package pkg

import (
	"encoding/json"
	"strconv"
	"strings"
	"time"
)

func StringToInt(e string) (int, error) {
	return strconv.Atoi(e)
}

func GetCurrentTimeStr() string {
	return time.Now().Format("2006-01-02 15:04:05")
}

func GetCurrentTime() time.Time {
	return time.Now()
}

func StructToJsonStr(e interface{}) (string, error) {
	if b, err := json.Marshal(e); err == nil {
		return string(b), err
	} else {
		return "", err
	}
}

func SnakeString(s string) string {
	data := make([]byte, 0, len(s)*2)
	j := false
	num := len(s)
	for i := 0; i < num; i++ {
		d := s[i]
		// or通过ASCII码进行大小写的转化
		// 65-90（A-Z），97-122（a-z）
		//判断如果字母为大写的A-Z就在前面拼接一个_
		if i > 0 && d >= 'A' && d <= 'Z' && j {
			data = append(data, '_')
		}
		if d != '_' {
			j = true
		}
		data = append(data, d)
	}
	//ToLower把大写字母统一转小写
	return strings.ToLower(string(data[:]))
}

func CamelString(s string) string {
	data := make([]byte, 0, len(s))
	j := false
	k := false
	num := len(s) - 1
	for i := 0; i <= num; i++ {
		d := s[i]
		if !k && d >= 'A' && d <= 'Z' {
			k = true
		}
		if d >= 'a' && d <= 'z' && (j || !k) {
			d = d - 32
			j = false
			k = true
		}
		if k && d == '_' && num > i && s[i+1] >= 'a' && s[i+1] <= 'z' {
			j = true
			continue
		}
		data = append(data, d)
	}
	return string(data[:])
}

func CaptainLower(s string) string {
	if len(s) == 0 {
		return ""
	}
	return strings.ToLower(s[:1]) + s[1:]
}