// Overpass proxy Tier A hardening (voice-engine evaluation doc §4.1, field test
// 2026-07-23): region/state boundary pivots return multi-MB coastline geometry that
// blew the old 12 MB read cap and 16 s client budget (Sicily never traced). The proxy
// now simplifies giant `out geom` payloads server-side before caching/serving, and
// boundary-class queries (is_in / pivot) get a longer disk TTL — boundaries change
// ≈never. Pure-function tests, no network.
//
// Run with: npm test   (node --test)
import { test } from 'node:test';
import assert from 'node:assert/strict';
import {
  simplifyOverpassPayloadBody,
  isOverpassBoundaryQuery,
  resolveOverpassPreflight,
} from '../../vite.config.js';

test('preflight checks memory, in-flight, then disk before consuming limiter quota', async () => {
  const key = 'normalized query';
  const fresh = { id: 'memory', status: 200, cachedAt: 900 };
  const joined = { id: 'inflight', status: 200, cachedAt: 950 };
  const disk = { id: 'disk', status: 200, cachedAt: 975 };
  let diskReads = 0;
  let limiterCalls = 0;
  const allowUpstream = () => { limiterCalls += 1; return true; };

  const memoryHit = await resolveOverpassPreflight({
    cacheKey: key,
    memoryCache: new Map([[key, fresh]]),
    inFlight: new Map([[key, Promise.resolve({ source: 'UPSTREAM', payload: joined })]]),
    readDisk: async () => { diskReads += 1; return disk; },
    allowUpstream,
    now: 1000,
    cacheMs: 200,
  });
  assert.equal(memoryHit.source, 'HIT');
  assert.equal(memoryHit.payload, fresh);
  assert.equal(diskReads, 0, 'memory hit must short-circuit before disk');
  assert.equal(limiterCalls, 0, 'memory hit must not consume limiter quota');

  const inFlightHit = await resolveOverpassPreflight({
    cacheKey: key,
    memoryCache: new Map([[key, { id: 'stale', status: 200, cachedAt: 0 }]]),
    inFlight: new Map([[key, Promise.resolve({ source: 'UPSTREAM', payload: joined })]]),
    readDisk: async () => { diskReads += 1; return disk; },
    allowUpstream,
    now: 1000,
    cacheMs: 200,
  });
  assert.equal(inFlightHit.source, 'INFLIGHT');
  assert.equal(inFlightHit.payload, joined);
  assert.equal(diskReads, 0, 'in-flight join must short-circuit before disk');
  assert.equal(limiterCalls, 0, 'in-flight join must not consume limiter quota');

  const diskMemory = new Map();
  const diskHit = await resolveOverpassPreflight({
    cacheKey: key,
    memoryCache: diskMemory,
    inFlight: new Map(),
    readDisk: async () => { diskReads += 1; return disk; },
    allowUpstream,
  });
  assert.equal(diskHit.source, 'DISK');
  assert.equal(diskHit.payload, disk);
  assert.equal(diskReads, 1);
  assert.equal(limiterCalls, 0, 'disk hit must not consume limiter quota');
  const publishedDisk = await resolveOverpassPreflight({ cacheKey: key, memoryCache: diskMemory, inFlight: new Map(), now: 1000, readDisk: async () => { throw new Error('disk result was not published'); }, allowUpstream });
  assert.equal(publishedDisk.source, 'HIT');

  const upstreamMiss = await resolveOverpassPreflight({
    cacheKey: key,
    memoryCache: new Map(),
    inFlight: new Map(),
    readDisk: async () => { diskReads += 1; return null; },
    allowUpstream,
  });
  assert.equal(upstreamMiss.source, 'UPSTREAM');
  assert.equal(diskReads, 2, 'disk must be checked before upstream admission');
  assert.equal(limiterCalls, 1, 'only a complete cache miss consumes quota');

  const denied = await resolveOverpassPreflight({
    cacheKey: key,
    memoryCache: new Map(),
    inFlight: new Map(),
    readDisk: async () => null,
    allowUpstream: () => false,
  });
  assert.equal(denied.source, 'RATE_LIMITED');
});

test('preflight treats cached refusals as misses without spending extra quota', async () => {
  for (const invalid of [{ status: 406 }, { status: 200, runtimeError: true }]) {
    let admissions = 0;
    const result = await resolveOverpassPreflight({
      cacheKey: 'refused',
      memoryCache: new Map([['refused', { ...invalid, cachedAt: Date.now() }]]),
      inFlight: new Map(),
      readDisk: async () => ({ ...invalid, cachedAt: Date.now() }),
      allowUpstream: () => { admissions++; return true; },
    });
    assert.equal(result.source, 'UPSTREAM');
    assert.equal(admissions, 1);
  }
});

