feat: Add GET previous template version endpoint (#5230)

coderd/database/databasefake/databasefake.go

@@ -1718,6 +1718,46 @@ func (q *fakeQuerier) GetTemplateVersionByJobID(_ context.Context, jobID uuid.UU
 	return database.TemplateVersion{}, sql.ErrNoRows
 }
 
+func (q *fakeQuerier) GetPreviousTemplateVersion(_ context.Context, arg database.GetPreviousTemplateVersionParams) (database.TemplateVersion, error) {
+	q.mutex.RLock()
+	defer q.mutex.RUnlock()
+
+	var currentTemplateVersion database.TemplateVersion
+	for _, templateVersion := range q.templateVersions {
+		if templateVersion.TemplateID != arg.TemplateID {
+			continue
+		}
+		if templateVersion.Name != arg.Name {
+			continue
+		}
+		if templateVersion.OrganizationID != arg.OrganizationID {
+			continue
+		}
+		currentTemplateVersion = templateVersion
+		break
+	}
+
+	previousTemplateVersions := make([]database.TemplateVersion, 0)
+	for _, templateVersion := range q.templateVersions {
+		if templateVersion.ID == currentTemplateVersion.ID {
+			continue
+		}
+		if templateVersion.CreatedAt.Before(currentTemplateVersion.CreatedAt) {
+			previousTemplateVersions = append(previousTemplateVersions, templateVersion)
+		}
+	}
+
+	if len(previousTemplateVersions) == 0 {
+		return database.TemplateVersion{}, sql.ErrNoRows
+	}
+
+	sort.Slice(previousTemplateVersions, func(i, j int) bool {
+		return previousTemplateVersions[i].CreatedAt.After(previousTemplateVersions[j].CreatedAt)
+	})
+
+	return previousTemplateVersions[0], nil
+}
+
 func (q *fakeQuerier) GetParameterSchemasByJobID(_ context.Context, jobID uuid.UUID) ([]database.ParameterSchema, error) {
 	q.mutex.RLock()
 	defer q.mutex.RUnlock()

coderd/database/querier.go

@@ -66,6 +66,7 @@ type sqlcQuerier interface {
 	GetParameterSchemasByJobID(ctx context.Context, jobID uuid.UUID) ([]ParameterSchema, error)
 	GetParameterSchemasCreatedAfter(ctx context.Context, createdAt time.Time) ([]ParameterSchema, error)
 	GetParameterValueByScopeAndName(ctx context.Context, arg GetParameterValueByScopeAndNameParams) (ParameterValue, error)
+	GetPreviousTemplateVersion(ctx context.Context, arg GetPreviousTemplateVersionParams) (TemplateVersion, error)
 	GetProvisionerDaemonByID(ctx context.Context, id uuid.UUID) (ProvisionerDaemon, error)
 	GetProvisionerDaemons(ctx context.Context) ([]ProvisionerDaemon, error)
 	GetProvisionerJobByID(ctx context.Context, id uuid.UUID) (ProvisionerJob, error)

coderd/database/queries.sql.go

@@ -3500,6 +3500,44 @@ func (q *sqlQuerier) UpdateTemplateMetaByID(ctx context.Context, arg UpdateTempl
 	return i, err
 }
 
+const getPreviousTemplateVersion = `-- name: GetPreviousTemplateVersion :one
+SELECT
+	id, template_id, organization_id, created_at, updated_at, name, readme, job_id, created_by
+FROM
+	template_versions
+WHERE
+	created_at < (
+		SELECT created_at
+		FROM template_versions AS tv
+		WHERE tv.organization_id = $1 AND tv.name = $2 AND tv.template_id = $3
+	)
+ORDER BY created_at DESC
+LIMIT 1
+`
+
+type GetPreviousTemplateVersionParams struct {
+	OrganizationID uuid.UUID     `db:"organization_id" json:"organization_id"`
+	Name           string        `db:"name" json:"name"`
+	TemplateID     uuid.NullUUID `db:"template_id" json:"template_id"`
+}
+
+func (q *sqlQuerier) GetPreviousTemplateVersion(ctx context.Context, arg GetPreviousTemplateVersionParams) (TemplateVersion, error) {
+	row := q.db.QueryRowContext(ctx, getPreviousTemplateVersion, arg.OrganizationID, arg.Name, arg.TemplateID)
+	var i TemplateVersion
+	err := row.Scan(
+		&i.ID,
+		&i.TemplateID,
+		&i.OrganizationID,
+		&i.CreatedAt,
+		&i.UpdatedAt,
+		&i.Name,
+		&i.Readme,
+		&i.JobID,
+		&i.CreatedBy,
+	)
+	return i, err
+}
+
 const getTemplateVersionByID = `-- name: GetTemplateVersionByID :one
 SELECT
 	id, template_id, organization_id, created_at, updated_at, name, readme, job_id, created_by

coderd/database/queries/templateversions.sql

@@ -110,3 +110,17 @@ SET
 	updated_at = $3
 WHERE
 	job_id = $1;
+
+-- name: GetPreviousTemplateVersion :one
+SELECT
+	*
+FROM
+	template_versions
+WHERE
+	created_at < (
+		SELECT created_at
+		FROM template_versions AS tv
+		WHERE tv.organization_id = $1 AND tv.name = $2 AND tv.template_id = $3
+	)
+ORDER BY created_at DESC
+LIMIT 1;