package event

import (
	"fmt"

	"git.nutfactory.org/hoernschen/Matrix/utils/database"
)

func CreateRoomMember(roomId string, userId string, server string) (err error) {
	sqlStmt := fmt.Sprintf(`INSERT INTO roomMember
		(roomId, userId, server)
		VALUES
		(?, ?, ?)`)

	tx, err := database.DB.Begin()
	if err != nil {
		return
	}

	stmt, err := tx.Prepare(sqlStmt)
	if err != nil {
		return
	}
	defer stmt.Close()

	_, err = stmt.Exec(roomId, userId, server)
	if err != nil {
		tx.Rollback()
		return
	}
	tx.Commit()
	return
}

func CreateParents(eventId string, parentIds map[string]EventHash) (err error) {
	sqlStmt := fmt.Sprintf(`INSERT INTO parent
		(eventId, parentId)
		VALUES
		(?, ?)`)

	tx, err := database.DB.Begin()
	if err != nil {
		return
	}

	stmt, err := tx.Prepare(sqlStmt)
	if err != nil {
		return
	}
	defer stmt.Close()

	for parentId, _ := range parentIds {
		_, err = stmt.Exec(
			eventId,
			parentId,
		)
		if err != nil {
			tx.Rollback()
			return
		}
	}

	tx.Commit()

	return
}

func CreateAuthEvents(eventId string, authEventIds map[string]EventHash) (err error) {
	sqlStmt := fmt.Sprintf(`INSERT INTO authEvent
		(eventId, authEventId)
		VALUES
		(?, ?)`)

	tx, err := database.DB.Begin()
	if err != nil {
		return
	}

	stmt, err := tx.Prepare(sqlStmt)
	if err != nil {
		return
	}
	defer stmt.Close()

	for authEventId, _ := range authEventIds {
		_, err = stmt.Exec(
			eventId,
			authEventId,
		)
		if err != nil {
			tx.Rollback()
			return
		}
	}

	tx.Commit()

	return
}

func CreateEvent(event *Event, txnId string) (err error) {
	sqlStmt := fmt.Sprintf(`INSERT INTO event
		(id, roomId, txnId, sender, origin, timestamp, eventType, stateKey, content, depth, hash, signature)
		VALUES
		(?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`)

	tx, err := database.DB.Begin()
	if err != nil {
		return
	}

	stmt, err := tx.Prepare(sqlStmt)
	if err != nil {
		return
	}
	defer stmt.Close()

	signatures := ""
	for _, signature := range event.Signatures[event.Origin] {
		signatures = signature
	}

	_, err = stmt.Exec(
		event.Id,
		event.RoomId,
		txnId,
		event.Sender,
		event.Origin,
		event.Timestamp,
		event.EventType,
		event.StateKey,
		event.Content,
		event.Depth,
		event.Hashes.SHA256,
		signatures,
	)
	if err != nil {
		tx.Rollback()
		return
	}
	tx.Commit()

	err = CreateParents(event.Id, event.PrevEventHashes)
	if err != nil {
		return
	}

	err = CreateAuthEvents(event.Id, event.AuthEventHashes)
	if err != nil {
		return
	}

	return
}

func CreateEventsFromTransaction(txnId string, pdus map[string]*Event) (err error) {
	sqlStmt := fmt.Sprintf(`INSERT INTO event
		(id, roomId, txnId, sender, origin, timestamp, eventType, stateKey, content, depth, hash, signature)
		VALUES
		(?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`)

	tx, err := database.DB.Begin()
	if err != nil {
		return
	}

	stmt, err := tx.Prepare(sqlStmt)
	if err != nil {
		return
	}
	defer stmt.Close()

	for _, pdu := range pdus {
		signatures := ""
		for _, signature := range pdu.Signatures[pdu.Origin] {
			signatures = signature
		}

