using AutoMapper;
using Microsoft.EntityFrameworkCore;
using Npgsql;
using SquirrelContract.DataModels;
using SquirrelContract.Exceptions;
using SquirrelContract.StoragesContracts;
using SquirrelDatabase.Models;

namespace SquirrelDatabase.Implementations;

public class CocktailStorageContract : ICocktailStorageContract
{
    private readonly SquirrelDbContext _dbContext;
    private readonly Mapper _mapper;

    public CocktailStorageContract(SquirrelDbContext dbContext)
    {
        _dbContext = dbContext;
        var config = new MapperConfiguration(cfg =>
        {
            cfg.CreateMap<Cocktail, CocktailDataModel>();
            cfg.CreateMap<CocktailDataModel, Cocktail>();
            cfg.CreateMap<CocktailHistory, CocktailHistoryDataModel>();
        });
        _mapper = new Mapper(config);
    }

    public List<CocktailDataModel> GetList()
    {
        try
        {
            return [.. _dbContext.Cocktails.Select(x => _mapper.Map<CocktailDataModel>(x))];
        }
        catch (Exception ex)
        {
            _dbContext.ChangeTracker.Clear();
            throw new StorageException(ex);
        }
    }

    public List<CocktailHistoryDataModel> GetHistoryByCocktailId(string cocktailId)
    {
        try
        {
            return [.. _dbContext.CocktailHistories.Include(x => x.Cocktail).Where(x => x.CocktailId == cocktailId).OrderByDescending(x => x.ChangeDate).Select(x => _mapper.Map<CocktailHistoryDataModel>(x))];
        }
        catch (Exception ex)
        {
            _dbContext.ChangeTracker.Clear();
            throw new StorageException(ex);
        }
    }

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

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

    public void AddElement(CocktailDataModel cocktailDataModel)
    {
        try
        {
            _dbContext.Cocktails.Add(_mapper.Map<Cocktail>(cocktailDataModel));
            _dbContext.SaveChanges();
        }
        catch (InvalidOperationException ex) when (ex.TargetSite?.Name == "ThrowIdentityConflict")
        {
            _dbContext.ChangeTracker.Clear();
            throw new ElementExistsException("Id", cocktailDataModel.Id);
        }
        catch (DbUpdateException ex) when (ex.InnerException is PostgresException { ConstraintName: "IX_Cocktails_CocktailName" })
        {
            _dbContext.ChangeTracker.Clear();
            throw new ElementExistsException("CocktailName", cocktailDataModel.CocktailName);
        }
        catch (Exception ex)
        {
            _dbContext.ChangeTracker.Clear();
            throw new StorageException(ex);
        }
    }

    public void UpdElement(CocktailDataModel cocktailDataModel)
    {
        try
        {
            var transaction = _dbContext.Database.BeginTransaction();
            try
            {
                var element = GetCocktailById(cocktailDataModel.Id) ?? throw new ElementNotFoundException(cocktailDataModel.Id);
                if (element.Price != cocktailDataModel.Price)
                {
                    _dbContext.CocktailHistories.Add(new CocktailHistory() { CocktailId = element.Id, OldPrice = element.Price });
                    _dbContext.SaveChanges();
                }
                _dbContext.Cocktails.Update(_mapper.Map(cocktailDataModel, element));
                _dbContext.SaveChanges();
                transaction.Commit();
            }
            catch
            {
                transaction.Rollback();
                throw;
            }
        }
        catch (DbUpdateException ex) when (ex.InnerException is PostgresException { ConstraintName: "IX_Cocktails_CocktailName" })
        {
            _dbContext.ChangeTracker.Clear();
            throw new ElementExistsException("CocktailName", cocktailDataModel.CocktailName);
        }
        catch (Exception ex) when (ex is ElementDeletedException || ex is ElementNotFoundException)
        {
            _dbContext.ChangeTracker.Clear();
            throw;
        }
        catch (Exception ex)
        {
            _dbContext.ChangeTracker.Clear();
            throw new StorageException(ex);
        }
    }

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

    private Cocktail? GetCocktailById(string id) => _dbContext.Cocktails.FirstOrDefault(x => x.Id == id);
}