package is

import (
	"encoding/json"
	"net"
	"net/url"
	"os"
	"reflect"
	"strconv"
	"strings"
	"time"
)

// Email 验证给出的字符串是不是有效的邮箱地址
func Email(str string) bool {
	return emailRegex.MatchString(str)
}

// E164 判断给出的字符串是否符合 e.164 规范的手机号码
func E164(str string) bool {
	return e164Regex.MatchString(str)
}

// PhoneNumber 判断给出的字符串是否符合中国大陆规范的手机号码
func PhoneNumber(str string) bool {
	return phoneNumberRegex.MatchString(str)
}

// Semver 判断给出的字符串是否符合语义化版本号规范
func Semver(str string) bool {
	return semverRegex.MatchString(str)
}

// Base64 判断给出的字符串是否为base64数据
func Base64(str string) bool {
	return base64Regex.MatchString(str)
}

// URL 判断给出的字符串是否为有效的URL
func URL(s string) bool {
	var i int
	// checks needed as of Go 1.6 because of change https://github.com/golang/go/commit/617c93ce740c3c3cc28cdd1a0d712be183d0b328#diff-6c2d018290e298803c0c9419d8739885L195
	// emulate browser and strip the '#' suffix prior to validation. see issue-#237
	if i = strings.Index(s, "#"); i > -1 {
		s = s[:i]
	}
	if len(s) == 0 {
		return false
	}
	u, err := url.ParseRequestURI(s)
	if err != nil || u.Scheme == "" {
		return false
	}
	return true
}

// Base64URL 判断给出的字符串是否为有效且安全的 base64URL
func Base64URL(str string) bool {
	return base64URLRegex.MatchString(str)
}

// JWT is the validation function for validating if the current field's value is a valid JWT string.
func JWT(str string) bool {
	return jWTRegex.MatchString(str)
}

// UUID5 is the validation function for validating if the field's value is a valid v5 UUID.
func UUID5(str string) bool {
	return uUID5Regex.MatchString(str)
}

// UUID4 is the validation function for validating if the field's value is a valid v4 UUID.
func UUID4(str string) bool {
	return uUID4Regex.MatchString(str)
}

// UUID3 is the validation function for validating if the field's value is a valid v3 UUID.
func UUID3(str string) bool {
	return uUID3Regex.MatchString(str)
}

// UUID is the validation function for validating if the field's value is a valid UUID of any version.
func UUID(str string) bool {
	return uUIDRegex.MatchString(str)
}

// ULID is the validation function for validating if the field's value is a valid ULID.
func ULID(str string) bool {
	return uLIDRegex.MatchString(str)
}

// MD4 is the validation function for validating if the field's value is a valid MD4.
func MD4(str string) bool {
	return md4Regex.MatchString(str)
}

// MD5 is the validation function for validating if the field's value is a valid MD5.
func MD5(str string) bool {
	return md5Regex.MatchString(str)
}

// SHA256 is the validation function for validating if the field's value is a valid SHA256.
func SHA256(str string) bool {
	return sha256Regex.MatchString(str)
}

// SHA384 is the validation function for validating if the field's value is a valid SHA384.
func SHA384(str string) bool {
	return sha384Regex.MatchString(str)
}

// SHA512 is the validation function for validating if the field's value is a valid SHA512.
func SHA512(str string) bool {
	return sha512Regex.MatchString(str)
}

// ASCII is the validation function for validating if the field's value is a valid ASCII character.
func ASCII(str string) bool {
	return aSCIIRegex.MatchString(str)
}

// Alpha is the validation function for validating if the current field's value is a valid alpha value.
func Alpha(str string) bool {
	return alphaRegex.MatchString(str)
}

// Alphanumeric is the validation function for validating if the current field's value is a valid alphanumeric value.
func Alphanumeric(str string) bool {
	return alphaNumericRegex.MatchString(str)
}

// AlphaUnicode is the validation function for validating if the current field's value is a valid alpha unicode value.
func AlphaUnicode(str string) bool {
	return alphaUnicodeRegex.MatchString(str)
}

// AlphanumericUnicode is the validation function for validating if the current field's value is a valid alphanumeric unicode value.
func AlphanumericUnicode(str string) bool {
	return alphaUnicodeNumericRegex.MatchString(str)
}

