package bootstrap

import (
	"context"
	"fmt"
	"path/filepath"
	"time"

	"github.com/gin-gonic/gin"
	"github.com/jackc/pgx/v5/pgxpool"
	goredis "github.com/redis/go-redis/v9"
	"go.uber.org/zap"

	"github.com/geo-platform/tenant-api/internal/shared/auditlog"
	"github.com/geo-platform/tenant-api/internal/shared/auth"
	sharedbootstrap "github.com/geo-platform/tenant-api/internal/shared/bootstrap"
	"github.com/geo-platform/tenant-api/internal/shared/cache"
	"github.com/geo-platform/tenant-api/internal/shared/config"
	"github.com/geo-platform/tenant-api/internal/shared/ipregion"
	"github.com/geo-platform/tenant-api/internal/shared/llm"
	"github.com/geo-platform/tenant-api/internal/shared/messaging/rabbitmq"
	"github.com/geo-platform/tenant-api/internal/shared/middleware"
	"github.com/geo-platform/tenant-api/internal/shared/objectstorage"
	"github.com/geo-platform/tenant-api/internal/shared/observability"
	"github.com/geo-platform/tenant-api/internal/shared/repository/postgres"
	"github.com/geo-platform/tenant-api/internal/shared/repository/redis"
	"github.com/geo-platform/tenant-api/internal/shared/response"
	"github.com/geo-platform/tenant-api/internal/shared/retrieval"
	"github.com/geo-platform/tenant-api/internal/shared/stream"
	tenantapp "github.com/geo-platform/tenant-api/internal/tenant/app"
	"github.com/geo-platform/tenant-api/internal/tenant/prompts"
	"github.com/geo-platform/tenant-api/internal/tenant/repository"
)

type App struct {
	ConfigStore             *config.Store
	Logger                  *zap.Logger
	DB                      *pgxpool.Pool
	MonitoringDB            *pgxpool.Pool
	RabbitMQ                *rabbitmq.Client
	Redis                   *goredis.Client
	Engine                  *gin.Engine
	JWT                     *auth.Manager
	Sessions                *auth.SessionStore
	LoginGuard              *auth.LoginGuard
	PasswordCipher          *auth.PasswordCipher
	LLM                     llm.Client
	ReloadableLLM           *llm.ReloadableClient
	RetrievalProvider       retrieval.Provider
	ReloadableRetrieval     *retrieval.ReloadableProvider
	VectorStore             retrieval.VectorStore
	ReloadableVectorStore   *retrieval.ReloadableVectorStore
	ObjectStorage           objectstorage.Client
	ReloadableObjectStorage *objectstorage.ReloadableClient
	AuditLogs               *auditlog.AsyncWriter
	GenerationStreams       *stream.GenerationHub
	DesktopTaskStreams      *stream.DesktopTaskHub
	DesktopDispatch         *stream.DesktopDispatchHub
	Cache                   cache.Cache
	IPRegions               *ipregion.Resolver
	BrandService            *tenantapp.BrandService
	QuestionExpansion       *tenantapp.QuestionExpansionService
	MonitoringService       *tenantapp.MonitoringService
	MediaSupplyService      *tenantapp.MediaSupplyService
	KolProfiles             repository.KolProfileRepository
	KolPackages             repository.KolPackageRepository
	KolMarketplace          repository.KolMarketplaceRepository
	KolPrompts              repository.KolPromptRepository
	KolSubscriptions        repository.KolSubscriptionRepository
	KolAssists              repository.KolAssistRepository
	KolPromptAsset          *tenantapp.KolPromptAsset
}

func New(configPath string) (*App, error) {
	configStore, err := config.NewStore(configPath)
	if err != nil {
		return nil, fmt.Errorf("load config: %w", err)
	}
	cfg := configStore.Current()
	prompts.SetConfigFile(filepath.Join(filepath.Dir(configPath), "prompts.yml"))

	logger, err := observability.NewLogger(cfg.Log.Level, cfg.Log.Format)
	if err != nil {
		return nil, fmt.Errorf("init logger: %w", err)
	}

	ctx := context.Background()

