src/app/services/groq.service.ts

import type { ChatMessage } from '../types/chat.types.ts';

const GROQ_API_URL = 'https://api.groq.com/openai/v1';
const MODEL = 'meta-llama/llama-4-scout-17b-16e-instruct';

export type GroqMessage = {
  role: 'user' | 'assistant' | 'system';
  content: string;
};

export type GroqChatResponse = {
  id: string;
  object: string;
  created: number;
  model: string;
  choices: Array<{
    index: number;
    message: {
      role: 'assistant';
      content: string;
    };
    finish_reason: string;
  }>;
  usage: {
    prompt_tokens: number;
    completion_tokens: number;
    total_tokens: number;
  };
};

export type GroqStreamChunk = {
  id: string;
  object: string;
  created: number;
  model: string;
  choices: Array<{
    index: number;
    delta: {
      role?: 'assistant';
      content?: string;
    };
    finish_reason: string | null;
  }>;
};

export type GroqError = {
  error: {
    message: string;
    type: string;
    code?: string;
  };
};

/**
 * Sends messages to Groq API and returns the assistant's response
 */
export async function sendChatMessage(messages: ChatMessage[]): Promise<string> {
  const apiKey = process.env.REACT_APP_GROQ_API_KEY;
  
  if (!apiKey) {
    throw new Error('REACT_APP_GROQ_API_KEY environment variable is not set');
  }

  // Convert our ChatMessage format to Groq's expected format
  const groqMessages: GroqMessage[] = messages.map(msg => ({
    role: msg.role,
    content: msg.content
  }));

  try {
    const response = await fetch(`${GROQ_API_URL}/chat/completions`, {
      method: 'POST',
      headers: {
        'Authorization': `Bearer ${apiKey}`,
        'Content-Type': 'application/json',
      },
      body: JSON.stringify({
        model: MODEL,
        messages: groqMessages,
        temperature: 0.7,
        max_tokens: 4096,
        top_p: 1,
        stream: true,
      }),
    });

    if (!response.ok) {
      const errorData: GroqError = await response.json();
      throw new Error(errorData.error?.message || `HTTP error! status: ${response.status}`);
    }

    const reader = response.body?.getReader();
    if (!reader) {
      throw new Error('Failed to get response reader');
    }

    const decoder = new TextDecoder();
    let fullContent = '';

    while (true) {
      const { done, value } = await reader.read();
      if (done) break;

      const chunk = decoder.decode(value, { stream: true });
      const lines = chunk.split('\n');

      for (const line of lines) {
        if (line.startsWith('data: ')) {
          const data = line.slice(6);
          if (data === '[DONE]') continue;

          try {
            const parsed: GroqStreamChunk = JSON.parse(data);
            const content = parsed.choices[0]?.delta?.content;
            if (content) {
              fullContent += content;
            }
          } catch (e) {
            // Skip invalid JSON
          }
        }
      }
    }

    return fullContent;
  } catch (error) {
    if (error instanceof Error) {
      throw error;
    }
    throw new Error('Failed to send message to Groq API');
  }
}

/**
 * Sends messages to Groq API with streaming support
 */
export async function sendChatMessageStream(
  messages: ChatMessage[],
  onChunk: (chunk: string) => void
): Promise<string> {
  const apiKey = process.env.REACT_APP_GROQ_API_KEY;
  
  if (!apiKey) {
    throw new Error('REACT_APP_GROQ_API_KEY environment variable is not set');
  }

  // Convert our ChatMessage format to Groq's expected format
  const groqMessages: GroqMessage[] = messages.map(msg => ({
    role: msg.role,
    content: msg.content
  }));

  try {
    const response = await fetch(`${GROQ_API_URL}/chat/completions`, {
      method: 'POST',
      headers: {
        'Authorization': `Bearer ${apiKey}`,
        'Content-Type': 'application/json',
      },
      body: JSON.stringify({
        model: MODEL,
        messages: groqMessages,
        temperature: 0.7,
        max_tokens: 4096,
        top_p: 1,
        stream: true,
      }),
    });

    if (!response.ok) {
      const errorData: GroqError = await response.json();
      throw new Error(errorData.error?.message || `HTTP error! status: ${response.status}`);
    }

    const reader = response.body?.getReader();
    if (!reader) {
      throw new Error('Failed to get response reader');
    }

    const decoder = new TextDecoder();
    let fullContent = '';

    while (true) {
      const { done, value } = await reader.read();
      if (done) break;

      const chunk = decoder.decode(value, { stream: true });
      const lines = chunk.split('\n');

      for (const line of lines) {
        if (line.startsWith('data: ')) {
          const data = line.slice(6);
          if (data === '[DONE]') continue;

          try {
            const parsed: GroqStreamChunk = JSON.parse(data);
            const content = parsed.choices[0]?.delta?.content;
            if (content) {
              fullContent += content;
              onChunk(content);
            }
          } catch (e) {
            // Skip invalid JSON
          }
        }
      }
    }

    return fullContent;
  } catch (error) {
    if (error instanceof Error) {
      throw error;
    }
    throw new Error('Failed to send message to Groq API');
  }
}