// Numeric is the validation function for validating if the current field's value is a valid numeric value.
func Numeric[T any](t T) bool {
	ctx := reflect.ValueOf(t)
	switch ctx.Kind() {
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64,
		reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr,
		reflect.Float32, reflect.Float64:
		return true
	default:
		return numericRegex.MatchString(ctx.String())
	}
}

// Number is the validation function for validating if the current field's value is a valid number.
func Number[T any](t T) bool {
	rv := reflect.ValueOf(t)
	switch rv.Kind() {
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64,
		reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr,
		reflect.Float32, reflect.Float64:
		return true
	default:
		return numberRegex.MatchString(rv.String())
	}
}

// Boolean is the validation function for validating if the current field's value can be safely converted to a boolean.
func Boolean[T any](t T) bool {
	ref := reflect.ValueOf(t)
	switch ref.Kind() {
	case reflect.String:
		switch ref.String() {
		case "1", "yes", "YES", "Yes", "on", "ON", "On", "true", "TRUE", "True",
			"0", "no", "NO", "No", "", "off", "OFF", "Off", "false", "FALSE", "False":
			return true
		default:
			return false
		}
	case reflect.Int, reflect.Int32, reflect.Int64:
		n := ref.Int()
		return n == 0 || n == 1
	case reflect.Uint, reflect.Uint32, reflect.Uint64:
		n := ref.Uint()
		return n == 0 || n == 1
	case reflect.Bool:
		return ref.Bool()
	}
	return false
}

// Default is the opposite of required aka HasValue
func Default(val any) bool {
	return !HasValue(val)
}

// HasValue is the validation function for validating if the current field's value is not the default static value.
func HasValue(val any) bool {
	rv := reflect.ValueOf(val)
	switch rv.Kind() {
	case reflect.Slice, reflect.Map, reflect.Ptr, reflect.Interface, reflect.Chan, reflect.Func:
		return !rv.IsNil()
	default:
		return rv.IsValid() && rv.Interface() != reflect.Zero(rv.Type()).Interface()
	}
}

// Hexadecimal is the validation function for validating if the current field's value is a valid hexadecimal.
func Hexadecimal(str string) bool {
	return hexadecimalRegex.MatchString(str)
}

// HEXColor is the validation function for validating if the current field's value is a valid HEX color.
func HEXColor(str string) bool {
	return hexColorRegex.MatchString(str)
}

// RGB is the validation function for validating if the current field's value is a valid RGB color.
func RGB(str string) bool {
	return rgbRegex.MatchString(str)
}

// RGBA is the validation function for validating if the current field's value is a valid RGBA color.
func RGBA(str string) bool {
	return rgbaRegex.MatchString(str)
}

// HSL is the validation function for validating if the current field's value is a valid HSL color.
func HSL(str string) bool {
	return hslRegex.MatchString(str)
}

// HSLA is the validation function for validating if the current field's value is a valid HSLA color.
func HSLA(str string) bool {
	return hslaRegex.MatchString(str)
}

func Color(str string) bool {
	return HEXColor(str) || HSLA(str) || HSL(str) || RGB(str) || RGBA(str)
}

// Latitude is the validation function for validating if the field's value is a valid latitude coordinate.
func Latitude[T any](t T) bool {
	ref := reflect.ValueOf(t)
	var v string
	switch ref.Kind() {
	case reflect.String:
		v = ref.String()
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
		v = strconv.FormatInt(ref.Int(), 10)
	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
		v = strconv.FormatUint(ref.Uint(), 10)
	case reflect.Float32:
		v = strconv.FormatFloat(ref.Float(), 'f', -1, 32)
	case reflect.Float64:
		v = strconv.FormatFloat(ref.Float(), 'f', -1, 64)
	default:
		//fmt.Errorf("bad ref type %T", ref.Interface())
		return false
	}
	return latitudeRegex.MatchString(v)
}

// Longitude is the validation function for validating if the field's value is a valid longitude coordinate.
func Longitude[T any](t T) bool {
	ref := reflect.ValueOf(t)
	var v string
	switch ref.Kind() {
	case reflect.String:
		v = ref.String()
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
		v = strconv.FormatInt(ref.Int(), 10)
	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
		v = strconv.FormatUint(ref.Uint(), 10)
	case reflect.Float32:
		v = strconv.FormatFloat(ref.Float(), 'f', -1, 32)
	case reflect.Float64:
		v = strconv.FormatFloat(ref.Float(), 'f', -1, 64)
	default:
		//fmt.Errorf("bad field type %T", ref.Interface())
		return false
	}
	return longitudeRegex.MatchString(v)
}

