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

namespace RackPeek.Domain.UseCases;

public interface IRenameResourceUseCase<T> : IResourceUseCase<T>
    where T : Resource {
    public Task ExecuteAsync(string originalName, string newName);
}

public class RenameResourceUseCase<T>(IResourceCollection repo) : IRenameResourceUseCase<T> where T : Resource {
    public async Task ExecuteAsync(string originalName, string newName) {
        originalName = Normalize.SystemName(originalName);
        ThrowIfInvalid.ResourceName(originalName);

        newName = Normalize.SystemName(newName);
        ThrowIfInvalid.ResourceName(newName);

        Resource? existingResource = await repo.GetByNameAsync(newName);
        if (existingResource != null)
            throw new ConflictException($"{existingResource.Kind} resource '{newName}' already exists.");

        Resource? original = await repo.GetByNameAsync(originalName);
        if (original == null) throw new NotFoundException($"Resource '{originalName}' not found.");

        original.Name = newName;
        await repo.UpdateAsync(original);

        IReadOnlyList<Resource> children = await repo.GetDependantsAsync(originalName);
        foreach (Resource child in children) {
            child.RunsOn = child.RunsOn.ConvertAll<string>(p => p == originalName ? newName : p);
            await repo.UpdateAsync(child);
        }
    }
}