package db

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

	_ "github.com/jackc/pgx/stdlib"
)

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
	// The username of the person who collected these statistics.
	// "unknown" if submitted without logging in.
	// Empty if the stats have not yet been collected.
	CollectedBy string
}

type NotesData struct {
	TeamNumber int32
	Notes      []string
}

// Opens a database at the specified port on localhost. We currently don't
// support connecting to databases on other hosts.
func NewDatabase(user string, password string, port int) (*Database, error) {
	var err error
	database := new(Database)

	psqlInfo := fmt.Sprintf("postgres://%s:%s@localhost:%d/postgres", user, password, port)
	database.DB, err = sql.Open("pgx", psqlInfo)
	if err != nil {
		return nil, errors.New(fmt.Sprint("Failed to connect to postgres: ", err))
	}
	statement, err := database.Prepare("CREATE TABLE IF NOT EXISTS matches (" +
		"id SERIAL PRIMARY KEY, " +
		"MatchNumber INTEGER, " +
		"Round INTEGER, " +
		"CompLevel VARCHAR, " +
		"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 {
		database.Close()
		return nil, errors.New(fmt.Sprint("Failed to prepare matches table creation: ", err))
	}
	defer statement.Close()

	_, err = statement.Exec()
	if err != nil {
		database.Close()
		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 SERIAL PRIMARY KEY, " +
		"TeamNumber INTEGER, " +
		"MatchNumber INTEGER, " +
		"ShotsMissed INTEGER, " +
		"UpperGoalShots INTEGER, " +
		"LowerGoalShots INTEGER, " +
		"ShotsMissedAuto INTEGER, " +
		"UpperGoalAuto INTEGER, " +
		"LowerGoalAuto INTEGER, " +
		"PlayedDefense INTEGER, " +
		"Climbing INTEGER, " +
		"CollectedBy VARCHAR)")
	if err != nil {
		database.Close()
		return nil, errors.New(fmt.Sprint("Failed to prepare stats table creation: ", err))
	}
	defer statement.Close()

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

	statement, err = database.Prepare("CREATE TABLE IF NOT EXISTS team_notes (" +
		"id SERIAL PRIMARY KEY, " +
		"TeamNumber INTEGER, " +
		"Notes TEXT)")
	if err != nil {
		return nil, errors.New(fmt.Sprint("Failed to prepare notes table creation: ", err))
	}
	defer statement.Close()

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

	statement, err = database.Prepare("DROP TABLE IF EXISTS team_notes")
	if err != nil {
		return errors.New(fmt.Sprint("Failed to prepare dropping notes table: ", err))
	}
	_, err = statement.Exec()
	if err != nil {
		return errors.New(fmt.Sprint("Failed to drop notes 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, CollectedBy) " +
		"VALUES (" +
		"$1, $2, " +
		"$3, $4, $5, " +
		"$6, $7, $8, " +
		"$9, $10, $11) " +
		"RETURNING id")
	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} {
		row := statement.QueryRow(TeamNumber, m.MatchNumber, 0, 0, 0, 0, 0, 0, 0, 0, "")
		err = row.Scan(&rowIds[i])
		if err != nil {
			return errors.New(fmt.Sprint("Failed to insert stats: ", err))
		}
	}

	statement, err = database.Prepare("INSERT INTO matches(" +
		"MatchNumber, Round, CompLevel, " +
		"R1, R2, R3, B1, B2, B3, " +
		"r1ID, r2ID, r3ID, b1ID, b2ID, b3ID) " +
		"VALUES (" +
		"$1, $2, $3, " +
		"$4, $5, $6, $7, $8, $9, " +
		"$10, $11, $12, $13, $14, $15)")
	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 = $1, MatchNumber = $2, " +
		"ShotsMissed = $3, UpperGoalShots = $4, LowerGoalShots = $5, " +
		"ShotsMissedAuto = $6, UpperGoalAuto = $7, LowerGoalAuto = $8, " +
		"PlayedDefense = $9, Climbing = $10, CollectedBy = $11 " +
		"WHERE MatchNumber = $12 AND TeamNumber = $13")
	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.CollectedBy,
		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, &team.CollectedBy)
		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 = $1 OR R2 = $2 OR R3 = $3 OR B1 = $4 OR B2 = $5 OR B3 = $6",
		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 = $1", 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, &team.CollectedBy)
		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) QueryNotes(TeamNumber int32) (NotesData, error) {
	rows, err := database.Query("SELECT * FROM team_notes WHERE TeamNumber = $1", TeamNumber)
	if err != nil {
		return NotesData{}, errors.New(fmt.Sprint("Failed to select from notes: ", err))
	}
	defer rows.Close()

	var notes []string
	for rows.Next() {
		var id int32
		var data string
		err = rows.Scan(&id, &TeamNumber, &data)
		if err != nil {
			return NotesData{}, errors.New(fmt.Sprint("Failed to scan from notes: ", err))
		}
		notes = append(notes, data)
	}
	return NotesData{TeamNumber, notes}, nil
}

func (database *Database) AddNotes(data NotesData) error {
	if len(data.Notes) > 1 {
		return errors.New("Can only insert one row of notes at a time")
	}
	statement, err := database.Prepare("INSERT INTO " +
		"team_notes(TeamNumber, Notes)" +
		"VALUES ($1, $2)")
	if err != nil {
		return errors.New(fmt.Sprint("Failed to prepare insertion into notes table: ", err))
	}
	defer statement.Close()

	_, err = statement.Exec(data.TeamNumber, data.Notes[0])
	if err != nil {
		return errors.New(fmt.Sprint("Failed to insert into Notes database: ", err))
	}
	return nil
}