import fs from 'fs-extra';
import path from 'path';
import fileUtils from '../utils/filepath-utils';

import logUtils from '../utils/log-utils';
import { AppConfig , ResourcesOptions } from '../index.d';
const log = logUtils.log;
// const warn = logUtils.warn;

/**
 *
 * @param  dir
 * @param  parseOptions
 * @param  [options] in/out parameter (will be created, if omitted)
 * @return return (modified) options argument or a newly created AppConfig
 */
function parseRootDir(dir: string, parseOptions: ResourcesOptions, options: AppConfig): AppConfig {

    options = options || {};
    var files = fs.readdirSync(dir);
    // log('parse root dir "'+dir+'" -> ', files);

    files.forEach(function(p){

        var absPath = path.join(dir, p);
        if(fileUtils.isDirectory(absPath)){

            var dirName = path.basename(absPath).toLowerCase();
            if(parseOptions[dirName] === false || (parseOptions.exclude && parseOptions.exclude.find(function(item){ return item === dirName;}))){
                log('parsing resources: excluding resources for ', dirName, parseOptions.exclude);
                return;////////// EARLY EXIT ////////////////
            }

            switch(dirName){
                case 'config':
                    parseConfigDir(absPath, parseOptions, options);
                    break;
                case 'controllers':
                case 'helpers':
                case 'models':
                    options[dirName] = {path: fileUtils.normalizePath(absPath), addModuleExport: parseOptions.addModuleExport};
                    break;
                case 'views':
                    options[dirName] = {path: fileUtils.normalizePath(absPath)};
                    break;
                default:
                    return;////////// EARLY EXIT ////////////////
            }
        }
    });

    return options;
}

 /**
  *
  * @param  dir
  * @param  parseOptions
  * @param  [options] in/out parameter (will be created, if omitted)
  * @return return (modified) options argument or a newly created AppConfig
  */
function parseConfigDir(dir: string, parseOptions: ResourcesOptions, options: AppConfig): AppConfig {

    options = options || {};
    var files = fs.readdirSync(dir);
    // log('parse config dir "'+dir+'" -> ', files);

    if(!parseOptions.exclude || !parseOptions.exclude.find(function(item){ return item === 'settings';})){

        options.settings = {path: fileUtils.normalizePath(dir)};

        if(parseOptions.exclude){
            //check if settings/<sub-type> needs to be excluded:
            parseOptions.exclude.filter(function(item){ return /^settings\//.test(item);}).forEach(function(entry){
                var subType = entry.substring('settings/'.length);

                log('parsing resources: excluding settings/'+subType+' resources for ', dir, parseOptions.exclude);//DEBUG

                options.settings[subType] = false;
            });
        }
    }
    else log('parsing resources: excluding all settings resources for ', dir, parseOptions.exclude);//DEBUG

    files.forEach(function(p){
        var absPath = path.join(dir, p);
        if(fileUtils.isDirectory(absPath)){
            var dirName = path.basename(absPath).toLowerCase();

            switch(dirName){
                case 'languages':
                    if(options.grammars !== false && (!parseOptions.exclude || !parseOptions.exclude.find(function(item){ return item === 'grammar';}))){
                        options.grammars = {path: fileUtils.normalizePath(absPath)};
                    }
                    else log('parsing resources: excluding grammar resources for ', dirName, parseOptions.exclude);//DEBUG
                    break;
                    // BACKWARDS COMPATIBILITY: check old/deprecated dir-name "statedef"
                case 'statedef':		/* intentional fall-through */
                case 'states':
                    if(options.states !== false && (!parseOptions.exclude || !parseOptions.exclude.find(function(item){ return item === 'state';}))){
                        options.states = {path: fileUtils.normalizePath(absPath)};
                    }
                    else log('parsing resources: excluding scxml resources for ', dirName, parseOptions.exclude);//DEBUG
                    break;
                default:
                    return;////// EARLY EXIT //////////////
            }
        }
    });

    return options;
}

export = {
    /**
     * [resourcePathsFrom description]
     * @param  {String} directory the directory that contains the default MMIR direcotry structure containing (possibly) config, languages, controllers, helpers etc.
     * @param  {ResourceParseOptions} parseOptions options for parsing the directories:
     * 													parseOptions.addModuleExport: {Boolean} use the addModuleExport option for controllers, helpers, and models
     * 													parseOptions.exclude: {Array<String>} exlude some resource types, like "controllers", or "models"
     * 																								for excluding sub-types for settings, e.g. dictionaries, use "settings/dictionary",
     * 																								or "settings/grammar" for excluding the sources of JSON grammars (i.e. exclude the sources for compiled grammars)
     * @return {AppConfig} the AppConfig with the 'path' option set for the corresponding resource type, so that the corresponding utils/loaders will the the resources from that path
     */
    resourcePathsFrom(directory: string, parseOptions: ResourcesOptions): AppConfig {

        parseOptions = parseOptions || {};
        var configOptions = {};

        parseRootDir(directory, parseOptions, configOptions);

        return configOptions;
    },
    /**
     * HELPER for merging the results of resourcePathsFrom() with the user-supplied AppConfig,
     *        without overwritting user-set options
     * @param  {AppConfig} userConfig the user-supplied AppConfig, into which  the generatedConfig will be merged)
     * @param  {AppConfig} generatedConfig the generated AppConfig containing the path-field for discovered resources
     * @return {AppConfig} the merge AppConfig (same as userConfig)
     */
    mergeResourceConfigs(userConfig: AppConfig, generatedConfig: AppConfig): AppConfig {

        let entry: any;
        for(let n in generatedConfig){
            entry = generatedConfig[n];
            if(!userConfig[n] && userConfig[n] !== false){

                userConfig[n] = entry;

            } else if(userConfig[n] && !userConfig[n].path && userConfig[n].path !== false){

                userConfig[n].path = entry.path;
            }
        }

        return userConfig;
    }
}