// Assertions over the stages below detection. Runs in the browser so the exact
// module graph the tool uses is what gets tested.
//
// The ring-simplicity check exists because "fixed topology" is load-bearing in
// docs/design.md: because hold parts CUT between poses rather than
// interpolating, a ring whose vertex order is wrong self-intersects and renders
// as blocks meeting at corners. It is invisible at some vertex counts and obvious
// at others, so it needs an assertion rather than an eyeball.

import { LIPS_OUTER, LIPS_INNER, FACE_OVAL, RIGID, subsampleSlots, subsampleRing } from './landmarks.js';
import { fitSimilarity, applySim, procrustesMean, smoothTransforms } from './mathutil.js';
import { stabilize, toRasterRing, selectKeys, activeKey, shiftIndex } from './pipeline.js';
import { IndexedRaster, hexToRgb } from './raster.js';
import { writeTake } from './take.js';
import { otsuForTest, scaleRing } from './interior.js';
import { synthDense } from './synth.js';

const results = [];
const ok = (name, cond, detail = '') => results.push({ name, pass: !!cond, detail });

/* ---- geometry helpers ---- */

function segmentsCross(a, b, c, d) {
  const o = (p, q, r) => Math.sign((q.x - p.x) * (r.y - p.y) - (q.y - p.y) * (r.x - p.x));
  const o1 = o(a, b, c), o2 = o(a, b, d), o3 = o(c, d, a), o4 = o(c, d, b);
  return o1 !== o2 && o3 !== o4 && o1 !== 0 && o2 !== 0 && o3 !== 0 && o4 !== 0;
}

// A closed ring is simple if no pair of non-adjacent edges crosses.
function ringSelfIntersections(pts) {
  const n = pts.length, hits = [];
  for (let i = 0; i < n; i++) {
    for (let j = i + 1; j < n; j++) {
      if (i === j || (j + 1) % n === i || (i + 1) % n === j) continue;
      if (segmentsCross(pts[i], pts[(i + 1) % n], pts[j], pts[(j + 1) % n])) hits.push([i, j]);
    }
  }
  return hits;
}

const spreadX = (frames, slot) => {
  const xs = frames.map((f) => f[slot].x);
  return Math.max(...xs) - Math.min(...xs);
};

/* ---- the tests ---- */

// Cross-check every el('id') in app.js against the ids in index.html.
//
// This bug class has bitten twice: a knob wired in app.js but absent from the
// markup throws during wiring, which aborts the rest of the module and leaves a
// blank page. The symptom ("nothing happens") points nowhere near the cause, so
// it is worth an automated check rather than vigilance.
export async function runWiring() {
  const out = [];
  try {
    const [app, html] = await Promise.all([
      fetch('./js/app.js').then((r) => r.text()),
      fetch('./index.html').then((r) => r.text()),
    ]);
    const ids = new Set([...app.matchAll(/\bel\(\s*['"]([\w-]+)['"]\s*\)/g)].map((m) => m[1]));
    const list = app.match(/for \(const id of \[([\s\S]*?)\]\)/);
    if (list) {
      for (const m of list[1].matchAll(/'([\w]+)'/g)) { ids.add(m[1]); ids.add(m[1] + 'v'); }
    }
    // Duplicate keys in an object literal are silent in JS - the last one wins.
    // In opts() that meant the teeth vertex slider was quietly driving the lip
    // vertex count while the lip slider did nothing at all.
    const lit = app.match(/const opts = \(\) => \(\{([\s\S]*?)\n\}\);/);
    if (lit) {
      const keys = [...lit[1].matchAll(/^\s*([A-Za-z_$][\w$]*)\s*:/gm)].map((m) => m[1]);
      const dupes = keys.filter((k, i) => keys.indexOf(k) !== i);
      out.push({ name: `opts() has no duplicate keys (${keys.length} checked)`,
                 pass: dupes.length === 0, detail: [...new Set(dupes)].join(', ') });
    } else {
      out.push({ name: 'opts() literal found for duplicate-key check', pass: false, detail: '' });
    }

    const have = new Set([...html.matchAll(/id="([\w-]+)"/g)].map((m) => m[1]));
    const missing = [...ids].filter((i) => !have.has(i));
    out.push({ name: `every el() id exists in index.html (${ids.size} checked)`,
               pass: missing.length === 0, detail: missing.join(', ') });
    const unused = [...have].filter((i) => !ids.has(i));
    out.push({ name: 'no orphaned ids in index.html', pass: unused.length === 0,
               detail: unused.join(', ') });
  } catch (e) {
    out.push({ name: 'wiring check ran', pass: false, detail: e.message });
  }
  return out;
}

export function run() {
  results.length = 0;

