// Detect view — find singing segments in one video, export editor markers.

import { h, clear, basename, fmtDur } from "../dom";
import { makeProgress, toast, renderSongs } from "../ui";
import {
  pickVideo, detectSongs, cancel, exportSegments, onDetectProgress, reveal,
  type Segment,
} from "../api";

export interface View { el: HTMLElement; onDrop: (paths: string[]) => void; setVideo: (p: string) => void; }

const FPS = ["29.97", "25", "23.976", "30", "60"];

function numField(label: string, value: number, step = "1"): [HTMLElement, HTMLInputElement] {
  const input = h("input", { class: "input", type: "number", value: String(value), step, min: "0" }) as HTMLInputElement;
  return [h("div", { class: "field" }, h("label", {}, label), input), input];
}

export function buildDetect(): View {
  let running = false;
  let segments: Segment[] = [];
  let videoPath = "";

  const videoInput = h("input", { class: "input grow", placeholder: "Select a video…", readonly: true }) as HTMLInputElement;
  const [gapF, gapI] = numField("Merge gap (s)", 10);
  const [minF, minI] = numField("Min duration (s)", 20);
  const [padF, padI] = numField("Padding (s)", 2);
  const fpsSel = h("select", { class: "input" }, ...FPS.map((f) => h("option", { value: f }, f))) as HTMLSelectElement;

  const detectBtn = h("button", { class: "btn primary lg", disabled: true }, "🎤  Detect Songs") as HTMLButtonElement;
  const stopBtn = h("button", { class: "btn danger", disabled: true }, "■ Stop") as HTMLButtonElement;
  const exportBtn = h("button", { class: "btn", disabled: true }, "⬇ Export EDL / CSV") as HTMLButtonElement;
  const revealBtn = h("button", { class: "btn ghost", style: "display:none" }, "Show in folder") as HTMLButtonElement;
  const progress = makeProgress();
  const statsEl = h("div", { class: "pills" });
  const songsEl = h("div", { class: "songs" });
  let lastExportDir = "";

  function setVideo(p: string) {
    videoPath = p;
    videoInput.value = basename(p);
    videoInput.title = p;
    detectBtn.disabled = running || !p;
  }

  async function detect() {
    if (!videoPath) return;
    running = true;
    detectBtn.disabled = true;
    stopBtn.disabled = false;
    exportBtn.disabled = true;
    revealBtn.style.display = "none";
    clear(songsEl); clear(statsEl);
    progress.reset();
    progress.indeterminate(true, "Starting detection…");

    const un = await onDetectProgress((msg) => {
      progress.indeterminate(true, msg);
      progress.appendLog(msg);
    });

    try {
      const res = await detectSongs(videoPath, +gapI.value, +minI.value, +padI.value);
      segments = res.segments;
      progress.indeterminate(false);
      progress.set(1, `Found ${segments.length} singing segment(s).`);
      renderSongs(songsEl, segments);
      const totalSing = segments.reduce((a, s) => a + s.duration, 0);
      statsEl.replaceChildren(
        h("span", { class: "pill" }, `${segments.length} songs`),
        h("span", { class: "pill" }, `singing ${fmtDur(totalSing)}`),
        ...Object.entries(res.stats || {}).map(([k, v]) =>
          h("span", { class: "pill" }, `${k} ${fmtDur(v as number)}`)),
      );
      exportBtn.disabled = segments.length === 0;
      if (!segments.length) toast("No singing detected — try a larger gap or smaller min duration.", "");
    } catch (e) {
      const msg = String(e);
      progress.indeterminate(false);
      if (msg.includes("__cancelled__")) progress.set(0, "Stopped by user.");
      else { progress.set(0, "Detection failed."); toast(msg, "err"); }
    } finally {
      un();
      running = false;
      stopBtn.disabled = true;
      detectBtn.disabled = !videoPath;
    }
  }

  exportBtn.addEventListener("click", async () => {
    if (!segments.length) return;
    try {
      const res = await exportSegments(segments, videoPath, null, +fpsSel.value);
      lastExportDir = res.files[0] ?? "";
      toast(`Exported ${res.files.length} files`, "ok");
      if (lastExportDir) revealBtn.style.display = "";
    } catch (e) { toast(String(e), "err"); }
  });
  revealBtn.addEventListener("click", () => lastExportDir && reveal(lastExportDir));
  detectBtn.addEventListener("click", detect);
  stopBtn.addEventListener("click", () => cancel());

  const el = h("div", { class: "view" },
    h("div", { class: "card" },
      h("h2", {}, h("span", { class: "step" }, "1"), "Source Video"),
      h("div", { class: "row" }, videoInput,
        h("button", { class: "btn", onclick: async () => { const p = await pickVideo(); if (p) setVideo(p); } }, "Browse…")),
      h("div", { class: "hint", style: "margin-top:8px" }, "Tip: drop a file here, or use a Concat output."),
    ),
    h("div", { class: "card" },
      h("h2", {}, h("span", { class: "step" }, "2"), "Detection Settings"),
      h("div", { class: "row wrap" },
        h("div", { class: "grow", style: "min-width:130px" }, gapF),
        h("div", { class: "grow", style: "min-width:130px" }, minF),
        h("div", { class: "grow", style: "min-width:130px" }, padF),
        h("div", { class: "field", style: "min-width:120px" }, h("label", {}, "FPS (export)"), fpsSel)),
      h("div", { class: "hint", style: "margin-top:8px" }, "Singing = \"music\". More chatting between songs → raise the gap. Short covers → lower the min duration."),
    ),
    h("div", { class: "card" },
      h("h2", {}, h("span", { class: "step" }, "3"), "Run"),
      h("div", { class: "row", style: "margin-bottom:14px" }, detectBtn, stopBtn, exportBtn, revealBtn),
      progress.root,
      h("div", { style: "margin-top:12px" }, statsEl),
      h("div", { style: "margin-top:10px" }, songsEl),
    ),
  );

  return { el, onDrop: (paths) => { if (paths[0]) setVideo(paths[0]); }, setVideo };
}