package oidc

import (
	"crypto/rsa"
	"crypto/x509"
	"encoding/pem"
	"net/url"
	"testing"

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

	"github.com/authelia/authelia/v4/internal/configuration/schema"
)

var exampleIssuerPrivateKey = "-----BEGIN RSA PRIVATE KEY-----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\nHEMMhFHlv8NDjVOXh1KwRoltNGVWYsSrD9wKU9GhRCEfmNCGrvBcEg==\n-----END RSA PRIVATE KEY-----"

func TestOpenIDConnectProvider_NewOpenIDConnectProvider_NotConfigured(t *testing.T) {
	provider, err := NewOpenIDConnectProvider(nil, nil, nil)

	assert.NoError(t, err)
	assert.Nil(t, provider)
}

func TestNewOpenIDConnectProvider_ShouldEnableOptionalDiscoveryValues(t *testing.T) {
	provider, err := NewOpenIDConnectProvider(&schema.OpenIDConnectConfiguration{
		IssuerCertificateChain:   schema.X509CertificateChain{},
		IssuerPrivateKey:         mustParseRSAPrivateKey(exampleIssuerPrivateKey),
		EnablePKCEPlainChallenge: true,
		HMACSecret:               "asbdhaaskmdlkamdklasmdlkams",
		Clients: []schema.OpenIDConnectClientConfiguration{
			{
				ID:               "a-client",
				Secret:           MustDecodeSecret("$plaintext$a-client-secret"),
				SectorIdentifier: url.URL{Host: "google.com"},
				Policy:           "one_factor",
				RedirectURIs: []string{
					"https://google.com",
				},
			},
		},
	}, nil, nil)

	assert.NoError(t, err)

	disco := provider.GetOpenIDConnectWellKnownConfiguration("https://example.com")

	assert.Len(t, disco.SubjectTypesSupported, 2)
	assert.Contains(t, disco.SubjectTypesSupported, SubjectTypePublic)
	assert.Contains(t, disco.SubjectTypesSupported, SubjectTypePairwise)

	assert.Len(t, disco.CodeChallengeMethodsSupported, 2)
	assert.Contains(t, disco.CodeChallengeMethodsSupported, PKCEChallengeMethodSHA256)
	assert.Contains(t, disco.CodeChallengeMethodsSupported, PKCEChallengeMethodSHA256)
}

func TestOpenIDConnectProvider_NewOpenIDConnectProvider_GoodConfiguration(t *testing.T) {
	provider, err := NewOpenIDConnectProvider(&schema.OpenIDConnectConfiguration{
		IssuerCertificateChain: schema.X509CertificateChain{},
		IssuerPrivateKey:       mustParseRSAPrivateKey(exampleIssuerPrivateKey),
		HMACSecret:             "asbdhaaskmdlkamdklasmdlkams",
		Clients: []schema.OpenIDConnectClientConfiguration{
			{
				ID:     "a-client",
				Secret: MustDecodeSecret("$plaintext$a-client-secret"),
				Policy: "one_factor",
				RedirectURIs: []string{
					"https://google.com",
				},
			},
			{
				ID:          "b-client",
				Description: "Normal DisplayName",
				Secret:      MustDecodeSecret("$plaintext$b-client-secret"),
				Policy:      "two_factor",
				RedirectURIs: []string{
					"https://google.com",
				},
				Scopes: []string{
					ScopeGroups,
				},
				GrantTypes: []string{
					GrantTypeRefreshToken,
				},
				ResponseTypes: []string{
					"token",
					"code",
				},
			},
		},
	}, nil, nil)

	assert.NotNil(t, provider)
	assert.NoError(t, err)
}

func TestOpenIDConnectProvider_NewOpenIDConnectProvider_GetOpenIDConnectWellKnownConfiguration(t *testing.T) {
	provider, err := NewOpenIDConnectProvider(&schema.OpenIDConnectConfiguration{
		IssuerCertificateChain: schema.X509CertificateChain{},
		IssuerPrivateKey:       mustParseRSAPrivateKey(exampleIssuerPrivateKey),
		HMACSecret:             "asbdhaaskmdlkamdklasmdlkams",
		Clients: []schema.OpenIDConnectClientConfiguration{
			{
				ID:     "a-client",
				Secret: MustDecodeSecret("$plaintext$a-client-secret"),
				Policy: "one_factor",
				RedirectURIs: []string{
					"https://google.com",
				},
			},
		},
	}, nil, nil)

