import { describe, it, expect, vi } from 'vitest';
import { ensureContentType, convertSseToJson } from '../lib/request/response-handler.js';

describe('Response Handler Module', () => {
	describe('ensureContentType', () => {
		it('should preserve existing content-type', () => {
			const headers = new Headers();
			headers.set('content-type', 'application/json');
			const result = ensureContentType(headers);
			expect(result.get('content-type')).toBe('application/json');
		});

		it('should add default content-type if missing', () => {
			const headers = new Headers();
			const result = ensureContentType(headers);
			expect(result.get('content-type')).toBe('text/event-stream; charset=utf-8');
		});

		it('should not modify original headers', () => {
			const headers = new Headers();
			const result = ensureContentType(headers);
			expect(headers.has('content-type')).toBe(false);
			expect(result.has('content-type')).toBe(true);
		});
	});

	describe('convertSseToJson', () => {
		it('should throw error if response has no body', async () => {
			const response = new Response(null);
			const headers = new Headers();

			await expect(convertSseToJson(response, headers)).rejects.toThrow(
				'Response has no body'
			);
		});

		it('should parse SSE stream with response.done event', async () => {
			const sseContent = `data: {"type":"response.started"}
data: {"type":"response.done","response":{"id":"resp_123","output":"test"}}
`;
			const response = new Response(sseContent);
			const headers = new Headers();

			const result = await convertSseToJson(response, headers);
			const body = await result.json();

			expect(body).toEqual({ id: 'resp_123', output: 'test' });
			expect(result.headers.get('content-type')).toBe('application/json; charset=utf-8');
		});

		it('should parse SSE stream with response.completed event', async () => {
			const sseContent = `data: {"type":"response.started"}
data: {"type":"response.completed","response":{"id":"resp_456","output":"done"}}
`;
			const response = new Response(sseContent);
			const headers = new Headers();

			const result = await convertSseToJson(response, headers);
			const body = await result.json();

			expect(body).toEqual({ id: 'resp_456', output: 'done' });
		});

		it('should return original text if no final response found', async () => {
			const sseContent = `data: {"type":"response.started"}
data: {"type":"chunk","delta":"text"}
`;
			const response = new Response(sseContent);
			const headers = new Headers();

			const result = await convertSseToJson(response, headers);
			const text = await result.text();

			expect(text).toBe(sseContent);
		});

		it('should skip malformed JSON in SSE stream', async () => {
			const sseContent = `data: not-json
data: {"type":"response.done","response":{"id":"resp_789"}}
`;
			const response = new Response(sseContent);
			const headers = new Headers();

			const result = await convertSseToJson(response, headers);
			const body = await result.json();

			expect(body).toEqual({ id: 'resp_789' });
		});

		it('should handle empty SSE stream', async () => {
			const response = new Response('');
			const headers = new Headers();

			const result = await convertSseToJson(response, headers);
			const text = await result.text();

			expect(text).toBe('');
		});

		it('should preserve response status and statusText', async () => {
			const sseContent = `data: {"type":"response.done","response":{"id":"x"}}`;
			const response = new Response(sseContent, {
				status: 200,
				statusText: 'OK',
			});
			const headers = new Headers();

			const result = await convertSseToJson(response, headers);

			expect(result.status).toBe(200);
			expect(result.statusText).toBe('OK');
		});
	});
});