package app

import (
	"context"
	"fmt"
	"net"
	"net/http"
	_ "net/http/pprof" // http profiler
	"time"

	"github.com/gorilla/handlers"
	"github.com/jmoiron/sqlx"

	"github.com/SigNoz/signoz/pkg/alertmanager"
	"github.com/SigNoz/signoz/pkg/apis/fields"
	"github.com/SigNoz/signoz/pkg/http/middleware"
	"github.com/SigNoz/signoz/pkg/licensing/nooplicensing"
	"github.com/SigNoz/signoz/pkg/modules/organization"
	"github.com/SigNoz/signoz/pkg/prometheus"
	"github.com/SigNoz/signoz/pkg/query-service/agentConf"
	"github.com/SigNoz/signoz/pkg/query-service/app/clickhouseReader"
	"github.com/SigNoz/signoz/pkg/query-service/app/cloudintegrations"
	"github.com/SigNoz/signoz/pkg/query-service/app/integrations"
	"github.com/SigNoz/signoz/pkg/query-service/app/logparsingpipeline"
	"github.com/SigNoz/signoz/pkg/query-service/app/opamp"
	opAmpModel "github.com/SigNoz/signoz/pkg/query-service/app/opamp/model"
	"github.com/SigNoz/signoz/pkg/signoz"
	"github.com/SigNoz/signoz/pkg/sqlstore"
	"github.com/SigNoz/signoz/pkg/telemetrystore"
	"github.com/SigNoz/signoz/pkg/types/authtypes"
	"github.com/SigNoz/signoz/pkg/web"
	"github.com/rs/cors"
	"github.com/soheilhy/cmux"

	"github.com/SigNoz/signoz/pkg/cache"
	"github.com/SigNoz/signoz/pkg/query-service/constants"
	"github.com/SigNoz/signoz/pkg/query-service/healthcheck"
	"github.com/SigNoz/signoz/pkg/query-service/interfaces"
	"github.com/SigNoz/signoz/pkg/query-service/rules"
	"github.com/SigNoz/signoz/pkg/query-service/telemetry"
	"github.com/SigNoz/signoz/pkg/query-service/utils"
	"go.uber.org/zap"
)

type ServerOptions struct {
	Config                     signoz.Config
	HTTPHostPort               string
	PrivateHostPort            string
	PreferSpanMetrics          bool
	CacheConfigPath            string
	FluxInterval               string
	FluxIntervalForTraceDetail string
	Cluster                    string
	SigNoz                     *signoz.SigNoz
	Jwt                        *authtypes.JWT
}

// Server runs HTTP, Mux and a grpc server
type Server struct {
	serverOptions *ServerOptions
	ruleManager   *rules.Manager

	// public http router
	httpConn   net.Listener
	httpServer *http.Server

	// private http
	privateConn net.Listener
	privateHTTP *http.Server

	opampServer *opamp.Server

	unavailableChannel chan healthcheck.Status
}

// HealthCheckStatus returns health check status channel a client can subscribe to
func (s Server) HealthCheckStatus() chan healthcheck.Status {
	return s.unavailableChannel
}

// NewServer creates and initializes Server
func NewServer(serverOptions *ServerOptions) (*Server, error) {

	fluxIntervalForTraceDetail, err := time.ParseDuration(serverOptions.FluxIntervalForTraceDetail)
	if err != nil {
		return nil, err
	}

	integrationsController, err := integrations.NewController(serverOptions.SigNoz.SQLStore)
	if err != nil {
		return nil, err
	}

	cloudIntegrationsController, err := cloudintegrations.NewController(serverOptions.SigNoz.SQLStore)
	if err != nil {
		return nil, err
	}

	reader := clickhouseReader.NewReader(
		serverOptions.SigNoz.SQLStore,
		serverOptions.SigNoz.TelemetryStore,
		serverOptions.SigNoz.Prometheus,
		serverOptions.Cluster,
		fluxIntervalForTraceDetail,
		serverOptions.SigNoz.Cache,
	)

	rm, err := makeRulesManager(
		serverOptions.SigNoz.SQLStore.SQLxDB(),
		reader,
		serverOptions.SigNoz.Cache,
		serverOptions.SigNoz.SQLStore,
		serverOptions.SigNoz.TelemetryStore,
		serverOptions.SigNoz.Prometheus,
		serverOptions.SigNoz.Modules.OrgGetter,
	)
	if err != nil {
		return nil, err
	}