		_, err = stmt.Exec(
			pdu.Id,
			pdu.RoomId,
			txnId,
			pdu.Sender,
			pdu.Origin,
			pdu.Timestamp,
			pdu.EventType,
			pdu.StateKey,
			pdu.Content,
			pdu.Depth,
			pdu.Hashes.SHA256,
			signatures,
		)
		if err != nil {
			tx.Rollback()
			return
		}

		err = CreateParents(pdu.Id, pdu.PrevEventHashes)
		if err != nil {
			return
		}

		err = CreateAuthEvents(pdu.Id, pdu.AuthEventHashes)
		if err != nil {
			return
		}
	}

	tx.Commit()
	return
}

func ReadEventHash(id string) (hash string, err error) {
	queryStmt := fmt.Sprintf(`SELECT hash 
		FROM event
		WHERE id = '%s'`, id)

	rows, err := database.DB.Query(queryStmt)
	if err != nil {
		return
	}

	defer rows.Close()

	if rows.Next() {
		err = rows.Scan(hash)
		if err != nil {
			return
		}
	}

	return
}

func ReadRoomMembers(roomId string) (roomMembers []string, err error) {
	queryStmt := fmt.Sprintf(`SELECT userId
		FROM roomMember
		WHERE roomId = '%s'`, roomId)

	rows, err := database.DB.Query(queryStmt)
	if err != nil {
		return
	}

	defer rows.Close()

	roomMembers = []string{}

	for rows.Next() {
		var foundUser string
		err = rows.Scan(&foundUser)
		if err != nil {
			return
		}
		roomMembers = append(roomMembers, foundUser)
	}

	return
}

func ReadServers(roomId string) (servers []string, err error) {
	queryStmt := fmt.Sprintf(`SELECT DISTINCT server
		FROM roomMember
		WHERE roomId = '%s'`, roomId)

	rows, err := database.DB.Query(queryStmt)
	if err != nil {
		return
	}

	defer rows.Close()

	servers = []string{}

	for rows.Next() {
		var foundUser string
		err = rows.Scan(&foundUser)
		if err != nil {
			return
		}
		servers = append(servers, foundUser)
	}

	return
}

func ReadParents(eventId string) (parents map[string]EventHash, err error) {
	queryStmt := fmt.Sprintf(`SELECT e.id, e.hash 
		FROM event as e
		join parent as p on e.id = p.parentId
		WHERE p.eventId = '%s'`, eventId)

	rows, err := database.DB.Query(queryStmt)
	if err != nil {
		return
	}

	defer rows.Close()

	parents = make(map[string]EventHash)

	for rows.Next() {
		var eventId string
		var foundEvent EventHash

		err = rows.Scan(&eventId,
			&foundEvent.SHA256,
		)

		if err != nil {
			return
		}

		parents[eventId] = foundEvent
	}

	return
}

func ReadEventsWithoutChild(roomId string) (events map[string]EventHash, depth int, err error) {
	queryStmt := fmt.Sprintf(`SELECT e.id, e.hash, e.depth
		FROM event as e
		LEFT JOIN parent as p on e.id = p.parentId
		WHERE p.eventId IS NULL AND e.roomId = '%s'`, roomId)

	rows, err := database.DB.Query(queryStmt)
	if err != nil {
		return
	}

	defer rows.Close()

	events = make(map[string]EventHash)

	for rows.Next() {
		var eventId string
		var foundEvent EventHash
		var foundDepth int
		err = rows.Scan(&eventId,
			&foundEvent.SHA256,
			&foundDepth,
		)

		if foundDepth > depth {
			depth = foundDepth
		}

		if err != nil {
			return
		}

		events[eventId] = foundEvent
	}

	return
}

func ReadAuthEvents(eventId string) (authEvents map[string]EventHash, err error) {
	queryStmt := fmt.Sprintf(`SELECT e.id, e.hash 
		FROM event as e
		join authEvent as a on e.id = a.authEventId
		WHERE a.eventId = '%s'`, eventId)

	rows, err := database.DB.Query(queryStmt)
	if err != nil {
		return
	}

	defer rows.Close()

