package org.yeshi.utils;

import freemarker.cache.StringTemplateLoader;
import freemarker.template.Configuration;
import freemarker.template.Template;
import org.apache.commons.io.IOUtils;

import java.io.*;
import java.util.Map;

public class FreemarkerUtils {

    private static String defaultCharacter = "UTF-8";
    private static Configuration cfg;

    private FreemarkerUtils() {
    }

    static {
        cfg = new Configuration(Configuration.getVersion());
        cfg.setDefaultEncoding(defaultCharacter);
        cfg.setTagSyntax(Configuration.AUTO_DETECT_TAG_SYNTAX);
    }

    /**
     * 对模板进行渲染
     *
     * @param data   数据Map
     * @param tplStr 模板
     * @return
     */
    public static String generateString(Object data, String tplStr) {
        String result = null;
        String name = "myStrTpl";
        try {
            StringTemplateLoader stringTemplateLoader = new StringTemplateLoader();
            stringTemplateLoader.putTemplate(name, tplStr);
            cfg.setTemplateLoader(stringTemplateLoader);
            Template template = cfg.getTemplate(name, defaultCharacter);
            StringWriter out = new StringWriter();
            template.process(data, out);
            out.flush();
            result = out.toString();
            out.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return result;
    }


    public static String generateInputStream(Object data, InputStream templateStream) throws IOException {
        String str = IOUtils.toString(templateStream, "UTF-8");
        return generateString(data, str);
    }

    /**
     * 将模板渲染以后保存到文件
     *
     * @param templateFileDir  模板目录
     * @param templateFileName 模板文件名称
     * @param targetFilePath   渲染后文件名称
     * @param data          数据
     * @return
     */
    public static boolean renderingTemplateAndGenerateFile(String templateFileDir,
                                                           String templateFileName, String targetFilePath,Object data) {
        boolean flag = true;
        try {
            // 设置文件所在目录的路径
            cfg.setDirectoryForTemplateLoading(new File(templateFileDir));//模板路径
            // 获取模版
            Template template = cfg.getTemplate(templateFileName);
            // 设置输出文件名,和保存路径
            File outFile = new File(targetFilePath);
            // 将模板和数据模型合并生成文件 重点设置编码集
            BufferedWriter out = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(outFile), "UTF-8"));
            // 生成文件
            template.process(data, out);
            // 关闭流
            out.flush();
            out.close();
        } catch (Exception e) {
            e.printStackTrace();
//            logger.error("生产模板文件失败！",e);
            flag = false;
        }
        return flag;
    }

    public static boolean renderingTemplateAndGenerateFile(InputStream templateInput, String targetFilePath, Object data) throws Exception {
        String result = generateInputStream(data, templateInput);
        if (result != null) {
            FileUtil.saveAsFileByte(result.getBytes("UTF-8"), targetFilePath);
            return true;
        }
        return false;
    }


}