	fluxInterval, err := time.ParseDuration(serverOptions.FluxInterval)
	if err != nil {
		return nil, err
	}

	logParsingPipelineController, err := logparsingpipeline.NewLogParsingPipelinesController(
		serverOptions.SigNoz.SQLStore, integrationsController.GetPipelinesForInstalledIntegrations,
	)
	if err != nil {
		return nil, err
	}

	telemetry.GetInstance().SetReader(reader)
	telemetry.GetInstance().SetSqlStore(serverOptions.SigNoz.SQLStore)
	telemetry.GetInstance().SetSavedViewsInfoCallback(telemetry.GetSavedViewsInfo)
	telemetry.GetInstance().SetAlertsInfoCallback(telemetry.GetAlertsInfo)
	telemetry.GetInstance().SetGetUsersCallback(telemetry.GetUsers)
	telemetry.GetInstance().SetUserCountCallback(telemetry.GetUserCount)
	telemetry.GetInstance().SetDashboardsInfoCallback(telemetry.GetDashboardsInfo)

	apiHandler, err := NewAPIHandler(APIHandlerOpts{
		Reader:                        reader,
		PreferSpanMetrics:             serverOptions.PreferSpanMetrics,
		RuleManager:                   rm,
		IntegrationsController:        integrationsController,
		CloudIntegrationsController:   cloudIntegrationsController,
		LogsParsingPipelineController: logParsingPipelineController,
		FluxInterval:                  fluxInterval,
		JWT:                           serverOptions.Jwt,
		AlertmanagerAPI:               alertmanager.NewAPI(serverOptions.SigNoz.Alertmanager),
		LicensingAPI:                  nooplicensing.NewLicenseAPI(),
		FieldsAPI:                     fields.NewAPI(serverOptions.SigNoz.TelemetryStore, serverOptions.SigNoz.Instrumentation.Logger()),
		Signoz:                        serverOptions.SigNoz,
	})
	if err != nil {
		return nil, err
	}

	s := &Server{
		ruleManager:        rm,
		serverOptions:      serverOptions,
		unavailableChannel: make(chan healthcheck.Status),
	}

	httpServer, err := s.createPublicServer(apiHandler, serverOptions.SigNoz.Web)

	if err != nil {
		return nil, err
	}

	s.httpServer = httpServer

	privateServer, err := s.createPrivateServer(apiHandler)
	if err != nil {
		return nil, err
	}

	s.privateHTTP = privateServer

	_, err = opAmpModel.InitDB(serverOptions.SigNoz.SQLStore.SQLxDB())
	if err != nil {
		return nil, err
	}

	agentConfMgr, err := agentConf.Initiate(&agentConf.ManagerOptions{
		DB: serverOptions.SigNoz.SQLStore.SQLxDB(),
		AgentFeatures: []agentConf.AgentFeature{
			logParsingPipelineController,
		},
	})
	if err != nil {
		return nil, err
	}

	s.opampServer = opamp.InitializeServer(
		&opAmpModel.AllAgents, agentConfMgr,
	)

	orgs, err := apiHandler.Signoz.Modules.OrgGetter.ListByOwnedKeyRange(context.Background())
	if err != nil {
		return nil, err
	}
	for _, org := range orgs {
		errorList := reader.PreloadMetricsMetadata(context.Background(), org.ID)
		for _, er := range errorList {
			zap.L().Error("failed to preload metrics metadata", zap.Error(er))
		}
	}

	return s, nil
}

func (s *Server) createPrivateServer(api *APIHandler) (*http.Server, error) {

	r := NewRouter()

	r.Use(middleware.NewAuth(s.serverOptions.Jwt, []string{"Authorization", "Sec-WebSocket-Protocol"}, s.serverOptions.SigNoz.Sharder, s.serverOptions.SigNoz.Instrumentation.Logger()).Wrap)
	r.Use(middleware.NewTimeout(s.serverOptions.SigNoz.Instrumentation.Logger(),
		s.serverOptions.Config.APIServer.Timeout.ExcludedRoutes,
		s.serverOptions.Config.APIServer.Timeout.Default,
		s.serverOptions.Config.APIServer.Timeout.Max,
	).Wrap)
	r.Use(middleware.NewAnalytics().Wrap)
	r.Use(middleware.NewAPIKey(s.serverOptions.SigNoz.SQLStore, []string{"SIGNOZ-API-KEY"}, s.serverOptions.SigNoz.Instrumentation.Logger(), s.serverOptions.SigNoz.Sharder).Wrap)
	r.Use(middleware.NewLogging(s.serverOptions.SigNoz.Instrumentation.Logger(), s.serverOptions.Config.APIServer.Logging.ExcludedRoutes).Wrap)

