import { Vector3 } from '../math/Vector3.js';
import { Vector2 } from '../math/Vector2.js';
import { Sphere } from '../math/Sphere.js';
import { Ray } from '../math/Ray.js';
import { Matrix4 } from '../math/Matrix4.js';
import { Object3D } from '../core/Object3D.js';
import { Triangle } from '../math/Triangle.js';
import { DoubleSide, BackSide } from '../constants.js';
import { MeshBasicMaterial } from '../materials/MeshBasicMaterial.js';
import { BufferGeometry } from '../core/BufferGeometry.js';

const _inverseMatrix = /*@__PURE__*/ new Matrix4();
const _ray = /*@__PURE__*/ new Ray();
const _sphere = /*@__PURE__*/ new Sphere();

const _vA = /*@__PURE__*/ new Vector3();
const _vB = /*@__PURE__*/ new Vector3();
const _vC = /*@__PURE__*/ new Vector3();

const _tempA = /*@__PURE__*/ new Vector3();
const _tempB = /*@__PURE__*/ new Vector3();
const _tempC = /*@__PURE__*/ new Vector3();

const _morphA = /*@__PURE__*/ new Vector3();
const _morphB = /*@__PURE__*/ new Vector3();
const _morphC = /*@__PURE__*/ new Vector3();

const _uvA = /*@__PURE__*/ new Vector2();
const _uvB = /*@__PURE__*/ new Vector2();
const _uvC = /*@__PURE__*/ new Vector2();

const _intersectionPoint = /*@__PURE__*/ new Vector3();
const _intersectionPointWorld = /*@__PURE__*/ new Vector3();

class Mesh extends Object3D {

	constructor( geometry = new BufferGeometry(), material = new MeshBasicMaterial() ) {

		super();

		this.type = 'Mesh';

		this.geometry = geometry;
		this.material = material;

		this.updateMorphTargets();

	}

	copy( source ) {

		super.copy( source );

		if ( source.morphTargetInfluences !== undefined ) {

			this.morphTargetInfluences = source.morphTargetInfluences.slice();

		}

		if ( source.morphTargetDictionary !== undefined ) {

			this.morphTargetDictionary = Object.assign( {}, source.morphTargetDictionary );

		}

		this.material = source.material;
		this.geometry = source.geometry;

		return this;

	}

	updateMorphTargets() {

		const geometry = this.geometry;

		if ( geometry.isBufferGeometry ) {

			const morphAttributes = geometry.morphAttributes;
			const keys = Object.keys( morphAttributes );

			if ( keys.length > 0 ) {

				const morphAttribute = morphAttributes[ keys[ 0 ] ];

				if ( morphAttribute !== undefined ) {

					this.morphTargetInfluences = [];
					this.morphTargetDictionary = {};

					for ( let m = 0, ml = morphAttribute.length; m < ml; m ++ ) {

						const name = morphAttribute[ m ].name || String( m );

						this.morphTargetInfluences.push( 0 );
						this.morphTargetDictionary[ name ] = m;

					}

				}

			}

		} else {

			const morphTargets = geometry.morphTargets;

			if ( morphTargets !== undefined && morphTargets.length > 0 ) {

				console.error( 'THREE.Mesh.updateMorphTargets() no longer supports THREE.Geometry. Use THREE.BufferGeometry instead.' );

			}

		}

	}

	raycast( raycaster, intersects ) {

		const geometry = this.geometry;
		const material = this.material;
		const matrixWorld = this.matrixWorld;

		if ( material === undefined ) return;

		// Checking boundingSphere distance to ray

		if ( geometry.boundingSphere === null ) geometry.computeBoundingSphere();

		_sphere.copy( geometry.boundingSphere );
		_sphere.applyMatrix4( matrixWorld );

		if ( raycaster.ray.intersectsSphere( _sphere ) === false ) return;

		//

		_inverseMatrix.copy( matrixWorld ).invert();
		_ray.copy( raycaster.ray ).applyMatrix4( _inverseMatrix );