	pool, err := postgres.NewPool(ctx, cfg.Database)
	if err != nil {
		return nil, fmt.Errorf("init postgres: %w", err)
	}

	if err := syncMembershipPlans(ctx, pool, cfg.Membership); err != nil {
		pool.Close()
		return nil, fmt.Errorf("sync membership plans: %w", err)
	}

	monitoringPool, err := postgres.NewPool(ctx, cfg.MonitoringDatabase)
	if err != nil {
		pool.Close()
		return nil, fmt.Errorf("init monitoring postgres: %w", err)
	}

	rdb, err := redis.NewClient(ctx, cfg.Redis)
	if err != nil {
		logger.Warn("redis unavailable during startup; continuing with degraded auth/cache fallback", zap.Error(err))
		rdb = redis.NewLazyClient(cfg.Redis)
	}

	mqClient, err := rabbitmq.New(ctx, cfg.RabbitMQ)
	if err != nil {
		pool.Close()
		monitoringPool.Close()
		_ = rdb.Close()
		return nil, fmt.Errorf("init rabbitmq: %w", err)
	}

	jwtMgr := auth.NewManager(cfg.JWT.Secret, cfg.JWT.AccessTTL, cfg.JWT.RefreshTTL)
	sessions := auth.NewSessionStore(rdb)
	passwordCipher, err := buildPasswordCipher(cfg.Auth.PasswordCipher)
	if err != nil {
		pool.Close()
		monitoringPool.Close()
		_ = rdb.Close()
		_ = mqClient.Close()
		return nil, fmt.Errorf("init password cipher: %w", err)
	}
	if passwordCipher == nil {
		logger.Warn("auth password cipher disabled; login request payloads may expose plaintext passwords in browser developer tools")
	}
	loginGuardCfg := auth.DefaultLoginGuardConfig("tenant")
	loginGuardCfg.Enabled = cfg.Auth.LoginGuard.Enabled
	if !loginGuardCfg.Enabled {
		logger.Warn("tenant login guard disabled by config; brute-force / rate-limit protection is off")
	}
	loginGuard := auth.NewLoginGuard(rdb, loginGuardCfg)
	llmClient := llm.NewReloadableClient(llm.New(cfg.LLM))
	retrievalProvider := retrieval.NewReloadableProvider(retrieval.NewProvider(cfg.Retrieval, logger))
	vectorStore := retrieval.NewReloadableVectorStore(retrieval.NewQdrantStore(cfg.Qdrant, logger))
	objectStorageClient := objectstorage.NewReloadableClient(objectstorage.New(cfg.ObjectStorage, logger))
	auditLogs := auditlog.NewAsyncWriter(pool, logger)
	generationStreams := stream.NewGenerationHub(mqClient)
	desktopTaskStreams := stream.NewDesktopTaskHub(mqClient)
	desktopDispatchBindings := []string{
		cfg.RabbitMQ.DesktopDispatchPublishPrefix + ".*",
		cfg.RabbitMQ.DesktopDispatchMonitorPrefix + ".*",
		cfg.RabbitMQ.DesktopDispatchMonitorPrefix + ".*.*",
	}
	desktopDispatch := stream.NewDesktopDispatchHub(mqClient, logger, desktopDispatchBindings)
	appCache := cache.NewWithOptions(cfg.Cache.Driver, rdb, cache.Options{
		Namespace:        cfg.Cache.Namespace,
		JitterRatio:      cfg.Cache.JitterRatio,
		MetricsEnabled:   cfg.Cache.MetricsEnabled,
		AsyncFillEnabled: cfg.Cache.AsyncFillEnabled,
		AsyncFillWorkers: cfg.Cache.AsyncFillWorkers,
		AsyncFillBuffer:  cfg.Cache.AsyncFillBuffer,
		AsyncFillTimeout: cfg.Cache.AsyncFillTimeout,
		L1Enabled:        cfg.Cache.L1Enabled,
		L1TTL:            cfg.Cache.L1TTL,
		DeleteScanCount:  cfg.Cache.DeleteScanCount,
	})
	ipRegions, err := ipregion.NewResolver(cfg.IPRegion.V4XDBPath, cfg.IPRegion.V6XDBPath, logger)
	if err != nil {
		logger.Warn("ip region resolver unavailable; location-aware defaults will be degraded", zap.Error(err))
	}
	brandService := tenantapp.NewBrandService(pool, monitoringPool, auditLogs, cfg.BrandLibrary).WithCache(appCache)
	questionExpansion := tenantapp.NewQuestionExpansionService(pool, llmClient, brandService).
		WithCache(appCache).
		WithIPRegionResolver(ipRegions)
	monitoringService := tenantapp.NewMonitoringService(pool, monitoringPool, mqClient, cfg.MonitoringDispatch, cfg.BrandLibrary, logger).WithRedis(rdb)
	mediaSupplyService := tenantapp.NewMediaSupplyService(pool, rdb, logger, configStore).WithObjectStorage(objectStorageClient)
	kolProfiles := repository.NewKolProfileRepository(pool)
	kolPackages := repository.NewKolPackageRepository(pool)
	kolMarketplace := repository.NewKolMarketplaceRepository(pool)
	kolPrompts := repository.NewKolPromptRepository(pool)
	kolSubscriptions := repository.NewKolSubscriptionRepository(pool)
	kolAssists := repository.NewKolAssistRepository(pool)
	kolPromptAsset := tenantapp.NewKolPromptAsset(objectStorageClient)

