import { Store } from './store.js';
import { Dialog } from './ui.js';
import { currentAttribute } from './dom.js';
import { startRequestInterceptor } from './interceptor.js';

function findAnchorElement() {
  // Try several selectors in priority order. Torn's gym page structure
  // varies; we cast a wide net and return the first match.
  const candidates = [
    'form[action*="train"]',
    'form.train-form',
    'form[class*="train"]',
    '[class*="train-button"]',
    'button[class*="train"]',
    'a[class*="train"]',
    'button[name="train"]',
    'a[href*="train"]',
  ];
  for (const sel of candidates) {
    const el = document.querySelector(sel);
    if (el) {
      // Prefer the form ancestor if the match is a button/link, since we
      // want to anchor above the whole form, not just the button.
      return el.closest('form') || el;
    }
  }
  // Last-ditch: any element inside the gym panel that looks like the
  // training form.
  const panel = document.querySelector('.gym, #gym, [class*="gym-"], [class*="Gym"]');
  if (panel) {
    const form = panel.querySelector('form');
    if (form) return form;
  }
  return null;
}

function start() {
  const store = new Store({
    storage: localStorage,
    onWarn: (m) => console.warn(m),
  });
  const prefs = store.getPrefs();

  const dialog = new Dialog({
    onTargetChange: (v) => {
      const attr = currentAttribute()?.attr;
      if (!attr) return;
      store.setTarget(attr, v);
      render();
    },
    onModeChange: (m) => {
      store.setMode(m);
      prefs.mode = m;
      applyMode();
    },
    onPosChange: (pos) => store.setPos(pos),
    onClose: () => dialog.destroy(),
  });

  dialog.mount({ initialMode: prefs.mode, initialPos: prefs.pos });
  applyMode();

  let lastSnapshot = null;
  let lastAttr = null;
  let lastDelta = 0;
  let anchorError = null;

  function snapshot() {
    const a = currentAttribute();
    if (!a) {
      return { error: "Couldn't read attribute — Torn may have updated the page." };
    }
    lastAttr = a.attr;
    const summary = store.getSummary(a.attr);
    return {
      attr: a.attr,
      gym: a.gym,
      current: a.current,
      target: store.getTarget(a.attr),
      perTrain: lastDelta,
      summary,
      warn: store._saveDisabled ? 'saving disabled this session' : null,
      anchorError: anchorError,
    };
  }

  function render() {
    lastSnapshot = snapshot();
    dialog.render(lastSnapshot);
  }

  function applyMode() {
    if (prefs.mode === 'anchored') {
      const el = findAnchorElement();
      if (el) {
        const rect = el.getBoundingClientRect();
        dialog.setMode('anchored', { canAnchor: true });
        dialog._positionAnchored(rect);
        // observe
        const ro = new ResizeObserver(() => {
          if (prefs.mode === 'anchored') dialog._positionAnchored(el.getBoundingClientRect());
        });
        ro.observe(el);
        anchorError = null;
        return;
      }
      // Anchor selector missed — don't snap to default, just keep current
      // position and show a note.
      anchorError = "Couldn't find the training form on this page.";
      render();
      return;
    }
    anchorError = null;
    dialog.setMode('free');
  }

  // initial paint
  render();

  // watch DOM for attribute changes
  let pending = false;
  const observer = new MutationObserver(() => {
    if (pending) return;
    pending = true;
    requestAnimationFrame(() => {
      pending = false;
      const a = currentAttribute();
      if (a && (a.attr !== lastAttr || a.current !== lastSnapshot?.current)) render();
    });
  });
  observer.observe(document.body, { childList: true, subtree: true, characterData: true });

  // intercept train requests
  const prev = currentAttribute()?.current ?? 0;
  startRequestInterceptor({
    prevValue: prev,
    currentAttr: lastAttr,
    onTrain: ({ attr, delta, ts }) => {
      store.recordTrain(attr, delta, ts);
      lastDelta = delta;
      render();
    },
    onParseFail: (url) => console.warn('[tat] could not parse train response from', url),
  });
}

if (location.hash === '#tat-test') {
  // Self-test path: the in-browser tests live in the bundled userscript.
  // The bundle runs the test block; nothing to do here.
} else if (/\/gym\.php(\?|$)/.test(location.pathname + location.search)) {
  start();
}