	authEvents = make(map[string]EventHash)

	for rows.Next() {
		var eventId string
		var foundEvent EventHash

		err = rows.Scan(&eventId,
			&foundEvent.SHA256,
		)

		if err != nil {
			return
		}

		authEvents[eventId] = foundEvent
	}

	return
}

func ReadEvent(id string) (foundEvent *Event, err error) {
	queryStmt := fmt.Sprintf(`SELECT id, roomId, txnId, sender, origin, timestamp, eventType, stateKey, content, depth, hash, signature
		FROM event
		WHERE id = '%s'`, id)

	rows, err := database.DB.Query(queryStmt)
	if err != nil {
		return
	}

	defer rows.Close()

	if rows.Next() {
		foundEvent = &Event{}
		var signature string
		err = rows.Scan(&foundEvent.Id,
			&foundEvent.RoomId,
			&foundEvent.Unsigned.TransactionId,
			&foundEvent.Sender,
			&foundEvent.Origin,
			&foundEvent.Timestamp,
			&foundEvent.EventType,
			&foundEvent.StateKey,
			&foundEvent.Content,
			&foundEvent.Depth,
			&foundEvent.Hashes.SHA256,
			&signature,
		)

		foundEvent.Signatures = make(map[string]map[string]string)
		foundEvent.Signatures[foundEvent.Origin] = make(map[string]string)
		foundEvent.Signatures[foundEvent.Origin]["ed25519:1"] = signature

		if err != nil {
			return
		}

		foundEvent.PrevEventHashes, err = ReadParents(foundEvent.Id)
		if err != nil {
			return
		}

		foundEvent.AuthEventHashes, err = ReadAuthEvents(foundEvent.Id)
		if err != nil {
			return
		}
	}

	return
}

func ReadStateEvent(roomId string, eventType string, stateKey string) (foundEvent *Event, err error) {
	queryStmt := fmt.Sprintf(`SELECT id, roomId, txnId, sender, origin, timestamp, eventType, stateKey, content, depth, hash, signature 
		FROM event
		WHERE roomId = '%s' 
		AND eventType = '%s'
		AND stateKey = '%s'`, roomId, eventType, stateKey)

	if stateKey == "" {
		queryStmt = fmt.Sprintf(`SELECT id, roomId, txnId, sender, origin, timestamp, eventType, stateKey, content, depth, hash, signature 
			FROM event
			WHERE roomId = '%s' 
			AND eventType = '%s'`, roomId, eventType)
	}

	rows, err := database.DB.Query(queryStmt)
	if err != nil {
		return
	}

	defer rows.Close()

	if rows.Next() {
		foundEvent = &Event{}
		var signature string
		err = rows.Scan(&foundEvent.Id,
			&foundEvent.RoomId,
			&foundEvent.Unsigned.TransactionId,
			&foundEvent.Sender,
			&foundEvent.Origin,
			&foundEvent.Timestamp,
			&foundEvent.EventType,
			&foundEvent.StateKey,
			&foundEvent.Content,
			&foundEvent.Depth,
			&foundEvent.Hashes.SHA256,
			&signature,
		)

		foundEvent.Signatures = make(map[string]map[string]string)
		foundEvent.Signatures[foundEvent.Origin] = make(map[string]string)
		foundEvent.Signatures[foundEvent.Origin]["ed25519:1"] = signature

		if err != nil {
			return
		}

		foundEvent.PrevEventHashes, err = ReadParents(foundEvent.Id)
		if err != nil {
			return
		}

		foundEvent.AuthEventHashes, err = ReadAuthEvents(foundEvent.Id)
		if err != nil {
			return
		}
	}

	return
}

func ReadStateEvents(roomId string, eventType string) (foundEvents []*Event, err error) {
	queryStmt := fmt.Sprintf(`SELECT id, roomId, txnId, sender, origin, timestamp, eventType, stateKey, content, depth, hash, signature 
		FROM event
		WHERE roomId = '%s' 
		AND eventType = '%s'`, roomId, eventType)

