import { NodeIO } from "@gltf-transform/core";
import { ALL_EXTENSIONS } from "@gltf-transform/extensions";
import { createRequire } from "node:module";
import { existsSync, readFileSync } from "node:fs";
import { resolve } from "node:path";
import { MeshoptDecoder } from "meshoptimizer";
import { BufferAttribute, BufferGeometry, Group, Mesh } from "three";
import {
  findNearestPartyNavigationSurface,
  findPartyNavigationPath,
} from "../src/game/partyNavigation";
import { preparePartyNavigationGraph } from "../src/game/partyNavigationAssetCache";
import type { DungeonDefinition } from "../src/game/dungeonTypes";
import { withWowDungeonEnvironment } from "../src/game/wowDungeonEnvironment";

const require = createRequire(import.meta.url);
const { DEFAULT_TEST_DUNGEON_ID, FULL_STOCKADE_DUNGEON_ID } = require("./playtest-defaults.cjs") as {
  DEFAULT_TEST_DUNGEON_ID: string;
  FULL_STOCKADE_DUNGEON_ID: string;
};
type Position = readonly [number, number, number];
type ProbeDungeon = {
  id: string;
  title: string;
  entrance: { footPosition: Position };
  assets: { navigation?: { fileName: string; url: string } | null };
  navigationLinks?: readonly { start: Position; end: Position; bidirectional: boolean }[];
  traversalRamps?: DungeonDefinition["traversalRamps"];
  bosses: readonly { id: string; name: string; position: Position; eventOnly?: boolean }[];
};
const campaignCatalogPath = resolve(process.cwd(), "src", "game", "generated", "dungeonCampaignCatalog.json");
const campaignCatalog = JSON.parse(readFileSync(campaignCatalogPath, "utf8")) as { definitions: ProbeDungeon[] };
function requireGeneratedDungeonDefinition(dungeonId: string): ProbeDungeon {
  const dungeon = campaignCatalog.definitions.find((candidate) => candidate.id === dungeonId);
  if (!dungeon) throw new Error(`Generated campaign catalog has no dungeon ${dungeonId}.`);
  return dungeon;
}
const navigationIo = new NodeIO()
  .registerExtensions(ALL_EXTENSIONS)
  .registerDependencies({ "meshopt.decoder": MeshoptDecoder });
const requestedDungeonIds = process.argv.slice(2).filter((argument) => !argument.startsWith("--"));
const dungeonIds = requestedDungeonIds.length ? requestedDungeonIds : [DEFAULT_TEST_DUNGEON_ID];

async function navigationGraph(dungeonId: string) {
  const dungeon = requireGeneratedDungeonDefinition(dungeonId);
  const navigation = dungeon.assets.navigation;
  if (!navigation) throw new Error(`${dungeonId} has no navigation asset.`);
  const publicAssetPath = navigation.url.startsWith("/")
    ? resolve(process.cwd(), "public", navigation.url.slice(1))
    : resolve(process.cwd(), "public", "assets", "game", "dungeons", dungeonId, navigation.fileName);
  const sourceAssetPath = resolve(process.cwd(), "src", "assets", "game", "dungeons", dungeonId, navigation.fileName);
  const file = [publicAssetPath, sourceAssetPath].find(existsSync);
  if (!file) throw new Error(`${dungeonId} navigation asset is missing at ${publicAssetPath} and ${sourceAssetPath}.`);
  await MeshoptDecoder.ready;
  const document = await navigationIo.read(file);
  const scene = new Group();
  for (const node of document.getRoot().listNodes()) {
    const mesh = node.getMesh();
    if (!mesh) continue;
    for (const primitive of mesh.listPrimitives()) {
      const accessor = primitive.getAttribute("POSITION");
      const source = accessor?.getArray();
      if (!source || !accessor) continue;
      const geometry = new BufferGeometry();
      geometry.setAttribute("position", new BufferAttribute(source, 3, accessor.getNormalized()));
      const sourceIndices = primitive.getIndices()?.getArray();
      if (sourceIndices) geometry.setIndex(Array.from(sourceIndices));
      const navigationMesh = new Mesh(geometry);
      navigationMesh.matrixAutoUpdate = false;
      navigationMesh.matrix.fromArray(node.getWorldMatrix());
      scene.add(navigationMesh);
    }
  }
  const definition = withWowDungeonEnvironment(dungeon as unknown as DungeonDefinition);
  try {
    return preparePartyNavigationGraph(navigation.url, scene, definition.navigationLinks ?? [], definition.traversalRamps ?? []);
  } finally {
    scene.traverse((node) => {
      if ((node as Mesh).isMesh) (node as Mesh).geometry.dispose();
    });
  }
}