	engine, err := sharedbootstrap.NewEngine(cfg.Server)
	if err != nil {
		return nil, fmt.Errorf("init http engine: %w", err)
	}

	engine.Use(
		middleware.Recovery(logger),
		middleware.RequestID(),
		middleware.Logger(logger),
	)
	if cfg.Server.SecurityHeaders.Enabled {
		engine.Use(middleware.SecurityHeaders())
	}
	engine.Use(middleware.CORSWithConfig(middleware.CORSConfig{
		AllowedOrigins: cfg.Server.AllowedOrigins,
		AllowAll:       len(cfg.Server.AllowedOrigins) == 0,
	}))

	engine.GET("/api/health/live", func(c *gin.Context) {
		response.Success(c, gin.H{"status": "alive"})
	})
	engine.GET("/api/health/ready", func(c *gin.Context) {
		if err := pool.Ping(c.Request.Context()); err != nil {
			response.Error(c, response.ErrServiceUnavailable(50301, "postgres_unavailable", "database is not reachable"))
			return
		}
		if err := monitoringPool.Ping(c.Request.Context()); err != nil {
			response.Error(c, response.ErrServiceUnavailable(50303, "monitoring_postgres_unavailable", "monitoring database is not reachable"))
			return
		}
		if err := rdb.Ping(c.Request.Context()).Err(); err != nil {
			response.Error(c, response.ErrServiceUnavailable(50302, "redis_unavailable", "redis is not reachable"))
			return
		}
		if err := mqClient.Ping(c.Request.Context()); err != nil {
			response.Error(c, response.ErrServiceUnavailable(50304, "rabbitmq_unavailable", "rabbitmq is not reachable"))
			return
		}
		response.Success(c, gin.H{"status": "ready"})
	})

	return &App{
		ConfigStore:             configStore,
		Logger:                  logger,
		DB:                      pool,
		MonitoringDB:            monitoringPool,
		RabbitMQ:                mqClient,
		Redis:                   rdb,
		Engine:                  engine,
		JWT:                     jwtMgr,
		Sessions:                sessions,
		LoginGuard:              loginGuard,
		PasswordCipher:          passwordCipher,
		LLM:                     llmClient,
		ReloadableLLM:           llmClient,
		RetrievalProvider:       retrievalProvider,
		ReloadableRetrieval:     retrievalProvider,
		VectorStore:             vectorStore,
		ReloadableVectorStore:   vectorStore,
		ObjectStorage:           objectStorageClient,
		ReloadableObjectStorage: objectStorageClient,
		AuditLogs:               auditLogs,
		GenerationStreams:       generationStreams,
		DesktopTaskStreams:      desktopTaskStreams,
		DesktopDispatch:         desktopDispatch,
		Cache:                   appCache,
		IPRegions:               ipRegions,
		BrandService:            brandService,
		QuestionExpansion:       questionExpansion,
		MonitoringService:       monitoringService,
		MediaSupplyService:      mediaSupplyService,
		KolProfiles:             kolProfiles,
		KolPackages:             kolPackages,
		KolMarketplace:          kolMarketplace,
		KolPrompts:              kolPrompts,
		KolSubscriptions:        kolSubscriptions,
		KolAssists:              kolAssists,
		KolPromptAsset:          kolPromptAsset,
	}, nil
}

