using System;
using System.IO;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.RateLimiting;
using PromotionExchangeBLL;

namespace PromotionExchangeSL.Controllers;

// ============================================================
// PromotionExchangeController — Tier 2 store-and-forward for Metadata
// Promotion packages (see the plan's Transport section). Callers here are
// NOT GB5 tenant sessions — no LoginDTO, no "Login" header, no
// ResponseStandardDTO wrapper — they're origin/destination environments
// authenticating purely via X-Api-Key, exactly the shape DXP's vendor
// portal already proves works for a party that may not run this codebase
// at all. MVC controller (not a FastEndpoint/BaseEndpoint), matching this
// repo's established file-upload exception (GopFileUploadService et al.)
// AND because BaseEndpoint's LoginDTO assumptions don't apply here at all.
//
// The destination for List/Download is ALWAYS the caller's own resolved
// identity (from its authenticated API key) — never a request parameter —
// so one party can never see or fetch another party's packages.
// ============================================================
[ApiController]
[Route("[controller]")]
[EnableRateLimiting("promotion-exchange")]
public class PromotionExchangeController : ControllerBase
{
    private readonly IPromotionExchangeBLL _ExchangeBLL;

    public PromotionExchangeController(IPromotionExchangeBLL exchangeBLL) => _ExchangeBLL = exchangeBLL;

    [HttpPost("UploadPackage")]
    public async Task<IActionResult> UploadPackage(
        IFormFile file,
        [FromForm] string destinationEnvironmentCode,
        [FromHeader(Name = "X-Api-Key")] string apiKey,
        CancellationToken ct)
    {
        try
        {
            if (file is null || file.Length == 0)
                return BadRequest(new { error = "No package file provided or file is empty." });

            byte[] bytes;
            using (var ms = new MemoryStream())
            {
                await file.CopyToAsync(ms, ct);
                bytes = ms.ToArray();
            }

            var packageId = await _ExchangeBLL.UploadPackageAsync(apiKey, destinationEnvironmentCode, bytes, ct)
                .ConfigureAwait(false);

            return Ok(new { packageId });
        }
        catch (UnauthorizedAccessException ex)
        {
            return Unauthorized(new { error = ex.Message });
        }
        catch (Exception ex)
        {
            return BadRequest(new { error = ex.Message });
        }
    }

    [HttpGet("ListPendingPackages")]
    public async Task<IActionResult> ListPendingPackages(
        [FromHeader(Name = "X-Api-Key")] string apiKey, CancellationToken ct)
    {
        try
        {
            var pending = await _ExchangeBLL.ListPendingAsync(apiKey, ct).ConfigureAwait(false);
            return Ok(pending);
        }
        catch (UnauthorizedAccessException ex)
        {
            return Unauthorized(new { error = ex.Message });
        }
    }

    [HttpGet("DownloadPackage/{packageId:int}")]
    public async Task<IActionResult> DownloadPackage(
        int packageId, [FromHeader(Name = "X-Api-Key")] string apiKey, CancellationToken ct)
    {
        try
        {
            var package = await _ExchangeBLL.DownloadPackageAsync(apiKey, packageId, ct).ConfigureAwait(false);
            return File(package.PackageBytes, "application/octet-stream", $"promotion-package-{packageId}.gbpromo");
        }
        catch (UnauthorizedAccessException ex)
        {
            return Unauthorized(new { error = ex.Message });
        }
        catch (InvalidOperationException ex)
        {
            return NotFound(new { error = ex.Message });
        }
    }
}