/** Synthetic dense ring: N points on a circle with sub-tolerance jitter. */
function denseRing(n, { latC = 37.5, lonC = 14.2, radiusDeg = 0.5 } = {}) {
  const pts = [];
  for (let i = 0; i < n; i++) {
    const a = (i / n) * 2 * Math.PI;
    // Jitter far below the simplification tolerance so the ring is genuinely
    // redundant — a correct simplifier should collapse most of it.
    const jitter = (i % 7) * 0.000004;
    pts.push({
      lat: latC + Math.sin(a) * (radiusDeg + jitter),
      lon: lonC + Math.cos(a) * (radiusDeg + jitter),
    });
  }
  pts.push({ ...pts[0] }); // closed ring
  return pts;
}

const TEST_OPTS = { minBytes: 0, minPoints: 200, toleranceDeg: 0.0004 };

test('simplify: giant way geometry is decimated, endpoints preserved', () => {
  const ring = denseRing(4000);
  const body = JSON.stringify({ elements: [{ type: 'way', id: 1, geometry: ring }] });
  const out = JSON.parse(simplifyOverpassPayloadBody(body, TEST_OPTS));
  const g = out.elements[0].geometry;
  assert.ok(g.length < ring.length * 0.5, `should shed most redundant points, got ${g.length}/${ring.length}`);
  assert.ok(g.length >= 16, `must keep enough points to stay a ring, got ${g.length}`);
  assert.deepEqual(g[0], ring[0]);
  assert.deepEqual(g[g.length - 1], ring[ring.length - 1]);
});

test('simplify: relation member geometries are decimated too', () => {
  const ring = denseRing(3000);
  const body = JSON.stringify({
    elements: [{
      type: 'relation',
      id: 2,
      members: [
        { type: 'way', role: 'outer', geometry: ring },
        { type: 'node', role: 'admin_centre' }, // no geometry — must survive untouched
      ],
    }],
  });
  const out = JSON.parse(simplifyOverpassPayloadBody(body, TEST_OPTS));
  assert.ok(out.elements[0].members[0].geometry.length < ring.length * 0.5);
  assert.equal(out.elements[0].members[1].geometry, undefined);
});

test('simplify: small geometries (building footprints) pass through untouched', () => {
  const square = [
    { lat: 30.27, lon: -97.74 }, { lat: 30.271, lon: -97.74 },
    { lat: 30.271, lon: -97.741 }, { lat: 30.27, lon: -97.741 },
    { lat: 30.27, lon: -97.74 },
  ];
  const body = JSON.stringify({ elements: [{ type: 'way', id: 3, geometry: square }] });
  const out = JSON.parse(simplifyOverpassPayloadBody(body, TEST_OPTS));
  assert.deepEqual(out.elements[0].geometry, square);
});

test('simplify: geometry stays within tolerance of the original shape', () => {
  const ring = denseRing(4000);
  const body = JSON.stringify({ elements: [{ type: 'way', id: 4, geometry: ring }] });
  const out = JSON.parse(simplifyOverpassPayloadBody(body, TEST_OPTS));
  const g = out.elements[0].geometry;
  // Every original vertex must lie near SOME kept vertex — a circle of kept
  // points at spacing s has every dropped point within ~s/2 along the arc, and
  // DP guarantees perpendicular deviation ≤ tolerance. Loose sanity bound: no
  // original point farther than 8× tolerance from the nearest kept point pair
  // is possible for a smooth ring; check a sampled subset for speed.
  for (let i = 0; i < ring.length; i += 97) {
    const p = ring[i];
    let best = Infinity;
    for (let j = 1; j < g.length; j++) {
      const d = pointSegDistDeg(p, g[j - 1], g[j]);
      if (d < best) best = d;
    }
    assert.ok(best <= TEST_OPTS.toleranceDeg * 1.01, `vertex ${i} deviates ${best} deg`);
  }
});

test('simplify: sub-threshold bodies and non-JSON pass through byte-identical', () => {
  const tiny = JSON.stringify({ elements: [{ type: 'way', geometry: denseRing(3000) }] });
  assert.equal(simplifyOverpassPayloadBody(tiny, { ...TEST_OPTS, minBytes: tiny.length + 1 }), tiny);
  const junk = 'this is not json {';
  assert.equal(simplifyOverpassPayloadBody(junk, TEST_OPTS), junk);
});

