/**
 * javaClient.ts
 * ---------------------
 * Fetches Java Programming topic data from the Go backend.
 */

export interface JavaSectionPreview {
  id: string;
  section: string;
  section_title: string;
  has_content: boolean;
}

export interface JavaChapterTopic {
  id: string;
  chapter_no: number;
  chapter_name: string;
  subtitle: string;
  level: string;
  section_count: number;
  content_count: number;
  sections: JavaSectionPreview[];
}

export interface JavaSection extends JavaSectionPreview {
  chapter?: number;
  chapter_no: number;
  chapter_name?: string;
  title?: string;
  content: string;
  [key: string]: any;
}

export interface JavaChapterContent extends JavaChapterTopic {
  sections: JavaSection[];
}

export async function fetchJavaTopics(): Promise<JavaChapterTopic[]> {
  const res = await fetch('/api/java/topics', {
    method: 'GET',
    headers: { 'Content-Type': 'application/json' },
  });
  if (!res.ok) throw new Error(`Java topics fetch failed: ${res.status}`);
  const data = await res.json();
  return data.topics ?? [];
}

export async function fetchJavaTopicContent(chapterNo: number): Promise<JavaChapterContent> {
  const res = await fetch(`/api/java/topics/${chapterNo}`, {
    method: 'GET',
    headers: { 'Content-Type': 'application/json' },
  });
  if (!res.ok) throw new Error(`Java topic content fetch failed: ${res.status}`);
  return res.json();
}