package store

import "context"

type Task struct {
	ID            int64             `json:"id"`
	Name          string            `json:"name"`
	SrcEndpointID int64             `json:"src_endpoint_id"`
	DstEndpointID int64             `json:"dst_endpoint_id"`
	Status        string            `json:"status"`
	FolderMapping map[string]string `json:"folder_mapping"`
}

func (s *Store) CreateTask(ctx context.Context, t Task) (int64, error) {
	if t.FolderMapping == nil {
		t.FolderMapping = map[string]string{}
	}
	var id int64
	err := s.Pool.QueryRow(ctx,
		`INSERT INTO tasks (name, src_endpoint_id, dst_endpoint_id, folder_mapping)
		 VALUES ($1,$2,$3,$4) RETURNING id`,
		t.Name, t.SrcEndpointID, t.DstEndpointID, t.FolderMapping).Scan(&id)
	return id, err
}

func (s *Store) GetTask(ctx context.Context, id int64) (Task, error) {
	var t Task
	err := s.Pool.QueryRow(ctx,
		`SELECT id, name, src_endpoint_id, dst_endpoint_id, status, folder_mapping
		 FROM tasks WHERE id=$1`, id).
		Scan(&t.ID, &t.Name, &t.SrcEndpointID, &t.DstEndpointID, &t.Status, &t.FolderMapping)
	return t, err
}

func (s *Store) ListTasks(ctx context.Context) ([]Task, error) {
	rows, err := s.Pool.Query(ctx,
		`SELECT id, name, src_endpoint_id, dst_endpoint_id, status, folder_mapping
		 FROM tasks ORDER BY id DESC`)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	var out []Task
	for rows.Next() {
		var t Task
		if err := rows.Scan(&t.ID, &t.Name, &t.SrcEndpointID, &t.DstEndpointID, &t.Status, &t.FolderMapping); err != nil {
			return nil, err
		}
		out = append(out, t)
	}
	return out, rows.Err()
}

func (s *Store) SetTaskStatus(ctx context.Context, id int64, status string) error {
	_, err := s.Pool.Exec(ctx, `UPDATE tasks SET status=$2 WHERE id=$1`, id, status)
	return err
}

// TryMarkTaskRunning atomically sets status='running' only if the task is not already running.
// Returns true if this call acquired the run (status was not 'running' before), false otherwise.
func (s *Store) TryMarkTaskRunning(ctx context.Context, id int64) (bool, error) {
	ct, err := s.Pool.Exec(ctx,
		`UPDATE tasks SET status='running' WHERE id=$1 AND status<>'running'`, id)
	if err != nil {
		return false, err
	}
	return ct.RowsAffected() == 1, nil
}