package main

import (
	"context"
	"errors"
	"fmt"
	"log/slog"
	"math/rand"
	"os"
	"strings"
	"time"

	"github.com/kelseyhightower/envconfig"
	"golang.org/x/time/rate"

	"github.com/mk6i/open-oscar-server/config"
	"github.com/mk6i/open-oscar-server/foodgroup"
	"github.com/mk6i/open-oscar-server/server/http"
	"github.com/mk6i/open-oscar-server/server/kerberos"
	"github.com/mk6i/open-oscar-server/server/oscar"
	oscarmiddleware "github.com/mk6i/open-oscar-server/server/oscar/middleware"
	"github.com/mk6i/open-oscar-server/server/toc"
	"github.com/mk6i/open-oscar-server/server/webapi"
	"github.com/mk6i/open-oscar-server/server/webapi/handlers"
	"github.com/mk6i/open-oscar-server/state"
	"github.com/mk6i/open-oscar-server/wire"
)

// Container groups together common dependencies.
type Container struct {
	cfg                    config.Config
	chatSessionManager     *state.InMemoryChatSessionManager
	hmacCookieBaker        state.HMACCookieBaker
	icbmSvc                *foodgroup.ICBMService
	inMemorySessionManager *state.InMemorySessionManager
	logger                 *slog.Logger
	rateLimitClasses       wire.RateLimitClasses
	snacRateLimits         wire.SNACRateLimits
	sqLiteUserStore        *state.SQLiteUserStore
	webAPISessionManager   *state.WebAPISessionManager
	Listeners              []config.Listener
}

// MakeCommonDeps creates common dependencies used by the food group services.
func MakeCommonDeps() (Container, error) {
	c := Container{}

	if err := validateConfigMigration(); err != nil {
		return c, fmt.Errorf("unable to validate config migration: %s", err.Error())
	}

	err := envconfig.Process("", &c.cfg)
	if err != nil {
		return c, fmt.Errorf("unable to process app config: %s", err.Error())
	}

	if err := c.cfg.Validate(); err != nil {
		return c, fmt.Errorf("configuration validation failed: %s", err.Error())
	}

	c.Listeners, err = c.cfg.ParseListenersCfg()
	if err != nil {
		return c, fmt.Errorf("unable to parse listener config: %s", err.Error())
	}

	c.sqLiteUserStore, err = state.NewSQLiteUserStore(c.cfg.DBPath)
	if err != nil {
		return c, fmt.Errorf("unable to create feedbag store: %s", err.Error())
	}

	c.hmacCookieBaker, err = state.NewHMACCookieBaker()
	if err != nil {
		return c, fmt.Errorf("unable to create HMAC cookie baker: %s", err.Error())
	}

	c.logger = oscarmiddleware.NewLogger(c.cfg)
	c.inMemorySessionManager = state.NewInMemorySessionManager(c.logger)
	c.chatSessionManager = state.NewInMemoryChatSessionManager(c.logger)
	c.webAPISessionManager = state.NewWebAPISessionManager()
	c.rateLimitClasses = wire.DefaultRateLimitClasses()
	c.snacRateLimits = wire.DefaultSNACRateLimits()

	// ICBM svc is a common dep because OSCAR and TOC need to share convo history state.
	c.icbmSvc = foodgroup.NewICBMService(
		c.sqLiteUserStore,
		c.inMemorySessionManager,
		c.sqLiteUserStore,
		c.sqLiteUserStore,
		c.inMemorySessionManager,
		c.sqLiteUserStore,
		c.sqLiteUserStore,
		c.snacRateLimits,
		c.logger,
	)

	return c, nil
}

func validateConfigMigration() error {
	// Old environment variables that should be removed
	oldEnvVars := []string{
		"API_HOST",
		"API_PORT",
		"KERBEROS_PORT",
		"ALERT_PORT",
		"AUTH_PORT",
		"BART_PORT",
		"BOS_PORT",
		"CHAT_NAV_PORT",
		"CHAT_PORT",
		"ADMIN_PORT",
		"ODIR_PORT",
		"OSCAR_HOST",
		"TOC_HOST",
		"TOC_PORT",
	}

