using RackPeek.Domain.Helpers;
using RackPeek.Domain.Persistence;
using RackPeek.Domain.Resources;
using RackPeek.Domain.Resources.Connections;

namespace RackPeek.Domain.UseCases;

public interface IDeleteResourceUseCase<T> : IResourceUseCase<T>
    where T : Resource {
    Task ExecuteAsync(string name);
}

public class DeleteResourceUseCase<T>(IResourceCollection repo) : IDeleteResourceUseCase<T> where T : Resource {
    public async Task ExecuteAsync(string name) {
        name = Normalize.HardwareName(name);
        ThrowIfInvalid.ResourceName(name);

        Resource? existingResource = await repo.GetByNameAsync(name);
        if (existingResource == null)
            throw new NotFoundException($"Resource '{name}' does not exist.");

        IReadOnlyList<Resource> dependants = await repo.GetDependantsAsync(name);
        foreach (Resource resource in dependants) {
            resource.RunsOn.Remove(name);
            await repo.UpdateAsync(resource);
        }

        IReadOnlyList<Connection> connections = await repo.GetConnectionsAsync();
        foreach (Connection connection in connections) {
            if (connection.A.Resource == name || connection.B.Resource == name) {
                await repo.RemoveConnectionAsync(connection);
            }
        }

        await repo.DeleteAsync(name);
    }
}