import { DirectoriesInfo, SettingsBuildEntry, SettingsBuildOptions } from '../index.d';

import fs from 'fs-extra';
import path from 'path';

// import _ from '.lodash';

import settingsUtil from '../tools/settings-utils';

import promise from '../utils/promise';

import logUtils from '../utils/log-utils';
const log = logUtils.log;
const warn = logUtils.warn;

async function writeDirectoriesJson(directories: DirectoriesInfo, targetDir: string): Promise<void | Error> {

    return fs.ensureDir(targetDir).then(async function(){
        return fs.writeFile(path.join(targetDir, 'directories.json'), JSON.stringify(directories), 'utf8').catch(function(err){
            var msg = 'ERROR writing directories.json to '+targetDir+': ';
            warn(msg, err);
            return err.stack? err : new Error(msg+err);
        });
    });
}

function getSettingTargetPath(setting: SettingsBuildEntry, targetDir: string): string {
    if(setting.type === 'configuration'){
        return path.join(targetDir, 'configuration.json');
    }

    let fileName: string;
    switch(setting.type){
        case 'dictionary':
            fileName = 'dictionary.json';
            break;
        case 'grammar':
            fileName = 'grammar.json';
            break;
        case 'speech':
            fileName = 'speech.json';
            break;
        default:
            warn('settingsCompiler: cannot determine target file path for settings with unknown type '+setting.type);
    }

    if(fileName){
        return path.join(targetDir, 'languages', setting.id, fileName);
    }
}

function prepareWriteSettings(settings: SettingsBuildEntry[], settingsOptions: SettingsBuildOptions): Promise<void|Error> {
    settingsUtil.applyDefaultOptions(settingsOptions, settings);
    return promise.resolve();
}

/**
 * HELPER write settings files to config/* (for configuration settings) and
 *        to config/languages/<id>/* (for dictionary, grammar, and speech settings),
 *        if settings options specify that files should be written.
 *
 * @param  {Array<SettingsEntry>} settings the list of settings
 * @param  {SettingsOptions} settingsOptions the settings options
 */
function writeSettings(settings: SettingsBuildEntry[], settingsOptions: SettingsBuildOptions): Promise<Array<Error|Error[]> | any[]> {

    // include all settings that
    // (1) do not match the exclude-type pattern
    // (2) are not specifically excluded
    // (3) have include-type 'file'
    var excludeTypePattern = settingsOptions.excludeTypePattern;
    var procSettings = settings.filter(function(item){
        if(settingsUtil.isExcludeType(item.type, excludeTypePattern)){
            return false;
        }
        return !item.exclude && item.include === 'file';
    });

    //log('processing settings: ', settings, settingsOptions, ' -> writing ', procSettings);

    var tasks = [];


    procSettings.forEach(function(setting){

        var targetPath = getSettingTargetPath(setting, settingsOptions.targetDir);
        if(!targetPath){
            return;
        }

        var t = fs.pathExists(targetPath).then(async function(exists){

            if(!exists || setting.force){

                return fs.ensureDir(path.dirname(targetPath)).then(async function(){
                    if(setting.include === 'file' && !setting.value){

                        return fs.copyFile(setting.file, targetPath).catch(function(err){
                            var msg = 'ERROR copying file to '+targetPath+': ';
                            warn(msg, err);
                            return err.stack? err : new Error(msg+err);
                        });

                    } else {

                        return fs.writeFile(targetPath, JSON.stringify(setting.value), 'utf8').catch(function(err){
                            var msg = 'ERROR writing '+targetPath+': ';
                            warn(msg, err);
                            return err.stack? err : new Error(msg+err);
                        });
                    }
                });

            } else {
                log('omit writing '+setting.type+' to '+targetPath+', since it already exists');//: ', setting);
            }
        });

        tasks.push(t);
    });

    return promise.all(tasks);
}

export = {
    writeDirectoriesJson: writeDirectoriesJson,
    writeSettings: writeSettings,
    prepareWriteSettings: prepareWriteSettings
}