package shadowtls

import (
	"crypto/rand"
	"math/big"

	utls "github.com/sagernet/utls"
)

func init() {
	bigInt, _ := rand.Int(rand.Reader, big.NewInt(int64(len(ModernFingerprints))))
	stopAt := int(bigInt.Int64())
	i := 0
	for _, v := range ModernFingerprints {
		if i == stopAt {
			PresetFingerprints["random"] = v
			break
		}
		i++
	}
	weights := utls.DefaultWeights
	weights.TLSVersMax_Set_VersionTLS13 = 1
	weights.FirstKeyShare_Set_CurveP256 = 0
	randomized := utls.HelloRandomized
	randomized.Seed, _ = utls.NewPRNGSeed()
	randomized.Weights = &weights
	PresetFingerprints["randomized"] = &randomized
}

func GetFingerprint(name string) (fingerprint *utls.ClientHelloID) {
	if name == "" {
		return
	}
	if fingerprint = PresetFingerprints[name]; fingerprint != nil {
		return
	}
	if fingerprint = ModernFingerprints[name]; fingerprint != nil {
		return
	}
	if fingerprint = OtherFingerprints[name]; fingerprint != nil {
		return
	}
	return
}

var PresetFingerprints = map[string]*utls.ClientHelloID{
	// Recommended preset options in GUI clients
	"chrome":     &utls.HelloChrome_Auto,
	"firefox":    &utls.HelloFirefox_Auto,
	"safari":     &utls.HelloSafari_Auto,
	"ios":        &utls.HelloIOS_Auto,
	"android":    &utls.HelloAndroid_11_OkHttp,
	"edge":       &utls.HelloEdge_Auto,
	"360":        &utls.Hello360_Auto,
	"qq":         &utls.HelloQQ_Auto,
	"random":     nil,
	"randomized": nil,
}

var ModernFingerprints = map[string]*utls.ClientHelloID{
	// One of these will be chosen as `random` at startup
	"hellofirefox_99":         &utls.HelloFirefox_99,
	"hellofirefox_102":        &utls.HelloFirefox_102,
	"hellofirefox_105":        &utls.HelloFirefox_105,
	"hellochrome_83":          &utls.HelloChrome_83,
	"hellochrome_87":          &utls.HelloChrome_87,
	"hellochrome_96":          &utls.HelloChrome_96,
	"hellochrome_100":         &utls.HelloChrome_100,
	"hellochrome_102":         &utls.HelloChrome_102,
	"hellochrome_106_shuffle": &utls.HelloChrome_106_Shuffle,
	"helloios_13":             &utls.HelloIOS_13,
	"helloios_14":             &utls.HelloIOS_14,
	"helloedge_85":            &utls.HelloEdge_85,
	"helloedge_106":           &utls.HelloEdge_106,
	"hellosafari_16_0":        &utls.HelloSafari_16_0,
	"hello360_11_0":           &utls.Hello360_11_0,
	"helloqq_11_1":            &utls.HelloQQ_11_1,
}

var OtherFingerprints = map[string]*utls.ClientHelloID{
	// Golang, randomized, auto, and fingerprints that are too old
	"hellogolang":            &utls.HelloGolang,
	"hellorandomized":        &utls.HelloRandomized,
	"hellorandomizedalpn":    &utls.HelloRandomizedALPN,
	"hellorandomizednoalpn":  &utls.HelloRandomizedNoALPN,
	"hellofirefox_auto":      &utls.HelloFirefox_Auto,
	"hellofirefox_55":        &utls.HelloFirefox_55,
	"hellofirefox_56":        &utls.HelloFirefox_56,
	"hellofirefox_63":        &utls.HelloFirefox_63,
	"hellofirefox_65":        &utls.HelloFirefox_65,
	"hellochrome_auto":       &utls.HelloChrome_Auto,
	"hellochrome_58":         &utls.HelloChrome_58,
	"hellochrome_62":         &utls.HelloChrome_62,
	"hellochrome_70":         &utls.HelloChrome_70,
	"hellochrome_72":         &utls.HelloChrome_72,
	"helloios_auto":          &utls.HelloIOS_Auto,
	"helloios_11_1":          &utls.HelloIOS_11_1,
	"helloios_12_1":          &utls.HelloIOS_12_1,
	"helloandroid_11_okhttp": &utls.HelloAndroid_11_OkHttp,
	"helloedge_auto":         &utls.HelloEdge_Auto,
	"hellosafari_auto":       &utls.HelloSafari_Auto,
	"hello360_auto":          &utls.Hello360_Auto,
	"hello360_7_5":           &utls.Hello360_7_5,
	"helloqq_auto":           &utls.HelloQQ_Auto,
}