'use server';

import { z } from 'zod';
import { revalidatePath } from 'next/cache';
import { redirect } from 'next/navigation';
import clientPromise from './mongodb';
import { BillingLocation } from './db-types';
import { ObjectId } from 'mongodb';

export type State = {
    errors?: {
        locationName?: string[];
        locationNotes?: string[],
    };
    message?:string | null;
}

const FormSchema = z.object({
    _id: z.string(),
    locationName: z.coerce.string().min(1, "Location Name is required."),
    locationNotes: z.string(),
  });

const UpdateLocation = FormSchema.omit({ _id: true });

/**
 * Server-side action which adds or updates a bill
 * @param locationId location of the bill
 * @param prevState previous state of the form
 * @param formData form data
 * @returns 
 */
export async function updateOrAddLocation(locationId?: string, yearMonth?: string, prevState:State, formData: FormData) {

    const validatedFields = UpdateLocation.safeParse({
        locationName: formData.get('locationName'),
        locationNotes: formData.get('locationNotes'),
    });

    // If form validation fails, return errors early. Otherwise, continue...
    if(!validatedFields.success) {
        return({
            errors: validatedFields.error.flatten().fieldErrors,
            message: "Missing Fields",
        });
    }

    const {
        locationName,
        locationNotes,
    } = validatedFields.data;

    // update the bill in the mongodb
    const client = await clientPromise;
    const db = client.db("rezije");

    if(locationId) {
        await db.collection<BillingLocation>("lokacije").updateOne(
            {
                _id: locationId // find a location with the given locationID
            },
            {
                $set: {
                    name: locationName,
                    notes: locationNotes,
                }
            });
    } else if(yearMonth) {
        await db.collection<BillingLocation>("lokacije").insertOne({
            _id: (new ObjectId()).toHexString(),
            name: locationName,
            notes: locationNotes,
            yearMonth: parseInt(yearMonth), // ToDo: get the current year and month
            bills: [],
        });
    }

    // clear the cache for the path
    revalidatePath('/');
    // go to the bill list
    redirect('/');
}

export const fetchLocationById = async (locationID:string) => {
    const client = await clientPromise;
    const db = client.db("rezije");

    // find a location with the given locationID
    const billLocation = await db.collection<BillingLocation>("lokacije").findOne({ _id: locationID });

    if(!billLocation) {
        console.log(`Location ${locationID} not found`);
        return(null);
    }

    return(billLocation);
}

export const deleteLocationById = async (locationID:string) => {
    const client = await clientPromise;
    const db = client.db("rezije");

    // find a location with the given locationID
    const post = await db.collection<BillingLocation>("lokacije").deleteOne({ _id: locationID });
    
    return(post.deletedCount);
}