import { describe, it, expect } from 'vitest';
import { rewriteVllmResponse } from '../src/proxy/vllm-response-rewriter';

describe('vLLM Response Rewriter', () => {
  it('rewrites XML tool call in OpenAI choices content into structured tool_calls', () => {
    const inputResponse = {
      id: "chatcmpl-123",
      choices: [{
        index: 0,
        message: {
          role: "assistant",
          content: "<function=read>\n<parameter=path>\n/tmp/test.txt\n</parameter>\n</function>"
        }
      }]
    };

    const result = rewriteVllmResponse(inputResponse);

    expect(result.choices[0].message.content).toBe("");
    expect(result.choices[0].message.tool_calls).toBeDefined();
    expect(result.choices[0].message.tool_calls).toHaveLength(1);
    
    const toolCall = result.choices[0].message.tool_calls![0];
    expect(toolCall.type).toBe('function');
    expect(toolCall.function.name).toBe('read');
    
    const argsObject = JSON.parse(toolCall.function.arguments);
    expect(argsObject).toEqual({ path: '/tmp/test.txt' });
  });

  it('normalizes response that already has tool_calls into a tool-first shape', () => {
    const inputResponse = {
      choices: [{
        message: {
          role: "assistant",
          content: "Here are the calls",
          thinking: "<think>internal</think>",
          tool_calls: [
            {
              id: "123",
              type: "function",
              function: { name: "read", arguments: "{}" }
            }
          ]
        }
      }]
    };

    const result = rewriteVllmResponse(inputResponse);

    expect(result.choices[0].message.content).toBe("");
    expect(result.choices[0].message.thinking).toBe("");
    expect(result.choices[0].message.tool_calls).toHaveLength(1);
  });

  it('rewrites tool call found in reasoning_content into structured tool_calls', () => {
    const inputResponse = {
      id: "chatcmpl-123",
      choices: [{
        index: 0,
        message: {
          role: "assistant",
          content: "",
          reasoning_content: "<tool_call>\n{\"name\":\"read\",\"arguments\":{\"path\":\"/tmp/test.txt\"}}\n</tool_call>"
        }
      }]
    };

    const result = rewriteVllmResponse(inputResponse);

    expect(result.choices[0].message.content).toBe("");
    expect(result.choices[0].message.tool_calls).toBeDefined();
    expect(result.choices[0].message.tool_calls).toHaveLength(1);
    expect(result.choices[0].message.tool_calls[0].function.name).toBe("read");
    expect(JSON.parse(result.choices[0].message.tool_calls[0].function.arguments)).toEqual({
      path: "/tmp/test.txt"
    });
    expect(result.choices[0].message.reasoning_content).toBe("");
  });
});