import type { AssetError, MeshAsset, Result } from '@forgeax/engine-types';
import { createBoxGeometry, meshFromInterleaved } from '../box';
import { createCylinderGeometry } from '../cylinder';
import { createPlaneGeometry } from '../plane';
import { createSphereGeometry } from '../sphere';

export type PrimitiveMeshKind =
  | 'cube'
  | 'triangle'
  | 'quad'
  | 'sphere'
  | 'cylinder'
  | 'nine-slice-quad';

const PROCEDURAL_MESH_KINDS: Readonly<Record<string, PrimitiveMeshKind>> = {
  'procedural-cube': 'cube',
  'procedural-triangle': 'triangle',
  'procedural-quad': 'quad',
  'procedural-sphere': 'sphere',
  'procedural-cylinder': 'cylinder',
  'procedural-nine-slice-quad': 'nine-slice-quad',
};

/** Create one ordinary mesh payload for allocation or interning by an owning World. */
export function createPrimitiveMesh(kind: PrimitiveMeshKind): Result<MeshAsset, AssetError> {
  switch (kind) {
    case 'cube':
      return createBoxGeometry(1, 1, 1);
    case 'triangle':
      return meshFromInterleaved(
        new Float32Array([
          0, 0.7, 0, 0, 0, 1, 0.5, 1, -0.7, -0.6, 0, 0, 0, 1, 0, 0, 0.7, -0.6, 0, 0, 0, 1, 1, 0,
        ]),
        new Uint16Array([0, 1, 2]),
      );
    case 'quad':
      return createPlaneGeometry(1, 1);
    case 'sphere':
      return createSphereGeometry(1, 16, 12);
    case 'cylinder':
      return createCylinderGeometry(0.5, 0.5, 1, 16, 1);
    case 'nine-slice-quad':
      return createPlaneGeometry(1, 1, 3, 3);
  }
}

/** Resolve the canonical Pack v2 procedural mesh descriptor without duplicating its alias table. */
export function createProceduralMesh(payload: unknown): Result<MeshAsset, AssetError> | undefined {
  if (payload === null || typeof payload !== 'object' || Array.isArray(payload)) return undefined;
  const geometry = (payload as { readonly geometry?: unknown }).geometry;
  if (typeof geometry !== 'string') return undefined;
  const kind = PROCEDURAL_MESH_KINDS[geometry];
  if (kind === undefined) return undefined;
  return createPrimitiveMesh(kind);
}