		// Check boundingBox before continuing

		if ( geometry.boundingBox !== null ) {

			if ( _ray.intersectsBox( geometry.boundingBox ) === false ) return;

		}

		let intersection;

		if ( geometry.isBufferGeometry ) {

			const index = geometry.index;
			const position = geometry.attributes.position;
			const morphPosition = geometry.morphAttributes.position;
			const morphTargetsRelative = geometry.morphTargetsRelative;
			const uv = geometry.attributes.uv;
			const uv2 = geometry.attributes.uv2;
			const groups = geometry.groups;
			const drawRange = geometry.drawRange;

			if ( index !== null ) {

				// indexed buffer geometry

				if ( Array.isArray( material ) ) {

					for ( let i = 0, il = groups.length; i < il; i ++ ) {

						const group = groups[ i ];
						const groupMaterial = material[ group.materialIndex ];

						const start = Math.max( group.start, drawRange.start );
						const end = Math.min( ( group.start + group.count ), ( drawRange.start + drawRange.count ) );

						for ( let j = start, jl = end; j < jl; j += 3 ) {

							const a = index.getX( j );
							const b = index.getX( j + 1 );
							const c = index.getX( j + 2 );

							intersection = checkBufferGeometryIntersection( this, groupMaterial, raycaster, _ray, position, morphPosition, morphTargetsRelative, uv, uv2, a, b, c );

							if ( intersection ) {

								intersection.faceIndex = Math.floor( j / 3 ); // triangle number in indexed buffer semantics
								intersection.face.materialIndex = group.materialIndex;
								intersects.push( intersection );

							}

						}

					}

				} else {

					const start = Math.max( 0, drawRange.start );
					const end = Math.min( index.count, ( drawRange.start + drawRange.count ) );

					for ( let i = start, il = end; i < il; i += 3 ) {

						const a = index.getX( i );
						const b = index.getX( i + 1 );
						const c = index.getX( i + 2 );

						intersection = checkBufferGeometryIntersection( this, material, raycaster, _ray, position, morphPosition, morphTargetsRelative, uv, uv2, a, b, c );

						if ( intersection ) {

							intersection.faceIndex = Math.floor( i / 3 ); // triangle number in indexed buffer semantics
							intersects.push( intersection );

						}

					}

				}

			} else if ( position !== undefined ) {

				// non-indexed buffer geometry

				if ( Array.isArray( material ) ) {

					for ( let i = 0, il = groups.length; i < il; i ++ ) {

						const group = groups[ i ];
						const groupMaterial = material[ group.materialIndex ];

						const start = Math.max( group.start, drawRange.start );
						const end = Math.min( ( group.start + group.count ), ( drawRange.start + drawRange.count ) );

						for ( let j = start, jl = end; j < jl; j += 3 ) {

							const a = j;
							const b = j + 1;
							const c = j + 2;

							intersection = checkBufferGeometryIntersection( this, groupMaterial, raycaster, _ray, position, morphPosition, morphTargetsRelative, uv, uv2, a, b, c );

							if ( intersection ) {

								intersection.faceIndex = Math.floor( j / 3 ); // triangle number in non-indexed buffer semantics
								intersection.face.materialIndex = group.materialIndex;
								intersects.push( intersection );

							}

						}

					}

				} else {

					const start = Math.max( 0, drawRange.start );
					const end = Math.min( position.count, ( drawRange.start + drawRange.count ) );

					for ( let i = start, il = end; i < il; i += 3 ) {

						const a = i;
						const b = i + 1;
						const c = i + 2;

						intersection = checkBufferGeometryIntersection( this, material, raycaster, _ray, position, morphPosition, morphTargetsRelative, uv, uv2, a, b, c );

						if ( intersection ) {

							intersection.faceIndex = Math.floor( i / 3 ); // triangle number in non-indexed buffer semantics
							intersects.push( intersection );

