import { Mesh } from '../core/Mesh.js'

export const OBJ = (obj) => {

    var verticies = []
    var indicies = []
    var normals = []
    var uvs = []

    var indexedNormals = [];
    var indexedUvs = [];

    obj.split('\n').forEach((line) => {
        const tokens = line.toLowerCase().trim().split(' ').filter((str) => str !== '')
        if(tokens.length < 1) return;
        if(tokens[0] === 'v') {
            verticies.push(parseFloat(tokens[1]))
            verticies.push(parseFloat(tokens[2]))
            verticies.push(parseFloat(tokens[3]))
        } else if(tokens[0] === 'vt') {
            uvs.push(parseFloat(tokens[1]))
            uvs.push(parseFloat(tokens[2]))
        } else if(tokens[0] === 'vn') {
            normals.push(parseFloat(tokens[1]))
            normals.push(parseFloat(tokens[2]))
            normals.push(parseFloat(tokens[3]))
        } else if(tokens[0] === 'f') {
            for (let i = 1; i < 4; i++) {
                const index = tokens[i].split('/').filter((str) => str !== '').map((s) => parseInt(s) - 1)
                indicies.push(index[0])
                indexedUvs[index[0]*2] = uvs[index[1]*2]
                indexedUvs[index[0]*2+1] = uvs[index[1]*2+1]
                indexedNormals[index[0]*3] = normals[index[2]*3]
                indexedNormals[index[0]*3+1] = normals[index[2]*3+1]
                indexedNormals[index[0]*3+2] = normals[index[2]*3+2]
            }
        }
    })
    
    return new Mesh(indicies.length)
        .indicies(indicies)
        .store(verticies, 3)
        .store(indexedNormals, 3)
        .store(indexedUvs, 2)
        .finish()

}