func buildPasswordCipher(cfg config.PasswordCipherConfig) (*auth.PasswordCipher, error) {
	if !cfg.Enabled {
		return nil, nil
	}
	if cfg.PrivateKeyPEM == "" {
		return auth.NewEphemeralPasswordCipher(cfg.KeyID)
	}
	return auth.NewPasswordCipher(cfg.PrivateKeyPEM, cfg.KeyID)
}

func (a *App) Config() *config.Config {
	if a == nil || a.ConfigStore == nil {
		return nil
	}
	return a.ConfigStore.Current()
}

func (a *App) StartConfigWatcher(ctx context.Context) {
	if a == nil || a.ConfigStore == nil {
		return
	}
	go func() {
		if err := a.ConfigStore.Watch(ctx, a.Logger, a.applyReloadedConfig); err != nil && a.Logger != nil {
			a.Logger.Warn("config hot reload watcher stopped", zap.Error(err))
		}
	}()
}

func (a *App) applyReloadedConfig(event config.ReloadEvent) {
	if a == nil || event.Current == nil {
		return
	}

	a.JWT.Update(event.Current.JWT.Secret, event.Current.JWT.AccessTTL, event.Current.JWT.RefreshTTL)
	if a.ReloadableLLM != nil {
		a.ReloadableLLM.Update(llm.New(event.Current.LLM))
	}
	if a.ReloadableRetrieval != nil {
		a.ReloadableRetrieval.Update(retrieval.NewProvider(event.Current.Retrieval, a.Logger))
	}
	if a.ReloadableVectorStore != nil {
		a.ReloadableVectorStore.Update(retrieval.NewQdrantStore(event.Current.Qdrant, a.Logger))
	}
	if a.ReloadableObjectStorage != nil {
		a.ReloadableObjectStorage.Update(objectstorage.New(event.Current.ObjectStorage, a.Logger))
	}
	if a.BrandService != nil {
		a.BrandService.UpdateConfig(event.Current.BrandLibrary)
	}
	if a.MonitoringService != nil {
		a.MonitoringService.UpdateConfig(event.Current.MonitoringDispatch, event.Current.BrandLibrary)
	}

	if err := syncMembershipPlans(context.Background(), a.DB, event.Current.Membership); err != nil {
		a.Logger.Warn("config reload membership plan sync failed", zap.Error(err))
	}

	if config.RestartRequired(event.Changes) && a.Logger != nil {
		a.Logger.Warn("config reload changed connection or listener settings; restart process to apply those fields")
	}
}

// syncMembershipPlans upserts all configured plans in a single transaction so
// that a partial failure (or concurrent startup) never leaves the `plans` table
// in a half-synced state.
func syncMembershipPlans(ctx context.Context, pool *pgxpool.Pool, membership config.MembershipConfig) error {
	tx, err := pool.Begin(ctx)
	if err != nil {
		return err
	}
	defer func() {
		_ = tx.Rollback(ctx)
	}()

	if err := repository.NewTenantPlanRepository(tx).UpsertConfiguredPlans(ctx, membership); err != nil {
		return err
	}
	return tx.Commit(ctx)
}

func (a *App) Close() {
	if a.ConfigStore != nil {
		a.ConfigStore.Close()
	}
	if a.AuditLogs != nil {
		ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
		if err := a.AuditLogs.Close(ctx); err != nil {
			a.Logger.Warn("shutdown with pending audit logs", zap.Error(err))
		}
		cancel()
	}
	if a.IPRegions != nil {
		a.IPRegions.Close()
	}
	a.DB.Close()
	if a.MonitoringDB != nil {
		a.MonitoringDB.Close()
	}
	if a.RabbitMQ != nil {
		_ = a.RabbitMQ.Close()
	}
	_ = a.Redis.Close()
	_ = a.Logger.Sync()
}