using FinancialApi.Domain;
using Wolverine.Attributes;
using Wolverine.Persistence;

namespace FinancialApi.Application;

public record ApplyFeeCommand(int AccountId, decimal Amount);

public record FeeAppliedEvent(int AccountId, decimal Amount);

public record FeePair(Account Source, Account Destination, DateTimeOffset TimeStamp);

public static class ApplyFeeHandler
{
    public static async Task<FeePair> LoadAsync(
        ApplyFeeCommand cmd,
        IAccountQuery query, TimeProvider timeProvider)
    {
        var source = await query.FindByIdAsync(cmd.AccountId);
        var dest = await query.FindByIdAsync(99999);
        if (source == null || dest == null)
        {
            throw new InvalidOperationException($"Cannot process transfer. Account(s) not found.");
        }

        return new FeePair(source, dest, timeProvider.GetUtcNow());
    }

    public static (
        IStorageAction<Account> CustomerWrite,
        IStorageAction<Account> RevenueWrite,
        IStorageAction<JournalEntry> JournalWrite,
        FeeAppliedEvent Event
        )
        Handle(
            ApplyFeeCommand cmd,
            FeePair pair
        )
    {
        var updatedSource = pair.Source.ApplyPosting(cmd.Amount, EntryType.Debit);
        var updatedRevenue = pair.Destination.ApplyPosting(cmd.Amount, EntryType.Credit);
        var lines = new List<JournalLine>
        {
            new(updatedSource.Id, cmd.Amount, EntryType.Debit),
            new(updatedRevenue.Id, cmd.Amount, EntryType.Credit)
        };
        var journalEntry = BalancedJournal.Create(Guid.NewGuid(),
            $"Service Fee Applied: {cmd.Amount} to Account {cmd.AccountId}",
            pair.TimeStamp, lines);

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

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