package gatewayauthsessionuser_test

import (
	"bytes"
	"context"
	"crypto/ed25519"
	"crypto/sha256"
	"encoding/base64"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"path/filepath"
	"testing"
	"time"

	gatewayv1 "galaxy/gateway/proto/galaxy/gateway/v1"
	contractsgatewayv1 "galaxy/integration/internal/contracts/gatewayv1"
	contractsuserv1 "galaxy/integration/internal/contracts/userv1"
	"galaxy/integration/internal/harness"
	usermodel "galaxy/model/user"

	"github.com/redis/go-redis/v9"
	"github.com/stretchr/testify/require"
	"google.golang.org/grpc"
	"google.golang.org/grpc/credentials/insecure"
)

const gatewayAuthsessionUserTestTimeZone = "Europe/Kaliningrad"

type gatewayAuthsessionUserHarness struct {
	redis *redis.Client

	mailStub *harness.MailStub

	authsessionPublicURL string
	userServiceURL       string
	gatewayPublicURL     string
	gatewayGRPCAddr      string

	responseSignerPublicKey ed25519.PublicKey

	gatewayProcess     *harness.Process
	authsessionProcess *harness.Process
	userServiceProcess *harness.Process
}

func newGatewayAuthsessionUserHarness(t *testing.T) *gatewayAuthsessionUserHarness {
	t.Helper()

	redisServer := harness.StartMiniredis(t)
	redisClient := redis.NewClient(&redis.Options{
		Addr:            redisServer.Addr(),
		Protocol:        2,
		DisableIdentity: true,
	})
	t.Cleanup(func() {
		require.NoError(t, redisClient.Close())
	})

	mailStub := harness.NewMailStub(t)

	responseSignerPath, responseSignerPublicKey := harness.WriteResponseSignerPEM(t, t.Name())
	userServiceAddr := harness.FreeTCPAddress(t)
	authsessionPublicAddr := harness.FreeTCPAddress(t)
	authsessionInternalAddr := harness.FreeTCPAddress(t)
	gatewayPublicAddr := harness.FreeTCPAddress(t)
	gatewayGRPCAddr := harness.FreeTCPAddress(t)

	userServiceBinary := harness.BuildBinary(t, "userservice", "./user/cmd/userservice")
	authsessionBinary := harness.BuildBinary(t, "authsession", "./authsession/cmd/authsession")
	gatewayBinary := harness.BuildBinary(t, "gateway", "./gateway/cmd/gateway")

	userServiceEnv := harness.StartUserServicePersistence(t, redisServer.Addr()).Env
	userServiceEnv["USERSERVICE_LOG_LEVEL"] = "info"
	userServiceEnv["USERSERVICE_INTERNAL_HTTP_ADDR"] = userServiceAddr
	userServiceEnv["OTEL_TRACES_EXPORTER"] = "none"
	userServiceEnv["OTEL_METRICS_EXPORTER"] = "none"
	userServiceProcess := harness.StartProcess(t, "userservice", userServiceBinary, userServiceEnv)
	harness.WaitForHTTPStatus(t, userServiceProcess, "http://"+userServiceAddr+"/api/v1/internal/users/user-missing/exists", http.StatusOK)

	authsessionEnv := map[string]string{
		"AUTHSESSION_LOG_LEVEL":                              "info",
		"AUTHSESSION_PUBLIC_HTTP_ADDR":                       authsessionPublicAddr,
		"AUTHSESSION_PUBLIC_HTTP_REQUEST_TIMEOUT":            time.Second.String(),
		"AUTHSESSION_INTERNAL_HTTP_ADDR":                     authsessionInternalAddr,
		"AUTHSESSION_INTERNAL_HTTP_REQUEST_TIMEOUT":          time.Second.String(),
		"AUTHSESSION_REDIS_MASTER_ADDR":                             redisServer.Addr(),

