = state.segments[i];
        const g = geom();
        tip.replaceChildren();
        const value = document.createElement("div");
        value.className = "tip-value";
        value.textContent = s.silent ? "silent" : `${fmtPct(s.bonafide_prob)} genuine`;
        const label = document.createElement("div");
        label.className = "tip-label";
        label.textContent = `${fmtSec(s.start)} – ${fmtSec(s.end)}`
            + (s.silent ? " · not scored" : ` · ${s.bonafide_prob >= 0.5 ? "Genuine" : "Spoof"}`);
        tip.append(value, label);
        tip.style.display = "block";
        const x = g.x(center(s));
        const tw = tip.offsetWidth;
        tip.style.left = `${Math.min(Math.max(x - tw / 2, 0), g.w - tw)}px`;
        tip.style.top = `${Math.max(0, (s.silent ? g.y1 : g.y(s.bonafide_prob)) - tip.offsetHeight - 10)}px`;
    }

    svg.addEventListener("pointermove", (e) => {
        if (!state.segments.length) return;
        const t = geom().t(e.offsetX);
        let best = 0;
        state.segments.forEach((s, i) => {
            if (Math.abs(center(s) - t) < Math.abs(center(state.segments[best]) - t)) best = i;
        });
        if (best !== state.hover) {
            state.hover = best;
            render();
        }
        showTip(best);
    });
    svg.addEventListener("pointerleave", () => {
        state.hover = null;
        tip.style.display = "none";
        render();
    });
    // Click to play from that point
    svg.addEventListener("click", (e) => {
        const g = geom();
        item.wavesurfer.seekTo(g.t(e.offsetX) / duration());
    });

    new ResizeObserver(() => render()).observe(plot);
    render();

    return {
        setStatus(text) { status.textContent = text; },
        setHeader(h) { state.header = h; updateStatus(); render(); },
        addSegment(s) { state.segments.push(s); addRow(s); updateStatus(); render(); },
        finish() { state.done = true; updateStatus(); render(); },
        setCursor(t) { state.cursor = t; render(); },
    };
}