API Gen Platform

export interface EntitySchema {
  name: string;
  dependencies: string[]; // Parent entity names
}

export function sortEntitiesTopologically(entities: EntitySchema[]): string[] {
  const inDegree = new Map<string, number>();
  const graph = new Map<string, string[]>();

  entities.forEach(e => {
    inDegree.set(e.name, 0);
    graph.set(e.name, []);
  });

  // Build dependency edges
  entities.forEach(e => {
    e.dependencies.forEach(parent => {
      graph.get(parent)?.push(e.name);
      inDegree.set(e.name, (inDegree.get(e.name) || 0) + 1);
    });
  });

  // Kahn's algorithm: queue nodes with 0 incoming dependencies
  const queue: string[] = [];
  inDegree.forEach((deg, name) => {
    if (deg === 0) queue.push(name);
  });

  const sortedOrder: string[] = [];
  while (queue.length > 0) {
    const current = queue.shift()!;
    sortedOrder.push(current);

    graph.get(current)?.forEach(neighbor => {
      inDegree.set(neighbor, inDegree.get(neighbor)! - 1);
      if (inDegree.get(neighbor) === 0) queue.push(neighbor);
    });
  }

  return sortedOrder; // Order: ['User', 'Category'] -> ['Product'] -> ['Order'] -> ['OrderItem']
}