		"AUTHSESSION_REDIS_PASSWORD":                             "integration",
		"AUTHSESSION_USER_SERVICE_MODE":                      "rest",
		"AUTHSESSION_USER_SERVICE_BASE_URL":                  "http://" + userServiceAddr,
		"AUTHSESSION_USER_SERVICE_REQUEST_TIMEOUT":           time.Second.String(),
		"AUTHSESSION_MAIL_SERVICE_MODE":                      "rest",
		"AUTHSESSION_MAIL_SERVICE_BASE_URL":                  mailStub.BaseURL(),
		"AUTHSESSION_MAIL_SERVICE_REQUEST_TIMEOUT":           time.Second.String(),
		"AUTHSESSION_REDIS_GATEWAY_SESSION_CACHE_KEY_PREFIX": "gateway:session:",
		"AUTHSESSION_REDIS_GATEWAY_SESSION_EVENTS_STREAM":    "gateway:session_events",
		"OTEL_TRACES_EXPORTER":                               "none",
		"OTEL_METRICS_EXPORTER":                              "none",
	}
	authsessionProcess := harness.StartProcess(t, "authsession", authsessionBinary, authsessionEnv)
	waitForAuthsessionPublicReady(t, authsessionProcess, "http://"+authsessionPublicAddr)

	gatewayEnv := map[string]string{
		"GATEWAY_LOG_LEVEL":                                                              "info",
		"GATEWAY_PUBLIC_HTTP_ADDR":                                                       gatewayPublicAddr,
		"GATEWAY_AUTHENTICATED_GRPC_ADDR":                                                gatewayGRPCAddr,
		"GATEWAY_AUTH_SERVICE_BASE_URL":                                                  "http://" + authsessionPublicAddr,
		"GATEWAY_USER_SERVICE_BASE_URL":                                                  "http://" + userServiceAddr,
		"GATEWAY_PUBLIC_AUTH_UPSTREAM_TIMEOUT":                                           (500 * time.Millisecond).String(),
		"GATEWAY_REDIS_MASTER_ADDR":                                               redisServer.Addr(),

		"GATEWAY_REDIS_PASSWORD":                                               "integration",
		"GATEWAY_SESSION_CACHE_REDIS_KEY_PREFIX":                                         "gateway:session:",
		"GATEWAY_SESSION_EVENTS_REDIS_STREAM":                                            "gateway:session_events",
		"GATEWAY_CLIENT_EVENTS_REDIS_STREAM":                                             "gateway:client_events",
		"GATEWAY_REPLAY_REDIS_KEY_PREFIX":                                                "gateway:replay:",
		"GATEWAY_RESPONSE_SIGNER_PRIVATE_KEY_PEM_PATH":                                   filepath.Clean(responseSignerPath),
		"GATEWAY_PUBLIC_HTTP_ANTI_ABUSE_PUBLIC_AUTH_RATE_LIMIT_REQUESTS":                 "100",
		"GATEWAY_PUBLIC_HTTP_ANTI_ABUSE_PUBLIC_AUTH_RATE_LIMIT_WINDOW":                   "1s",
		"GATEWAY_PUBLIC_HTTP_ANTI_ABUSE_PUBLIC_AUTH_RATE_LIMIT_BURST":                    "100",
		"GATEWAY_PUBLIC_HTTP_ANTI_ABUSE_SEND_EMAIL_CODE_IDENTITY_RATE_LIMIT_REQUESTS":    "100",
		"GATEWAY_PUBLIC_HTTP_ANTI_ABUSE_SEND_EMAIL_CODE_IDENTITY_RATE_LIMIT_WINDOW":      "1s",
		"GATEWAY_PUBLIC_HTTP_ANTI_ABUSE_SEND_EMAIL_CODE_IDENTITY_RATE_LIMIT_BURST":       "100",
		"GATEWAY_PUBLIC_HTTP_ANTI_ABUSE_CONFIRM_EMAIL_CODE_IDENTITY_RATE_LIMIT_REQUESTS": "100",
		"GATEWAY_PUBLIC_HTTP_ANTI_ABUSE_CONFIRM_EMAIL_CODE_IDENTITY_RATE_LIMIT_WINDOW":   "1s",
		"GATEWAY_PUBLIC_HTTP_ANTI_ABUSE_CONFIRM_EMAIL_CODE_IDENTITY_RATE_LIMIT_BURST":    "100",
		"OTEL_TRACES_EXPORTER":                                                           "none",
		"OTEL_METRICS_EXPORTER":                                                          "none",
	}
	gatewayProcess := harness.StartProcess(t, "gateway", gatewayBinary, gatewayEnv)
	harness.WaitForHTTPStatus(t, gatewayProcess, "http://"+gatewayPublicAddr+"/healthz", http.StatusOK)
	harness.WaitForTCP(t, gatewayProcess, gatewayGRPCAddr)