	// New environment variables that should be present
	newEnvVars := []string{
		"API_LISTENER",
		"OSCAR_ADVERTISED_LISTENERS_PLAIN",
		"OSCAR_LISTENERS",
		"TOC_LISTENERS",
	}

	var oldEnvVarsFound []string
	var newEnvVarsMissing []string

	// Check for old environment variables that should be removed
	for _, envVar := range oldEnvVars {
		if os.Getenv(envVar) != "" {
			oldEnvVarsFound = append(oldEnvVarsFound, envVar)
		}
	}

	// Check for new environment variables that should be present
	for _, envVar := range newEnvVars {
		if os.Getenv(envVar) == "" {
			newEnvVarsMissing = append(newEnvVarsMissing, envVar)
		}
	}

	// If there are any issues, return an error with details
	if len(oldEnvVarsFound) > 0 || len(newEnvVarsMissing) > 0 {
		var errorMsg strings.Builder
		errorMsg.WriteString("Open OSCAR Server v0.19.0 introduced some breaking configuration changes that you need to fix.\n")

		if len(oldEnvVarsFound) > 0 {
			errorMsg.WriteString("\nOld environment variables that must be removed:\n\n")
			for _, envVar := range oldEnvVarsFound {
				errorMsg.WriteString(fmt.Sprintf("  - %s\n", envVar))
			}
		}

		if len(newEnvVarsMissing) > 0 {
			errorMsg.WriteString("\nNew environment variables that must be provided:\n\n")
			for _, envVar := range newEnvVarsMissing {
				errorMsg.WriteString(fmt.Sprintf("  - %s\n", envVar))
			}

			// Generate export commands based on old environment variables
			errorMsg.WriteString("\nCopy/paste this updated configuration into your settings file:\n\n")

			if contains(newEnvVarsMissing, "API_LISTENER") {
				apiHost := getEnvOrDefault("API_HOST", "127.0.0.1")
				apiPort := getEnvOrDefault("API_PORT", "8080")
				errorMsg.WriteString(fmt.Sprintf("export API_LISTENER=%s:%s\n", apiHost, apiPort))
			}

			if contains(newEnvVarsMissing, "OSCAR_ADVERTISED_LISTENERS_PLAIN") {
				oscarHost := getEnvOrDefault("OSCAR_HOST", "127.0.0.1")
				authPort := getEnvOrDefault("AUTH_PORT", "5190")
				errorMsg.WriteString(fmt.Sprintf("export OSCAR_ADVERTISED_LISTENERS_PLAIN=LOCAL://%s:%s\n", oscarHost, authPort))
			}

			if contains(newEnvVarsMissing, "OSCAR_LISTENERS") {
				authPort := getEnvOrDefault("AUTH_PORT", "5190")
				errorMsg.WriteString(fmt.Sprintf("export OSCAR_LISTENERS=LOCAL://0.0.0.0:%s\n", authPort))
			}

			if contains(newEnvVarsMissing, "KERBEROS_LISTENERS") {
				kerberosPort := getEnvOrDefault("KERBEROS_PORT", "1088")
				errorMsg.WriteString(fmt.Sprintf("export KERBEROS_LISTENERS=LOCAL://0.0.0.0:%s\n", kerberosPort))
			}

			if contains(newEnvVarsMissing, "TOC_LISTENERS") {
				tocHost := getEnvOrDefault("TOC_HOST", "0.0.0.0")
				tocPort := getEnvOrDefault("TOC_PORT", "9898")
				errorMsg.WriteString(fmt.Sprintf("export TOC_LISTENERS=%s:%s\n", tocHost, tocPort))
			}
		}

		return errors.New(errorMsg.String())
	}

	return nil
}

// Helper function to check if a slice contains a string
func contains(slice []string, item string) bool {
	for _, s := range slice {
		if s == item {
			return true
		}
	}
	return false
}

