package webauthn

import (
	"encoding/base64"
	"encoding/binary"
	"encoding/hex"
	"fmt"
	"reflect"
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

const (
	noneAuthDataBase64 = "pkLSG3xtVeHOI8U5mCjSx0m/am7y/gPMnhDN9O1ttItBAAAAAAAAAAAAAAAAAAAAAAAAAAAAQMAxl6G32ykWaLrv/ouCs5HoGsvONqBtOb7ZmyMs8K8PccnwyyqPzWn/yZuyQmQBguvjYSvH6gDBlFG65quUDCSlAQIDJiABIVggyJGP+ra/u/eVjqN4OeYXUShRWxrEeC6Sb5/bZmJ9q8MiWCCHIkRdg5oRb1RHoFVYUpogcjlObCKFsV1ls1T+uUc6rA=="
	attAuthDataBase64  = "lWkIjx7O4yMpVANdvRDXyuORMFonUbVZu4/Xy7IpvdRBAAAAAAAAAAAAAAAAAAAAAAAAAAAAQIniszxcGnhupdPFOHJIm6dscrWCC2h8xHicBMu91THD0kdOdB0QQtkaEn+6KfsfT1o3NmmFT8YfXrG734WfVSmlAQIDJiABIVggyoHHeiUw5aSbt8/GsL9zaqZGRzV26A4y3CnCGUhVXu4iWCBMnc8za5xgPzIygngAv9W+vZTMGJwwZcM4sjiqkcb/1g=="
)

func TestAuthenticatorFlags_UserPresent(t *testing.T) {
	var (
		goodByte byte = 0x01
		badByte  byte = 0x10
	)

	tests := []struct {
		name string
		flag AuthenticatorFlags
		want bool
	}{
		{
			"Present",
			AuthenticatorFlags(goodByte),
			true,
		},
		{
			"Missing",
			AuthenticatorFlags(badByte),
			false,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if got := tt.flag.UserPresent(); got != tt.want {
				t.Errorf("AuthenticatorFlags.UserPresent() = %v, want %v", got, tt.want)
			}
		})
	}
}

func TestAuthenticatorFlags_UserVerified(t *testing.T) {
	var (
		goodByte byte = 0x04
		badByte  byte = 0x02
	)

	tests := []struct {
		name string
		flag AuthenticatorFlags
		want bool
	}{
		{
			"Present",
			AuthenticatorFlags(goodByte),
			true,
		},
		{
			"Missing",
			AuthenticatorFlags(badByte),
			false,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if got := tt.flag.UserVerified(); got != tt.want {
				t.Errorf("AuthenticatorFlags.UserVerified() = %v, want %v", got, tt.want)
			}
		})
	}
}

func TestAuthenticatorFlags_HasAttestedCredentialData(t *testing.T) {
	var (
		goodByte byte = 0x40
		badByte  byte = 0x01
	)

	tests := []struct {
		name string
		flag AuthenticatorFlags
		want bool
	}{
		{
			"Present",
			AuthenticatorFlags(goodByte),
			true,
		},
		{
			"Missing",
			AuthenticatorFlags(badByte),
			false,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if got := tt.flag.HasAttestedCredentialData(); got != tt.want {
				t.Errorf(
					"AuthenticatorFlags.HasAttestedCredentialData() = %v, want %v",
					got,
					tt.want,
				)
			}
		})
	}
}

func TestAuthenticatorFlags_HasExtensions(t *testing.T) {
	var (
		goodByte byte = 0x80
		badByte  byte = 0x01
	)

	tests := []struct {
		name string
		flag AuthenticatorFlags
		want bool
	}{
		{
			"Present",
			AuthenticatorFlags(goodByte),
			true,
		},
		{
			"Missing",
			AuthenticatorFlags(badByte),
			false,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if got := tt.flag.HasExtensions(); got != tt.want {
				t.Errorf("AuthenticatorFlags.HasExtensions() = %v, want %v", got, tt.want)
			}
		})
	}
}

func TestAuthenticatorData_Unmarshal(t *testing.T) {
	type fields struct {
		RPIDHash []byte
		Flags    AuthenticatorFlags
		Counter  uint32
		AttData  AttestedCredentialData
		ExtData  []byte
	}