	return &gatewayAuthsessionUserHarness{
		redis:                   redisClient,
		mailStub:                mailStub,
		authsessionPublicURL:    "http://" + authsessionPublicAddr,
		userServiceURL:          "http://" + userServiceAddr,
		gatewayPublicURL:        "http://" + gatewayPublicAddr,
		gatewayGRPCAddr:         gatewayGRPCAddr,
		responseSignerPublicKey: responseSignerPublicKey,
		gatewayProcess:          gatewayProcess,
		authsessionProcess:      authsessionProcess,
		userServiceProcess:      userServiceProcess,
	}
}

func (h *gatewayAuthsessionUserHarness) sendChallenge(t *testing.T, email string) string {
	t.Helper()

	return h.sendChallengeWithAcceptLanguage(t, email, "")
}

func (h *gatewayAuthsessionUserHarness) sendChallengeWithAcceptLanguage(t *testing.T, email string, acceptLanguage string) string {
	t.Helper()

	response := postJSONValueWithHeaders(
		t,
		h.gatewayPublicURL+"/api/v1/public/auth/send-email-code",
		map[string]string{"email": email},
		map[string]string{"Accept-Language": acceptLanguage},
	)
	require.Equal(t, http.StatusOK, response.StatusCode)

	var body struct {
		ChallengeID string `json:"challenge_id"`
	}
	require.NoError(t, decodeStrictJSONPayload([]byte(response.Body), &body))
	return body.ChallengeID
}

func (h *gatewayAuthsessionUserHarness) confirmCode(t *testing.T, challengeID string, code string, clientPrivateKey ed25519.PrivateKey) httpResponse {
	t.Helper()

	return postJSONValue(t, h.gatewayPublicURL+"/api/v1/public/auth/confirm-email-code", map[string]string{
		"challenge_id":      challengeID,
		"code":              code,
		"client_public_key": base64.StdEncoding.EncodeToString(clientPrivateKey.Public().(ed25519.PublicKey)),
		"time_zone":         gatewayAuthsessionUserTestTimeZone,
	})
}

func (h *gatewayAuthsessionUserHarness) ensureUser(t *testing.T, email string, preferredLanguage string, timeZone string) ensureByEmailResponse {
	t.Helper()

	response := postJSONValue(t, h.userServiceURL+"/api/v1/internal/users/ensure-by-email", map[string]any{
		"email": email,
		"registration_context": map[string]string{
			"preferred_language": preferredLanguage,
			"time_zone":          timeZone,
		},
	})

	var body ensureByEmailResponse
	requireJSONStatus(t, response, http.StatusOK, &body)
	return body
}

func (h *gatewayAuthsessionUserHarness) lookupUserByEmail(t *testing.T, email string) (httpResponse, userLookupResponse) {
	t.Helper()

	response := postJSONValue(t, h.userServiceURL+"/api/v1/internal/user-lookups/by-email", map[string]string{
		"email": email,
	})
	if response.StatusCode != http.StatusOK {
		return response, userLookupResponse{}
	}

	var body userLookupResponse
	require.NoError(t, decodeStrictJSONPayload([]byte(response.Body), &body))
	return response, body
}

func (h *gatewayAuthsessionUserHarness) blockByEmail(t *testing.T, email string) {
	t.Helper()

	response := postJSONValue(t, h.userServiceURL+"/api/v1/internal/user-blocks/by-email", map[string]string{
		"email":       email,
		"reason_code": "policy_blocked",
	})
	require.Equal(t, http.StatusOK, response.StatusCode, "response body: %s", response.Body)
}

func (h *gatewayAuthsessionUserHarness) waitForGatewaySession(t *testing.T, deviceSessionID string) gatewaySessionRecord {
	t.Helper()

	deadline := time.Now().Add(5 * time.Second)
	for time.Now().Before(deadline) {
		payload, err := h.redis.Get(context.Background(), "gateway:session:"+deviceSessionID).Bytes()
		if err == nil {
			var record gatewaySessionRecord
			require.NoError(t, decodeStrictJSONPayload(payload, &record))
			return record
		}

