package shared

import (
	"context"
	"database/sql"

	"github.com/matrix-org/dendrite/internal"
	"github.com/matrix-org/dendrite/roomserver/storage/tables"
	"github.com/matrix-org/dendrite/roomserver/types"
	"github.com/matrix-org/gomatrixserverlib"
)

type Database struct {
	DB                  *sql.DB
	EventsTable         tables.Events
	EventJSONTable      tables.EventJSON
	EventTypesTable     tables.EventTypes
	EventStateKeysTable tables.EventStateKeys
	RoomsTable          tables.Rooms
}

// EventTypeNIDs implements state.RoomStateDatabase
func (d *Database) EventTypeNIDs(
	ctx context.Context, eventTypes []string,
) (map[string]types.EventTypeNID, error) {
	return d.EventTypesTable.BulkSelectEventTypeNID(ctx, eventTypes)
}

// EventStateKeys implements query.RoomserverQueryAPIDatabase
func (d *Database) EventStateKeys(
	ctx context.Context, eventStateKeyNIDs []types.EventStateKeyNID,
) (map[types.EventStateKeyNID]string, error) {
	return d.EventStateKeysTable.BulkSelectEventStateKey(ctx, eventStateKeyNIDs)
}

// EventStateKeyNIDs implements state.RoomStateDatabase
func (d *Database) EventStateKeyNIDs(
	ctx context.Context, eventStateKeys []string,
) (map[string]types.EventStateKeyNID, error) {
	return d.EventStateKeysTable.BulkSelectEventStateKeyNID(ctx, eventStateKeys)
}

// StateEntriesForEventIDs implements input.EventDatabase
func (d *Database) StateEntriesForEventIDs(
	ctx context.Context, eventIDs []string,
) ([]types.StateEntry, error) {
	return d.EventsTable.BulkSelectStateEventByID(ctx, eventIDs)
}

// EventNIDs implements query.RoomserverQueryAPIDatabase
func (d *Database) EventNIDs(
	ctx context.Context, eventIDs []string,
) (map[string]types.EventNID, error) {
	return d.EventsTable.BulkSelectEventNID(ctx, eventIDs)
}

// SetState implements input.EventDatabase
func (d *Database) SetState(
	ctx context.Context, eventNID types.EventNID, stateNID types.StateSnapshotNID,
) error {
	return d.EventsTable.UpdateEventState(ctx, eventNID, stateNID)
}

// StateAtEventIDs implements input.EventDatabase
func (d *Database) StateAtEventIDs(
	ctx context.Context, eventIDs []string,
) ([]types.StateAtEvent, error) {
	return d.EventsTable.BulkSelectStateAtEventByID(ctx, eventIDs)
}

// SnapshotNIDFromEventID implements state.RoomStateDatabase
func (d *Database) SnapshotNIDFromEventID(
	ctx context.Context, eventID string,
) (types.StateSnapshotNID, error) {
	_, stateNID, err := d.EventsTable.SelectEvent(ctx, nil, eventID)
	return stateNID, err
}

// EventIDs implements input.RoomEventDatabase
func (d *Database) EventIDs(
	ctx context.Context, eventNIDs []types.EventNID,
) (map[types.EventNID]string, error) {
	return d.EventsTable.BulkSelectEventID(ctx, eventNIDs)
}

// RoomNID implements query.RoomserverQueryAPIDB
func (d *Database) RoomNID(ctx context.Context, roomID string) (types.RoomNID, error) {
	roomNID, err := d.RoomsTable.SelectRoomNID(ctx, nil, roomID)
	if err == sql.ErrNoRows {
		return 0, nil
	}
	return roomNID, err
}

// RoomNIDExcludingStubs implements query.RoomserverQueryAPIDB
func (d *Database) RoomNIDExcludingStubs(ctx context.Context, roomID string) (roomNID types.RoomNID, err error) {
	roomNID, err = d.RoomNID(ctx, roomID)
	if err != nil {
		return
	}
	latestEvents, _, err := d.RoomsTable.SelectLatestEventNIDs(ctx, nil, roomNID)
	if err != nil {
		return
	}
	if len(latestEvents) == 0 {
		roomNID = 0
		return
	}
	return
}

// LatestEventIDs implements query.RoomserverQueryAPIDatabase
func (d *Database) LatestEventIDs(
	ctx context.Context, roomNID types.RoomNID,
) (references []gomatrixserverlib.EventReference, currentStateSnapshotNID types.StateSnapshotNID, depth int64, err error) {
	err = internal.WithTransaction(d.DB, func(txn *sql.Tx) error {
		var eventNIDs []types.EventNID
		eventNIDs, currentStateSnapshotNID, err = d.RoomsTable.SelectLatestEventNIDs(ctx, txn, roomNID)
		if err != nil {
			return err
		}
		references, err = d.EventsTable.BulkSelectEventReference(ctx, txn, eventNIDs)
		if err != nil {
			return err
		}
		depth, err = d.EventsTable.SelectMaxEventDepth(ctx, txn, eventNIDs)
		if err != nil {
			return err
		}
		return nil
	})
	return
}

func (d *Database) GetRoomVersionForRoom(
	ctx context.Context, roomID string,
) (gomatrixserverlib.RoomVersion, error) {
	return d.RoomsTable.SelectRoomVersionForRoomID(
		ctx, nil, roomID,
	)
}

func (d *Database) GetRoomVersionForRoomNID(
	ctx context.Context, roomNID types.RoomNID,
) (gomatrixserverlib.RoomVersion, error) {
	return d.RoomsTable.SelectRoomVersionForRoomNID(
		ctx, nil, roomNID,
	)
}