using AutoMapper;
using MagicCarpetContracts.DataModels;
using MagicCarpetContracts.Exceptions;
using MagicCarpetContracts.StoragesContracts;
using MagicCarpetDatabase.Models;
using Microsoft.EntityFrameworkCore;
using Npgsql;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace MagicCarpetDatabase.Implementations;

internal class TourStorageContract : ITourStorageContract
{
    private readonly MagicCarpetDbContext _dbContext;
    private readonly Mapper _mapper;

    public TourStorageContract(MagicCarpetDbContext dbContext)
    {
        _dbContext = dbContext;
        var config = new MapperConfiguration(cfg =>
        {
            cfg.AddMaps(typeof(Tour));
        });
        _mapper = new Mapper(config);
    }
    public List<TourDataModel> GetList()
    {
        try
        {
            return [.. _dbContext.Tours.Select(x => _mapper.Map<TourDataModel>(x))];
        }
        catch (Exception ex)
        {
            _dbContext.ChangeTracker.Clear();
            throw new StorageException(ex);
        }
    }

    public List<TourHistoryDataModel> GetHistoryByTourId(string tourId)
    {
        try
        {
            return [.. _dbContext.TourHistories.Where(x => x.TourId == tourId).OrderByDescending(x => x.ChangeDate).Select(x => _mapper.Map<TourHistoryDataModel>(x))];
        }
        catch (Exception ex)
        {
            _dbContext.ChangeTracker.Clear();
            throw new StorageException(ex);
        }
    }

    public TourDataModel? GetElementById(string id)
    {
        try
        {
            return _mapper.Map<TourDataModel>(GetTourById(id));
        }
        catch (Exception ex)
        {
            _dbContext.ChangeTracker.Clear();
            throw new StorageException(ex);
        }
    }

    public TourDataModel? GetElementByName(string name)
    {
        try
        {
            return _mapper.Map<TourDataModel>(_dbContext.Tours.FirstOrDefault(x => x.TourName == name));
        }
        catch (Exception ex)
        {
            _dbContext.ChangeTracker.Clear();
            throw new StorageException(ex);
        }
    }

    public void AddElement(TourDataModel tourDataModel)
    {
        try
        {
            _dbContext.Tours.Add(_mapper.Map<Tour>(tourDataModel));
            _dbContext.SaveChanges();
        }
        catch (InvalidOperationException ex) when (ex.TargetSite?.Name == "ThrowIdentityConflict")
        {
            _dbContext.ChangeTracker.Clear();
            throw new ElementExistsException("Id", tourDataModel.Id);
        }
        catch (DbUpdateException ex) when (ex.InnerException is PostgresException { ConstraintName: "IX_Tours_TourName" })
        {
            _dbContext.ChangeTracker.Clear();
            throw new ElementExistsException("TourName", tourDataModel.TourName);
        }
        catch (Exception ex)
        {
            _dbContext.ChangeTracker.Clear();
            throw new StorageException(ex);
        }
    }

    public void UpdElement(TourDataModel tourDataModel)
    {
        try
        {
            var element = GetTourById(tourDataModel.Id) ?? throw new ElementNotFoundException(tourDataModel.Id);
            _dbContext.Tours.Update(_mapper.Map(tourDataModel, element));
            _dbContext.SaveChanges();
        }
        catch (ElementNotFoundException)
        {
            _dbContext.ChangeTracker.Clear();
            throw;
        }
        catch (DbUpdateException ex) when (ex.InnerException is PostgresException { ConstraintName: "IX_Tours_TourName" })
        {
            _dbContext.ChangeTracker.Clear();
            throw new ElementExistsException("TourName", tourDataModel.TourName);
        }
        catch (Exception ex)
        {
            _dbContext.ChangeTracker.Clear();
            throw new StorageException(ex);
        }
    }

    public void DelElement(string id)
    {
        try
        {
            var element = GetTourById(id) ?? throw new ElementNotFoundException(id);
            _dbContext.Tours.Remove(element);
            _dbContext.SaveChanges();
        }
        catch (ElementNotFoundException)
        {
            _dbContext.ChangeTracker.Clear();
            throw;
        }
        catch (Exception ex)
        {
            _dbContext.ChangeTracker.Clear();
            throw new StorageException(ex);
        }
    }

    public void ResElement(string id)
    {
        try
        {
            var element = GetTourById(id) ?? throw new ElementNotFoundException(id);
            _dbContext.SaveChanges();
        }
        catch
        {
            _dbContext.ChangeTracker.Clear();
            throw;
        }
    }

    private Tour? GetTourById(string id) => _dbContext.Tours.FirstOrDefault(x => x.Id == id);
}