  // tables
  ok('LIPS_OUTER has 20 distinct ids', new Set(LIPS_OUTER).size === 20);
  ok('LIPS_INNER has 20 distinct ids', new Set(LIPS_INNER).size === 20);
  ok('FACE_OVAL has 36 distinct ids', new Set(FACE_OVAL).size === 36);
  ok('RIGID excludes every lip vertex',
     !RIGID.some((i) => LIPS_OUTER.includes(i) || LIPS_INNER.includes(i)),
     'a moving feature in the rigid set bleeds performance into stabilisation');

  // subsampling preserves order and count at every budget
  for (let n = 4; n <= 16; n += 2) {
    const s = subsampleSlots(20, n);
    const mono = s.every((v, i) => i === 0 || v > s[i - 1]);
    ok(`subsampleSlots(20,${n}) is strictly increasing, n=${n}`, mono && s.length === n, s.join(','));
  }
  ok('subsampleRing agrees with subsampleSlots',
     subsampleRing(LIPS_OUTER, 8).join(',') === subsampleSlots(20, 8).map((s) => LIPS_OUTER[s]).join(','));

  const dense = synthDense(72);

  // rings must be simple at EVERY vertex budget, on every frame
  for (const [label, table] of [['outer', LIPS_OUTER], ['inner', LIPS_INNER]]) {
    let worst = null;
    for (let n = 4; n <= 16 && !worst; n += 2) {
      const slots = subsampleSlots(table.length, n);
      for (let f = 0; f < dense.length; f++) {
        const pts = slots.map((s) => dense[f][table[s]]);
        const hits = ringSelfIntersections(pts);
        if (hits.length) { worst = `verts=${n} frame=${f} edges ${JSON.stringify(hits[0])}`; break; }
      }
    }
    ok(`${label} ring is simple at every vertex budget`, !worst, worst || '');
  }

  // FACE_OVAL traversal: never checked before, and a wrong ordering here shows up
  // as a lumpy plate rather than an obvious bowtie, so it needs asserting.
  {
    let bad = null;
    for (let f = 0; f < dense.length && !bad; f++) {
      const h = ringSelfIntersections(FACE_OVAL.map((i) => dense[f][i]));
      if (h.length) bad = `frame ${f} edges ${JSON.stringify(h[0])}`;
    }
    ok('FACE_OVAL is a simple ring on every frame', !bad, bad || '');
  }

  // similarity fit recovers a known transform
  const src = [{ x: 0, y: 0 }, { x: 1, y: 0 }, { x: 0, y: 1 }, { x: 2, y: 3 }];
  const truth = { s: 1.7, theta: 0.6, tx: 4, ty: -2 };
  const dst = src.map((p) => applySim(truth, p));
  const got = fitSimilarity(src, dst);
  ok('fitSimilarity recovers a known transform',
     Math.abs(got.s - truth.s) < 1e-9 && Math.abs(got.theta - truth.theta) < 1e-9 &&
     Math.abs(got.tx - truth.tx) < 1e-9 && Math.abs(got.ty - truth.ty) < 1e-9,
     `s=${got.s.toFixed(6)} th=${got.theta.toFixed(6)}`);

  // stabilisation: head motion out, mouth motion kept
  const stab = stabilize(dense, 0);
  const rawSpread = spreadX(dense, 133);
  const stabSpread = (() => {
    const xs = stab.eyes.map((e) => e[0].x);
    return Math.max(...xs) - Math.min(...xs);
  })();
  ok('stabilisation removes >90% of head translation',
     stabSpread < rawSpread * 0.1, `raw ${rawSpread.toFixed(4)} -> ${stabSpread.toFixed(4)}`);
  const apRange = Math.max(...stab.aperture) - Math.min(...stab.aperture);
  ok('stabilisation preserves mouth motion', apRange > 0.05, `aperture range ${apRange.toFixed(4)}`);

