using Application.Abstractions.Data;
using Application.Abstractions.Messaging;
using Application.Helpers;
using Domain.Entities.Developers;
using Microsoft.EntityFrameworkCore;
using SharedKernel.Results;

namespace Application.Features.Api.Developers.Tokens.IssuePat;

internal sealed class Handler(IAppDbContext db) : ICommandHandler<Command, Result<Response>>
{
    private const int MaxActivePatPerMember = 10;

    public async Task<Result<Response>> Handle(Command request, CancellationToken ct)
    {
        if (string.IsNullOrWhiteSpace(request.Name) || request.Name.Length > 100)
        {
            return Result.Failure<Response>(Error.Problem("Pat.NameInvalid", "Name is required (1-100 chars)."));
        }

        var activeCount = await db.ApiPersonalAccessToken
            .CountAsync(c => c.OwnerMemberID == request.OwnerMemberID && c.RevokedAt == null, ct);

        if (activeCount >= MaxActivePatPerMember)
        {
            return Result.Failure<Response>(Error.Problem("Pat.LimitExceeded", $"Max {MaxActivePatPerMember} active PAT per member."));
        }

        var token = ApiTokenGenerator.GeneratePat();
        var scopesCsv = string.Join(",", (request.Scopes ?? []).Where(s => !string.IsNullOrWhiteSpace(s)).Select(s => s.Trim()));

        var pat = ApiPersonalAccessToken.Create(
            request.OwnerMemberID,
            request.Name,
            ApiTokenGenerator.Hash(token),
            ApiTokenGenerator.Hint(token),
            scopesCsv,
            request.ExpiresAt
        );

        await db.ApiPersonalAccessToken.AddAsync(pat, ct);
        await db.SaveChangesAsync(ct);

        return Result.Success(new Response(
            pat.ID,
            pat.Name,
            token,
            pat.TokenHint,
            scopesCsv.Split(',', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries),
            pat.ExpiresAt,
            pat.CreatedAt
        ));
    }
}