'use server';

import { z } from 'zod';
import { revalidatePath } from 'next/cache';
import { redirect } from 'next/navigation';
import postgres from 'postgres';
import { signIn } from '@/auth';
import { AuthError } from 'next-auth';

const sql = postgres(process.env.POSTGRES_URL!, {ssl: 'require'});

export async function authenticate(
    prevState: string | undefined,
    formData: FormData,
){
    try{
        await signIn('credentials', formData)
    } catch(error){
        if(error instanceof AuthError){
            switch(error.type){
                case 'CredentialsSignIn':
                    return 'Invalid credentials.';
                default:
                    return 'Something went wrong.';
            }
        }
        throw error;
    }
}

const FormSchema = z.object({
    id: z.string(),
    customerId: z.string({
        invalid_type_error: 'Please select a customer.',
    }),
    amount: z.coerce.number().gt(0, { message: 'Please enter an amount greater than $0.'}),
    status: z.enum(['pending', 'paid'], {
        invalid_type_error: 'Please select an invoice status.',
    }),
    date: z.string(),
});

const CreateInvoice = FormSchema.omit({id: true, date: true});

export type State = {
    errors?: {
        customerId?: string[];
        amount?: string[];
        status?: string[];
    };
    message?: string | null;
};

export async function createInvoice(prevState: State, formData: FormData){
    const validateFields = CreateInvoice.safeParse({
        customerId: formData.get('customerId'),
        amount: formData.get('amount'),
        status: formData.get('status'),
    });

    if(!validateFields.success){
        return{
            errors: validateFields.error.flatten().fieldErrors,
            message: 'Missing fields. Failed to create invoice.',
        }
    }

    const { customerId, amount, status } = validateFields.data;
    const amountInCents = amount * 100;
    const date = new Date().toISOString().split('T')[0];

    try{
        await sql`
        INSERT INTO invoices (customer_Id, amount, status, date)
        VALUES (${customerId}, ${amountInCents}, ${status}, ${date})
        `;
    } catch(error){
        console.error(error);
    }

    revalidatePath('/dashboard/invoices');
    redirect('/dashboard/invoices');
}

const UpdateInvoice = FormSchema.omit({id: true, date: true});

export async function updateInvoice(id: string, formData: FormData){
    const { customerId, amount, status } = UpdateInvoice.parse({
        customerId: formData.get('customerId'),
        amount: formData.get('amount'),
        status: formData.get('status'),
    });

    const amountInCents = amount * 100;

    try{
        await sql`
        UPDATE invoices
        SET customer_id = ${customerId}, amount = ${amountInCents}, status = ${status}
        WHERE id = ${id}
        `;
    } catch(error){
        console.error(error);
    }

    revalidatePath('/dashboard/invoices');
    redirect('/dashboard/invoices');
}

export async function deleteInvoice(id: string){  
    try{
        await sql`DELETE FROM invoices WHERE id = ${id}`;
    } catch (error){
        console.error(error);
    }

    revalidatePath('/dashboard/invoices');
}