package zitadel_test

import (
	"context"
	"encoding/base64"
	"encoding/json"
	"io"
	"net/http"
	"net/http/httptest"
	"net/url"
	"strings"
	"testing"

	"gateway/internal/library/zitadel"

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

func TestAuthorizeURL(t *testing.T) {
	t.Parallel()

	client, err := zitadel.NewClient(zitadel.Conf{
		Issuer:        testIssuerURL,
		OAuthClientID: testClientID,
		GoogleIdPID:   "google-idp-1",
	})
	require.NoError(t, err)

	raw, err := client.AuthorizeURL("https://app.example.com/callback", "state-abc", "google")
	require.NoError(t, err)

	u, err := url.Parse(raw)
	require.NoError(t, err)
	require.Equal(t, "https", u.Scheme)
	require.Equal(t, "zitadel.example.com", u.Host)
	require.Equal(t, "/oauth/v2/authorize", u.Path)

	q := u.Query()
	require.Equal(t, testClientID, q.Get("client_id"))
	require.Equal(t, "https://app.example.com/callback", q.Get("redirect_uri"))
	require.Equal(t, "code", q.Get("response_type"))
	require.Equal(t, "openid profile email", q.Get("scope"))
	require.Equal(t, "state-abc", q.Get("state"))
	require.Equal(t, "google-idp-1", q.Get("idp_id"))
}

func TestAuthorizeURLWithoutGoogleIdP(t *testing.T) {
	t.Parallel()

	client, err := zitadel.NewClient(zitadel.Conf{
		Issuer:        testIssuerURL,
		OAuthClientID: testClientID,
	})
	require.NoError(t, err)

	raw, err := client.AuthorizeURL("https://app.example.com/callback", "state-abc", "google")
	require.NoError(t, err)
	require.NotContains(t, raw, "idp_id=")
}

func TestAuthorizeURLRequiresClientAndParams(t *testing.T) {
	t.Parallel()

	client, err := zitadel.NewClient(zitadel.Conf{Issuer: testIssuerURL})
	require.NoError(t, err)

	_, err = client.AuthorizeURL("https://app/callback", "state", "google")
	require.Error(t, err)
	require.Contains(t, err.Error(), "oauth client id")

	_, err = client.AuthorizeURL("", "state", "google")
	require.Error(t, err)

	var nilClient *zitadel.Client
	_, err = nilClient.AuthorizeURL("https://app/callback", "state", "google")
	require.ErrorIs(t, err, zitadel.ErrNotConfigured)
}

func TestExchangeAuthorizationCode(t *testing.T) {
	t.Parallel()

	var gotForm url.Values
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		assert.Equal(t, "/oauth/v2/token", r.URL.Path)
		body, err := io.ReadAll(r.Body)
		assert.NoError(t, err)
		gotForm, err = url.ParseQuery(string(body))
		assert.NoError(t, err)

		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(`{"access_token":"at","id_token":"id","expires_in":3600,"token_type":"Bearer"}`))
	}))
	t.Cleanup(srv.Close)

	client, err := zitadel.NewClient(zitadel.Conf{
		Issuer:            srv.URL,
		OAuthClientID:     testClientID,
		OAuthClientSecret: testSecret,
	})
	require.NoError(t, err)

	tok, err := client.ExchangeAuthorizationCode(
		context.Background(),
		"auth-code-1",
		"https://app.example.com/callback",
	)
	require.NoError(t, err)
	require.Equal(t, "at", tok.AccessToken)
	require.Equal(t, "id", tok.IDToken)
	require.Equal(t, "authorization_code", gotForm.Get("grant_type"))
	require.Equal(t, testClientID, gotForm.Get("client_id"))
	require.Equal(t, testSecret, gotForm.Get("client_secret"))
	require.Equal(t, "auth-code-1", gotForm.Get("code"))
	require.Equal(t, "https://app.example.com/callback", gotForm.Get("redirect_uri"))
}

func TestExchangeAuthorizationCodeInvalid(t *testing.T) {
	t.Parallel()

	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		http.Error(w, "invalid", http.StatusUnauthorized)
	}))
	t.Cleanup(srv.Close)

	client, err := zitadel.NewClient(zitadel.Conf{
		Issuer:            srv.URL,
		OAuthClientID:     testClientID,
		OAuthClientSecret: testSecret,
	})
	require.NoError(t, err)

