package org.yeshi.utils.generater.mybatis;

import org.springframework.data.annotation.Transient;

import java.lang.annotation.Annotation;
import java.lang.reflect.Field;

public class ColumnParseUtil {

    /**
     * 将属性转为数据库字段
     *
     * @param fieldName
     * @return
     */
    private static String convertFieldToColumn(String fieldName) {
        String column = "";
        for (int i = 0; i < fieldName.length(); i++) {
            //大写字母
            if (fieldName.charAt(i) >= 65 && fieldName.charAt(i) <= 90) {
                //前面一个为非大写
                if (i > 0 && (fieldName.charAt(i - 1) < 65 || fieldName.charAt(i - 1) > 90)) {
                    column += "_" + fieldName.charAt(i);
                } else {
                    column += fieldName.charAt(i);
                }
            } else {
                column += fieldName.charAt(i);
            }
        }
        return column.toLowerCase();
    }

    public static void parseColumn(Class<?> clz, String path) {
        Field[] fields = clz.getDeclaredFields();
        for (Field fd : fields) {

            //private/public 非final，static属性才会参与解析
            if (fd.getModifiers() != 1 && fd.getModifiers() != 2) {
                continue;
            }


            String columName = convertFieldToColumn(fd.getName());
            Annotation[] as = fd.getAnnotations();
            for (Annotation a : as) {
                //不参与解析
                if (a instanceof Column) {
                    Column c = (Column) a;
                    columName = c.name();

                }
            }

            for (Annotation a : as) {
                //不参与解析
                if (a instanceof Transient || a instanceof java.beans.Transient) {
                    columName = null;
                    break;
                }
            }

            if (columName != null) {
                ColumnUtil.addColumnToMapper(path, columName, fd.getName(), getJDBCType(fd.getType().getName()));
            }

        }
    }

    public static String getJDBCType(String type) {
        if (type.endsWith("java.lang.Long")) {
            return "BIGINT";
        } else if (type.endsWith("java.lang.Integer")) {
            return "INTEGER";
        } else if (type.endsWith("java.lang.String")) {
            return "VARCHAR";
        } else if (type.endsWith("java.lang.Boolean")) {
            return "BOOLEAN";
        } else if (type.endsWith("java.math.BigDecimal")) {
            return "DECIMAL";
        } else if (type.endsWith("java.util.Date")) {
            return "TIMESTAMP";
        } else if (type.endsWith("java.lang.Double")) {
            return "DOUBLE";
        } else {
            return "VARCHAR";
        }
    }


    public static String getMysqlType(String type) {
        if (type.endsWith("java.lang.Long")) {
            return "bigint";
        } else if (type.endsWith("java.lang.Integer")) {
            return "int";
        } else if (type.endsWith("java.lang.String")) {
            return "varchar";
        } else if (type.endsWith("java.lang.Boolean")) {
            return "tinyint";
        } else if (type.endsWith("java.math.BigDecimal")) {
            return "decimal";
        } else if (type.endsWith("java.util.Date")) {
            return "datetime";
        } else if (type.endsWith("java.lang.Double")) {
            return "double";
        } else {
            return "varchar";
        }
    }

}