package store

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

	"g.fc.run/ai/byre/internal/api"
)

func (s *Store) SummaryReads(ctx context.Context, login string) (map[string]int64, error) {
	rows, err := s.db.QueryContext(ctx, `
		SELECT summary_reads.task_id, summary_reads.seq FROM summary_reads
		JOIN tasks ON tasks.id = summary_reads.task_id
		WHERE summary_reads.login = ? AND tasks.status = ?
	`, login, string(api.TaskStatusActive))
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	reads := map[string]int64{}
	for rows.Next() {
		taskID := ""
		seq := int64(0)
		err = rows.Scan(&taskID, &seq)
		if err != nil {
			return nil, err
		}
		reads[taskID] = seq
	}
	return reads, rows.Err()
}

func (s *Store) MarkSummaryRead(ctx context.Context, login, taskID string, seq int64) error {
	return s.write(ctx, func(tx *sql.Tx, emit emitFunc) error {
		err := tx.QueryRowContext(ctx, `SELECT id FROM tasks WHERE id = ?`, taskID).Scan(&taskID)
		if errors.Is(err, sql.ErrNoRows) {
			return fmt.Errorf("task %s: %w", taskID, ErrNotFound)
		}
		if err != nil {
			return err
		}
		res, err := tx.ExecContext(ctx, `
			INSERT INTO summary_reads (login, task_id, seq) VALUES (?, ?, ?)
			ON CONFLICT (login, task_id) DO UPDATE SET seq = excluded.seq WHERE excluded.seq > summary_reads.seq
		`, login, taskID, seq)
		if err != nil {
			return err
		}
		n, err := res.RowsAffected()
		if err != nil {
			return err
		}
		if n == 0 {
			return nil
		}
		return emit(api.Event{Kind: "summary.read", Owner: &login, Actor: login, Payload: map[string]any{"task_id": taskID, "seq": seq}})
	})
}