		time.Sleep(25 * time.Millisecond)
	}

	t.Fatalf("gateway session projection for %s was not published in time", deviceSessionID)
	return gatewaySessionRecord{}
}

func (h *gatewayAuthsessionUserHarness) executeGetMyAccount(t *testing.T, deviceSessionID string, requestID string, clientPrivateKey ed25519.PrivateKey) *usermodel.AccountResponse {
	t.Helper()

	conn := h.dialGateway(t)
	client := gatewayv1.NewEdgeGatewayClient(conn)

	payload, err := contractsuserv1.EncodeGetMyAccountRequest()
	require.NoError(t, err)

	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()

	response, err := client.ExecuteCommand(ctx, newExecuteCommandRequest(deviceSessionID, requestID, contractsuserv1.MessageTypeGetMyAccount, payload, clientPrivateKey))
	require.NoError(t, err)
	require.Equal(t, contractsuserv1.ResultCodeOK, response.GetResultCode())
	assertSignedExecuteCommandResponse(t, response, h.responseSignerPublicKey)

	accountResponse, err := contractsuserv1.DecodeAccountResponse(response.GetPayloadBytes())
	require.NoError(t, err)
	return accountResponse
}

func (h *gatewayAuthsessionUserHarness) dialGateway(t *testing.T) *grpc.ClientConn {
	t.Helper()

	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()

	conn, err := grpc.DialContext(
		ctx,
		h.gatewayGRPCAddr,
		grpc.WithTransportCredentials(insecure.NewCredentials()),
		grpc.WithBlock(),
	)
	require.NoError(t, err)
	t.Cleanup(func() {
		require.NoError(t, conn.Close())
	})

	return conn
}

type httpResponse struct {
	StatusCode int
	Body       string
	Header     http.Header
}

type ensureByEmailResponse struct {
	Outcome string `json:"outcome"`
	UserID  string `json:"user_id,omitempty"`
}

type gatewaySessionRecord struct {
	DeviceSessionID string `json:"device_session_id"`
	UserID          string `json:"user_id"`
	ClientPublicKey string `json:"client_public_key"`
	Status          string `json:"status"`
	RevokedAtMS     *int64 `json:"revoked_at_ms,omitempty"`
}

type userLookupResponse struct {
	User usermodel.Account `json:"user"`
}

func postJSONValue(t *testing.T, targetURL string, body any) httpResponse {
	t.Helper()

	return postJSONValueWithHeaders(t, targetURL, body, nil)
}

func postJSONValueWithHeaders(t *testing.T, targetURL string, body any, headers map[string]string) httpResponse {
	t.Helper()

	payload, err := json.Marshal(body)
	require.NoError(t, err)

	request, err := http.NewRequest(http.MethodPost, targetURL, bytes.NewReader(payload))
	require.NoError(t, err)
	request.Header.Set("Content-Type", "application/json")
	for key, value := range headers {
		if value == "" {
			continue
		}
		request.Header.Set(key, value)
	}

	client := &http.Client{Timeout: 5 * time.Second}
	response, err := client.Do(request)
	require.NoError(t, err)
	defer response.Body.Close()

	responseBody, err := io.ReadAll(response.Body)
	require.NoError(t, err)

	return httpResponse{
		StatusCode: response.StatusCode,
		Body:       string(responseBody),
		Header:     response.Header.Clone(),
	}
}

func decodeStrictJSONPayload(payload []byte, target any) error {
	decoder := json.NewDecoder(bytes.NewReader(payload))
	decoder.DisallowUnknownFields()

	if err := decoder.Decode(target); err != nil {
		return err
	}
	if err := decoder.Decode(&struct{}{}); err != io.EOF {
		if err == nil {
			return fmt.Errorf("unexpected trailing JSON input")
		}
		return err
	}

	return nil
}

func requireJSONStatus(t *testing.T, response httpResponse, wantStatus int, target any) {
	t.Helper()

	require.Equal(t, wantStatus, response.StatusCode, "response body: %s", response.Body)
	require.NoError(t, decodeStrictJSONPayload([]byte(response.Body), target))
}

func requireLookupNotFound(t *testing.T, response httpResponse) {
	t.Helper()

