package db

import (
	"database/sql"
	"errors"
	"fmt"

	_ "github.com/mattn/go-sqlite3"
)

type Database struct {
	*sql.DB
}

type Match struct {
	MatchNumber, Round     int32
	CompLevel              string
	R1, R2, R3, B1, B2, B3 int32
	// Each of these variables holds the matchID of the corresponding Stats row
	r1ID, r2ID, r3ID, b1ID, b2ID, b3ID int
}

type Stats struct {
	TeamNumber, MatchNumber                                      int32
	ShotsMissed, UpperGoalShots, LowerGoalShots                  int32
	ShotsMissedAuto, UpperGoalAuto, LowerGoalAuto, PlayedDefense int32
	Climbing                                                     int32
}

// Opens a database at the specified path. If the path refers to a non-existent
// file, the database will be created and initialized with empty tables.
func NewDatabase(path string) (*Database, error) {
	var err error
	database := new(Database)
	database.DB, err = sql.Open("sqlite3", path)
	if err != nil {
		return nil, errors.New(fmt.Sprint("Failed to create postgres db: ", err))
	}

	statement, err := database.Prepare("CREATE TABLE IF NOT EXISTS matches (" +
		"id INTEGER PRIMARY KEY, " +
		"MatchNumber INTEGER, " +
		"Round INTEGER, " +
		"CompLevel INTEGER, " +
		"R1 INTEGER, " +
		"R2 INTEGER, " +
		"R3 INTEGER, " +
		"B1 INTEGER, " +
		"B2 INTEGER, " +
		"B3 INTEGER, " +
		"r1ID INTEGER, " +
		"r2ID INTEGER, " +
		"r3ID INTEGER, " +
		"b1ID INTEGER, " +
		"b2ID INTEGER, " +
		"b3ID INTEGER)")
	if err != nil {
		return nil, errors.New(fmt.Sprint("Failed to prepare matches table creation: ", err))
	}
	defer statement.Close()

	_, err = statement.Exec()
	if err != nil {
		return nil, errors.New(fmt.Sprint("Failed to create matches table: ", err))
	}

	statement, err = database.Prepare("CREATE TABLE IF NOT EXISTS team_match_stats (" +
		"id INTEGER PRIMARY KEY, " +
		"TeamNumber INTEGER, " +
		"MatchNumber INTEGER, " +
		"ShotsMissed INTEGER, " +
		"UpperGoalShots INTEGER, " +
		"LowerGoalShots INTEGER, " +
		"ShotsMissedAuto INTEGER, " +
		"UpperGoalAuto INTEGER, " +
		"LowerGoalAuto INTEGER, " +
		"PlayedDefense INTEGER, " +
		"Climbing INTEGER)")
	if err != nil {
		return nil, errors.New(fmt.Sprint("Failed to prepare stats table creation: ", err))
	}
	defer statement.Close()

	_, err = statement.Exec()
	if err != nil {
		return nil, errors.New(fmt.Sprint("Failed to create team_match_stats table: ", err))
	}

	return database, nil
}

func (database *Database) Delete() error {
	statement, err := database.Prepare("DROP TABLE IF EXISTS matches")
	if err != nil {
		return errors.New(fmt.Sprint("Failed to prepare dropping matches table: ", err))
	}
	_, err = statement.Exec()
	if err != nil {
		return errors.New(fmt.Sprint("Failed to drop matches table: ", err))
	}

	statement, err = database.Prepare("DROP TABLE IF EXISTS team_match_stats")
	if err != nil {
		return errors.New(fmt.Sprint("Failed to prepare dropping stats table: ", err))
	}
	_, err = statement.Exec()
	if err != nil {
		return errors.New(fmt.Sprint("Failed to drop stats table: ", err))
	}
	return nil
}

// This function will also populate the Stats table with six empty rows every time a match is added
func (database *Database) AddToMatch(m Match) error {
	statement, err := database.Prepare("INSERT INTO team_match_stats(" +
		"TeamNumber, MatchNumber, " +
		"ShotsMissed, UpperGoalShots, LowerGoalShots, " +
		"ShotsMissedAuto, UpperGoalAuto, LowerGoalAuto, " +
		"PlayedDefense, Climbing) " +
		"VALUES (" +
		"?, ?, " +
		"?, ?, ?, " +
		"?, ?, ?, " +
		"?, ?)")
	if err != nil {
		return errors.New(fmt.Sprint("Failed to prepare insertion into stats database: ", err))
	}
	defer statement.Close()

	var rowIds [6]int64
	for i, TeamNumber := range []int32{m.R1, m.R2, m.R3, m.B1, m.B2, m.B3} {
		result, err := statement.Exec(TeamNumber, m.MatchNumber, 0, 0, 0, 0, 0, 0, 0, 0)
		if err != nil {
			return errors.New(fmt.Sprint("Failed to insert stats: ", err))
		}
		rowIds[i], err = result.LastInsertId()
		if err != nil {
			return errors.New(fmt.Sprint("Failed to get last insert ID: ", err))
		}
	}

	statement, err = database.Prepare("INSERT INTO matches(" +
		"MatchNumber, Round, CompLevel, " +
		"R1, R2, R3, B1, B2, B3, " +
		"r1ID, r2ID, r3ID, b1ID, b2ID, b3ID) " +
		"VALUES (" +
		"?, ?, ?, " +
		"?, ?, ?, ?, ?, ?, " +
		"?, ?, ?, ?, ?, ?)")
	if err != nil {
		return errors.New(fmt.Sprint("Failed to prepare insertion into match database: ", err))
	}
	defer statement.Close()