	type args struct {
		rawAuthData []byte
	}

	noneAuthData, _ := base64.StdEncoding.DecodeString(noneAuthDataBase64)
	attAuthData, _ := base64.StdEncoding.DecodeString(attAuthDataBase64)
	// Empty data
	badAuthData1 := []byte{}
	// Attested credential data missing
	badAuthData2 := make([]byte, minAttestedAuthLength-1)
	copy(badAuthData2, attAuthData)
	// Flags not set but data exists
	badAuthData3 := make([]byte, len(attAuthData))
	copy(badAuthData3, attAuthData)
	badAuthData3[32] &= 0b0011_1111
	// Extensions data missing
	badAuthData4 := make([]byte, len(attAuthData))
	copy(badAuthData4, attAuthData)
	badAuthData4[32] |= 0b1000_0000
	// Leftover bytes
	badAuthData5 := make([]byte, len(attAuthData))
	copy(badAuthData5, attAuthData)
	badAuthData5 = append(badAuthData5, []byte("Hello World")...)

	tests := []struct {
		name   string
		fields fields
		args   args

		errString  string
		errType    string
		errDetails string
		errInfo    string
	}{
		{
			name:   "None Marshall Successfully",
			fields: fields{},
			args: args{
				noneAuthData,
			},
		},
		{
			name:   "Att Data Marshall Successfully",
			fields: fields{},
			args: args{
				attAuthData,
			},
		},
		{
			name:   "Authenticator data too short",
			fields: fields{},
			args: args{
				badAuthData1,
			},
			errString:  "Authenticator data length too short",
			errType:    "invalid_request",
			errDetails: "Authenticator data length too short",
			errInfo: fmt.Sprintf(
				"Expected data greater than %d bytes. Got %d bytes",
				minAuthDataLength,
				len(badAuthData1),
			),
		},
		{
			name:   "Attested credential missing",
			fields: fields{},
			args: args{
				badAuthData2,
			},
			errString:  "Attested credential flag set but data is missing",
			errType:    "invalid_request",
			errDetails: "Attested credential flag set but data is missing",
			errInfo:    "",
		},
		{
			name:   "Attested credential missing",
			fields: fields{},
			args: args{
				badAuthData3,
			},
			errString:  "Attested credential flag not set",
			errType:    "invalid_request",
			errDetails: "Attested credential flag not set",
			errInfo:    "",
		},
		{
			name:   "Extensions data missing",
			fields: fields{},
			args: args{
				badAuthData4,
			},
			errString:  "Extensions flag set but extensions data is missing",
			errType:    "invalid_request",
			errDetails: "Extensions flag set but extensions data is missing",
			errInfo:    "",
		},
		{
			name:   "Leftover bytes",
			fields: fields{},
			args: args{
				badAuthData5,
			},
			errString:  "Leftover bytes decoding AuthenticatorData",
			errType:    "invalid_request",
			errDetails: "Leftover bytes decoding AuthenticatorData",
			errInfo:    "",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			a := &AuthenticatorData{
				RPIDHash: tt.fields.RPIDHash,
				Flags:    tt.fields.Flags,
				Counter:  tt.fields.Counter,
				AttData:  tt.fields.AttData,
				ExtData:  tt.fields.ExtData,
			}

			err := a.Unmarshal(tt.args.rawAuthData)
			if tt.errString != "" {
				assert.EqualError(t, err, tt.errString)

				AssertIsProtocolError(t, err, tt.errType, tt.errDetails, tt.errInfo)

				return
			}

			require.NoError(t, err)
		})
	}
}

func TestAuthenticatorData_unmarshalAttestedData(t *testing.T) {
	type fields struct {
		RPIDHash []byte
		Flags    AuthenticatorFlags
		Counter  uint32
		AttData  AttestedCredentialData
		ExtData  []byte
	}

	type args struct {
		rawAuthData []byte
	}

	noneAuthData, _ := base64.StdEncoding.DecodeString(noneAuthDataBase64)
	attAuthData, _ := base64.StdEncoding.DecodeString(attAuthDataBase64)
	// Data length too short
	badAuthData1 := make([]byte, len(attAuthData))
	copy(badAuthData1, attAuthData)
	binary.BigEndian.PutUint16(badAuthData1[53:], 256)
	// ID length too long
	badAuthData2 := make([]byte, len(attAuthData)+maxCredentialIDLength+1)
	copy(badAuthData2, attAuthData)
	binary.BigEndian.PutUint16(badAuthData2[53:], maxCredentialIDLength+1)
	// Malformed public key
	badAuthData3 := make([]byte, 119)
	copy(badAuthData3, attAuthData[:119])
	badData, _ := hex.DecodeString("83FF20030102")
	badAuthData3 = append(badAuthData3, badData...)

