"use strict";

/* ------------------------------------------------------------------ *
 * Radar System web client.
 * Streams the live Qt plot as an image (latest-wins) + REST controls +
 * the processor live-settings panel, synced both ways with the desktop.
 * ------------------------------------------------------------------ */

/* ---- DOM handles ------------------------------------------------- */
const plotImg = document.getElementById("plot");

const btnStart = document.getElementById("btn-start");
const btnSingle = document.getElementById("btn-single");
const btnStop = document.getElementById("btn-stop");
const btnTmpRef = document.getElementById("btn-tmp-ref");
const btnApply = document.getElementById("btn-apply");
const btnResetHistory = document.getElementById("btn-reset-history");
const btnLoadConfig = document.getElementById("btn-load-config");
const configSelect = document.getElementById("config-select");
const configActiveEl = document.getElementById("config-active");
const savePathInput = document.getElementById("save-path");
const saveNameInput = document.getElementById("save-name");
const btnSaveDataset = document.getElementById("btn-save-dataset");

const settingsToggle = document.getElementById("settings-toggle");
const sidePanel = document.querySelector(".side-panel");
const settingsFields = document.getElementById("settings-fields");
const settingsNote = document.getElementById("settings-note");

const runningEl = document.getElementById("stat-running");
const processorEl = document.getElementById("stat-processor");
const ringEl = document.getElementById("stat-ring");
const scansEl = document.getElementById("stat-scans");
const staleEl = document.getElementById("stat-stale");
const toastEl = document.getElementById("toast");

/* ---- state ------------------------------------------------------- */
let pendingPng = null;       // newest PNG (base64), shown on the next animation frame
let lastFrameTs = 0;         // performance.now() of the last received frame
let pipelineRunning = false; // gates the config loader (loading requires a stopped pipeline)
let saveFieldsPrefilled = false; // seed the save path/name fields once, then leave the operator's edits

/* ---- helpers ----------------------------------------------------- */
function toast(message, isError) {
  toastEl.textContent = message;
  toastEl.classList.toggle("error", !!isError);
  toastEl.classList.add("show");
  clearTimeout(toast._t);
  toast._t = setTimeout(() => toastEl.classList.remove("show"), 2600);
}

async function api(path, body) {
  const opts = { method: body === undefined ? "GET" : "POST" };
  if (body !== undefined) {
    opts.headers = { "Content-Type": "application/json" };
    opts.body = JSON.stringify(body);
  }
  const res = await fetch(path, opts);
  let data = null;
  try { data = await res.json(); } catch (_) { /* empty body */ }
  if (!res.ok) {
    const detail = (data && data.detail) || `HTTP ${res.status}`;
    throw new Error(detail);
  }
  return data;
}

/* ---- controls ---------------------------------------------------- */
function bindControl(button, path, body) {
  button.addEventListener("click", async () => {
    button.disabled = true;
    try {
      await api(path, body);
    } catch (err) {
      toast(err.message, true);
    } finally {
      button.disabled = false;
    }
  });
}
bindControl(btnStart, "/api/start", {});
bindControl(btnSingle, "/api/single_capture", {});
bindControl(btnStop, "/api/stop", {});
bindControl(btnTmpRef, "/api/tmp_reference", {});

/* ---- settings panel --------------------------------------------- */
settingsToggle.addEventListener("click", () => sidePanel.classList.toggle("collapsed"));

// The form is built ENTIRELY from the schema the server derives from the Qt widgets
// (field, group, kind, options, ranges, value, enabled). The web hardcodes nothing
// and shows only the active mode's fields, so it always mirrors the desktop.
const fieldInputs = {}; // field name -> { el, kind, dirty }
let formSignature = ""; // field names currently in the form (detect mode/structure change)

function makeFieldRow(entry) {
  const row = document.createElement("div");
  row.className = "field";
  const label = document.createElement("label");
  label.textContent = entry.name;
  label.htmlFor = "f_" + entry.name;
  if (entry.applies_on_start) {
    // Stable run_config field: editing it here takes effect on the next pipeline start.
    const hint = document.createElement("span");
    hint.className = "on-start-hint";
    hint.textContent = " (on Start)";
    hint.title = "Applied when the pipeline next starts";
    label.appendChild(hint);
  }
  row.appendChild(label);