// JSON is the validation function for validating if the current field's value is a valid json string.
func JSON[T any](t T) bool {
	rv := reflect.ValueOf(t)
	if rv.Type() == nilType {
		return json.Valid(rv.Bytes())
	}
	if rv.Kind() == reflect.String {
		return json.Valid([]byte(rv.String()))
	}
	return false
}

func Datetime(str, layout string) bool {
	_, err := time.Parse(layout, str)
	return err == nil
}

// Timezone is the validation function for validating if the current field's value is a valid time zone string.
func Timezone(str string) bool {
	// empty value is converted to UTC by time.LoadLocation but disallow it as it is not a valid time zone name
	if str == "" {
		return false
	}

	// Local value is converted to the current system time zone by time.LoadLocation but disallow it as it is not a valid time zone name
	if strings.ToLower(str) == "local" {
		return false
	}

	_, err := time.LoadLocation(str)
	return err == nil
}

// IPv4 is the validation function for validating if a value is a valid v4 IP address.
func IPv4(str string) bool {
	ip := net.ParseIP(str)
	return ip != nil && ip.To4() != nil
}

// IPv6 is the validation function for validating if the field's value is a valid v6 IP address.
func IPv6(str string) bool {
	ip := net.ParseIP(str)
	return ip != nil && ip.To4() == nil
}

// IP is the validation function for validating if the field's value is a valid v4 or v6 IP address.
func IP(str string) bool {
	ip := net.ParseIP(str)
	return ip != nil
}

// MAC is the validation function for validating if the field's value is a valid MAC address.
func MAC(str string) bool {
	_, err := net.ParseMAC(str)
	return err == nil
}

// Lowercase is the validation function for validating if the current field's value is a lowercase string.
func Lowercase(str string) bool {
	if str == "" {
		return false
	}
	return str == strings.ToLower(str)
}

// Uppercase is the validation function for validating if the current field's value is an uppercase string.
func Uppercase(str string) bool {
	if str == "" {
		return false
	}
	return str == strings.ToUpper(str)
}

// Empty checks if a value is empty or not.
// A value is considered empty if
// - integer, float: zero
// - bool: false
// - string, array: len() == 0
// - slice, map: nil or len() == 0
// - interface, pointer: nil or the referenced value is empty
func Empty[T any](t T) bool {
	rv := reflect.ValueOf(t)
	switch rv.Kind() {
	case reflect.String, reflect.Array, reflect.Map, reflect.Slice:
		return rv.Len() == 0
	case reflect.Bool:
		return !rv.Bool()
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
		return rv.Int() == 0
	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
		return rv.Uint() == 0
	case reflect.Float32, reflect.Float64:
		return rv.Float() == 0
	case reflect.Invalid:
		return true
	case reflect.Interface, reflect.Ptr:
		if rv.IsNil() {
			return true
		}
		return Empty(rv.Elem().Interface())
	case reflect.Struct:
		v, ok := rv.Interface().(time.Time)
		if ok && v.IsZero() {
			return true
		}
	}
	return false
}

func NotEmpty[T any](t T) bool {
	return !Empty(t)
}

func URLEncoded(str string) bool {
	return uRLEncodedRegex.MatchString(str)
}

func HTMLEncoded(str string) bool {
	return hTMLEncodedRegex.MatchString(str)
}

func HTML(str string) bool {
	return hTMLRegex.MatchString(str)
}

// File is the validation function for validating if the current field's value is a valid file path.
func File(val any) bool {
	field := reflect.ValueOf(val)
	switch field.Kind() {
	case reflect.String:
		fileInfo, err := os.Stat(field.String())
		if err != nil {
			return false
		}
		return !fileInfo.IsDir()
	}
	//fmt.Errorf("bad value type %T", field.Interface())
	return false
}