	require.Equal(t, http.StatusNotFound, response.StatusCode, "response body: %s", response.Body)
	require.JSONEq(t, `{"error":{"code":"subject_not_found","message":"subject not found"}}`, response.Body)
}

func lastMailCodeFor(t *testing.T, stub *harness.MailStub, email string) string {
	t.Helper()

	deliveries := stub.RecordedDeliveries()
	for index := len(deliveries) - 1; index >= 0; index-- {
		if deliveries[index].Email == email {
			return deliveries[index].Code
		}
	}

	t.Fatalf("mail stub did not record delivery for %s", email)
	return ""
}

func waitForAuthsessionPublicReady(t *testing.T, process *harness.Process, baseURL string) {
	t.Helper()

	client := &http.Client{Timeout: 250 * time.Millisecond}
	deadline := time.Now().Add(10 * time.Second)

	for time.Now().Before(deadline) {
		response, err := postJSONValueMaybe(client, baseURL+"/api/v1/public/auth/send-email-code", map[string]string{
			"email": "",
		})
		if err == nil && response.StatusCode == http.StatusBadRequest {
			return
		}

		time.Sleep(25 * time.Millisecond)
	}

	t.Fatalf("wait for authsession public readiness: timeout\n%s", process.Logs())
}

func postJSONValueMaybe(client *http.Client, targetURL string, body any) (httpResponse, error) {
	payload, err := json.Marshal(body)
	if err != nil {
		return httpResponse{}, err
	}

	request, err := http.NewRequest(http.MethodPost, targetURL, bytes.NewReader(payload))
	if err != nil {
		return httpResponse{}, err
	}
	request.Header.Set("Content-Type", "application/json")

	response, err := client.Do(request)
	if err != nil {
		return httpResponse{}, err
	}
	defer response.Body.Close()

	responseBody, err := io.ReadAll(response.Body)
	if err != nil {
		return httpResponse{}, err
	}

	return httpResponse{
		StatusCode: response.StatusCode,
		Body:       string(responseBody),
		Header:     response.Header.Clone(),
	}, nil
}

func newClientPrivateKey(label string) ed25519.PrivateKey {
	seed := sha256.Sum256([]byte("galaxy-integration-gateway-authsession-user-client-" + label))
	return ed25519.NewKeyFromSeed(seed[:])
}

func newExecuteCommandRequest(deviceSessionID string, requestID string, messageType string, payload []byte, clientPrivateKey ed25519.PrivateKey) *gatewayv1.ExecuteCommandRequest {
	payloadHash := contractsgatewayv1.ComputePayloadHash(payload)

	request := &gatewayv1.ExecuteCommandRequest{
		ProtocolVersion: contractsgatewayv1.ProtocolVersionV1,
		DeviceSessionId: deviceSessionID,
		MessageType:     messageType,
		TimestampMs:     time.Now().UnixMilli(),
		RequestId:       requestID,
		PayloadBytes:    payload,
		PayloadHash:     payloadHash,
		TraceId:         "trace-" + requestID,
	}
	request.Signature = contractsgatewayv1.SignRequest(clientPrivateKey, contractsgatewayv1.RequestSigningFields{
		ProtocolVersion: request.GetProtocolVersion(),
		DeviceSessionID: request.GetDeviceSessionId(),
		MessageType:     request.GetMessageType(),
		TimestampMS:     request.GetTimestampMs(),
		RequestID:       request.GetRequestId(),
		PayloadHash:     request.GetPayloadHash(),
	})

	return request
}

func assertSignedExecuteCommandResponse(t *testing.T, response *gatewayv1.ExecuteCommandResponse, publicKey ed25519.PublicKey) {
	t.Helper()

	require.NoError(t, contractsgatewayv1.VerifyPayloadHash(response.GetPayloadBytes(), response.GetPayloadHash()))
	require.NoError(t, contractsgatewayv1.VerifyResponseSignature(publicKey, response.GetSignature(), contractsgatewayv1.ResponseSigningFields{
		ProtocolVersion: response.GetProtocolVersion(),
		RequestID:       response.GetRequestId(),
		TimestampMS:     response.GetTimestampMs(),
		ResultCode:      response.GetResultCode(),
		PayloadHash:     response.GetPayloadHash(),
	}))
}