						}

					}

				}

			}

		} else if ( geometry.isGeometry ) {

			console.error( 'THREE.Mesh.raycast() no longer supports THREE.Geometry. Use THREE.BufferGeometry instead.' );

		}

	}

}

Mesh.prototype.isMesh = true;

function checkIntersection( object, material, raycaster, ray, pA, pB, pC, point ) {

	let intersect;

	if ( material.side === BackSide ) {

		intersect = ray.intersectTriangle( pC, pB, pA, true, point );

	} else {

		intersect = ray.intersectTriangle( pA, pB, pC, material.side !== DoubleSide, point );

	}

	if ( intersect === null ) return null;

	_intersectionPointWorld.copy( point );
	_intersectionPointWorld.applyMatrix4( object.matrixWorld );

	const distance = raycaster.ray.origin.distanceTo( _intersectionPointWorld );

	if ( distance < raycaster.near || distance > raycaster.far ) return null;

	return {
		distance: distance,
		point: _intersectionPointWorld.clone(),
		object: object
	};

}

function checkBufferGeometryIntersection( object, material, raycaster, ray, position, morphPosition, morphTargetsRelative, uv, uv2, a, b, c ) {

	_vA.fromBufferAttribute( position, a );
	_vB.fromBufferAttribute( position, b );
	_vC.fromBufferAttribute( position, c );

	const morphInfluences = object.morphTargetInfluences;

	if ( material.morphTargets && morphPosition && morphInfluences ) {

		_morphA.set( 0, 0, 0 );
		_morphB.set( 0, 0, 0 );
		_morphC.set( 0, 0, 0 );

		for ( let i = 0, il = morphPosition.length; i < il; i ++ ) {

			const influence = morphInfluences[ i ];
			const morphAttribute = morphPosition[ i ];

			if ( influence === 0 ) continue;

			_tempA.fromBufferAttribute( morphAttribute, a );
			_tempB.fromBufferAttribute( morphAttribute, b );
			_tempC.fromBufferAttribute( morphAttribute, c );

			if ( morphTargetsRelative ) {

				_morphA.addScaledVector( _tempA, influence );
				_morphB.addScaledVector( _tempB, influence );
				_morphC.addScaledVector( _tempC, influence );

			} else {

				_morphA.addScaledVector( _tempA.sub( _vA ), influence );
				_morphB.addScaledVector( _tempB.sub( _vB ), influence );
				_morphC.addScaledVector( _tempC.sub( _vC ), influence );

			}

		}

		_vA.add( _morphA );
		_vB.add( _morphB );
		_vC.add( _morphC );

	}

	if ( object.isSkinnedMesh && material.skinning ) {

		object.boneTransform( a, _vA );
		object.boneTransform( b, _vB );
		object.boneTransform( c, _vC );

	}

	const intersection = checkIntersection( object, material, raycaster, ray, _vA, _vB, _vC, _intersectionPoint );

	if ( intersection ) {

		if ( uv ) {

			_uvA.fromBufferAttribute( uv, a );
			_uvB.fromBufferAttribute( uv, b );
			_uvC.fromBufferAttribute( uv, c );

			intersection.uv = Triangle.getUV( _intersectionPoint, _vA, _vB, _vC, _uvA, _uvB, _uvC, new Vector2() );

		}

		if ( uv2 ) {

			_uvA.fromBufferAttribute( uv2, a );
			_uvB.fromBufferAttribute( uv2, b );
			_uvC.fromBufferAttribute( uv2, c );

			intersection.uv2 = Triangle.getUV( _intersectionPoint, _vA, _vB, _vC, _uvA, _uvB, _uvC, new Vector2() );

		}

		const face = {
			a: a,
			b: b,
			c: c,
			normal: new Vector3(),
			materialIndex: 0
		};

		Triangle.getNormal( _vA, _vB, _vC, face.normal );

		intersection.face = face;

	}

	return intersection;

}

export { Mesh };