// Dir is the validation function for validating if the current field's value is a valid directory.
func Dir(val any) bool {
	field := reflect.ValueOf(val)
	if field.Kind() == reflect.String {
		fileInfo, err := os.Stat(field.String())
		if err != nil {
			return false
		}
		return fileInfo.IsDir()
	}
	//fmt.Errorf("bad field type %T", field.Interface())
	return false
}

func OneOf(val any, vals []any) bool {
	//rv := reflect.ValueOf(val)
	//
	//var v string
	//switch rv.Kind() {
	//case reflect.String:
	//	v = rv.String()
	//case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
	//	v = strconv.FormatInt(rv.Int(), 10)
	//case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
	//	v = strconv.FormatUint(rv.Uint(), 10)
	//default:
	//	//fmt.Errorf("Bad rv type %T", rv.Interface())
	//	return false
	//}
	//for i := 0; i < len(vals); i++ {
	//	if vals[i] == v {
	//		return true
	//	}
	//}
	if len(vals) == 0 {
		return false
	}
	for _, a := range vals {
		if Equal(val, a) {
			return true
		}
	}
	return false
}

func Length(val any, length int, op string) bool {
	if n := calcLength(val); n == -1 {
		return false
	} else {
		return Compare(n, length, op)
	}
}

func LengthBetween(val any, min, max int) bool {
	if !Compare(min, max, "<") {
		panic(ErrBadType)
	} else if n, err := getLength(val, false); err != nil {
		return false
	} else {
		return Compare(n, min, ">=") && Compare(n, max, "<=")
	}
}

// Compare intX,floatX value by given op. returns `srcVal op(=,!=,<,<=,>,>=) dstVal`
//
// Usage:
//
//	compare(2, 3, ">") // false
//	compare(2, 1.3, ">") // true
//	compare(2.2, 1.3, ">") // true
//	compare(2.1, 2, ">") // true
func Compare(srcVal, dstVal any, op string) bool {
	srv := reflect.ValueOf(srcVal)

	switch srv.Kind() {
	case reflect.Struct:
		if srv.Type().ConvertibleTo(timeType) {
			drv := reflect.ValueOf(dstVal)
			if drv.Type().ConvertibleTo(timeType) {
				at := srv.Convert(timeType).Interface().(time.Time)
				bt := drv.Convert(timeType).Interface().(time.Time)
				return compTime(at, bt, op)
			}
		}
	case reflect.Bool:
		drv := reflect.ValueOf(dstVal)
		switch drv.Kind() {
		case reflect.Bool:
			return compBool(srv.Bool(), drv.Bool(), op)
		case reflect.String:
			if bl, err := strconv.ParseBool(drv.String()); err == nil {
				return compBool(srv.Bool(), bl, op)
			}
		}
	default:
		if srcStr, ok := srcVal.(string); ok {
			if dstStr, ok2 := dstVal.(string); ok2 {
				return compString(srcStr, dstStr, op)
			}
			break
		}

		// float
		if srcFlt, ok := srcVal.(float64); ok {
			if dstFlt, err := toFloat(dstVal); err == nil {
				return compNum(srcFlt, dstFlt, op)
			}
			break
		}

		if srcFlt, ok := srcVal.(float32); ok {
			if dstFlt, err := toFloat(dstVal); err == nil {
				return compNum(float64(srcFlt), dstFlt, op)
			}
			break
		}

		// as int64
		if srcInt, err := toInt64(srcVal); err != nil {
			break
		} else if dstInt, ex := toInt64(dstVal); ex != nil {
			break
		} else {
			return compNum(srcInt, dstInt, op)
		}
	}

	switch op {
	case "=":
		return srcVal == dstVal
	case "!=":
		return srcVal != dstVal
	default:
		//ErrBadType
		return false
	}
}

// GreaterThan is the validation function for validating if the current field's value is greater than the param's value.
func GreaterThan(a, b any) bool {
	return Compare(a, b, ">")
}

// GreaterEqualThan is the validation function for validating if the current field's value is greater than or equal to the param's value.
func GreaterEqualThan(a, b any) bool {
	return Compare(a, b, ">=")
}

// LessThan is the validation function for validating if the current field's value is less than the param's value.
func LessThan(a, b any) bool {
	return Compare(a, b, "<")
}

// LessEqualThan is the validation function for validating if the current field's value is less than or equal to the param's value.
func LessEqualThan(a, b any) bool {
	return Compare(a, b, "<=")
}

// Equal is the validation function for validating if the current field's value is equal to the param's value.
func Equal(a, b any) bool {
	return Compare(a, b, "=")
}

func NotEqual(a, b any) bool {
	return Compare(a, b, "!=")
}

func Between(val, min, max any) bool {
	if !Compare(min, max, ">") {
		panic(ErrBadRange)
	}

	return Compare(val, min, ">=") && Compare(val, max, "<=")
}

func NotBetween(val, min, max any) bool {
	if !Compare(min, max, ">") {
		panic(ErrBadRange)
	}

	return Compare(val, min, "<") || Compare(val, max, ">")
}