// Helper function to get environment variable or return default
func getEnvOrDefault(key, defaultValue string) string {
	if value := os.Getenv(key); value != "" {
		return value
	}
	return defaultValue
}

// OSCAR creates an OSCAR server for the OSCAR food group.
func OSCAR(deps Container) *oscar.Server {
	logger := deps.logger.With("svc", "OSCAR")

	adminService := foodgroup.NewAdminService(
		deps.sqLiteUserStore,
		deps.sqLiteUserStore,
		deps.sqLiteUserStore,
		deps.inMemorySessionManager,
		deps.inMemorySessionManager,
		deps.logger,
	)
	authService := foodgroup.NewAuthService(
		deps.cfg,
		deps.inMemorySessionManager,
		deps.inMemorySessionManager,
		deps.chatSessionManager,
		deps.sqLiteUserStore,
		deps.hmacCookieBaker,
		deps.chatSessionManager,
		deps.sqLiteUserStore,
		deps.sqLiteUserStore,
		deps.rateLimitClasses,
		state.NewAccountCreator(deps.sqLiteUserStore.InsertUser),
		logger,
	)
	bartService := foodgroup.NewBARTService(
		logger,
		deps.sqLiteUserStore,
		deps.inMemorySessionManager,
		deps.sqLiteUserStore,
		deps.inMemorySessionManager,
	)
	buddyService := foodgroup.NewBuddyService(
		deps.inMemorySessionManager,
		deps.sqLiteUserStore,
		deps.sqLiteUserStore,
		deps.inMemorySessionManager,
		deps.sqLiteUserStore,
	)
	chatService := foodgroup.NewChatService(deps.chatSessionManager)
	chatNavService := foodgroup.NewChatNavService(logger, deps.sqLiteUserStore)
	feedbagService := foodgroup.NewFeedbagService(
		logger,
		deps.inMemorySessionManager,
		deps.sqLiteUserStore,
		deps.sqLiteUserStore,
		deps.sqLiteUserStore,
		deps.inMemorySessionManager,
	)
	permitDenyService := foodgroup.NewPermitDenyService(
		deps.sqLiteUserStore,
		deps.sqLiteUserStore,
		deps.sqLiteUserStore,
		deps.inMemorySessionManager,
		deps.inMemorySessionManager,
	)
	icqService := foodgroup.NewICQService(
		deps.inMemorySessionManager,
		deps.sqLiteUserStore,
		deps.sqLiteUserStore,
		logger,
		deps.inMemorySessionManager,
		deps.sqLiteUserStore,
	)
	locateService := foodgroup.NewLocateService(
		deps.sqLiteUserStore,
		deps.inMemorySessionManager,
		deps.sqLiteUserStore,
		deps.sqLiteUserStore,
		deps.inMemorySessionManager,
		deps.sqLiteUserStore,
	)
	oServiceService := foodgroup.NewOServiceService(
		deps.cfg,
		deps.inMemorySessionManager,
		logger,
		deps.hmacCookieBaker,
		deps.sqLiteUserStore,
		deps.sqLiteUserStore,
		deps.inMemorySessionManager,
		deps.sqLiteUserStore,
		deps.snacRateLimits,
		deps.chatSessionManager,
		deps.sqLiteUserStore,
		deps.sqLiteUserStore,
	)
	userLookupService := foodgroup.NewUserLookupService(deps.sqLiteUserStore)
	statsService := foodgroup.NewStatsService()
	oDirService := foodgroup.NewODirService(logger, deps.sqLiteUserStore)

	if err := deps.sqLiteUserStore.ClearBuddyListRegistry(context.Background()); err != nil {
		panic(err)
	}

