import type { RequestHandler } from '@sveltejs/kit';
import fs from 'fs';
import path from 'path';
import { mkdir } from 'fs/promises';
import { Payment } from '$lib/models/Payment'; // adjust path as needed
import { dbConnect, dbDisconnect } from '$lib/db/db';
import { error } from '@sveltejs/kit';

const UPLOAD_DIR = './static/cospend';
const BASE_CURRENCY = 'CHF'; // Default currency

export const POST: RequestHandler = async ({ request, locals }) => {
   let auth =  await locals.auth();
   if(!auth){
   	throw error(401, "Not logged in")
   }

  const formData = await request.formData();

  try {
    const name = formData.get('name') as string;
    const category = formData.get('category') as string;
    const transaction_date= new Date(formData.get('transaction_date') as string);
    const description = formData.get('description') as string;
    const note = formData.get('note') as string;
    const tags = JSON.parse(formData.get('tags') as string) as string[];
    const paid_by = formData.get('paid_by') as string
    const type = formData.get('type') as string

    let currency = formData.get('currency') as string;
    let original_amount = parseFloat(formData.get('original_amount') as string);
    let total_amount = NaN;

    let for_self = parseFloat(formData.get('for_self') as string);
    let for_other = parseFloat(formData.get('for_other') as string);
    let conversion_rate = 1.0; // Default conversion rate

    // if currency is not BASE_CURRENCY, fetch current conversion rate using frankfurter API and date in YYYY-MM-DD format
    if (!currency || currency === BASE_CURRENCY) {
        currency = BASE_CURRENCY;
    	total_amount = original_amount;
    } else {
	console.log(transaction_date);
        const date_fmt = transaction_date.toISOString().split('T')[0]; // Convert date to YYYY-MM-DD format
        // Fetch conversion rate logic here (not implemented in this example)
	console.log(`Fetching conversion rate for ${currency} to ${BASE_CURRENCY} on ${date_fmt}`);
        const res = await fetch(`https://api.frankfurter.app/${date_fmt}?from=${currency}&to=${BASE_CURRENCY}`)
	console.log(res);
	const result = await res.json();
	console.log(result);
	if (!result || !result.rates[BASE_CURRENCY]) {
	    return new Response(JSON.stringify({ message: 'Currency conversion failed.' }), { status: 400 });
	}
	// Assuming you want to convert the total amount to BASE_CURRENCY
	conversion_rate = parseFloat(result.rates[BASE_CURRENCY]);
	console.log(`Conversion rate from ${currency} to ${BASE_CURRENCY} on ${date_fmt}: ${conversion_rate}`);
	total_amount = original_amount * conversion_rate;
	for_self = for_self * conversion_rate;
	for_other = for_other * conversion_rate;
    }

    //const personal_amounts = JSON.parse(formData.get('personal_amounts') as string) as { user: string, amount: number }[];

    if (!name || isNaN(total_amount)) {
      return new Response(JSON.stringify({ message: 'Invalid required fields.' }), { status: 400 });
    }

    await mkdir(UPLOAD_DIR, { recursive: true });

    const images: { mediapath: string }[] = [];
    const imageFiles = formData.getAll('images') as File[];

    for (const file of imageFiles) {
      const arrayBuffer = await file.arrayBuffer();
      const buffer = Buffer.from(arrayBuffer);
      const safeName = `${Date.now()}_${file.name.replace(/[^a-zA-Z0-9_.-]/g, '_')}`;
      const fullPath = path.join(UPLOAD_DIR, safeName);
      fs.writeFileSync(fullPath, buffer);
      images.push({ mediapath: `/static/test/${safeName}` });
    }

    await dbConnect();
    const payment = new Payment({
      type,
      name,
      category,
      transaction_date,
      images,
      description,
      note,
      tags,
      original_amount,
      total_amount,
      paid_by,
      for_self,
      for_other,
      conversion_rate,
      currency,
    });







    try{
    	await Payment.create(payment);
    } catch(e){

	    return new Response(JSON.stringify({ message: `Error creating payment event. ${e}` }), { status: 500 });
    }
    await dbDisconnect();
    return new Response(JSON.stringify({ message: 'Payment event created successfully.' }), { status: 201 });
  } catch (err) {
    console.error(err);
    return new Response(JSON.stringify({ message: 'Error processing request.' }), { status: 500 });
  }
};