	assert.NoError(t, err)

	disco := provider.GetOpenIDConnectWellKnownConfiguration("https://example.com")

	assert.Equal(t, "https://example.com", disco.Issuer)
	assert.Equal(t, "https://example.com/jwks.json", disco.JWKSURI)
	assert.Equal(t, "https://example.com/api/oidc/authorization", disco.AuthorizationEndpoint)
	assert.Equal(t, "https://example.com/api/oidc/token", disco.TokenEndpoint)
	assert.Equal(t, "https://example.com/api/oidc/userinfo", disco.UserinfoEndpoint)
	assert.Equal(t, "https://example.com/api/oidc/introspection", disco.IntrospectionEndpoint)
	assert.Equal(t, "https://example.com/api/oidc/revocation", disco.RevocationEndpoint)
	assert.Equal(t, "", disco.RegistrationEndpoint)

	assert.Len(t, disco.CodeChallengeMethodsSupported, 1)
	assert.Contains(t, disco.CodeChallengeMethodsSupported, PKCEChallengeMethodSHA256)

	assert.Len(t, disco.ScopesSupported, 5)
	assert.Contains(t, disco.ScopesSupported, ScopeOpenID)
	assert.Contains(t, disco.ScopesSupported, ScopeOfflineAccess)
	assert.Contains(t, disco.ScopesSupported, ScopeProfile)
	assert.Contains(t, disco.ScopesSupported, ScopeGroups)
	assert.Contains(t, disco.ScopesSupported, ScopeEmail)

	assert.Len(t, disco.ResponseModesSupported, 3)
	assert.Contains(t, disco.ResponseModesSupported, ResponseModeFormPost)
	assert.Contains(t, disco.ResponseModesSupported, ResponseModeQuery)
	assert.Contains(t, disco.ResponseModesSupported, ResponseModeFragment)

	assert.Len(t, disco.SubjectTypesSupported, 1)
	assert.Contains(t, disco.SubjectTypesSupported, SubjectTypePublic)

	assert.Len(t, disco.ResponseTypesSupported, 8)
	assert.Contains(t, disco.ResponseTypesSupported, "code")
	assert.Contains(t, disco.ResponseTypesSupported, "token")
	assert.Contains(t, disco.ResponseTypesSupported, "id_token")
	assert.Contains(t, disco.ResponseTypesSupported, "code token")
	assert.Contains(t, disco.ResponseTypesSupported, "code id_token")
	assert.Contains(t, disco.ResponseTypesSupported, "token id_token")
	assert.Contains(t, disco.ResponseTypesSupported, "code token id_token")
	assert.Contains(t, disco.ResponseTypesSupported, "none")

	assert.Len(t, disco.IDTokenSigningAlgValuesSupported, 1)
	assert.Contains(t, disco.IDTokenSigningAlgValuesSupported, SigningAlgorithmRSAWithSHA256)

	assert.Len(t, disco.UserinfoSigningAlgValuesSupported, 2)
	assert.Contains(t, disco.UserinfoSigningAlgValuesSupported, SigningAlgorithmRSAWithSHA256)
	assert.Contains(t, disco.UserinfoSigningAlgValuesSupported, SigningAlgorithmNone)

	assert.Len(t, disco.RequestObjectSigningAlgValuesSupported, 2)
	assert.Contains(t, disco.RequestObjectSigningAlgValuesSupported, SigningAlgorithmRSAWithSHA256)
	assert.Contains(t, disco.RequestObjectSigningAlgValuesSupported, SigningAlgorithmNone)