	api.RegisterPrivateRoutes(r)

	c := cors.New(cors.Options{
		//todo(amol): find out a way to add exact domain or
		// ip here for alert manager
		AllowedOrigins: []string{"*"},
		AllowedMethods: []string{"GET", "DELETE", "POST", "PUT", "PATCH"},
		AllowedHeaders: []string{"Accept", "Authorization", "Content-Type", "X-SIGNOZ-QUERY-ID", "Sec-WebSocket-Protocol"},
	})

	handler := c.Handler(r)
	handler = handlers.CompressHandler(handler)

	return &http.Server{
		Handler: handler,
	}, nil
}

func (s *Server) createPublicServer(api *APIHandler, web web.Web) (*http.Server, error) {
	r := NewRouter()

	r.Use(middleware.NewAuth(s.serverOptions.Jwt, []string{"Authorization", "Sec-WebSocket-Protocol"}, s.serverOptions.SigNoz.Sharder, s.serverOptions.SigNoz.Instrumentation.Logger()).Wrap)
	r.Use(middleware.NewTimeout(s.serverOptions.SigNoz.Instrumentation.Logger(),
		s.serverOptions.Config.APIServer.Timeout.ExcludedRoutes,
		s.serverOptions.Config.APIServer.Timeout.Default,
		s.serverOptions.Config.APIServer.Timeout.Max,
	).Wrap)
	r.Use(middleware.NewAnalytics().Wrap)
	r.Use(middleware.NewAPIKey(s.serverOptions.SigNoz.SQLStore, []string{"SIGNOZ-API-KEY"}, s.serverOptions.SigNoz.Instrumentation.Logger(), s.serverOptions.SigNoz.Sharder).Wrap)
	r.Use(middleware.NewLogging(s.serverOptions.SigNoz.Instrumentation.Logger(), s.serverOptions.Config.APIServer.Logging.ExcludedRoutes).Wrap)

	am := middleware.NewAuthZ(s.serverOptions.SigNoz.Instrumentation.Logger())

	api.RegisterRoutes(r, am)
	api.RegisterLogsRoutes(r, am)
	api.RegisterIntegrationRoutes(r, am)
	api.RegisterCloudIntegrationsRoutes(r, am)
	api.RegisterFieldsRoutes(r, am)
	api.RegisterQueryRangeV3Routes(r, am)
	api.RegisterInfraMetricsRoutes(r, am)
	api.RegisterWebSocketPaths(r, am)
	api.RegisterQueryRangeV4Routes(r, am)
	api.RegisterMessagingQueuesRoutes(r, am)
	api.RegisterThirdPartyApiRoutes(r, am)
	api.MetricExplorerRoutes(r, am)
	api.RegisterTraceFunnelsRoutes(r, am)

	c := cors.New(cors.Options{
		AllowedOrigins: []string{"*"},
		AllowedMethods: []string{"GET", "DELETE", "POST", "PUT", "PATCH", "OPTIONS"},
		AllowedHeaders: []string{"Accept", "Authorization", "Content-Type", "cache-control", "X-SIGNOZ-QUERY-ID", "Sec-WebSocket-Protocol"},
	})

	handler := c.Handler(r)

	handler = handlers.CompressHandler(handler)

	err := web.AddToRouter(r)
	if err != nil {
		return nil, err
	}

	return &http.Server{
		Handler: handler,
	}, nil
}

// initListeners initialises listeners of the server
func (s *Server) initListeners() error {
	// listen on public port
	var err error
	publicHostPort := s.serverOptions.HTTPHostPort
	if publicHostPort == "" {
		return fmt.Errorf("constants.HTTPHostPort is required")
	}

	s.httpConn, err = net.Listen("tcp", publicHostPort)
	if err != nil {
		return err
	}

	zap.L().Info(fmt.Sprintf("Query server started listening on %s...", s.serverOptions.HTTPHostPort))

