import { syncAriaRadioGroup } from "../shared/dom.js";
import { clampNum } from "../shared/math.js";
import { subscribePrefersColorSchemeChange } from "../shared/media.js";
import {
  PICK,
  S_RANGE,
  L_RANGE,
  RADIUS_IDS,
  THEME_MODE_IDS,
  effectiveThemeMode,
  FONT_IDS,
  MESH_BG_IDS,
  applyThemeState,
  drawSLPlane,
  readThemeState,
  updateKnob,
  writeThemeState,
} from "./theme-core.js";
import { ensureThemeFontLoaded } from "./theme-fonts.js";

export function initThemeControls() {
  const picker = document.querySelector("[data-theme-picker]");
  const panel = document.querySelector("[data-theme-panel]");
  const panelBtns = document.querySelectorAll("[data-theme-panel-btn]");
  const themeModeBtns = document.querySelectorAll("[data-theme-mode]");
  const canvas = document.querySelector("[data-sl-canvas]");
  const knob = document.querySelector("[data-sl-knob]");
  const hueSlider = document.querySelector("[data-hue-slider]");
  const radiusBtns = document.querySelectorAll("[data-radius-option]");
  const fontBtns = document.querySelectorAll("[data-font-option]");
  const meshBgBtns = document.querySelectorAll("[data-mesh-bg-option]");

  const themeOk =
    picker && panel && panelBtns.length > 0 && themeModeBtns.length === 3 && canvas && hueSlider;
  if (!themeOk) {
    window.siteThemePanel = { open: () => {}, close: () => {}, toggle: () => {} };
    return;
  }

  const state = readThemeState();
  applyThemeState(state);
  ensureThemeFontLoaded(state.font);

  function acc() {
    return state[effectiveThemeMode(state)] || state.light;
  }

  function syncHueSlider() {
    hueSlider.value = String(Math.round(acc().h));
    hueSlider.setAttribute("aria-valuenow", String(Math.round(acc().h)));
  }

  function persistAndApply() {
    applyThemeState(state);
    ensureThemeFontLoaded(state.font);
    writeThemeState(state);
  }

  function bindOptionButtons(btns, attr, ids, stateKey) {
    btns.forEach((btn) => {
      btn.addEventListener("click", (e) => {
        e.stopPropagation();
        const id = btn.getAttribute(attr);
        if (!ids.includes(id)) return;
        state[stateKey] = id;
        syncAriaRadioGroup(btns, attr, state[stateKey]);
        persistAndApply();
      });
    });
  }

  syncHueSlider();
  drawSLPlane(canvas, acc().h);
  updateKnob(knob, acc().s, acc().l);
  syncAriaRadioGroup(radiusBtns, "data-radius-option", state.radius);
  syncAriaRadioGroup(themeModeBtns, "data-theme-mode", state.mode);
  syncAriaRadioGroup(fontBtns, "data-font-option", state.font);
  if (meshBgBtns.length >= 2) syncAriaRadioGroup(meshBgBtns, "data-mesh-bg-option", state.meshBg);

  bindOptionButtons(radiusBtns, "data-radius-option", RADIUS_IDS, "radius");
  bindOptionButtons(fontBtns, "data-font-option", FONT_IDS, "font");
  bindOptionButtons(themeModeBtns, "data-theme-mode", THEME_MODE_IDS, "mode");
  themeModeBtns.forEach((btn) =>
    btn.addEventListener("click", () => {
      if (!panel.hidden) {
        syncHueSlider();
        drawSLPlane(canvas, acc().h);
        updateKnob(knob, acc().s, acc().l);
      }
    }),
  );
  if (meshBgBtns.length >= 2) bindOptionButtons(meshBgBtns, "data-mesh-bg-option", MESH_BG_IDS, "meshBg");

  function setPanelOpen(open) {
    panel.hidden = !open;
    panelBtns.forEach((btn) => {
      btn.setAttribute("aria-expanded", open ? "true" : "false");
      btn.setAttribute("aria-label", open ? "Закрыть настройки стиля" : "Настройки стиля");
    });
    if (open) {
      drawSLPlane(canvas, acc().h);
      updateKnob(knob, acc().s, acc().l);
      syncAriaRadioGroup(themeModeBtns, "data-theme-mode", state.mode);
      syncAriaRadioGroup(fontBtns, "data-font-option", state.font);
      if (meshBgBtns.length >= 2) syncAriaRadioGroup(meshBgBtns, "data-mesh-bg-option", state.meshBg);
    }
  }

  subscribePrefersColorSchemeChange(() => {
    if (state.mode !== "system") return;
    applyThemeState(state);
    if (!panel.hidden) {
      syncHueSlider();
      drawSLPlane(canvas, acc().h);
      updateKnob(knob, acc().s, acc().l);
    }
  });

  panelBtns.forEach((btn) => {
    btn.addEventListener("click", (e) => {
      e.preventDefault();
      e.stopPropagation();
      setPanelOpen(panel.hidden);
    });
  });

  picker.addEventListener("click", (e) => e.stopPropagation());

  document.addEventListener("click", (e) => {
    const t = e.target;
    if (!(t instanceof Node)) return;
    const el = t instanceof Element ? t : t.parentElement;
    if (el?.closest("[data-theme-panel-btn]")) return;
    if (panel.contains(t) || picker.contains(t) || panel.hidden) return;
    setPanelOpen(false);
  });

  document.addEventListener("keydown", (e) => {
    if (e.key === "Escape" && !panel.hidden) {
      setPanelOpen(false);
      e.preventDefault();
    }
  });

  try {
    const params = new URLSearchParams(window.location.search);
    if (params.get("themePanel") === "open") requestAnimationFrame(() => setPanelOpen(true));
  } catch {
    /* ignore */
  }

  window.siteThemePanel = {
    open: () => setPanelOpen(true),
    close: () => setPanelOpen(false),
    toggle: () => setPanelOpen(!!panel.hidden),
  };

  let canvasRect = null;

  function pickFromClientXY(clientX, clientY) {
    const r = canvasRect || canvas.getBoundingClientRect();
    if (r.width <= 0 || r.height <= 0) return;
    const x = clampNum(((clientX - r.left) / r.width) * 100, 0, 100, 0) / 100;
    const y = clampNum(((clientY - r.top) / r.height) * 100, 0, 100, 0) / 100;
    const a = acc();
    a.s = Math.round(PICK.sMin + x * S_RANGE);
    a.l = Math.round(PICK.lMin + (1 - y) * L_RANGE);
    updateKnob(knob, a.s, a.l);
    persistAndApply();
  }

  canvas.addEventListener("pointerdown", (e) => {
    e.preventDefault();
    canvasRect = canvas.getBoundingClientRect();
    canvas.setPointerCapture(e.pointerId);
    pickFromClientXY(e.clientX, e.clientY);
  });

  canvas.addEventListener("pointermove", (e) => {
    if (!canvas.hasPointerCapture(e.pointerId)) return;
    e.preventDefault();
    pickFromClientXY(e.clientX, e.clientY);
  });

  canvas.addEventListener("pointerup", (e) => {
    if (canvas.hasPointerCapture(e.pointerId)) canvas.releasePointerCapture(e.pointerId);
    canvasRect = null;
  });

  hueSlider.addEventListener("input", () => {
    const a = acc();
    a.h = clampNum(hueSlider.value, 0, 360, a.h);
    syncHueSlider();
    drawSLPlane(canvas, a.h);
    updateKnob(knob, a.s, a.l);
    persistAndApply();
  });
}