test('boundary-class queries detected for the long disk TTL', () => {
  assert.equal(isOverpassBoundaryQuery(
    '[out:json][timeout:25];is_in(37.5,14.2)->.a;area.a["boundary"="administrative"]["admin_level"];out tags;',
  ), true);
  assert.equal(isOverpassBoundaryQuery(
    '[out:json][timeout:25];area(3600039152)->.x;rel(pivot.x);out geom;',
  ), true);
  // The enclosing-compound sweep and road fetches keep the default TTL.
  assert.equal(isOverpassBoundaryQuery(
    '[out:json][timeout:25];( way(around:1200,30.27,-97.74)["leisure"]["name"]; );out geom;',
  ), false);
  assert.equal(isOverpassBoundaryQuery(
    '[out:json][timeout:12];way["highway"~"motorway|trunk"](30.1,-97.9,30.5,-97.5);out geom;',
  ), false);
});

/** Perpendicular distance (deg, planar approx) from p to segment a-b. */
function pointSegDistDeg(p, a, b) {
  const vx = b.lon - a.lon;
  const vy = b.lat - a.lat;
  const wx = p.lon - a.lon;
  const wy = p.lat - a.lat;
  const c1 = vx * wx + vy * wy;
  if (c1 <= 0) return Math.hypot(wx, wy);
  const c2 = vx * vx + vy * vy;
  if (c2 <= c1) return Math.hypot(p.lon - b.lon, p.lat - b.lat);
  const t = c1 / c2;
  return Math.hypot(wx - t * vx, wy - t * vy);
}


test('cold disk lookup is single-flight through upstream publication and quota admission', async () => {
  const inFlight = new Map();
  let release;
  const disk = new Promise((resolve) => { release = resolve; });
  let reads = 0, admissions = 0, upstreams = 0;
  const payload = { status: 200, body: '{"elements":[]}' };
  const options = {
    cacheKey: 'cold', memoryCache: new Map(), inFlight,
    readDisk: () => { reads++; return disk; },
    allowUpstream: () => { admissions++; return true; },
    loadUpstream: async () => { upstreams++; return payload; },
  };
  const pending = Array.from({ length: 4 }, () => resolveOverpassPreflight(options));
  await Promise.resolve();
  assert.equal(inFlight.size, 1);
  release(null);
  const results = await Promise.all(pending);
  assert.equal(reads, 1);
  assert.equal(admissions, 1);
  assert.equal(upstreams, 1);
  assert.ok(results.every((result) => result.payload === payload));
  assert.deepEqual(results.map((result) => result.source), ['UPSTREAM', 'INFLIGHT', 'INFLIGHT', 'INFLIGHT']);
  assert.equal(inFlight.size, 0);
  const failed = { ...options, readDisk: async () => { throw new Error('disk failed'); } };
  const rejected = await Promise.allSettled([resolveOverpassPreflight(failed), resolveOverpassPreflight(failed)]);
  assert.ok(rejected.every((result) => result.status === 'rejected'));
  assert.equal(inFlight.size, 0);
  await resolveOverpassPreflight({ ...options, readDisk: async () => null });
  assert.equal(upstreams, 2, 'a rejected reservation does not poison the next retry');
});

test('a joined client retries admission with its own quota after another client is rate limited', async () => {
  const inFlight = new Map();
  let release;
  const disk = new Promise((resolve) => { release = resolve; });
  let reads = 0, upstreams = 0;
  const admissions = { a: 0, b: 0, c: 0 };
  const quota = { a: false, b: true, c: false };
  const payload = { status: 200, body: '{"elements":[]}' };
  const client = (name) => resolveOverpassPreflight({
    cacheKey: 'quota', memoryCache: new Map(), inFlight,
    readDisk: () => { reads++; return reads === 1 ? disk : null; },
    allowUpstream: () => { admissions[name]++; return quota[name]; },
    loadUpstream: async () => { upstreams++; return payload; },
  });
  // A (quota exhausted) owns the cold reservation; B (quota available) and
  // C (quota exhausted) join it while the disk lookup is pending.
  const pending = [client('a'), client('b'), client('c')];
  await Promise.resolve();
  assert.equal(inFlight.size, 1);
  release(null);
  const [a, b, c] = await Promise.all(pending);
  assert.equal(a.source, 'RATE_LIMITED', "A's own quota still rejects A");
  assert.equal(b.source, 'UPSTREAM', 'B is admitted on its own quota');
  assert.equal(b.payload, payload);
  assert.equal(c.source, 'INFLIGHT', "C coalesces onto B's admitted fetch");
  assert.equal(c.payload, payload);
  assert.deepEqual(admissions, { a: 1, b: 1, c: 0 });
  assert.equal(upstreams, 1);
  assert.equal(inFlight.size, 0);
});