backend/controllers/cropRotationController.js

import { generateAIContent } from '../utils/aiHelper.js';
import { extractLanguage, getLanguageName } from '../utils/aiOrchestrator.js';
import dotenv from "dotenv";

export const cropRotationRecommendations = async (req, res) => {
    dotenv.config();

    const { previousCrop, npkDepletion, waterAvailability, soilType, region } =
        req.body;

    if (
        !previousCrop ||
        !npkDepletion ||
        !waterAvailability ||
        !soilType ||
        !region
    ) {
        return res.status(400).json({
            error: "Missing required inputs: previousCrop, npkDepletion, waterAvailability, soilType, region",
        });
    }

    const lang = extractLanguage(req);
    const langName = getLanguageName(lang);
    const langInstruction = lang !== 'en' ? `\n\nRespond STRICTLY in ${langName} language. Translate all fields and values.` : '';

    try {
        const prompt = `
        You are an expert agricultural crop rotation scientist.

        Based on the following:
        - Previous Crop: ${previousCrop}
        - NPK Depletion (major nutrient lost): ${npkDepletion}
        - Water Availability: ${waterAvailability}
        - Soil Type: ${soilType}
        - Region: ${region}

        Suggest the best crop to plant next to:
        - Restore depleted nutrients naturally
        - Increase soil fertility long-term
        - Improve economic profitability

        Provide the answer ONLY in this strict JSON format:

        {
            "recommended_crop": "",
            "reasons": ["", "", ""],
            "nutrient_restoration_benefit": "",
            "expected_profitability": "",
            "note": ""
        }${langInstruction}
        `;

        const recommendation = await generateAIContent(prompt.trim());
        const formattedRecommendation = recommendation
            .replace("```json", "")
            .replace("```", "")
            .trim();
        res.status(200).json({
            recommendation: formattedRecommendation,
        });
    } catch (err) {
        console.error("Error fetching recommendations: ", err);
        res.status(500).json({ error: "Failed to fetch recommendations" });
    }
};