import lombok.extern.slf4j.Slf4j;
import org.yaml.snakeyaml.Yaml;
import org.yaml.snakeyaml.constructor.Constructor;
import org.yaml.snakeyaml.introspector.Property;
import org.yaml.snakeyaml.introspector.PropertyUtils;
import java.io.FileInputStream;
import java.io.InputStream;
@Slf4j
public class YamlUtil {
  // 变成驼峰样式
    static String camelize(String input) {
        for (int i = 0; i < input.length(); i++) {
            if(input.substring(i, i+1).equals("-")) {
                input.replace("-", "");
                input = input.substring(0, i) + input.substring(i+1, i+2).toUpperCase() + input.substring(i+2);
            }
            if(input.substring(i, i+1).equals(" ")) {
                input.replace(" ", "");
                input = input.substring(0, i) + input.substring(i+1, i+2).toUpperCase() + input.substring(i+2);
            }
        }
        return input;
    }
    public static Yaml buildYamlInstance(Class<? extends Object> theRoot){
        Constructor c = new Constructor(theRoot);
        c.setPropertyUtils(new PropertyUtils() {
            @Override
            public Property getProperty(Class<? extends Object> type, String name){
                if ( name.indexOf('-') > -1 ) {
                    name = YamlUtil.camelize(name);
                }
                // 关键代码 忽略yaml中无法在类中找到属性的字段
                setSkipMissingProperties(true);
                return super.getProperty(type, name);
            }
        });
        Yaml parser = new Yaml(c);
        return parser;
    }
    public static <T> T loadConfigFromFile(String path, Class<T> config_clazz) {
        Yaml yaml = YamlUtil.buildYamlInstance(config_clazz);
        T eConfig = null;
        try{
            InputStream in = new FileInputStream(path);
            eConfig = yaml.loadAs(in, config_clazz);
            String configJson = JsonUtil.toJSONString(eConfig);
            eConfig = JsonUtil.parseObject(configJson, config_clazz);
            in.close();
        }catch(Exception e){
            log.error(String.format("load config file %s failed ...", path), e);
        }
        return eConfig;
    }
}