	tests := []struct {
		name       string
		fields     fields
		args       args
		errString  string
		errType    string
		errDetails string
		errInfo    string
	}{
		{
			name:   "None Marshall Successfully",
			fields: fields{},
			args: args{
				noneAuthData,
			},
		},
		{
			name:   "Att Data Marshall Successfully",
			fields: fields{},
			args: args{
				attAuthData,
			},
		},
		{
			name:   "Data length too short",
			fields: fields{},
			args: args{
				badAuthData1,
			},
			errString:  "Authenticator attestation data length too short",
			errType:    "invalid_request",
			errDetails: "Authenticator attestation data length too short",
			errInfo:    "",
		},
		{
			name:   "ID length too long",
			fields: fields{},
			args: args{
				badAuthData2,
			},
			errString:  "Authenticator attestation data credential id length too long",
			errType:    "invalid_request",
			errDetails: "Authenticator attestation data credential id length too long",
			errInfo:    "",
		},
		{
			name:   "Could not unmarshal Credential Public Key",
			fields: fields{},
			args: args{
				badAuthData3,
			},
			errString:  "Could not unmarshal Credential Public Key: cbor: unexpected \"break\" code",
			errType:    "invalid_request",
			errDetails: "Could not unmarshal Credential Public Key: cbor: unexpected \"break\" code",
			errInfo:    "",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			a := &AuthenticatorData{
				RPIDHash: tt.fields.RPIDHash,
				Flags:    tt.fields.Flags,
				Counter:  tt.fields.Counter,
				AttData:  tt.fields.AttData,
				ExtData:  tt.fields.ExtData,
			}
			err := a.unmarshalAttestedData(tt.args.rawAuthData)
			if tt.errString != "" {
				assert.EqualError(t, err, tt.errString)

				AssertIsProtocolError(t, err, tt.errType, tt.errDetails, tt.errInfo)

				return
			}

			require.NoError(t, err)
		})
	}
}

func Test_unmarshalCredentialPublicKey(t *testing.T) {
	type args struct {
		keyBytes []byte
	}

	tests := []struct {
		name string
		args args
		want []byte
	}{
		{
			name: "Valid EC2 P-256 public key",
			args: args{
				keyBytes: []byte{
					0xa5,       // map(5)
					0x01, 0x02, // kty: EC2 (2)
					0x03, 0x26, // alg: ES256 (-7)
					0x20, 0x01, // crv: P-256 (1)
					0x21, 0x58, 0x20, // x coordinate (32 bytes)
					0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
					0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10,
					0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18,
					0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20,
					0x22, 0x58, 0x20, // y coordinate (32 bytes)
					0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28,
					0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 0x30,
					0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38,
					0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, 0x40,
				},
			},
			want: []byte{
				0xa5,       // map(5)
				0x01, 0x02, // kty: EC2 (2)
				0x03, 0x26, // alg: ES256 (-7)
				0x20, 0x01, // crv: P-256 (1)
				0x21, 0x58, 0x20, // x coordinate (32 bytes)
				0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
				0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10,
				0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18,
				0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20,
				0x22, 0x58, 0x20, // y coordinate (32 bytes)
				0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28,
				0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 0x30,
				0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38,
				0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, 0x40,
			},
		},
		{
			name: "Valid RSA public key",
			args: args{
				keyBytes: append([]byte{
					0xa4,       // map(4)
					0x01, 0x03, // kty: RSA (3)
					0x03, 0x39, 0x01, 0x00, // alg: RS256 (-257)
					0x20, 0x59, 0x01, 0x00, // n: modulus (256 bytes)
				}, append(make([]byte, 256), []byte{
					0x21, 0x43, // e: exponent (3 bytes)
					0x01, 0x00, 0x01, // 65537
				}...)...),
			},
			want: append([]byte{
				0xa4,       // map(4)
				0x01, 0x03, // kty: RSA (3)
				0x03, 0x39, 0x01, 0x00, // alg: RS256 (-257)
				0x20, 0x59, 0x01, 0x00, // n: modulus (256 bytes)
			}, append(make([]byte, 256), []byte{
				0x21, 0x43, // e: exponent (3 bytes)
				0x01, 0x00, 0x01, // 65537
			}...)...),
		},
		{
			name: "Valid Ed25519 public key",
			args: args{
				keyBytes: []byte{
					0xa4,       // map(4)
					0x01, 0x01, // kty: OKP (1)
					0x03, 0x27, // alg: EdDSA (-8)
					0x20, 0x06, // crv: Ed25519 (6)
					0x21, 0x58, 0x20, // x coordinate (32 bytes)
					0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18,
					0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20,
					0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28,
					0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 0x30,
				},
			},
			want: []byte{
				0xa4,       // map(4)
				0x01, 0x01, // kty: OKP (1)
				0x03, 0x27, // alg: EdDSA (-8)
				0x20, 0x06, // crv: Ed25519 (6)
				0x21, 0x58, 0x20, // x coordinate (32 bytes)
				0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18,
				0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20,
				0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28,
				0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 0x30,
			},
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got, err := unmarshalCredentialPublicKey(tt.args.keyBytes)