	// listen on private port to support internal services
	privateHostPort := s.serverOptions.PrivateHostPort

	if privateHostPort == "" {
		return fmt.Errorf("constants.PrivateHostPort is required")
	}

	s.privateConn, err = net.Listen("tcp", privateHostPort)
	if err != nil {
		return err
	}
	zap.L().Info(fmt.Sprintf("Query server started listening on private port %s...", s.serverOptions.PrivateHostPort))

	return nil
}

// Start listening on http and private http port concurrently
func (s *Server) Start(ctx context.Context) error {
	s.ruleManager.Start(ctx)

	err := s.initListeners()
	if err != nil {
		return err
	}

	var httpPort int
	if port, err := utils.GetPort(s.httpConn.Addr()); err == nil {
		httpPort = port
	}

	go func() {
		zap.L().Info("Starting HTTP server", zap.Int("port", httpPort), zap.String("addr", s.serverOptions.HTTPHostPort))

		switch err := s.httpServer.Serve(s.httpConn); err {
		case nil, http.ErrServerClosed, cmux.ErrListenerClosed:
			// normal exit, nothing to do
		default:
			zap.L().Error("Could not start HTTP server", zap.Error(err))
		}
		s.unavailableChannel <- healthcheck.Unavailable
	}()

	go func() {
		zap.L().Info("Starting pprof server", zap.String("addr", constants.DebugHttpPort))

		err = http.ListenAndServe(constants.DebugHttpPort, nil)
		if err != nil {
			zap.L().Error("Could not start pprof server", zap.Error(err))
		}
	}()

	var privatePort int
	if port, err := utils.GetPort(s.privateConn.Addr()); err == nil {
		privatePort = port
	}
	fmt.Println("starting private http")
	go func() {
		zap.L().Info("Starting Private HTTP server", zap.Int("port", privatePort), zap.String("addr", s.serverOptions.PrivateHostPort))

		switch err := s.privateHTTP.Serve(s.privateConn); err {
		case nil, http.ErrServerClosed, cmux.ErrListenerClosed:
			// normal exit, nothing to do
			zap.L().Info("private http server closed")
		default:
			zap.L().Error("Could not start private HTTP server", zap.Error(err))
		}

		s.unavailableChannel <- healthcheck.Unavailable

	}()

	go func() {
		zap.L().Info("Starting OpAmp Websocket server", zap.String("addr", constants.OpAmpWsEndpoint))
		err := s.opampServer.Start(constants.OpAmpWsEndpoint)
		if err != nil {
			zap.L().Info("opamp ws server failed to start", zap.Error(err))
			s.unavailableChannel <- healthcheck.Unavailable
		}
	}()

	return nil
}

func (s *Server) Stop(ctx context.Context) error {
	if s.httpServer != nil {
		if err := s.httpServer.Shutdown(context.Background()); err != nil {
			return err
		}
	}

	if s.privateHTTP != nil {
		if err := s.privateHTTP.Shutdown(context.Background()); err != nil {
			return err
		}
	}

	s.opampServer.Stop()

	if s.ruleManager != nil {
		s.ruleManager.Stop(ctx)
	}

	return nil
}

func makeRulesManager(
	db *sqlx.DB,
	ch interfaces.Reader,
	cache cache.Cache,
	sqlstore sqlstore.SQLStore,
	telemetryStore telemetrystore.TelemetryStore,
	prometheus prometheus.Prometheus,
	orgGetter organization.Getter,
) (*rules.Manager, error) {
	// create manager opts
	managerOpts := &rules.ManagerOptions{
		TelemetryStore: telemetryStore,
		Prometheus:     prometheus,
		DBConn:         db,
		Context:        context.Background(),
		Logger:         zap.L(),
		Reader:         ch,
		Cache:          cache,
		EvalDelay:      constants.GetEvalDelay(),
		SQLStore:       sqlstore,
		OrgGetter:      orgGetter,
	}

	// create Manager
	manager, err := rules.NewManager(managerOpts)
	if err != nil {
		return nil, fmt.Errorf("rule manager error: %v", err)
	}

	zap.L().Info("rules manager is ready")

	return manager, nil
}