using System;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using System.Collections.Generic;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Options;
using DigitalData.Modules.Interfaces;
using DigitalData.Modules.Logging;

namespace ZUGFeRDRESTService.Controllers
{    
    [Route("api/[controller]")]
    [ApiController]
    public class ValidationController : ControllerBase
    {
        public static string RESPONSE_OK = "OK";
        public static string RESPONSE_ERROR = "ERROR";

        private readonly ZUGFeRDInterface _zugferd;
        private readonly IDatabase _database;

        private readonly DigitalData.Modules.Logging.LogConfig _logConfig;
        private readonly DigitalData.Modules.Logging.Logger _logger;

        private readonly PropertyValues _props;
        private readonly Dictionary<String, XmlItemProperty> _propertyMap;

        public class ValidationResponse
        {
            public string status;
            public string message;
            public List<string> errors;
        
            public ValidationResponse()
            {
                status = RESPONSE_OK;
                message = String.Empty;
                errors = new List<string>();
            }
        }

        public ValidationController(ILogging logging, IDatabase database)
        {
            _logConfig = logging.LogConfig;
            _logger = _logConfig.GetLogger();

            _logger.Debug("Validation Controller initializing");

            _database = database;
            var oGDPictureKey = database.GetGDPictureKey();
            var oPropertyMap = database.GetPropertyMap();

            _propertyMap = oPropertyMap;

            _zugferd = new ZUGFeRDInterface(_logConfig, oGDPictureKey);
            _props = new PropertyValues(_logConfig);

            _logger.Debug("Validation Controller initialized!");
        }

        /// <summary>
        /// POST: api/Validation
        /// </summary>
        /// <param name="files">This parameter's name needs to correspond to the html form's file-input name</param>
        [HttpPost]
        public async Task<ValidationResponse> Post(IFormFile file, string user_id)
        {
            string oFilePath;
            string oFileName;

            oFilePath = Path.Combine(Path.GetTempPath(), file.FileName);
            oFileName = file.FileName;

            using FileStream oStream = new FileStream(oFilePath, FileMode.Create);
            await file.CopyToAsync(oStream);

            CrossIndustryDocumentType oDocument;

            try
            {
                oDocument = _zugferd.ExtractZUGFeRDFileWithGDPicture(oFilePath);
            }
            catch (Exception ex)
            {
                _logger.Error(ex);
                return new ValidationResponse()
                {
                    status = RESPONSE_ERROR,
                    message = "The uploaded file is not a valid ZUGFeRD Invoice!"
                };
            }

            try
            {
                PropertyValues.CheckPropertyValuesResult oResult = _props.CheckPropertyValues(oDocument, _propertyMap, "MESSAGEID");

                if (oResult.MissingProperties.Count > 0)
                {
                    return new ValidationResponse()
                    {
                        status = RESPONSE_ERROR,
                        message = "The uploaded file is a valid ZUGFeRD Invoice but missing some properties!",
                        errors = oResult.MissingProperties
                    };
                }
            }
            catch (Exception ex)
            {
                _logger.Error(ex);
                return new ValidationResponse()
                {
                    status = RESPONSE_ERROR,
                    message = "The uploaded file is not a valid ZUGFeRD Invoice!"
                };
            }
           
            return new ValidationResponse()
            {
                status = RESPONSE_OK,
                message = "The uploaded files is a valid ZUGFeRD Invoice!"
            };
        }
    }
}