using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Routing;
using System;
using System.Collections.Generic;
using System.Threading;
using System.Threading.Tasks;

namespace StellaOps.Policy.Engine.Endpoints;

public static class VerifyDeterminismEndpoints
{
    public static RouteGroupBuilder MapVerifyDeterminismEndpoints(this IEndpointRouteBuilder endpoints)
    {
        var group = endpoints.MapGroup("/api/v1/verify")
            .WithTags("Verification");

        group.MapPost("/determinism", HandleVerifyDeterminismAsync)
            .WithName("VerifyDeterminism")
            .WithDescription("Verify that a verdict can be deterministically replayed")
            .Produces<VerificationResult>(StatusCodes.Status200OK)
            .Produces(StatusCodes.Status400BadRequest);

        return group;
    }

    private static async Task<IResult> HandleVerifyDeterminismAsync(
        [FromBody] VerifyDeterminismRequest request,
        [FromServices] IReplayVerificationService verifyService,
        CancellationToken ct)
    {
        if (string.IsNullOrEmpty(request.SnapshotId) || string.IsNullOrEmpty(request.VerdictId))
        {
            return Results.BadRequest(new { error = "snapshotId and verdictId are required" });
        }

        var result = await verifyService.VerifyAsync(request.SnapshotId, request.VerdictId, ct);
        return Results.Ok(result);
    }
}

public record VerifyDeterminismRequest
{
    public string SnapshotId { get; init; } = string.Empty;
    public string VerdictId { get; init; } = string.Empty;
}

public record VerificationResult
{
    public string Status { get; init; } = "pending";
    public string OriginalDigest { get; init; } = string.Empty;
    public string ReplayedDigest { get; init; } = string.Empty;
    public string MatchType { get; init; } = "unknown";
    public List<Difference> Differences { get; init; } = new();
    public int Duration { get; init; }
    public DateTime VerifiedAt { get; init; } = DateTime.UtcNow;
}

public record Difference
{
    public string Field { get; init; } = string.Empty;
    public string Original { get; init; } = string.Empty;
    public string Replayed { get; init; } = string.Empty;
    public string Severity { get; init; } = "minor";
}

// Service interface (would be implemented elsewhere)
public interface IReplayVerificationService
{
    Task<VerificationResult> VerifyAsync(string snapshotId, string verdictId, CancellationToken ct = default);
}