const PROFILE_DEFINITIONS = Object.freeze({
  "treated-room": Object.freeze({
    reflection: Object.freeze({ wallGainDb: -14, scattering: 0.15 }),
    diffuse: Object.freeze({ rt60Seconds: 0.2, gainDb: -26, tapCount: 4 }),
  }),
  "typical-room": Object.freeze({
    reflection: Object.freeze({ wallGainDb: -8, scattering: 0.25 }),
    diffuse: Object.freeze({ rt60Seconds: 0.4, gainDb: -20, tapCount: 6 }),
  }),
  "reflective-room": Object.freeze({
    reflection: Object.freeze({ wallGainDb: -4, scattering: 0.4 }),
    diffuse: Object.freeze({ rt60Seconds: 0.8, gainDb: -14, tapCount: 10 }),
  }),
});

function finitePosition(position) {
  return Array.isArray(position) && position.length === 3 && position.every(Number.isFinite);
}

function roundCoordinate(value) {
  return Number(value.toFixed(6));
}

function geometryPositions(scene, arrayDefinition, experiment) {
  const positions = [];
  for (const microphone of arrayDefinition?.microphones ?? []) {
    if (finitePosition(microphone.position)) positions.push(microphone.position);
  }
  for (const source of scene?.sources ?? []) {
    if (finitePosition(source.position)) positions.push(source.position);
    for (const keyframe of source.trajectory ?? []) {
      if (finitePosition(keyframe.position)) positions.push(keyframe.position);
    }
  }
  const scan = experiment?.scan;
  if (scan && ["xMin", "xMax", "yMin", "yMax", "z"].every((key) => Number.isFinite(scan[key]))) {
    positions.push(
      [scan.xMin, scan.yMin, scan.z],
      [scan.xMin, scan.yMax, scan.z],
      [scan.xMax, scan.yMin, scan.z],
      [scan.xMax, scan.yMax, scan.z],
    );
  }
  return positions.length > 0 ? positions : [[0, 0, 0], [1, 1, 1]];
}

export function inferShoeboxRoom(scene, arrayDefinition, experiment) {
  const positions = geometryPositions(scene, arrayDefinition, experiment);
  const minimum = [0, 1, 2].map((axis) =>
    Math.min(...positions.map((position) => position[axis])),
  );
  const maximum = [0, 1, 2].map((axis) =>
    Math.max(...positions.map((position) => position[axis])),
  );
  const padding = [0, 1, 2].map((axis) =>
    Math.max(axis === 2 ? 0.75 : 1, (maximum[axis] - minimum[axis]) * 0.35),
  );
  return {
    min: minimum.map((value, axis) => roundCoordinate(value - padding[axis])),
    max: maximum.map((value, axis) => roundCoordinate(value + padding[axis])),
  };
}

export function applyAcousticProfile(scene, arrayDefinition, experiment, profileId) {
  if (!scene || typeof scene !== "object") throw new TypeError("scene이 필요합니다.");
  if (profileId === "free-field") {
    scene.acoustics = { model: "free-field" };
    return scene.acoustics;
  }
  const definition = PROFILE_DEFINITIONS[profileId];
  if (!definition) throw new RangeError("지원하지 않는 음향 환경 profile: " + profileId);
  scene.acoustics = {
    model: "shoebox",
    room: inferShoeboxRoom(scene, arrayDefinition, experiment),
    reflections: {
      order: 1,
      wallGainDb: definition.reflection.wallGainDb,
      scattering: definition.reflection.scattering,
    },
    diffuseReverb: {
      enabled: true,
      rt60Seconds: definition.diffuse.rt60Seconds,
      gainDb: definition.diffuse.gainDb,
      tapCount: definition.diffuse.tapCount,
    },
  };
  return scene.acoustics;
}

export function detectAcousticProfile(scene) {
  const acoustics = scene?.acoustics;
  if (!acoustics || acoustics.model === "free-field") return "free-field";
  if (acoustics.model !== "shoebox" || (acoustics.occluders?.length ?? 0) > 0) return "custom";
  for (const [profileId, definition] of Object.entries(PROFILE_DEFINITIONS)) {
    if (
      acoustics.reflections?.order === 1 &&
      acoustics.reflections.wallGainDb === definition.reflection.wallGainDb &&
      acoustics.reflections.scattering === definition.reflection.scattering &&
      acoustics.diffuseReverb?.enabled === true &&
      acoustics.diffuseReverb.rt60Seconds === definition.diffuse.rt60Seconds &&
      acoustics.diffuseReverb.gainDb === definition.diffuse.gainDb &&
      acoustics.diffuseReverb.tapCount === definition.diffuse.tapCount
    ) {
      return profileId;
    }
  }
  return "custom";
}

export function maximumSparsePathsPerReceiver(scene) {
  const acoustics = scene?.acoustics;
  if (!acoustics || acoustics.model === "free-field") return 1;
  let count = 1;
  const reflections = acoustics.reflections;
  if (reflections?.order === 1) {
    count += 6;
    if (reflections.scattering > 0) count += 6;
  }
  count += acoustics.occluders?.length ?? 0;
  if (acoustics.diffuseReverb?.enabled) count += acoustics.diffuseReverb.tapCount;
  return count;
}