package internal

import (
	"context"

	"github.com/Shopify/sarama"
	fsAPI "github.com/matrix-org/dendrite/federationsender/api"
	"github.com/matrix-org/dendrite/internal/caching"
	"github.com/matrix-org/dendrite/internal/config"
	"github.com/matrix-org/dendrite/roomserver/acls"
	"github.com/matrix-org/dendrite/roomserver/api"
	"github.com/matrix-org/dendrite/roomserver/internal/input"
	"github.com/matrix-org/dendrite/roomserver/internal/perform"
	"github.com/matrix-org/dendrite/roomserver/internal/query"
	"github.com/matrix-org/dendrite/roomserver/storage"
	"github.com/matrix-org/gomatrixserverlib"
)

// RoomserverInternalAPI is an implementation of api.RoomserverInternalAPI
type RoomserverInternalAPI struct {
	*input.Inputer
	*query.Queryer
	*perform.Inviter
	*perform.Joiner
	*perform.Leaver
	*perform.Publisher
	*perform.Backfiller
	DB                   storage.Database
	Cfg                  *config.RoomServer
	Producer             sarama.SyncProducer
	Cache                caching.RoomServerCaches
	ServerName           gomatrixserverlib.ServerName
	KeyRing              gomatrixserverlib.JSONVerifier
	fsAPI                fsAPI.FederationSenderInternalAPI
	OutputRoomEventTopic string // Kafka topic for new output room events
}

func NewRoomserverAPI(
	cfg *config.RoomServer, roomserverDB storage.Database, producer sarama.SyncProducer,
	outputRoomEventTopic string, caches caching.RoomServerCaches,
	keyRing gomatrixserverlib.JSONVerifier,
) *RoomserverInternalAPI {
	a := &RoomserverInternalAPI{
		DB:         roomserverDB,
		Cfg:        cfg,
		Cache:      caches,
		ServerName: cfg.Matrix.ServerName,
		KeyRing:    keyRing,
		Queryer: &query.Queryer{
			DB:         roomserverDB,
			Cache:      caches,
			ServerACLs: acls.NewServerACLs(roomserverDB),
		},
		Inputer: &input.Inputer{
			DB:                   roomserverDB,
			OutputRoomEventTopic: outputRoomEventTopic,
			Producer:             producer,
			ServerName:           cfg.Matrix.ServerName,
		},
		// perform-er structs get initialised when we have a federation sender to use
	}
	return a
}

// SetFederationSenderInputAPI passes in a federation sender input API reference
// so that we can avoid the chicken-and-egg problem of both the roomserver input API
// and the federation sender input API being interdependent.
func (r *RoomserverInternalAPI) SetFederationSenderAPI(fsAPI fsAPI.FederationSenderInternalAPI) {
	r.fsAPI = fsAPI

	r.Inviter = &perform.Inviter{
		DB:      r.DB,
		Cfg:     r.Cfg,
		FSAPI:   r.fsAPI,
		Inputer: r.Inputer,
	}
	r.Joiner = &perform.Joiner{
		ServerName: r.Cfg.Matrix.ServerName,
		Cfg:        r.Cfg,
		DB:         r.DB,
		FSAPI:      r.fsAPI,
		Inputer:    r.Inputer,
	}
	r.Leaver = &perform.Leaver{
		Cfg:     r.Cfg,
		DB:      r.DB,
		FSAPI:   r.fsAPI,
		Inputer: r.Inputer,
	}
	r.Publisher = &perform.Publisher{
		DB: r.DB,
	}
	r.Backfiller = &perform.Backfiller{
		ServerName: r.ServerName,
		DB:         r.DB,
		FSAPI:      r.fsAPI,
		KeyRing:    r.KeyRing,
	}
}

func (r *RoomserverInternalAPI) PerformInvite(
	ctx context.Context,
	req *api.PerformInviteRequest,
	res *api.PerformInviteResponse,
) error {
	outputEvents, err := r.Inviter.PerformInvite(ctx, req, res)
	if err != nil {
		return err
	}
	if len(outputEvents) == 0 {
		return nil
	}
	return r.WriteOutputEvents(req.Event.RoomID(), outputEvents)
}

func (r *RoomserverInternalAPI) PerformLeave(
	ctx context.Context,
	req *api.PerformLeaveRequest,
	res *api.PerformLeaveResponse,
) error {
	outputEvents, err := r.Leaver.PerformLeave(ctx, req, res)
	if err != nil {
		return err
	}
	if len(outputEvents) == 0 {
		return nil
	}
	return r.WriteOutputEvents(req.RoomID, outputEvents)
}