package main

import (
	"bytes"
	"context"
	"fmt"
	"io"
	"time"

	"github.com/fiatjaf/eventstore/badger"
	"github.com/fiatjaf/eventstore/lmdb"
	"github.com/fiatjaf/khatru"
	"github.com/fiatjaf/khatru/blossom"
	"github.com/fiatjaf/khatru/policies"
	"github.com/nbd-wtf/go-nostr"
)

var (
	privateRelay = khatru.NewRelay()
	privateDB    = getPrivateDB()
)

var (
	chatRelay = khatru.NewRelay()
	chatDB    = getChatDB()
)

var (
	outboxRelay = khatru.NewRelay()
	outboxDB    = getOutboxDB()
)

var (
	inboxRelay = khatru.NewRelay()
	inboxDB    = getInboxDB()
)

type DBBackend interface {
	Init() error
	Close()
	CountEvents(ctx context.Context, filter nostr.Filter) (int64, error)
	DeleteEvent(ctx context.Context, evt *nostr.Event) error
	QueryEvents(ctx context.Context, filter nostr.Filter) (chan *nostr.Event, error)
	SaveEvent(ctx context.Context, evt *nostr.Event) error
	Serial() []byte
}

func getPrivateDB() DBBackend {
	switch config.DBEngine {
	case "lmdb":
		return &lmdb.LMDBBackend{
			Path: "db/private",
		}
	case "badger":
		return &badger.BadgerBackend{
			Path: "db/private",
		}
	default:
		return &lmdb.LMDBBackend{
			Path: "db/private",
		}
	}
}

func getChatDB() DBBackend {
	switch config.DBEngine {
	case "lmdb":
		return &lmdb.LMDBBackend{
			Path: "db/chat",
		}
	case "badger":
		return &badger.BadgerBackend{
			Path: "db/chat",
		}
	default:
		return &lmdb.LMDBBackend{
			Path: "db/chat",
		}
	}
}

func getOutboxDB() DBBackend {
	switch config.DBEngine {
	case "lmdb":
		return &lmdb.LMDBBackend{
			Path: "db/outbox",
		}
	case "badger":
		return &badger.BadgerBackend{
			Path: "db/outbox",
		}
	default:
		return &lmdb.LMDBBackend{
			Path: "db/outbox",
		}
	}
}

func getInboxDB() DBBackend {
	switch config.DBEngine {
	case "lmdb":
		return &lmdb.LMDBBackend{
			Path: "db/inbox",
		}
	case "badger":
		return &badger.BadgerBackend{
			Path: "db/inbox",
		}
	default:
		return &lmdb.LMDBBackend{
			Path: "db/inbox",
		}
	}
}

func initRelays() {
	if err := privateDB.Init(); err != nil {
		panic(err)
	}

	if err := chatDB.Init(); err != nil {
		panic(err)
	}

	if err := outboxDB.Init(); err != nil {
		panic(err)
	}

	if err := inboxDB.Init(); err != nil {
		panic(err)
	}

	initRelayLimits()

	privateRelay.Info.Name = config.PrivateRelayName
	privateRelay.Info.PubKey = nPubToPubkey(config.PrivateRelayNpub)
	privateRelay.Info.Description = config.PrivateRelayDescription
	privateRelay.Info.Icon = config.PrivateRelayIcon
	privateRelay.Info.Version = config.RelayVersion
	privateRelay.Info.Software = config.RelaySoftware
	privateRelay.ServiceURL = "https://" + config.RelayURL + "/private"

	if !privateRelayLimits.AllowEmptyFilters {
		privateRelay.RejectFilter = append(privateRelay.RejectFilter, policies.NoEmptyFilters)
	}

	if !privateRelayLimits.AllowComplexFilters {
		privateRelay.RejectFilter = append(privateRelay.RejectFilter, policies.NoComplexFilters)
	}

	privateRelay.RejectEvent = append(privateRelay.RejectEvent,
		policies.RejectEventsWithBase64Media,
		policies.EventIPRateLimiter(
			privateRelayLimits.EventIPLimiterTokensPerInterval,
			time.Minute*time.Duration(privateRelayLimits.EventIPLimiterInterval),
			privateRelayLimits.EventIPLimiterMaxTokens,
		),
	)

	privateRelay.RejectConnection = append(privateRelay.RejectConnection,
		policies.ConnectionRateLimiter(
			privateRelayLimits.ConnectionRateLimiterTokensPerInterval,
			time.Minute*time.Duration(privateRelayLimits.ConnectionRateLimiterInterval),
			privateRelayLimits.ConnectionRateLimiterMaxTokens,
		),
	)

	chatRelay.Info.Name = config.ChatRelayName
	chatRelay.Info.PubKey = nPubToPubkey(config.ChatRelayNpub)
	chatRelay.Info.Description = config.ChatRelayDescription
	chatRelay.Info.Icon = config.ChatRelayIcon
	chatRelay.Info.Version = config.RelayVersion
	chatRelay.Info.Software = config.RelaySoftware
	chatRelay.ServiceURL = "https://" + config.RelayURL + "/chat"

	if !chatRelayLimits.AllowEmptyFilters {
		chatRelay.RejectFilter = append(chatRelay.RejectFilter, policies.NoEmptyFilters)
	}

