using System.Linq;
using System.Net;
using ParadoxSaveParser.WebAPI.BackgroundTasks;
using ParadoxSaveParser.WebAPI.HttpHelpers;

namespace ParadoxSaveParser.WebAPI.Routes;

public class UploadSaveHandler : RouteHandlerBase
{
    private readonly BackgroundJobManager _bgJobManager;
    private readonly Dictionary<Game, ISearchExpression> _searchQueries;

    public UploadSaveHandler(
        CancellationToken cancelAllToken, 
        BackgroundJobManager bgJobManager,
        Dictionary<Game, ISearchExpression> searchQueries) 
        : base(cancelAllToken)
    {
        _bgJobManager = bgJobManager;
        _searchQueries = searchQueries;
    }

    public override async Task<HttpStatusCode> HandleRequest(
        HttpListenerContext ctx, ContextLogger requestLogger)
    {
        string? contentType = ctx.Request.Headers.GetValues("Content-Type")?.FirstOrDefault();
        if (contentType != "application/octet-stream")
            return await ReturnHelper.ResponseError(ctx, requestLogger, _cancelAllToken,
                    new ErrorMessage(HttpStatusCode.BadRequest,
                $"Invalid request Content-Type: '{contentType}'")
                    );

        string saveId = Guid.NewGuid().ToString();
        var metaFilePath = PathHelper.GetMetaFilePath(saveId);
        if (File.Exists(metaFilePath))
            return await ReturnHelper.ResponseError(ctx, requestLogger, _cancelAllToken,
                    new ErrorMessage(HttpStatusCode.InternalServerError,
                $"Guid collision! file' {metaFilePath}' already exists.")
                    );

        var meta = new SaveFileMetadata
            { id = saveId, game = Game.EU4, status = SaveFileProcessingStatus.Initialized };
        if (!Program._saveMetadataStorage.TryAdd(saveId, meta))
            return await ReturnHelper.ResponseError(ctx, requestLogger, _cancelAllToken,
                    new ErrorMessage(HttpStatusCode.InternalServerError,
                $"Guid collision! Can't create metadata with id {saveId}")
                    );

        meta.status = SaveFileProcessingStatus.Uploading;
        var saveFilePath = PathHelper.GetSaveFilePath(meta.id);
        await using var saveFile = File.OpenWrite(saveFilePath);
        await using var remoteStream = ctx.Request.InputStream;
        await remoteStream.CopyToAsync(saveFile, _cancelAllToken);
        meta.status = SaveFileProcessingStatus.Uploaded;

        _bgJobManager.StartNewParsingOperation(meta, _searchQueries[meta.game], _cancelAllToken);
        dynamic responseData = new { saveId };
        return await ReturnHelper.ResponseJson(ctx, requestLogger, _cancelAllToken, responseData);
    }
}