package store

import "context"

// Counts is the summary behind GET /api/v1/system/info.
type Counts struct {
	Projects    int64
	Deployments int64
	Blobs       int64
	// CASBytes is the size of the blobs the store believes are on disk. It is
	// the deduplicated total, so it is smaller — usually much smaller — than the
	// sum of the deployments' sizes.
	CASBytes int64
}

// Counts gathers the summary in one round trip.
//
// The subqueries are counted separately rather than joined: a join would have
// to fan out over deployment_files and then collapse again, which on a large
// manifest is thousands of times the work for the same four numbers.
func (d *DB) Counts(ctx context.Context) (Counts, error) {
	var c Counts
	err := d.r.QueryRowContext(ctx, `
		SELECT (SELECT count(*) FROM projects),
		       (SELECT count(*) FROM deployments),
		       (SELECT count(*) FROM blobs WHERE present = 1),
		       (SELECT coalesce(sum(size), 0) FROM blobs WHERE present = 1)`).
		Scan(&c.Projects, &c.Deployments, &c.Blobs, &c.CASBytes)
	return c, err
}