	if !chatRelayLimits.AllowComplexFilters {
		chatRelay.RejectFilter = append(chatRelay.RejectFilter, policies.NoComplexFilters)
	}

	chatRelay.RejectEvent = append(chatRelay.RejectEvent,
		policies.RejectEventsWithBase64Media,
		policies.EventIPRateLimiter(
			chatRelayLimits.EventIPLimiterTokensPerInterval,
			time.Minute*time.Duration(chatRelayLimits.EventIPLimiterInterval),
			chatRelayLimits.EventIPLimiterMaxTokens,
		),
	)

	chatRelay.RejectConnection = append(chatRelay.RejectConnection,
		policies.ConnectionRateLimiter(
			chatRelayLimits.ConnectionRateLimiterTokensPerInterval,
			time.Minute*time.Duration(chatRelayLimits.ConnectionRateLimiterInterval),
			chatRelayLimits.ConnectionRateLimiterMaxTokens,
		),
	)

	outboxRelay.Info.Name = config.OutboxRelayName
	outboxRelay.Info.PubKey = nPubToPubkey(config.OutboxRelayNpub)
	outboxRelay.Info.Description = config.OutboxRelayDescription
	outboxRelay.Info.Icon = config.OutboxRelayIcon
	outboxRelay.Info.Version = config.RelayVersion
	outboxRelay.Info.Software = config.RelaySoftware

	if !outboxRelayLimits.AllowEmptyFilters {
		outboxRelay.RejectFilter = append(outboxRelay.RejectFilter, policies.NoEmptyFilters)
	}

	if !outboxRelayLimits.AllowComplexFilters {
		outboxRelay.RejectFilter = append(outboxRelay.RejectFilter, policies.NoComplexFilters)
	}

	outboxRelay.RejectEvent = append(outboxRelay.RejectEvent,
		policies.RejectEventsWithBase64Media,
		policies.EventIPRateLimiter(
			outboxRelayLimits.EventIPLimiterTokensPerInterval,
			time.Minute*time.Duration(outboxRelayLimits.EventIPLimiterInterval),
			outboxRelayLimits.EventIPLimiterMaxTokens,
		),
	)

	outboxRelay.RejectConnection = append(outboxRelay.RejectConnection,
		policies.ConnectionRateLimiter(
			outboxRelayLimits.ConnectionRateLimiterTokensPerInterval,
			time.Minute*time.Duration(outboxRelayLimits.ConnectionRateLimiterInterval),
			outboxRelayLimits.ConnectionRateLimiterMaxTokens,
		),
	)
	addr := fmt.Sprintf("%s:%d", config.RelayBindAddress, config.RelayPort)

	bl := blossom.New(outboxRelay, addr)
	bl.Store = blossom.EventStoreBlobIndexWrapper{Store: outboxDB, ServiceURL: bl.ServiceURL}
	bl.StoreBlob = append(bl.StoreBlob, func(ctx context.Context, sha256 string, body []byte) error {
		if khatru.GetAuthed(ctx) != nPubToPubkey(config.OwnerNpub) {
			return fmt.Errorf("auth-required: only the relay owner can store media")
		}

		file, err := fs.Create(config.BlossomPath + sha256)
		if err != nil {
			return err
		}
		if _, err := io.Copy(file, bytes.NewReader(body)); err != nil {
			return err
		}
		return nil
	})
	bl.LoadBlob = append(bl.LoadBlob, func(ctx context.Context, sha256 string) (io.Reader, error) {
		return fs.Open(config.BlossomPath + sha256)
	})
	bl.DeleteBlob = append(bl.DeleteBlob, func(ctx context.Context, sha256 string) error {
		return fs.Remove(config.BlossomPath + sha256)
	})

	inboxRelay.Info.Name = config.InboxRelayName
	inboxRelay.Info.PubKey = nPubToPubkey(config.InboxRelayNpub)
	inboxRelay.Info.Description = config.InboxRelayDescription
	inboxRelay.Info.Icon = config.InboxRelayIcon
	inboxRelay.Info.Version = config.RelayVersion
	inboxRelay.Info.Software = config.RelaySoftware
	inboxRelay.ServiceURL = "https://" + config.RelayURL + "/inbox"

	if !inboxRelayLimits.AllowEmptyFilters {
		inboxRelay.RejectFilter = append(inboxRelay.RejectFilter, policies.NoEmptyFilters)
	}

	if !inboxRelayLimits.AllowComplexFilters {
		inboxRelay.RejectFilter = append(inboxRelay.RejectFilter, policies.NoComplexFilters)
	}

	inboxRelay.RejectEvent = append(inboxRelay.RejectEvent,
		policies.RejectEventsWithBase64Media,
		policies.EventIPRateLimiter(
			inboxRelayLimits.EventIPLimiterTokensPerInterval,
			time.Minute*time.Duration(inboxRelayLimits.EventIPLimiterInterval),
			inboxRelayLimits.EventIPLimiterMaxTokens,
		),
	)

	inboxRelay.RejectConnection = append(inboxRelay.RejectConnection,
		policies.ConnectionRateLimiter(
			inboxRelayLimits.ConnectionRateLimiterTokensPerInterval,
			time.Minute*time.Duration(inboxRelayLimits.ConnectionRateLimiterInterval),
			inboxRelayLimits.ConnectionRateLimiterMaxTokens,
		),
	)

}