	assert.Len(t, disco.ClaimsSupported, 18)
	assert.Contains(t, disco.ClaimsSupported, ClaimAuthenticationMethodsReference)
	assert.Contains(t, disco.ClaimsSupported, ClaimAudience)
	assert.Contains(t, disco.ClaimsSupported, ClaimAuthorizedParty)
	assert.Contains(t, disco.ClaimsSupported, ClaimClientIdentifier)
	assert.Contains(t, disco.ClaimsSupported, ClaimExpirationTime)
	assert.Contains(t, disco.ClaimsSupported, ClaimIssuedAt)
	assert.Contains(t, disco.ClaimsSupported, ClaimIssuer)
	assert.Contains(t, disco.ClaimsSupported, ClaimJWTID)
	assert.Contains(t, disco.ClaimsSupported, ClaimRequestedAt)
	assert.Contains(t, disco.ClaimsSupported, ClaimSubject)
	assert.Contains(t, disco.ClaimsSupported, ClaimAuthenticationTime)
	assert.Contains(t, disco.ClaimsSupported, ClaimNonce)
	assert.Contains(t, disco.ClaimsSupported, ClaimPreferredEmail)
	assert.Contains(t, disco.ClaimsSupported, ClaimEmailVerified)
	assert.Contains(t, disco.ClaimsSupported, ClaimEmailAlts)
	assert.Contains(t, disco.ClaimsSupported, ClaimGroups)
	assert.Contains(t, disco.ClaimsSupported, ClaimPreferredUsername)
	assert.Contains(t, disco.ClaimsSupported, ClaimFullName)
}

func TestOpenIDConnectProvider_NewOpenIDConnectProvider_GetOAuth2WellKnownConfiguration(t *testing.T) {
	provider, err := NewOpenIDConnectProvider(&schema.OpenIDConnectConfiguration{
		IssuerCertificateChain: schema.X509CertificateChain{},
		IssuerPrivateKey:       mustParseRSAPrivateKey(exampleIssuerPrivateKey),
		HMACSecret:             "asbdhaaskmdlkamdklasmdlkams",
		Clients: []schema.OpenIDConnectClientConfiguration{
			{
				ID:     "a-client",
				Secret: MustDecodeSecret("$plaintext$a-client-secret"),
				Policy: "one_factor",
				RedirectURIs: []string{
					"https://google.com",
				},
			},
		},
	}, nil, nil)

	assert.NoError(t, err)

	disco := provider.GetOAuth2WellKnownConfiguration("https://example.com")

	assert.Equal(t, "https://example.com", disco.Issuer)
	assert.Equal(t, "https://example.com/jwks.json", disco.JWKSURI)
	assert.Equal(t, "https://example.com/api/oidc/authorization", disco.AuthorizationEndpoint)
	assert.Equal(t, "https://example.com/api/oidc/token", disco.TokenEndpoint)
	assert.Equal(t, "https://example.com/api/oidc/introspection", disco.IntrospectionEndpoint)
	assert.Equal(t, "https://example.com/api/oidc/revocation", disco.RevocationEndpoint)
	assert.Equal(t, "", disco.RegistrationEndpoint)

	require.Len(t, disco.CodeChallengeMethodsSupported, 1)
	assert.Equal(t, "S256", disco.CodeChallengeMethodsSupported[0])

	assert.Len(t, disco.ScopesSupported, 5)
	assert.Contains(t, disco.ScopesSupported, ScopeOpenID)
	assert.Contains(t, disco.ScopesSupported, ScopeOfflineAccess)
	assert.Contains(t, disco.ScopesSupported, ScopeProfile)
	assert.Contains(t, disco.ScopesSupported, ScopeGroups)
	assert.Contains(t, disco.ScopesSupported, ScopeEmail)

	assert.Len(t, disco.ResponseModesSupported, 3)
	assert.Contains(t, disco.ResponseModesSupported, ResponseModeFormPost)
	assert.Contains(t, disco.ResponseModesSupported, ResponseModeQuery)
	assert.Contains(t, disco.ResponseModesSupported, ResponseModeFragment)

	assert.Len(t, disco.SubjectTypesSupported, 1)
	assert.Contains(t, disco.SubjectTypesSupported, SubjectTypePublic)