  // ASPECT: a shape that is circular in PIXEL space must stay circular in raster
  // space. MediaPipe normalises x by width and y by height, so for a portrait
  // frame equal normalised numbers are unequal pixel distances; feeding those
  // straight through stretches everything horizontally by H/W. This asserts the
  // isotropic conversion, and fails at ~1.78 for a 1080x1920 clip without it.
  for (const [W, H] of [[1080, 1920], [1920, 1080], [640, 640]]) {
    const aspect = W / H;
    const N = 24, cx = 0.5, cy = 0.5, rPx = 200;
    // a true circle of radius rPx, expressed in MediaPipe normalised coords
    const circleFrames = [];
    for (let t = 0; t < 4; t++) {
      const pts = new Array(478).fill(null).map(() => ({ x: 0.5, y: 0.5, z: 0 }));
      RIGID.forEach((id, k) => {
        const a = (k / RIGID.length) * Math.PI * 2;
        pts[id] = { x: cx + (120 * Math.cos(a)) / W, y: cy + (120 * Math.sin(a)) / H, z: 0 };
      });
      LIPS_OUTER.forEach((id, k) => {
        const a = -(k / LIPS_OUTER.length) * Math.PI * 2;
        pts[id] = { x: cx + (rPx * Math.cos(a)) / W, y: cy + (rPx * Math.sin(a)) / H, z: 0 };
      });
      FACE_OVAL.forEach((id, k) => {
        const a = -(k / FACE_OVAL.length) * Math.PI * 2;
        pts[id] = { x: cx + (420 * Math.cos(a)) / W, y: cy + (420 * Math.sin(a)) / H, z: 0 };
      });
      circleFrames.push(pts);
    }
    const st2 = stabilize(circleFrames, 0, aspect);
    const ring = toRasterRing(st2.outer[0], LIPS_OUTER, 16, (p) => p);
    const xs = ring.map((p) => p.x), ys = ring.map((p) => p.y);
    const ratio = (Math.max(...xs) - Math.min(...xs)) / (Math.max(...ys) - Math.min(...ys));
    ok(`circle stays circular at ${W}x${H}`, Math.abs(ratio - 1) < 0.02,
       `w/h ratio ${ratio.toFixed(4)}`);
  }

  // key selection
  const xf = (p) => ({ x: p.x * 320, y: p.y * 200 });
  const shapes = stab.outer.map((r) => toRasterRing(r, LIPS_OUTER, 8, xf));
  const sel = selectKeys(shapes, { minHold: 2, distThresh: 0.6, velSmooth: 3, exposure: 2 });
  ok('keys are strictly increasing in f', sel.keys.every((k, i) => i === 0 || k.f > sel.keys[i - 1].f));
  ok('keys respect the minimum hold',
     sel.keys.every((k, i) => i === 0 || k.src - sel.keys[i - 1].src >= 2));
  ok('keys land on the exposure grid', sel.keys.every((k) => k.f % 2 === 0));
  ok('selection reduces candidates', sel.keys.length < sel.candidates.length,
     `${sel.candidates.length} candidates -> ${sel.keys.length} keys`);
  ok('first key is frame 0', sel.keys[0].f === 0);
  ok('activeKey holds between keys',
     activeKey(sel.keys, sel.keys[1].f - 1).f === sel.keys[0].f);

  // mouth lead: a shift that "feels like it does nothing" is indistinguishable
  // from one that does nothing, so assert the arithmetic directly.
  ok('lead 0 is identity', [0, 5, 71].every((f) => shiftIndex(f, 0, 72) === f));
  ok('positive lead moves the source frame forward', shiftIndex(10, 2, 72) === 12);
  ok('negative lead moves it back', shiftIndex(10, -3, 72) === 7);
  ok('lead clamps at the start', shiftIndex(1, -6, 72) === 0);
  ok('lead clamps at the end', shiftIndex(70, 6, 72) === 71);
  {
    // ...and that it selects different POSES, not merely different indices.
    // Checked across the whole track rather than at one pair: synthetic poses
    // hold for nine-frame beats, so any single pair can legitimately be
    // identical while the shift works perfectly.
    const N = shapes.length;
    let moved = 0, total = 0;
    for (let f = 0; f < N; f++) {
      const a = shapes[shiftIndex(f, 0, N)], b = shapes[shiftIndex(f, 3, N)];
      let d = 0;
      for (let i = 0; i < a.length; i++) d += Math.hypot(a[i].x - b[i].x, a[i].y - b[i].y);
      total++;
      if (d / a.length > 0.5) moved++;
    }
    ok('a lead of 3 changes the pose on a good share of frames', moved / total > 0.2,
       `${moved}/${total} frames differ`);
  }

