package store

import (
	"context"
	"database/sql"
	"errors"
	"time"

	"github.com/google/uuid"
	"github.com/jmoiron/sqlx"
)

type Round struct {
	ID       string     `db:"id" json:"id"`
	TopicID  string     `db:"topic_id" json:"topic_id"`
	RoundNo  int        `db:"round_no" json:"round_no"`
	OpenedAt time.Time  `db:"opened_at" json:"opened_at"`
	ClosedAt *time.Time `db:"closed_at" json:"closed_at,omitempty"`
}

type RoundStore struct {
	db *sqlx.DB
}

func NewRoundStore(db *sqlx.DB) *RoundStore { return &RoundStore{db: db} }

// Open creates the round-0 row for a topic entering `debating`. Subsequent
// rounds (1, 2, ...) are inserted by the round driver as the debate
// advances; we leave round-bumping logic outside the store so the policy
// (time-based? all-participants-posted?) can evolve without DB churn.
func (s *RoundStore) Open(ctx context.Context, topicID string, roundNo int) (*Round, error) {
	id := uuid.NewString()
	if _, err := s.db.ExecContext(ctx,
		`INSERT INTO rounds (id, topic_id, round_no) VALUES (?, ?, ?)`,
		id, topicID, roundNo); err != nil {
		return nil, err
	}
	var r Round
	if err := s.db.GetContext(ctx, &r, `SELECT * FROM rounds WHERE id = ?`, id); err != nil {
		return nil, err
	}
	return &r, nil
}

func (s *RoundStore) Latest(ctx context.Context, topicID string) (*Round, error) {
	var r Round
	err := s.db.GetContext(ctx, &r,
		`SELECT * FROM rounds WHERE topic_id = ? ORDER BY round_no DESC LIMIT 1`, topicID)
	if errors.Is(err, sql.ErrNoRows) {
		return nil, ErrNotFound
	}
	if err != nil {
		return nil, err
	}
	return &r, nil
}

func (s *RoundStore) ListByTopic(ctx context.Context, topicID string) ([]Round, error) {
	var rows []Round
	if err := s.db.SelectContext(ctx, &rows,
		`SELECT * FROM rounds WHERE topic_id = ? ORDER BY round_no ASC`, topicID); err != nil {
		return nil, err
	}
	return rows, nil
}