	assert.Len(t, disco.ResponseTypesSupported, 8)
	assert.Contains(t, disco.ResponseTypesSupported, "code")
	assert.Contains(t, disco.ResponseTypesSupported, "token")
	assert.Contains(t, disco.ResponseTypesSupported, "id_token")
	assert.Contains(t, disco.ResponseTypesSupported, "code token")
	assert.Contains(t, disco.ResponseTypesSupported, "code id_token")
	assert.Contains(t, disco.ResponseTypesSupported, "token id_token")
	assert.Contains(t, disco.ResponseTypesSupported, "code token id_token")
	assert.Contains(t, disco.ResponseTypesSupported, "none")

	assert.Len(t, disco.ClaimsSupported, 18)
	assert.Contains(t, disco.ClaimsSupported, ClaimAuthenticationMethodsReference)
	assert.Contains(t, disco.ClaimsSupported, ClaimAudience)
	assert.Contains(t, disco.ClaimsSupported, ClaimAuthorizedParty)
	assert.Contains(t, disco.ClaimsSupported, ClaimClientIdentifier)
	assert.Contains(t, disco.ClaimsSupported, ClaimExpirationTime)
	assert.Contains(t, disco.ClaimsSupported, ClaimIssuedAt)
	assert.Contains(t, disco.ClaimsSupported, ClaimIssuer)
	assert.Contains(t, disco.ClaimsSupported, ClaimJWTID)
	assert.Contains(t, disco.ClaimsSupported, ClaimRequestedAt)
	assert.Contains(t, disco.ClaimsSupported, ClaimSubject)
	assert.Contains(t, disco.ClaimsSupported, ClaimAuthenticationTime)
	assert.Contains(t, disco.ClaimsSupported, ClaimNonce)
	assert.Contains(t, disco.ClaimsSupported, ClaimPreferredEmail)
	assert.Contains(t, disco.ClaimsSupported, ClaimEmailVerified)
	assert.Contains(t, disco.ClaimsSupported, ClaimEmailAlts)
	assert.Contains(t, disco.ClaimsSupported, ClaimGroups)
	assert.Contains(t, disco.ClaimsSupported, ClaimPreferredUsername)
	assert.Contains(t, disco.ClaimsSupported, ClaimFullName)
}

func TestOpenIDConnectProvider_NewOpenIDConnectProvider_GetOpenIDConnectWellKnownConfigurationWithPlainPKCE(t *testing.T) {
	provider, err := NewOpenIDConnectProvider(&schema.OpenIDConnectConfiguration{
		IssuerCertificateChain:   schema.X509CertificateChain{},
		IssuerPrivateKey:         mustParseRSAPrivateKey(exampleIssuerPrivateKey),
		HMACSecret:               "asbdhaaskmdlkamdklasmdlkams",
		EnablePKCEPlainChallenge: true,
		Clients: []schema.OpenIDConnectClientConfiguration{
			{
				ID:     "a-client",
				Secret: MustDecodeSecret("$plaintext$a-client-secret"),
				Policy: "one_factor",
				RedirectURIs: []string{
					"https://google.com",
				},
			},
		},
	}, nil, nil)

	assert.NoError(t, err)

	disco := provider.GetOpenIDConnectWellKnownConfiguration("https://example.com")

	require.Len(t, disco.CodeChallengeMethodsSupported, 2)
	assert.Equal(t, PKCEChallengeMethodSHA256, disco.CodeChallengeMethodsSupported[0])
	assert.Equal(t, PKCEChallengeMethodPlain, disco.CodeChallengeMethodsSupported[1])
}

func mustParseRSAPrivateKey(data string) *rsa.PrivateKey {
	block, _ := pem.Decode([]byte(data))
	if block == nil || block.Bytes == nil || len(block.Bytes) == 0 {
		panic("not pem encoded")
	}

	if block.Type != "RSA PRIVATE KEY" {
		panic("not private key")
	}

	key, err := x509.ParsePKCS1PrivateKey(block.Bytes)
	if err != nil {
		panic(err)
	}

	return key
}