  // rasteriser: indexed, hard-edged, no blending
  const r = new IndexedRaster(64, 48);
  r.clear(0);
  r.fillPoly([{ x: 8, y: 8 }, { x: 56, y: 8 }, { x: 56, y: 40 }, { x: 8, y: 40 }], 2);
  const present = new Set(r.buf);
  ok('raster contains only written indices', present.size === 2 && present.has(0) && present.has(2),
     `indices ${[...present].join(',')}`);
  let count = 0;
  for (const v of r.buf) if (v === 2) count++;
  ok('axis-aligned rect fills the exact pixel count', count === 48 * 32, `${count} vs ${48 * 32}`);
  const pal = ['#000000', '#ffffff', '#ff8800'];
  const img = r.toImageData(pal, 2);
  const seen = new Set();
  for (let i = 0; i < img.data.length; i += 4) {
    seen.add(`${img.data[i]},${img.data[i + 1]},${img.data[i + 2]}`);
  }
  const allowed = new Set(pal.map((h) => hexToRgb(h).join(',')));
  ok('palette expansion introduces no intermediate colours',
     [...seen].every((c) => allowed.has(c)), `${seen.size} distinct colours`);

  // scaleRing is what pulls the sampled region in from MediaPipe's inner lip
  // landmarks, which sit slightly outside the real opening.
  {
    const ring = [{ x: 0, y: 0 }, { x: 10, y: 0 }, { x: 10, y: 10 }, { x: 0, y: 10 }];
    const small = scaleRing(ring, 0.5);
    const w = Math.max(...small.map((p) => p.x)) - Math.min(...small.map((p) => p.x));
    ok('scaleRing(0.5) halves the extent', Math.abs(w - 5) < 1e-9, `width ${w}`);
    const same = scaleRing(ring, 1);
    ok('scaleRing(1) is identity', same.every((p, i) => Math.abs(p.x - ring[i].x) < 1e-9));
    let cx = 0; for (const p of small) cx += p.x;
    ok('scaleRing keeps the centroid', Math.abs(cx / 4 - 5) < 1e-9);
  }

  // Otsu on a uniform region must report near-zero class separation. It will
  // still return a threshold - that is what Otsu does - so the separation is the
  // only thing that distinguishes "found teeth" from "split noise in a dark
  // mouth", which is what made the band fill the whole cavity.
  {
    const flat = new Uint32Array(256); flat[40] = 500;
    const f = otsuForTest(flat, 500);
    ok('uniform region yields ~no class separation',
       Math.abs(f.mBright - f.mDark) / 255 < 0.02, `sep ${((f.mBright - f.mDark) / 255).toFixed(4)}`);

    const noisy = new Uint32Array(256);
    for (let i = 30; i <= 60; i++) noisy[i] = 20;          // dark cavity, some spread
    const nz = otsuForTest(noisy, 31 * 20);
    ok('dark-but-noisy region stays below a sane gate',
       (nz.mBright - nz.mDark) / 255 < 0.14, `sep ${((nz.mBright - nz.mDark) / 255).toFixed(4)}`);

    const teeth = new Uint32Array(256);
    for (let i = 20; i <= 45; i++) teeth[i] = 40;          // cavity
    for (let i = 180; i <= 220; i++) teeth[i] = 30;        // teeth
    const tt = otsuForTest(teeth, 26 * 40 + 41 * 30);
    ok('real bright/dark split clears the gate',
       (tt.mBright - tt.mDark) / 255 > 0.4, `sep ${((tt.mBright - tt.mDark) / 255).toFixed(4)}`);
  }

  // take writer round-trip
  const take = {
    name: 'test', frames: 72, width: 320, height: 200, exposure: 2,
    palette: [{ name: 'bg' }, { name: 'skin' }],
    slot: { x: 160, y: 100 },
    parts: [
      { name: 'head', kind: 'plate', z: 0, interp: 'hold', keys: [{ f: 0, plate: 0 }] },
      { name: 'mouth', kind: 'poly', z: 30, color: 'skin', interp: 'hold',
        keys: sel.keys.map((k) => ({ f: k.f, src: k.src, pts: shapes[k.src] })) },
    ],
  };
  const text = writeTake(take);
  const keyLines = text.split('\n').filter((l) => l.startsWith('key') && l.includes('n='));
  ok('every key line declares n= matching its point count',
     keyLines.every((l) => {
       const n = +l.match(/n=(\d+)/)[1];
       const pts = l.split(/n=\d+\s+/)[1].trim().split(/\s+/);
       return pts.length === n;
     }), `${keyLines.length} key lines`);
  ok('take declares a plate and a part table',
     /^plate\s+0/m.test(text) && /^part\s+mouth/m.test(text));
  ok('coordinates are integers', !/-?\d+\.\d/.test(text.split('\n').filter((l) => l.startsWith('key')).join('')));

  return results;
}