package db

import (
	"context"

	"github.com/pkg/errors"
	"github.com/uptrace/bun"
)

type League struct {
	bun.BaseModel `bun:"table:leagues,alias:l"`

	ID          int    `bun:"id,pk,autoincrement"`
	Name        string `bun:"name,unique,notnull"`
	ShortName   string `bun:"short_name,unique,notnull"`
	Description string `bun:"description"`

	Seasons []Season `bun:"m2m:season_leagues,join:League=Season"`
	Teams   []Team   `bun:"m2m:team_participations,join:League=Team"`
}

type SeasonLeague struct {
	SeasonID int     `bun:",pk"`
	Season   *Season `bun:"rel:belongs-to,join:season_id=id"`
	LeagueID int     `bun:",pk"`
	League   *League `bun:"rel:belongs-to,join:league_id=id"`
}

func GetLeagues(ctx context.Context, tx bun.Tx) ([]*League, error) {
	return GetList[League](tx).Relation("Seasons").GetAll(ctx)
}

func GetLeague(ctx context.Context, tx bun.Tx, shortname string) (*League, error) {
	if shortname == "" {
		return nil, errors.New("shortname cannot be empty")
	}
	return GetByField[League](tx, "short_name", shortname).Relation("Seasons").Get(ctx)
}

// GetSeasonLeague retrieves a specific season-league combination with teams
func GetSeasonLeague(ctx context.Context, tx bun.Tx, seasonShortName, leagueShortName string) (*Season, *League, []*Team, error) {
	if seasonShortName == "" {
		return nil, nil, nil, errors.New("season short_name cannot be empty")
	}
	if leagueShortName == "" {
		return nil, nil, nil, errors.New("league short_name cannot be empty")
	}

	// Get the season
	season, err := GetSeason(ctx, tx, seasonShortName)
	if err != nil {
		return nil, nil, nil, errors.Wrap(err, "GetSeason")
	}

	// Get the league
	league, err := GetLeague(ctx, tx, leagueShortName)
	if err != nil {
		return nil, nil, nil, errors.Wrap(err, "GetLeague")
	}
	if season == nil || league == nil || !season.HasLeague(league.ID) {
		return nil, nil, nil, nil
	}

	// Get all teams participating in this season+league
	var teams []*Team
	err = tx.NewSelect().
		Model(&teams).
		Join("INNER JOIN team_participations AS tp ON tp.team_id = t.id").
		Where("tp.season_id = ? AND tp.league_id = ?", season.ID, league.ID).
		Order("t.name ASC").
		Scan(ctx)
	if err != nil {
		return nil, nil, nil, errors.Wrap(err, "tx.Select teams")
	}

	return season, league, teams, nil
}