// https://www.w3.org/TR/webgpu/#enumdef-gpuvertexformat

import { Union } from '/public/vendor/kojima/union.js'
import { capitalizen } from '/src/utils/index'

/** @typedef {Uint8ArrayConstructor | Int8ArrayConstructor | Uint16ArrayConstructor | Int16ArrayConstructor | Uint32ArrayConstructor | Int32ArrayConstructor | Float32ArrayConstructor | Float64ArrayConstructor} TypedArrayConstructor */

/** @type {GPUVertexFormat[]} */
export const GPUVertexFormats = ['uint8', 'uint8x2', 'uint8x4', 'sint8', 'sint8x2', 'sint8x4', 'unorm8', 'unorm8x2', 'unorm8x4', 'snorm8', 'snorm8x2', 'snorm8x4', 'uint16', 'uint16x2', 'uint16x4', 'sint16', 'sint16x2', 'sint16x4', 'unorm16', 'unorm16x2', 'unorm16x4', 'snorm16', 'snorm16x2', 'snorm16x4', 'float16', 'float16x2', 'float16x4', 'float32', 'float32x2', 'float32x3', 'float32x4', 'uint32', 'uint32x2', 'uint32x3', 'uint32x4', 'sint32', 'sint32x2', 'sint32x3', 'sint32x4', 'unorm10-10-10-2', 'unorm8x4-bgra']

export class MeshAttributeData {
    #format
    #buffer

    /**
     * @param {VertexFormat} format 
     * @param {ArrayBufferLike} buffer
     */
    constructor(format, buffer) {
        this.#format = format
        this.#buffer = buffer
    }

    get format() { return this.#format }
    get buffer() { return this.#buffer }
}

export class VertexFormat {
    #name
    #components
    #size
    #bufferType

    /**
     * @param {GPUVertexFormat} name 
     * @param {number} components 
     * @param {number} size 
     * @param {TypedArrayConstructor} bufferType 
     */
    constructor(name, components, size, bufferType) {
        this.#name = name
        this.#components = components
        this.#size = size
        this.#bufferType = bufferType
    }

    get name() { return this.#name }
    get components() { return this.#components }
    get size() { return this.#size }
    get bufferType() { return this.#bufferType }
}


// INFO: ugly initialization code for VertexFormat statics
// this is for doing VertexFormat.Uint8 to get that format
(() => {

    /** @type {[GPUVertexFormat, number, number, TypedArrayConstructor][]} */
    const formats = [
        ['uint8', 1, 1, Uint8Array],
        ['uint8x2', 2, 2, Uint8Array],
        ['uint8x4', 4, 4, Uint8Array],
        ['sint8', 1, 1, Int8Array],
        ['sint8x2', 2, 2, Int8Array],
        ['sint8x4', 4, 4, Int8Array],
        ['unorm8', 1, 1, Uint8Array],
        ['unorm8x2', 2, 2, Uint8Array],
        ['unorm8x4', 4, 4, Uint8Array],
        ['snorm8', 1, 1, Int8Array],
        ['snorm8x2', 2, 2, Int8Array],
        ['snorm8x4', 4, 4, Int8Array],
        ['uint16', 1, 2, Uint16Array],
        ['uint16x2', 2, 4, Uint16Array],
        ['uint16x4', 4, 8, Uint16Array],
        ['sint16', 1, 2, Int16Array],
        ['sint16x2', 2, 4, Int16Array],
        ['sint16x4', 4, 8, Int16Array],
        ['unorm16', 1, 2, Uint16Array],
        ['unorm16x2', 2, 4, Uint16Array],
        ['unorm16x4', 4, 8, Uint16Array],
        ['snorm16', 1, 2, Int16Array],
        ['snorm16x2', 2, 4, Int16Array],
        ['snorm16x4', 4, 8, Int16Array],
        ['float16', 1, 2, Uint16Array],
        ['float16x2', 2, 4, Uint16Array],
        ['float16x4', 4, 8, Uint16Array],
        ['float32', 1, 4, Float32Array],
        ['float32x2', 2, 8, Float32Array],
        ['float32x3', 3, 12, Float32Array],
        ['float32x4', 4, 16, Float32Array],
        ['uint32', 1, 4, Uint32Array],
        ['uint32x2', 2, 8, Uint32Array],
        ['uint32x3', 3, 12, Uint32Array],
        ['uint32x4', 4, 16, Uint32Array],
        ['sint32', 1, 4, Int32Array],
        ['sint32x2', 2, 8, Int32Array],
        ['sint32x3', 3, 12, Int32Array],
        ['sint32x4', 4, 16, Int32Array],
        ['unorm10-10-10-2', 4, 4, Uint32Array],
        ['unorm8x4-bgra', 4, 4, Uint8Array]
    ]

    /**
     * @param {string} name
     */
    const capitalize = name => name.charAt(0).toUpperCase() + name.slice(1)

    formats.forEach(([name, components, size]) => {
        Object.defineProperty(VertexFormat, capitalize(value.name), {
            value: new VertexFormat(name, components, size),
            writable: false,
            configurable: false
        })
    })
})()