// luma.gl
// SPDX-License-Identifier: MIT
// Copyright (c) vis.gl contributors
import { ShaderModuleInstance } from "./shader-module/shader-module-instance.js";
import { selectShaders } from "./shader-assembly/select-shaders.js";
import { assembleShaderWGSL, assembleShaderPairWGSL, assembleShaderPairGLSL } from "./shader-assembly/assemble-shaders.js";
/**
 * A stateful version of `assembleShaders` that can be used to assemble shaders.
 * Supports setting of default modules and hooks.
 */
export class ShaderAssembler {
    /** Default ShaderAssembler instance */
    static defaultShaderAssembler;
    /** Hook functions */
    _hookFunctions = [];
    /** Shader modules */
    _defaultModules = [];
    /**
     * A default shader assembler instance - the natural place to register default modules and hooks
     * @returns
     */
    static getDefaultShaderAssembler() {
        ShaderAssembler.defaultShaderAssembler =
            ShaderAssembler.defaultShaderAssembler || new ShaderAssembler();
        return ShaderAssembler.defaultShaderAssembler;
    }
    /**
     * Add a default module that does not have to be provided with every call to assembleShaders()
     */
    addDefaultModule(module) {
        if (!this._defaultModules.find(m => m.name === (typeof module === 'string' ? module : module.name))) {
            this._defaultModules.push(module);
        }
    }
    /**
     * Remove a default module
     */
    removeDefaultModule(module) {
        const moduleName = typeof module === 'string' ? module : module.name;
        this._defaultModules = this._defaultModules.filter(m => m.name !== moduleName);
    }
    /**
     * Register a shader hook
     * @param hook
     * @param opts
     */
    addShaderHook(hook, opts) {
        if (opts) {
            hook = Object.assign(opts, { hook });
        }
        this._hookFunctions.push(hook);
    }
    /**
     * Assemble a pair of shaders into a single shader program
     * @param platformInfo
     * @param props
     * @returns
     */
    assembleShader(props) {
        const modules = this._getModuleList(props.modules); // Combine with default modules
        const hookFunctions = this._hookFunctions; // TODO - combine with default hook functions
        const options = selectShaders(props);
        const assembled = assembleShaderWGSL({
            platformInfo: props.platformInfo,
            ...options,
            modules,
            hookFunctions
        });
        return { ...assembled, modules };
    }
    /**
     * Assemble a pair of shaders into a single shader program
     * @param platformInfo
     * @param props
     * @returns
     */
    assembleShaderPair(props) {
        const options = selectShaders(props);
        const modules = this._getModuleList(props.modules); // Combine with default modules
        const hookFunctions = this._hookFunctions; // TODO - combine with default hook functions
        const { platformInfo } = props;
        const isWGSL = props.platformInfo.shaderLanguage === 'wgsl';
        const assembled = isWGSL
            ? assembleShaderPairWGSL({ platformInfo, ...options, modules, hookFunctions })
            : assembleShaderPairGLSL({ platformInfo, ...options, modules, hookFunctions });
        return { ...assembled, modules };
    }
    /**
     * Dedupe and combine with default modules
     */
    _getModuleList(appModules = []) {
        const modules = new Array(this._defaultModules.length + appModules.length);
        const seen = {};
        let count = 0;
        for (let i = 0, len = this._defaultModules.length; i < len; ++i) {
            const module = this._defaultModules[i];
            const name = module.name;
            modules[count++] = module;
            seen[name] = true;
        }
        for (let i = 0, len = appModules.length; i < len; ++i) {
            const module = appModules[i];
            const name = module.name;
            if (!seen[name]) {
                modules[count++] = module;
                seen[name] = true;
            }
        }
        modules.length = count;
        return ShaderModuleInstance.instantiateModules(modules);
    }
}