	_, err = client.ExchangeAuthorizationCode(context.Background(), "bad", "https://app/callback")
	require.ErrorIs(t, err, zitadel.ErrInvalidCredentials)
}

func TestExchangeAuthorizationCodeRequiresParams(t *testing.T) {
	t.Parallel()

	client, err := zitadel.NewClient(zitadel.Conf{
		Issuer:            testIssuerURL,
		OAuthClientID:     testClientID,
		OAuthClientSecret: testSecret,
	})
	require.NoError(t, err)

	_, err = client.ExchangeAuthorizationCode(context.Background(), "", "https://app/callback")
	require.Error(t, err)

	var nilClient *zitadel.Client
	_, err = nilClient.ExchangeAuthorizationCode(context.Background(), "code", "https://app/callback")
	require.ErrorIs(t, err, zitadel.ErrNotConfigured)
}

func TestFetchUserInfo(t *testing.T) {
	t.Parallel()

	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		assert.Equal(t, "/oidc/v1/userinfo", r.URL.Path)
		assert.Equal(t, "Bearer access-token", r.Header.Get("Authorization"))
		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(`{
			"sub":"zitadel-sub-2",
			"email":"bob@example.com",
			"email_verified":true,
			"name":"Bob",
			"locale":"zh-tw"
		}`))
	}))
	t.Cleanup(srv.Close)

	client, err := zitadel.NewClient(zitadel.Conf{Issuer: srv.URL})
	require.NoError(t, err)

	claims, err := client.FetchUserInfo(context.Background(), "access-token")
	require.NoError(t, err)
	require.Equal(t, "zitadel-sub-2", claims.Sub)
	require.Equal(t, "bob@example.com", claims.Email)
	require.True(t, claims.EmailVerified)
	require.Equal(t, "Bob", claims.Name)
	require.Equal(t, "zh-tw", claims.Locale)
}

func TestFetchUserInfoUnauthorized(t *testing.T) {
	t.Parallel()

	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		http.Error(w, "invalid", http.StatusUnauthorized)
	}))
	t.Cleanup(srv.Close)

	client, err := zitadel.NewClient(zitadel.Conf{Issuer: srv.URL})
	require.NoError(t, err)

	_, err = client.FetchUserInfo(context.Background(), "bad-token")
	require.ErrorIs(t, err, zitadel.ErrInvalidCredentials)
}

func TestFetchUserInfoMissingSub(t *testing.T) {
	t.Parallel()

	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(`{"email":"nobody@example.com"}`))
	}))
	t.Cleanup(srv.Close)

	client, err := zitadel.NewClient(zitadel.Conf{Issuer: srv.URL})
	require.NoError(t, err)

	_, err = client.FetchUserInfo(context.Background(), "access-token")
	require.Error(t, err)
	require.Contains(t, err.Error(), "missing sub")
}

func TestParseIDTokenClaims(t *testing.T) {
	t.Parallel()

	payload, err := json.Marshal(map[string]any{
		"sub":            "sub-1",
		"email":          "alice@example.com",
		"email_verified": true,
		"name":           "Alice",
		"locale":         "en-us",
	})
	require.NoError(t, err)

	raw := strings.Join([]string{
		base64.RawURLEncoding.EncodeToString([]byte(`{"alg":"RS256"}`)),
		base64.RawURLEncoding.EncodeToString(payload),
		"signature",
	}, ".")

	claims, err := zitadel.ParseIDTokenClaims(raw)
	require.NoError(t, err)
	require.Equal(t, "sub-1", claims.Sub)
	require.Equal(t, "alice@example.com", claims.Email)
	require.True(t, claims.EmailVerified)
	require.Equal(t, "Alice", claims.Name)
	require.Equal(t, "en-us", claims.Locale)
}

func TestParseIDTokenClaimsErrors(t *testing.T) {
	t.Parallel()

	_, err := zitadel.ParseIDTokenClaims("")
	require.Error(t, err)

	_, err = zitadel.ParseIDTokenClaims("not-a-jwt")
	require.Error(t, err)
	require.Contains(t, err.Error(), "malformed")

	payload := base64.RawURLEncoding.EncodeToString([]byte(`{"email":"x@example.com"}`))
	raw := "header." + payload + ".sig"
	_, err = zitadel.ParseIDTokenClaims(raw)
	require.Error(t, err)
	require.Contains(t, err.Error(), "missing sub")
}