package gorm

import (
	"bytes"
	"strings"
)

var smap = map[string]string{}

func ToDBColumnName(u string) string {
	if v, ok := smap[u]; ok {
		return v
	}

	buf := bytes.NewBufferString("")
	for i, v := range u {
		if i > 0 && v >= 'A' && v <= 'Z' {
			buf.WriteRune('_')
		}
		buf.WriteRune(v)
	}

	s := strings.ToLower(buf.String())
	smap[u] = s
	return s
}

func parseTagSetting(str string) map[string]string {
	tags := strings.Split(str, ";")
	setting := map[string]string{}
	for _, value := range tags {
		v := strings.Split(value, ":")
		k := strings.TrimSpace(strings.ToUpper(v[0]))
		if len(v) == 2 {
			setting[k] = v[1]
		} else {
			setting[k] = k
		}
	}
	return setting
}