const { OpenAI } = require('openai');
const chromadb = require('chromadb');
const fs = require('fs');
const path = require('path');

// Initialize OpenAI client
const openai = new OpenAI({
  apiKey: process.env.OPENAI_API_KEY,
});

// Handler for the Netlify serverless function
exports.handler = async (event, context) => {
  try {
    // Only allow POST requests
    if (event.httpMethod !== 'POST') {
      return {
        statusCode: 405,
        body: JSON.stringify({ error: 'Method Not Allowed' }),
      };
    }

    // Parse the request body
    const body = JSON.parse(event.body);
    const { message, conversation_history = [] } = body;

    if (!message) {
      return {
        statusCode: 400,
        body: JSON.stringify({ error: 'Message is required' }),
      };
    }

    // Prepare the query with conversation history context
    let query = message;
    if (conversation_history.length > 0) {
      const context = conversation_history
        .slice(-3)
        .map(msg => `User: ${msg.message}\nAssistant: ${msg.response}`)
        .join('\n');
      query = `Conversation history:\n${context}\n\nCurrent question: ${query}`;
    }

    // Add instruction for APA7 citations
    query += "\nPlease include APA7 citations for any information provided.";

    // Call the OpenAI API with Command R+ model
    const completion = await openai.chat.completions.create({
      model: "gpt-4", // Replace with Command R+ model ID when available
      messages: [
        {
          role: "system",
          content: "You are an educational research methods assistant for experienced academics. Provide accurate information about research methods with proper APA7 citations."
        },
        {
          role: "user",
          content: query
        }
      ],
      temperature: 0.7,
      max_tokens: 1000,
    });

    // Extract the response
    const response = completion.choices[0].message.content;

    // Extract citations (in a real implementation, this would be more sophisticated)
    const citations = [];
    const citationRegex = /\((.*?)\)/g;
    let match;
    let i = 0;
    while ((match = citationRegex.exec(response)) !== null) {
      citations.push({
        id: i + 1,
        text: match[1],
        page: ""
      });
      i++;
    }

    return {
      statusCode: 200,
      headers: {
        'Content-Type': 'application/json',
        'Access-Control-Allow-Origin': '*',
      },
      body: JSON.stringify({
        response,
        citations
      }),
    };
  } catch (error) {
    console.error('Error:', error);
    return {
      statusCode: 500,
      body: JSON.stringify({ error: 'Internal Server Error' }),
    };
  }
};