			if err != nil {
				t.Errorf("unmarshalCredentialPublicKey() returned err %v", err)
			} else if !reflect.DeepEqual(got, tt.want) {
				t.Errorf("unmarshalCredentialPublicKey() = %v, want %v", got, tt.want)
			}
		})
	}
}

func TestAuthenticatorData_Verify(t *testing.T) {
	type fields struct {
		RPIDHash []byte
		Flags    AuthenticatorFlags
		Counter  uint32
		AttData  AttestedCredentialData
		ExtData  []byte
	}

	type args struct {
		rpIdHash                 []byte
		userVerificationRequired bool
		userPresenceRequired     bool
	}

	tests := []struct {
		name       string
		fields     fields
		args       args
		errString  string
		errType    string
		errDetails string
		errInfo    string
	}{
		{
			name: "Success",
			fields: fields{
				RPIDHash: []byte{1, 2, 3},
				Flags:    AuthenticatorFlags(0x05),
			},
			args: args{
				rpIdHash: []byte{1, 2, 3},
			},
			errString: "",
		},
		{
			name: "RP hash mismatch",
			fields: fields{
				RPIDHash: []byte{0xff},
			},
			args: args{
				rpIdHash: []byte{0xaa},
			},
			errString:  "Error validating the authenticator response",
			errType:    "verification_error",
			errDetails: "Error validating the authenticator response",
			errInfo:    "RP Hash mismatch. Expected ff and Received aa",
		},
		{
			name: "UP flag not set",
			fields: fields{
				RPIDHash: []byte{1, 2, 3},
				Flags:    AuthenticatorFlags(0x04),
			},
			args: args{
				rpIdHash:             []byte{1, 2, 3},
				userPresenceRequired: true,
			},
			errString:  "Error validating the authenticator response",
			errType:    "verification_error",
			errDetails: "Error validating the authenticator response",
			errInfo:    "User presence required but flag not set by authenticator",
		},
		{
			name: "User verification required",
			fields: fields{
				RPIDHash: []byte{1, 2, 3},
				Flags:    AuthenticatorFlags(0x01),
			},
			args: args{
				rpIdHash:                 []byte{1, 2, 3},
				userVerificationRequired: true,
				userPresenceRequired:     true,
			},
			errString:  "Error validating the authenticator response",
			errType:    "verification_error",
			errDetails: "Error validating the authenticator response",
			errInfo:    "User verification required but flag not set by authenticator",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			a := &AuthenticatorData{
				RPIDHash: tt.fields.RPIDHash,
				Flags:    tt.fields.Flags,
				Counter:  tt.fields.Counter,
				AttData:  tt.fields.AttData,
				ExtData:  tt.fields.ExtData,
			}
			err := a.Verify(
				tt.args.rpIdHash,
				nil,
				tt.args.userVerificationRequired,
				tt.args.userPresenceRequired,
			)
			if tt.errString != "" {
				assert.EqualError(t, err, tt.errString)

				AssertIsProtocolError(t, err, tt.errType, tt.errDetails, tt.errInfo)

				return
			}

			require.NoError(t, err)
		})
	}
}