using FinancialApi.Application;
using Microsoft.EntityFrameworkCore;
using Wolverine.Attributes;
using Wolverine.Persistence;

namespace FinancialApi.Infrastructure;

public record ApplyFeeCommand(int AccountId, decimal Amount);

public record FeePair(Account CustomerAccount, Account RevenueAccount);

public record FeeAppliedEvent(int AccountId, decimal Amount);

public static class ApplyFeeHandler
{
    public static async Task<FeePair?> LoadAsync(
        ApplyFeeCommand cmd,
        AccountDbContext db)
    {
        var customer = await db.Accounts.AsNoTracking().SingleOrDefaultAsync(x => x.Id == cmd.AccountId);
        var revenue = await db.Accounts.AsNoTracking().SingleOrDefaultAsync(x => x.Id == 99999);
        return (customer == null || revenue == null) ? null : new FeePair(customer, revenue);
    }

    [Transactional]
    public static (
        IStorageAction<Account> CustomerWrite,
        IStorageAction<Account> RevenueWrite,
        IStorageAction<JournalEntry> JournalWrite,
        FeeAppliedEvent Event
        )
        Handle(
            ApplyFeeCommand cmd,
            FeePair pair
        )
    {
        var updatedCustomer = pair.CustomerAccount.ApplyPosting(cmd.Amount, EntryType.Debit);
        var updatedRevenue = pair.RevenueAccount.ApplyPosting(cmd.Amount, EntryType.Credit);
        var lines = new List<JournalLine>
        {
            new(pair.CustomerAccount.Id, cmd.Amount, EntryType.Debit),
            new(9999, cmd.Amount, EntryType.Credit)
        };
        var journalEntry = BalancedJournal.Create(Guid.NewGuid(),
            $"Service Fee Applied: {cmd.Amount} to Account {cmd.AccountId}",
            DateTimeOffset.UtcNow, lines);

        var @event = new FeeAppliedEvent(cmd.AccountId, cmd.Amount);

        return (
            Storage.Update(updatedCustomer),
            Storage.Update(updatedRevenue),
            Storage.Insert(journalEntry.Entry),
            @event
        );
    }
}