/**
 * Browser → template-server client. Mirrors every endpoint in
 * `components/server/index.ts`. Each function builds a request, throws on
 * non-2xx with the server's error body, and parses the response — keeping
 * the React components free of fetch boilerplate.
 *
 * IMPORTANT: keep these as relative requests. Kazzle injects the
 * sibling server URL into Vite only so the dev-server proxy can route these
 * calls inside the checkout computer. Browser code must not read or fetch
 * KAZZLE_APP_COMPONENT_*_URL directly.
 */

import type {
  AsyncJob,
  ChatMessage,
  ChatOptions,
  ChatResponse,
  ImageResult,
  StructuredOutputSchema,
  TranscriptionResult,
} from './types';

async function jsonRequest<T>(path: string, body: unknown): Promise<T> {
  const res = await fetch(path, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify(body),
  });
  if (!res.ok) throw new Error(`${path} failed: ${res.status} ${await res.text()}`);
  return res.json() as Promise<T>;
}

export async function sendChat(messages: ChatMessage[], options: ChatOptions = {}): Promise<ChatMessage> {
  const data = await jsonRequest<ChatResponse>('/chat', { messages, ...options });
  return data.message;
}

export async function sendStructuredChat<T>(
  messages: ChatMessage[],
  jsonSchema: StructuredOutputSchema,
  options: Omit<ChatOptions, 'response_format'> = {},
): Promise<T> {
  const data = await jsonRequest<ChatResponse>('/chat', {
    messages,
    ...options,
    response_format: {
      type: 'json_schema',
      json_schema: jsonSchema,
    },
  });
  if (!('structured' in data)) throw new Error('/chat returned no structured output');
  return data.structured as T;
}

export async function generateImage(prompt: string): Promise<ImageResult> {
  return jsonRequest<ImageResult>('/image', { prompt });
}

export async function synthesizeSpeech(text: string, voice = 'alloy'): Promise<Blob> {
  const res = await fetch('/speech', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ text, voice }),
  });
  if (!res.ok) throw new Error(`/speech failed: ${res.status} ${await res.text()}`);
  return res.blob();
}

export async function transcribeAudio(audio: Blob): Promise<TranscriptionResult> {
  const form = new FormData();
  form.append('file', audio, 'audio.mp3');
  const res = await fetch('/transcribe', { method: 'POST', body: form });
  if (!res.ok) throw new Error(`/transcribe failed: ${res.status} ${await res.text()}`);
  return res.json() as Promise<TranscriptionResult>;
}

export async function startVideoJob(prompt: string): Promise<AsyncJob> {
  return jsonRequest<AsyncJob>('/video', { prompt });
}

export async function pollVideoJob(jobId: string): Promise<AsyncJob> {
  const res = await fetch(`/video/${encodeURIComponent(jobId)}`);
  if (!res.ok) throw new Error(`/video/${jobId} failed: ${res.status} ${await res.text()}`);
  return res.json() as Promise<AsyncJob>;
}