/*
 * generates (strigified) module code from app-specific configruation:
 *  * additional/replaced modules/module-paths
 *  * included (optional) modules/functionality
 */

import { existsSync } from 'fs';
import { WebpackAppConfig } from 'mmir-tooling';
import * as appConfigUtils from 'mmir-tooling/utils/module-config-init';


type AppConfigUtils = typeof appConfigUtils;
interface WebpackAppConfigUtils extends AppConfigUtils {
    generateModuleCode(mmirAppConfig: WebpackAppConfig): string;
}

/**
 * [description]
 * @param  {PlainObject} mmirAppConfig JSON-like configuration object:
 * 							mmirAppConfig.config: module configuration object (analogous to requirejs module configuration)
 * 							mmirAppConfig.paths: mapping of module names to file-paths (additional or overwriting implemenation of existing modules)
 * @return {string} stringified module code
 */
function generateFromAppConfig(mmirAppConfig: WebpackAppConfig): string {

    var moduleImplStr = '';
    var moduleExportsStr = '';
    if(mmirAppConfig){

        var moduleExports = [];
        if(mmirAppConfig.config) {
            moduleImplStr += 'var appConfig = ' + JSON.stringify([{config: mmirAppConfig.config}], null, 2) + ';\n';
            moduleExports.push(['configList', 'appConfig']);
            // console.log('app config module -> appConfig: ', moduleImplStr);
        }

        if(mmirAppConfig.includeModules) {
            // ['asyncGrammar'] -> 'var doIncludeModules = function(){\n  require.resolve("mmirf/asyncGrammar");\n};\n';

            var rePrefix = /^(mmirf\/)|mmir-plugin-/;
            moduleImplStr += 'var doIncludeModules = function(){\n' +
                        mmirAppConfig.includeModules.map(function(incl){
                            incl = rePrefix.test(incl) || existsSync(incl)? incl : 'mmirf/' + incl;
                            return '  require.resolve("'+incl+'");'
                        }).join('\n') +
                '\n};\n';

            moduleExports.push(['applyIncludes', 'doIncludeModules']);
            // console.log('app config module -> includeModules: ', moduleImplStr);
        }

        if(mmirAppConfig.loadAfterInit) {
            // ['grammar/de'] -> 'var doLoadAfterInit = function(){\n  require("mmirf/grammar/de");\n};\n';

            var rePrefix = /^(mmirf\/)|mmir-plugin-/;
            moduleImplStr += 'var doLoadAfterInit = function(){\n' +
                        mmirAppConfig.loadAfterInit.map(function(incl){
                            incl = rePrefix.test(incl) || existsSync(incl)? incl : 'mmirf/' + incl;
                            return '  require("'+incl+'");'
                        }).join('\n') +
                '\n};\n';

            moduleExports.push(['applyAutoLoads', 'doLoadAfterInit']);
            // console.log('app config module -> doLoadAfterInit: ', moduleImplStr);
        }

        if(mmirAppConfig.loadBeforeInit) {
            // ['polyfill'] -> 'var doLoadBeforeInit = function(){\n  require("mmirf/polyfill");\n};\n';

            var rePrefix = /^(mmirf\/)|mmir-plugin-/;
            moduleImplStr += 'var doLoadBeforeInit = function(){\n' +
                        mmirAppConfig.loadBeforeInit.map(function(incl){
                            incl = rePrefix.test(incl) || existsSync(incl)? incl : 'mmirf/' + incl;
                            return '  require("'+incl+'");'
                        }).join('\n') +
                '\n};\n';

            moduleExports.push(['applyAutoPreloads', 'doLoadBeforeInit']);
            // console.log('app config module -> doLoadBeforeInit: ', moduleImplStr);
        }

        if(mmirAppConfig.runtimeSettings) {
            moduleImplStr += 'var appSettings = ' + JSON.stringify(mmirAppConfig.runtimeSettings, null, 2) + ';\n';
            moduleExports.push(['settings', 'appSettings']);
            // console.log('app config module -> settings: ', moduleImplStr);
        }

        if(mmirAppConfig.jquery){
            moduleImplStr += 'var doInitJQuery = function(){ require("mmirf/core").jquery = require("jquery"); };\n';
            moduleExports.push(['jqueryInit', 'doInitJQuery']);
        }

        moduleExportsStr = moduleExports.length > 0?
            '{' + (moduleExports.map(
                    function(pairs){
                        return pairs[0] +': ' + pairs[1];
                    })).join(',\n')+
            '};' : 'false;';

    } else {

        moduleExportsStr = 'false;';
    }

    // console.log('app config module exports: ', moduleExportsStr);
    // // console.log('app config module impl.: ', moduleImplStr);

    return moduleImplStr + '\nmodule.exports=' + moduleExportsStr;
}

const webpackAppConfigUtils: WebpackAppConfigUtils = appConfigUtils as WebpackAppConfigUtils;
webpackAppConfigUtils.generateModuleCode = generateFromAppConfig;

export = webpackAppConfigUtils;