Function transformSchemas

backend/api/mcp/tool_schema.go:522–574

transformSchemas converts decoded metadata into the response shape for the given include level. Applies sorting and per-schema truncation.

(metadata *databaseMetadata, include string)

// transformSchemas converts decoded metadata into the response shape for the
// given include level. Applies sorting and per-schema truncation.
func transformSchemas(metadata *databaseMetadata, include string) []SchemaSection {
	// Only bulk-detail modes ask the server for limit+1 and need the "trim to
	// schemaTableLimit and flag Truncated" dance. Summary mode is designed to
	// return every table because the per-table payload is tiny — applying the
	// cap there would silently drop tables from agents' view.
	applyTruncation := include == schemaIncludeColumns || include == schemaIncludeDetails

	sections := make([]SchemaSection, 0, len(metadata.Schemas))
	for i := range metadata.Schemas {
		schema := &metadata.Schemas[i]

		// Sort tables alphabetically by name.
		slices.SortStableFunc(schema.Tables, func(a, b tableMetadata) int {
			return strings.Compare(a.Name, b.Name)
		})

		truncated := false
		tablesShown := 0
		if applyTruncation && len(schema.Tables) > schemaTableLimit {
			// Drop the sentinel 201st entry.
			schema.Tables = schema.Tables[:schemaTableLimit]
			truncated = true
			tablesShown = schemaTableLimit
		}

		tables := make([]TableEntry, 0, len(schema.Tables))
		for j := range schema.Tables {
			tables = append(tables, buildTableEntry(&schema.Tables[j], include))
		}

		views := make([]string, 0, len(schema.Views))
		for _, v := range schema.Views {
			views = append(views, v.Name)
		}
		slices.Sort(views)

		sections = append(sections, SchemaSection{
			Name:           schema.Name,
			Tables:         tables,
			Views:          views,
			FunctionCount:  len(schema.Functions),
			ProcedureCount: len(schema.Procedures),
			Truncated:      truncated,
			TablesShown:    tablesShown,
		})
	}

	// Sort schemas alphabetically by name (empty string sorts first → MySQL friendly).
	slices.SortStableFunc(sections, func(a, b SchemaSection) int {
		return strings.Compare(a.Name, b.Name)
	})
	return sections
}

// buildTableEntry converts a single tableMetadata into the response shape at the
// requested detail level.