  let el;
  if (entry.kind === "bool") {
    el = document.createElement("input");
    el.type = "checkbox";
    el.checked = !!entry.value;
  } else if (entry.kind === "select") {
    el = document.createElement("select");
    for (const opt of entry.options || []) {
      const o = document.createElement("option");
      o.value = opt;
      o.textContent = opt;
      el.appendChild(o);
    }
    el.value = String(entry.value);
  } else if (entry.kind === "int" || entry.kind === "float") {
    el = document.createElement("input");
    el.type = "number";
    if (entry.min != null) el.min = entry.min;
    if (entry.max != null) el.max = entry.max;
    el.step = entry.kind === "float" ? (entry.step || "any") : (entry.step || 1);
    el.value = entry.value;
  } else if (entry.kind === "textarea") {
    el = document.createElement("textarea");
    el.rows = 3;
    el.value = entry.value == null ? "" : String(entry.value);
  } else {
    el = document.createElement("input");
    el.type = "text";
    el.value = entry.value == null ? "" : String(entry.value);
  }
  el.id = "f_" + entry.name;
  if (entry.enabled === false) el.disabled = true;

  // Mark dirty while edited so a live push never overwrites a half-entered value.
  const markDirty = () => { fieldInputs[entry.name].dirty = true; };
  el.addEventListener("input", markDirty);
  el.addEventListener("change", markDirty);
  // Switching mode changes which settings are shown — apply it immediately.
  if (entry.name === "processor_mode") {
    el.addEventListener("change", () => applyOne("processor_mode", el.value));
  }
  row.appendChild(el);
  fieldInputs[entry.name] = { el, kind: entry.kind, dirty: false };
  return row;
}

function buildSettingsForm(schema) {
  settingsFields.innerHTML = "";
  for (const key in fieldInputs) delete fieldInputs[key];
  let lastGroup = null;
  for (const entry of schema) {
    if (entry.group !== lastGroup) {
      lastGroup = entry.group;
      const heading = document.createElement("div");
      heading.className = "group-title";
      heading.textContent = entry.group;
      settingsFields.appendChild(heading);
    }
    settingsFields.appendChild(makeFieldRow(entry));
  }
  formSignature = schema.map((e) => e.name).join(",");
}

function collectFields() {
  const out = {};
  for (const key in fieldInputs) {
    const { el, kind } = fieldInputs[key];
    if (kind === "bool") out[key] = el.checked;
    else if (kind === "int") out[key] = parseInt(el.value, 10);
    else if (kind === "float") out[key] = parseFloat(el.value);
    else out[key] = el.value; // select + text (positions are sent as CSV text)
  }
  return out;
}

function setFieldValue(input, value) {
  const { el, kind } = input;
  if (kind === "bool") el.checked = !!value;
  else if (kind === "select") el.value = String(value);
  else el.value = value == null ? "" : value;
}

function clearDirty() {
  for (const key in fieldInputs) fieldInputs[key].dirty = false;
}

async function applyOne(field, value) {
  try {
    await api("/api/live_settings", { [field]: value });
  } catch (err) {
    toast(err.message, true);
  }
}

// Update the form from a schema pushed by the desktop. Rebuild if the field set
// changed (e.g. the mode switched); otherwise update values in place without
// clobbering a field the operator is editing here.
function applySettings(schema) {
  if (schema.map((e) => e.name).join(",") !== formSignature) {
    buildSettingsForm(schema);
    return;
  }
  for (const entry of schema) {
    const input = fieldInputs[entry.name];
    if (!input || input.el === document.activeElement || input.dirty) continue;
    setFieldValue(input, entry.value);
    if (entry.enabled !== undefined) input.el.disabled = entry.enabled === false;
  }
}

btnApply.addEventListener("click", async () => {
  btnApply.disabled = true;
  try {
    await api("/api/live_settings", collectFields());
    clearDirty();  // applied; let live pushes update the form again
    settingsNote.textContent = "Applied.";
  } catch (err) {
    settingsNote.textContent = err.message;
    toast(err.message, true);
  } finally {
    btnApply.disabled = false;
  }
});

btnResetHistory.addEventListener("click", async () => {
  btnResetHistory.disabled = true;
  try {
    await api("/api/live_settings", { history_command: "clear_all" });
    settingsNote.textContent = "History reset requested.";
  } catch (err) {
    settingsNote.textContent = err.message;
    toast(err.message, true);
  } finally {
    btnResetHistory.disabled = false;
  }
});

async function loadSettings() {
  try {
    const cfg = await api("/api/live_settings");
    buildSettingsForm(cfg);
  } catch (err) {
    settingsNote.textContent = "Could not load settings: " + err.message;
  }
}

