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

namespace MagicCarpetDatabase.Implementations;

internal class TourStorageContract(MagicCarpetDbContext dbContext, IStringLocalizer<Messages> localizer) : ITourStorageContract
{
    private readonly MagicCarpetDbContext _dbContext = dbContext;
    private readonly IStringLocalizer<Messages> _localizer = localizer;

    public List<TourDataModel> GetList()
    {
        try
        {
            return [.. _dbContext.Tours.Select(x => CustomMapper.MapObject<TourDataModel>(x))];
        }
        catch (Exception ex)
        {
            _dbContext.ChangeTracker.Clear();
            throw new StorageException(ex, _localizer);
        }
    }

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

    public async Task<List<TourHistoryDataModel>> GetHistoriesListAsync(CancellationToken ct)
    {
        try
        {
            return [.. await _dbContext.TourHistories.Include(x => x.Tour).Select(x => CustomMapper.MapObject<TourHistoryDataModel>(x)).ToListAsync(ct)];
        }
        catch (Exception ex)
        {
            _dbContext.ChangeTracker.Clear();
            throw new StorageException(ex, _localizer);
        }
    }

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

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

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

    public void UpdElement(TourDataModel tourDataModel)
    {
        try
        {
            var transaction = _dbContext.Database.BeginTransaction();
            try
            {
                var element = GetTourById(tourDataModel.Id) ?? throw new ElementNotFoundException(tourDataModel.Id, _localizer);
                if (element.Price != tourDataModel.Price)
                {
                    _dbContext.TourHistories.Add(new TourHistory() { TourId = element.Id, OldPrice = element.Price });
                    _dbContext.SaveChanges();
                }
                _dbContext.Tours.Update(CustomMapper.MapObject(tourDataModel, element));
                _dbContext.SaveChanges();
                transaction.Commit();
            }
            catch
            {
                transaction.Rollback();
                throw;
            }
        }
        catch (DbUpdateException ex) when (ex.InnerException is PostgresException { ConstraintName: "IX_Tours_TourName" })
        {
            _dbContext.ChangeTracker.Clear();
            throw new ElementExistsException("TourName", tourDataModel.TourName, _localizer);
        }
        catch (Exception ex) when (ex is ElementDeletedException || ex is ElementNotFoundException)
        {
            _dbContext.ChangeTracker.Clear();
            throw;
        }
        catch (Exception ex)
        {
            _dbContext.ChangeTracker.Clear();
            throw new StorageException(ex, _localizer);
        }
    }

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

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

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