	return oscar.NewServer(
		authService,
		deps.sqLiteUserStore,
		deps.chatSessionManager,
		buddyService,
		logger,
		oServiceService,
		oscar.Handler{
			AdminService:      adminService,
			BARTService:       bartService,
			BuddyService:      buddyService,
			ChatNavService:    chatNavService,
			ChatService:       chatService,
			FeedbagService:    feedbagService,
			ICBMService:       deps.icbmSvc,
			ICQService:        icqService,
			LocateService:     locateService,
			ODirService:       oDirService,
			OServiceService:   oServiceService,
			PermitDenyService: permitDenyService,
			StatsService:      statsService,
			UserLookupService: userLookupService,
			RouteLogger: oscarmiddleware.RouteLogger{
				Logger: logger,
			},
		}.Handle,
		oServiceService,
		deps.snacRateLimits,
		oscar.NewIPRateLimiter(rate.Every(1*time.Minute), 10, 1*time.Minute),
		deps.Listeners,
		deps.icbmSvc.RestoreWarningLevel,
		deps.icbmSvc.UpdateWarnLevel,
	)
}

// KerberosAPI creates an HTTP server for the Kerberos server.
func KerberosAPI(deps Container) *kerberos.Server {
	logger := deps.logger.With("svc", "Kerberos")
	authService := foodgroup.NewAuthService(
		deps.cfg,
		deps.inMemorySessionManager,
		deps.inMemorySessionManager,
		deps.chatSessionManager,
		deps.sqLiteUserStore,
		deps.hmacCookieBaker,
		deps.chatSessionManager,
		deps.sqLiteUserStore,
		deps.sqLiteUserStore,
		deps.rateLimitClasses,
		state.NewAccountCreator(deps.sqLiteUserStore.InsertUser),
		logger,
	)
	return kerberos.NewKerberosServer(deps.Listeners, logger, authService)
}

// MgmtAPI creates an HTTP server for the management API.
func MgmtAPI(deps Container) *http.Server {
	bld := config.Build{
		Version: version,
		Commit:  commit,
		Date:    date,
	}
	logger := deps.logger.With("svc", "API")
	buddyService := foodgroup.NewBuddyService(
		deps.inMemorySessionManager,
		deps.sqLiteUserStore,
		deps.sqLiteUserStore,
		deps.inMemorySessionManager,
		deps.sqLiteUserStore,
	)
	return http.NewManagementAPI(
		bld,
		deps.cfg.APIListener,
		deps.sqLiteUserStore,        // userManager
		deps.inMemorySessionManager, // sessionRetriever
		buddyService,
		deps.sqLiteUserStore,        // chatRoomRetriever
		deps.sqLiteUserStore,        // chatRoomCreator
		deps.sqLiteUserStore,        // chatRoomDeleter
		deps.chatSessionManager,     // chatSessionRetriever
		deps.sqLiteUserStore,        // directoryManager
		deps.inMemorySessionManager, // messageRelayer
		deps.sqLiteUserStore,        // bartAssetManager
		deps.sqLiteUserStore,        // feedbagRetriever
		deps.sqLiteUserStore,        // feedbagManager
		deps.sqLiteUserStore,        // accountManager
		deps.sqLiteUserStore,        // profileRetriever
		deps.sqLiteUserStore,        // webAPIKeyManager
		state.NewAccountCreator(deps.sqLiteUserStore.InsertUser),
		logger,
	)
}

// TOC creates a TOC server.
func TOC(deps Container) *toc.Server {
	logger := deps.logger.With("svc", "TOC")