	rows, err := database.DB.Query(queryStmt)
	if err != nil {
		return
	}

	defer rows.Close()

	for rows.Next() {
		foundEvent := &Event{}
		var signature string
		err = rows.Scan(&foundEvent.Id,
			&foundEvent.RoomId,
			&foundEvent.Unsigned.TransactionId,
			&foundEvent.Sender,
			&foundEvent.Origin,
			&foundEvent.Timestamp,
			&foundEvent.EventType,
			&foundEvent.StateKey,
			&foundEvent.Content,
			&foundEvent.Depth,
			&foundEvent.Hashes.SHA256,
			&signature,
		)

		foundEvent.Signatures = make(map[string]map[string]string)
		foundEvent.Signatures[foundEvent.Origin] = make(map[string]string)
		foundEvent.Signatures[foundEvent.Origin]["ed25519:1"] = signature

		if err != nil {
			return
		}

		foundEvent.PrevEventHashes, err = ReadParents(foundEvent.Id)
		if err != nil {
			return
		}

		foundEvent.AuthEventHashes, err = ReadAuthEvents(foundEvent.Id)
		if err != nil {
			return
		}

		foundEvents = append(foundEvents, foundEvent)
	}

	return
}

func ReadEventsFromRoom(roomId string) (events map[string]*Event, err error) {
	queryStmt := fmt.Sprintf(`SELECT id, roomId, txnId, sender, origin, timestamp, eventType, stateKey, content, depth, hash, signature 
		FROM event
		WHERE roomId = '%s'`, roomId)

	rows, err := database.DB.Query(queryStmt)
	if err != nil {
		return
	}

	defer rows.Close()

	events = make(map[string]*Event)

	for rows.Next() {
		foundEvent := &Event{}
		var signature string
		err = rows.Scan(&foundEvent.Id,
			&foundEvent.RoomId,
			&foundEvent.Unsigned.TransactionId,
			&foundEvent.Sender,
			&foundEvent.Origin,
			&foundEvent.Timestamp,
			&foundEvent.EventType,
			&foundEvent.StateKey,
			&foundEvent.Content,
			&foundEvent.Depth,
			&foundEvent.Hashes.SHA256,
			&signature,
		)

		foundEvent.Signatures = make(map[string]map[string]string)
		foundEvent.Signatures[foundEvent.Origin] = make(map[string]string)
		foundEvent.Signatures[foundEvent.Origin]["ed25519:1"] = signature

		if err != nil {
			return
		}

		foundEvent.PrevEventHashes, err = ReadParents(foundEvent.Id)
		if err != nil {
			return
		}

		foundEvent.AuthEventHashes, err = ReadAuthEvents(foundEvent.Id)
		if err != nil {
			return
		}

		events[foundEvent.Id] = foundEvent
	}

	return
}

func ReadStateEventsFromRoom(roomId string) (events []*Event, err error) {
	queryStmt := fmt.Sprintf(`SELECT id, roomId, txnId, sender, origin, timestamp, eventType, stateKey, content, depth, hash, signature 
		FROM event
		WHERE eventType <> 'm.room.message' AND roomId = '%s'`, roomId)

	rows, err := database.DB.Query(queryStmt)
	if err != nil {
		return
	}

	defer rows.Close()

	for rows.Next() {
		foundEvent := &Event{}
		var signature string
		err = rows.Scan(&foundEvent.Id,
			&foundEvent.RoomId,
			&foundEvent.Unsigned.TransactionId,
			&foundEvent.Sender,
			&foundEvent.Origin,
			&foundEvent.Timestamp,
			&foundEvent.EventType,
			&foundEvent.StateKey,
			&foundEvent.Content,
			&foundEvent.Depth,
			&foundEvent.Hashes.SHA256,
			&signature,
		)