	_, err = statement.Exec(m.MatchNumber, m.Round, m.CompLevel,
		m.R1, m.R2, m.R3, m.B1, m.B2, m.B3,
		rowIds[0], rowIds[1], rowIds[2], rowIds[3], rowIds[4], rowIds[5])
	if err != nil {
		return errors.New(fmt.Sprint("Failed to insert into match database: ", err))
	}
	return nil
}

func (database *Database) AddToStats(s Stats) error {
	statement, err := database.Prepare("UPDATE team_match_stats SET " +
		"TeamNumber = ?, MatchNumber = ?, " +
		"ShotsMissed = ?, UpperGoalShots = ?, LowerGoalShots = ?, " +
		"ShotsMissedAuto = ?, UpperGoalAuto = ?, LowerGoalAuto = ?, " +
		"PlayedDefense = ?, Climbing = ? " +
		"WHERE MatchNumber = ? AND TeamNumber = ?")
	if err != nil {
		return errors.New(fmt.Sprint("Failed to prepare stats update statement: ", err))
	}
	defer statement.Close()

	result, err := statement.Exec(s.TeamNumber, s.MatchNumber,
		s.ShotsMissed, s.UpperGoalShots, s.LowerGoalShots,
		s.ShotsMissedAuto, s.UpperGoalAuto, s.LowerGoalAuto,
		s.PlayedDefense, s.Climbing,
		s.MatchNumber, s.TeamNumber)
	if err != nil {
		return errors.New(fmt.Sprint("Failed to update stats database: ", err))
	}

	numRowsAffected, err := result.RowsAffected()
	if err != nil {
		return errors.New(fmt.Sprint("Failed to query rows affected: ", err))
	}
	if numRowsAffected == 0 {
		return errors.New(fmt.Sprint(
			"Failed to find team ", s.TeamNumber,
			" in match ", s.MatchNumber, " in the schedule."))
	}
	return nil
}

func (database *Database) ReturnMatches() ([]Match, error) {
	rows, err := database.Query("SELECT * FROM matches")
	if err != nil {
		return nil, errors.New(fmt.Sprint("Failed to select from matches: ", err))
	}
	defer rows.Close()

	matches := make([]Match, 0)
	for rows.Next() {
		var match Match
		var id int
		err := rows.Scan(&id, &match.MatchNumber, &match.Round, &match.CompLevel,
			&match.R1, &match.R2, &match.R3, &match.B1, &match.B2, &match.B3,
			&match.r1ID, &match.r2ID, &match.r3ID, &match.b1ID, &match.b2ID, &match.b3ID)
		if err != nil {
			return nil, errors.New(fmt.Sprint("Failed to scan from matches: ", err))
		}
		matches = append(matches, match)
	}
	return matches, nil
}

func (database *Database) ReturnStats() ([]Stats, error) {
	rows, err := database.Query("SELECT * FROM team_match_stats")
	if err != nil {
		return nil, errors.New(fmt.Sprint("Failed to SELECT * FROM team_match_stats: ", err))
	}
	defer rows.Close()

	teams := make([]Stats, 0)
	for rows.Next() {
		var team Stats
		var id int
		err = rows.Scan(&id, &team.TeamNumber, &team.MatchNumber,
			&team.ShotsMissed, &team.UpperGoalShots, &team.LowerGoalShots,
			&team.ShotsMissedAuto, &team.UpperGoalAuto, &team.LowerGoalAuto,
			&team.PlayedDefense, &team.Climbing)
		if err != nil {
			return nil, errors.New(fmt.Sprint("Failed to scan from stats: ", err))
		}
		teams = append(teams, team)
	}
	return teams, nil
}

func (database *Database) QueryMatches(teamNumber_ int32) ([]Match, error) {
	rows, err := database.Query("SELECT * FROM matches WHERE "+
		"R1 = ? OR R2 = ? OR R3 = ? OR B1 = ? OR B2 = ? OR B3 = ?",
		teamNumber_, teamNumber_, teamNumber_, teamNumber_, teamNumber_, teamNumber_)
	if err != nil {
		return nil, errors.New(fmt.Sprint("Failed to select from matches for team: ", err))
	}
	defer rows.Close()

	var matches []Match
	for rows.Next() {
		var match Match
		var id int
		err = rows.Scan(&id, &match.MatchNumber, &match.Round, &match.CompLevel,
			&match.R1, &match.R2, &match.R3, &match.B1, &match.B2, &match.B3,
			&match.r1ID, &match.r2ID, &match.r3ID, &match.b1ID, &match.b2ID, &match.b3ID)
		if err != nil {
			return nil, errors.New(fmt.Sprint("Failed to scan from matches: ", err))
		}
		matches = append(matches, match)
	}
	return matches, nil
}

func (database *Database) QueryStats(teamNumber_ int) ([]Stats, error) {
	rows, err := database.Query("SELECT * FROM team_match_stats WHERE TeamNumber = ?", teamNumber_)
	if err != nil {
		return nil, errors.New(fmt.Sprint("Failed to select from stats: ", err))
	}
	defer rows.Close()

	var teams []Stats
	for rows.Next() {
		var team Stats
		var id int
		err = rows.Scan(&id, &team.TeamNumber, &team.MatchNumber,
			&team.ShotsMissed, &team.UpperGoalShots, &team.LowerGoalShots,
			&team.ShotsMissedAuto, &team.UpperGoalAuto, &team.LowerGoalAuto,
			&team.PlayedDefense, &team.Climbing)
		if err != nil {
			return nil, errors.New(fmt.Sprint("Failed to scan from stats: ", err))
		}
		teams = append(teams, team)
	}
	return teams, nil
}