	return toc.NewServer(
		deps.cfg.TOCListeners,
		logger,
		toc.OSCARProxy{
			AdminService: foodgroup.NewAdminService(
				deps.sqLiteUserStore,
				deps.sqLiteUserStore,
				deps.sqLiteUserStore,
				deps.inMemorySessionManager,
				deps.inMemorySessionManager,
				deps.logger,
			),
			AuthService: foodgroup.NewAuthService(
				deps.cfg,
				deps.inMemorySessionManager,
				deps.inMemorySessionManager,
				deps.chatSessionManager,
				deps.sqLiteUserStore,
				deps.hmacCookieBaker,
				deps.chatSessionManager,
				deps.sqLiteUserStore,
				deps.sqLiteUserStore,
				deps.rateLimitClasses,
				state.NewAccountCreator(deps.sqLiteUserStore.InsertUser),
				logger,
			),
			BuddyListRegistry: deps.sqLiteUserStore,
			BuddyService: foodgroup.NewBuddyService(
				deps.inMemorySessionManager,
				deps.sqLiteUserStore,
				deps.sqLiteUserStore,
				deps.inMemorySessionManager,
				deps.sqLiteUserStore,
			),
			ChatSessionManager: deps.chatSessionManager,
			CookieBaker:        deps.hmacCookieBaker,
			DirSearchService:   foodgroup.NewODirService(logger, deps.sqLiteUserStore),
			ICBMService:        deps.icbmSvc,
			LocateService: foodgroup.NewLocateService(
				deps.sqLiteUserStore,
				deps.inMemorySessionManager,
				deps.sqLiteUserStore,
				deps.sqLiteUserStore,
				deps.inMemorySessionManager,
				deps.sqLiteUserStore,
			),
			Logger: logger,
			OServiceService: foodgroup.NewOServiceService(
				deps.cfg,
				deps.inMemorySessionManager,
				logger,
				deps.hmacCookieBaker,
				deps.sqLiteUserStore,
				deps.sqLiteUserStore,
				deps.inMemorySessionManager,
				deps.sqLiteUserStore,
				deps.snacRateLimits,
				deps.chatSessionManager,
				deps.sqLiteUserStore,
				deps.sqLiteUserStore,
			),
			PermitDenyService: foodgroup.NewPermitDenyService(
				deps.sqLiteUserStore,
				deps.sqLiteUserStore,
				deps.sqLiteUserStore,
				deps.inMemorySessionManager,
				deps.inMemorySessionManager,
			),
			TOCConfigStore: deps.sqLiteUserStore,
			ChatService:    foodgroup.NewChatService(deps.chatSessionManager),
			ChatNavService: foodgroup.NewChatNavService(logger, deps.sqLiteUserStore),
			FeedbagManager: deps.sqLiteUserStore,
			FeedbagService: foodgroup.NewFeedbagService(
				logger,
				deps.inMemorySessionManager,
				deps.sqLiteUserStore,
				deps.sqLiteUserStore,
				deps.sqLiteUserStore,
				deps.inMemorySessionManager,
			),
			SNACRateLimits:    deps.snacRateLimits,
			HTTPIPRateLimiter: toc.NewIPRateLimiter(rate.Every(1*time.Minute), 10, 1*time.Minute),
			SessionRetriever:  deps.inMemorySessionManager,
			RandIntn:          rand.Intn,
		},
		toc.NewIPRateLimiter(rate.Every(1*time.Minute), 100000, 1*time.Minute),
		deps.icbmSvc.RestoreWarningLevel,
		deps.icbmSvc.UpdateWarnLevel,
	)
}

// WebAPI creates an HTTP server for the webapi protocol.
func WebAPI(deps Container) *webapi.Server {
	logger := deps.logger.With("svc", "webapi")

	// Create feedbag adapter for WebAPI
	feedbagAdapter := &webapi.FeedbagAdapter{
		Store: deps.sqLiteUserStore,
	}

	// Create WebAPI buddy list manager (local to WebAPI)
	buddyListManager := handlers.NewBuddyListManager(
		feedbagAdapter,
		deps.inMemorySessionManager,
		logger,
	)

	// Create the OSCAR buddy broadcaster for WebAPI to use
	oscarBuddyBroadcaster := foodgroup.NewBuddyService(
		deps.inMemorySessionManager,
		deps.sqLiteUserStore,
		deps.sqLiteUserStore,
		deps.inMemorySessionManager,
		deps.sqLiteUserStore,
	)