		foundEvent.Signatures = make(map[string]map[string]string)
		foundEvent.Signatures[foundEvent.Origin] = make(map[string]string)
		foundEvent.Signatures[foundEvent.Origin]["ed25519:1"] = signature

		if err != nil {
			return
		}

		foundEvent.PrevEventHashes, err = ReadParents(foundEvent.Id)
		if err != nil {
			return
		}

		foundEvent.AuthEventHashes, err = ReadAuthEvents(foundEvent.Id)
		if err != nil {
			return
		}

		events = append(events, foundEvent)
	}

	return
}

func ReadEventsFromTransaction(txnId string) (events []*Event, err error) {
	queryStmt := fmt.Sprintf(`SELECT id, roomId, txnId, sender, origin, timestamp, eventType, stateKey, content, depth, hash, signature 
		FROM event
		WHERE txnId = '%s'`, txnId)

	rows, err := database.DB.Query(queryStmt)
	if err != nil {
		return
	}

	defer rows.Close()

	for rows.Next() {
		foundEvent := &Event{}
		var signature string
		err = rows.Scan(&foundEvent.Id,
			&foundEvent.RoomId,
			&foundEvent.Unsigned.TransactionId,
			&foundEvent.Sender,
			&foundEvent.Origin,
			&foundEvent.Timestamp,
			&foundEvent.EventType,
			&foundEvent.StateKey,
			&foundEvent.Content,
			&foundEvent.Depth,
			&foundEvent.Hashes.SHA256,
			&signature,
		)

		foundEvent.Signatures = make(map[string]map[string]string)
		foundEvent.Signatures[foundEvent.Origin] = make(map[string]string)
		foundEvent.Signatures[foundEvent.Origin]["ed25519:1"] = signature

		if err != nil {
			return
		}

		foundEvent.PrevEventHashes, err = ReadParents(foundEvent.Id)
		if err != nil {
			return
		}

		foundEvent.AuthEventHashes, err = ReadAuthEvents(foundEvent.Id)
		if err != nil {
			return
		}

		events = append(events, foundEvent)
	}

	return
}

func UpdateEvent(event *Event) (err error) {
	sqlStmt := fmt.Sprintf(`UPDATE event SET
			eventType = ?,
			content = ?,
		WHERE id = ?`)

	tx, err := database.DB.Begin()
	if err != nil {
		return
	}

	stmt, err := tx.Prepare(sqlStmt)
	if err != nil {
		return
	}
	defer stmt.Close()

	_, err = stmt.Exec(
		event.EventType,
		event.Content,
		event.Id,
	)
	if err != nil {
		tx.Rollback()
		return
	}

	tx.Commit()
	return
}

func DeleteEvent(id string) (err error) {
	queryStmt := fmt.Sprintf(`DELETE FROM event 
		WHERE id = '%s'`, id)

	tx, err := database.DB.Begin()
	if err != nil {
		return
	}

	_, err = tx.Exec(queryStmt)
	if err != nil {
		tx.Rollback()
		return
	}

	err = DeleteParents(id)
	if err != nil {
		return
	}

	err = DeleteAuthEvents(id)
	if err != nil {
		return
	}

	tx.Commit()
	return
}

func DeleteParents(eventId string) (err error) {
	queryStmt := fmt.Sprintf(`DELETE FROM parent 
		WHERE eventId = '%s'`, eventId)

	tx, err := database.DB.Begin()
	if err != nil {
		return
	}

	_, err = tx.Exec(queryStmt)
	if err != nil {
		tx.Rollback()
		return
	}

	tx.Commit()
	return
}

func DeleteAuthEvents(eventId string) (err error) {
	queryStmt := fmt.Sprintf(`DELETE FROM authEvent 
		WHERE eventId = '%s'`, eventId)

	tx, err := database.DB.Begin()
	if err != nil {
		return
	}

	_, err = tx.Exec(queryStmt)
	if err != nil {
		tx.Rollback()
		return
	}

	tx.Commit()
	return
}