/* ---- config profile --------------------------------------------- */
// Loading a config does exactly what the desktop "Load Config" button does. The file
// list comes from the server's run_configs/ directory (the browser has no file access),
// and loading is gated to a stopped pipeline — mirroring the desktop precondition.
function updateLoadButtonState() {
  btnLoadConfig.disabled = pipelineRunning || configSelect.options.length === 0;
}

async function loadConfigList() {
  try {
    const { names = [] } = await api("/api/configs");
    const previous = configSelect.value;
    configSelect.innerHTML = "";
    for (const name of names) {
      const opt = document.createElement("option");
      opt.value = name;
      opt.textContent = name;
      configSelect.appendChild(opt);
    }
    if (names.includes(previous)) configSelect.value = previous; // keep the operator's choice
    updateLoadButtonState();
  } catch (err) {
    toast("Could not load config list: " + err.message, true);
  }
}

btnLoadConfig.addEventListener("click", async () => {
  const name = configSelect.value;
  if (!name) return;
  btnLoadConfig.disabled = true;
  try {
    await api("/api/load_config", { name });
    toast(`Config loaded: ${name}`); // the new settings schema arrives via the live status push
  } catch (err) {
    toast(err.message, true);
  } finally {
    updateLoadButtonState();
  }
});

/* ---- save dataset ----------------------------------------------- */
// Saves to the path in the field, mirroring the desktop "Save Dataset" button exactly.
btnSaveDataset.addEventListener("click", async () => {
  btnSaveDataset.disabled = true;
  try {
    await api("/api/save_dataset", {
      path: savePathInput.value.trim(),
      name: saveNameInput.value.trim(),
    });
    toast("Save requested"); // a radar-config prefix is prepended to the name server-side
  } catch (err) {
    toast(err.message, true);
  } finally {
    btnSaveDataset.disabled = false;
  }
});

/* ---- status ------------------------------------------------------ */
function setStat(el, label, value, cls) {
  el.className = "stat" + (cls ? " " + cls : "");
  el.innerHTML = label + ": <b></b>";
  el.querySelector("b").textContent = value;
}

function applyStatus(s) {
  if ("running" in s) {
    setStat(runningEl, "running", s.running ? "yes" : "no", s.running ? "ok" : "off");
    pipelineRunning = !!s.running;
    updateLoadButtonState();
  }
  if ("active_config" in s)
    configActiveEl.textContent = s.active_config ? `current: ${s.active_config}` : "";
  if ("save_path" in s && !saveFieldsPrefilled) {
    savePathInput.value = s.save_path || ""; // seed once; don't clobber later edits
    saveNameInput.value = s.save_name || "";
    saveFieldsPrefilled = true;
  }
  if ("processor_running" in s)
    setStat(processorEl, "processor", s.processor_running ? "yes" : "no",
      s.processor_running ? "ok" : "off");
  if ("ring_name" in s) setStat(ringEl, "ring", s.ring_name || "—",
    s.ring_name ? "" : "off");
  if ("raw_count" in s)
    setStat(scansEl, "scans",
      `raw ${s.raw_count} / preprocessed ${s.preprocessed_count} / results ${s.result_count}`);
}

/* ---- frame rendering (latest-wins; the frame IS the Qt plot image) - */
function renderLoop() {
  if (pendingPng !== null) {
    // Show exactly what the desktop draws; the browser scales it to fit (CSS).
    plotImg.src = "data:image/png;base64," + pendingPng;
    pendingPng = null;
  }
  // Stale indicator (>2s without a frame).
  const stale = performance.now() - lastFrameTs > 2000;
  staleEl.classList.toggle("stale", stale && lastFrameTs > 0);
  staleEl.textContent = lastFrameTs === 0 ? "no data" : stale ? "stale" : "live";
  requestAnimationFrame(renderLoop);
}

/* ---- WebSocket --------------------------------------------------- */
function connectWs() {
  const proto = location.protocol === "https:" ? "wss:" : "ws:";
  const ws = new WebSocket(`${proto}//${location.host}/ws`);
  ws.onmessage = (ev) => {
    let msg;
    try { msg = JSON.parse(ev.data); } catch (_) { return; }
    if (msg.type === "frame") {
      pendingPng = msg.png_b64; // latest-wins; rAF swaps the image
      lastFrameTs = performance.now();
    } else if (msg.type === "status") {
      applyStatus(msg);
    } else if (msg.type === "settings") {
      applySettings(msg.schema); // live desktop schema mirrors into the form
    }
  };
  ws.onclose = () => setTimeout(connectWs, 1500);
  ws.onerror = () => ws.close();
}

/* ---- boot -------------------------------------------------------- */
async function init() {
  requestAnimationFrame(renderLoop);
  try {
    applyStatus(await api("/api/status"));
  } catch (err) {
    settingsNote.textContent = "Status unavailable: " + err.message;
  }
  await loadSettings();
  await loadConfigList();
  connectWs();
}
init();