	handler := webapi.Handler{
		AdminService: foodgroup.NewAdminService(
			deps.sqLiteUserStore,
			deps.sqLiteUserStore,
			deps.sqLiteUserStore,
			deps.inMemorySessionManager,
			deps.inMemorySessionManager,
			deps.logger,
		),
		AuthService: foodgroup.NewAuthService(
			deps.cfg,
			deps.inMemorySessionManager,
			deps.inMemorySessionManager,
			deps.chatSessionManager,
			deps.sqLiteUserStore,
			deps.hmacCookieBaker,
			deps.chatSessionManager,
			deps.sqLiteUserStore,
			deps.sqLiteUserStore,
			deps.rateLimitClasses,
			state.NewAccountCreator(deps.sqLiteUserStore.InsertUser),
			logger,
		),
		BuddyListRegistry: deps.sqLiteUserStore,
		BuddyService: foodgroup.NewBuddyService(
			deps.inMemorySessionManager,
			deps.sqLiteUserStore,
			deps.sqLiteUserStore,
			deps.inMemorySessionManager,
			deps.sqLiteUserStore,
		),
		CookieBaker:      deps.hmacCookieBaker,
		DirSearchService: foodgroup.NewODirService(logger, deps.sqLiteUserStore),
		ICBMService:      deps.icbmSvc,
		LocateService: foodgroup.NewLocateService(
			deps.sqLiteUserStore,
			deps.inMemorySessionManager,
			deps.sqLiteUserStore,
			deps.sqLiteUserStore,
			deps.inMemorySessionManager,
			deps.sqLiteUserStore,
		),
		Logger: logger,
		OServiceService: foodgroup.NewOServiceService(
			deps.cfg,
			deps.inMemorySessionManager,
			logger,
			deps.hmacCookieBaker,
			deps.sqLiteUserStore,
			deps.sqLiteUserStore,
			deps.inMemorySessionManager,
			deps.sqLiteUserStore,
			deps.snacRateLimits,
			deps.chatSessionManager,
			deps.sqLiteUserStore,
			deps.sqLiteUserStore,
		),
		PermitDenyService: foodgroup.NewPermitDenyService(
			deps.sqLiteUserStore,
			deps.sqLiteUserStore,
			deps.sqLiteUserStore,
			deps.inMemorySessionManager,
			deps.inMemorySessionManager,
		),
		TOCConfigStore: deps.sqLiteUserStore,
		ChatService:    foodgroup.NewChatService(deps.chatSessionManager),
		ChatNavService: foodgroup.NewChatNavService(logger, deps.sqLiteUserStore),
		SNACRateLimits: deps.snacRateLimits,
		// New fields for WebAPI handlers
		SessionRetriever: deps.inMemorySessionManager,
		FeedbagRetriever: feedbagAdapter,
		FeedbagManager:   feedbagAdapter,
		// Phase 2 additions
		MessageRelayer:        deps.inMemorySessionManager,
		OfflineMessageManager: deps.sqLiteUserStore,
		BuddyBroadcaster:      oscarBuddyBroadcaster,
		ProfileManager:        deps.sqLiteUserStore,
		RelationshipFetcher:   deps.sqLiteUserStore,
		// Authentication support
		UserManager: deps.sqLiteUserStore,
		TokenStore:  deps.sqLiteUserStore.NewWebAPITokenStore(),
		// Phase 3 additions
		PreferenceManager: deps.sqLiteUserStore.NewWebPreferenceManager(),
		PermitDenyManager: deps.sqLiteUserStore.NewWebPermitDenyManager(),
		// Phase 4 additions for OSCAR Bridge
		OSCARBridgeStore: deps.sqLiteUserStore.NewOSCARBridgeStore(),
		OSCARConfig:      webapi.NewOSCARConfigAdapter(deps.cfg),
		// Phase 5 additions for buddy list and messaging
		BuddyListManager: buddyListManager,
		// Phase 5 additions for chat rooms
		ChatManager: deps.sqLiteUserStore.NewWebAPIChatManager(logger, deps.webAPISessionManager),
	}
	// Pass SQLiteUserStore as the API key validator (it implements middleware.APIKeyValidator)
	return webapi.NewServer([]string{"0.0.0.0:9000"}, logger, handler, deps.sqLiteUserStore, deps.webAPISessionManager)
}