for (const dungeonId of dungeonIds) {
  const dungeon = requireGeneratedDungeonDefinition(dungeonId);
  const eligibleBosses = dungeon.bosses.filter((candidate) => !candidate.eventOnly);
  const bosses = dungeonId === DEFAULT_TEST_DUNGEON_ID || dungeonId === FULL_STOCKADE_DUNGEON_ID
    ? eligibleBosses : eligibleBosses.slice(0, 1);
  if (!bosses.length) throw new Error(`${dungeonId} has no normal campaign bosses.`);
  const graph = await navigationGraph(dungeonId);
  const start = findNearestPartyNavigationSurface(graph, dungeon.entrance.footPosition, 3);
  if (!start) throw new Error(`${dungeonId} entrance does not snap to navigation.`);
  const waypoints: number[][] = [[...start.position]];
  const objectives: Array<{ id: string; name: string; position: readonly number[]; navigationPosition: readonly number[];
    waypointIndex: number; expectedNavigationDistance: number; snapDistance: number }> = [];
  let segmentStart = start.position;
  let expectedDistance = 0;
  for (const boss of bosses) {
    const end = findNearestPartyNavigationSurface(graph, boss.position, 6);
    if (!end) throw new Error(`${dungeonId} ${boss.name} does not snap to navigation.`);
    const path = findPartyNavigationPath(graph, segmentStart, end.position, {
      maxStartSnapDistance: 3,
      maxEndSnapDistance: 6,
      simplifyTolerance: 0.01,
    });
    if (!path?.length) throw new Error(`${dungeonId} has no navigation path to ${boss.name}.`);
    const startIndex = waypoints.length - 1;
    let segmentDistance = 0;
    for (let index = 1; index < path.length; index += 1) {
      const segmentLength = Math.hypot(
        path[index][0] - path[index - 1][0],
        path[index][1] - path[index - 1][1],
        path[index][2] - path[index - 1][2],
      );
      segmentDistance += segmentLength;
      expectedDistance += segmentLength;
      waypoints.push([...path[index]]);
    }
    objectives.push({
      id: boss.id,
      name: boss.name,
      position: boss.position,
      navigationPosition: end.position,
      waypointIndex: waypoints.length - 1,
      expectedNavigationDistance: Number(segmentDistance.toFixed(2)),
      snapDistance: end.distance,
    });
    if (waypoints.length - 1 <= startIndex) {
      throw new Error(`${dungeonId} navigation path to ${boss.name} has no traversable segment.`);
    }
    segmentStart = end.position;
  }
  process.stdout.write(`${JSON.stringify({
    dungeonId,
    status: "navigation-guidance-only; live UI traversal required",
    objective: bosses.at(-1)!.name,
    objectiveId: bosses.at(-1)!.id,
    objectives,
    entrance: start.position,
    objectivePosition: bosses.at(-1)!.position,
    startSnapDistance: start.distance,
    objectiveSnapDistance: objectives.at(-1)!.snapDistance,
    waypointCount: waypoints.length,
    expectedNavigationDistance: Number(expectedDistance.toFixed(2)),
    waypoints,
  })}\n`);
}