using Microsoft.EntityFrameworkCore;
using WyvernInventory.Core.Interfaces.Repos;
using WyvernInventory.Core.Models;
using WyvernInventory.Infrastructure.Data;

namespace WyvernInventory.Infrastructure.Repos;

public class InventoryItemRepo(DBContext dbContext) : IInventoryItemRepo
{
    private DBContext _dbContext = dbContext;
    
    public async Task<List<InventoryItemDto>> GetAsync(List<InventoryItemRequest>? filterList = null)
    {
        return _dbContext.InventoryItems
            .Include(_ => _.AttributeValues)
            .Include(_ => _.Type)
            .Select(_ => new InventoryItemDto
            {
                Id = (int)_.Id!,
                Name = _.Name,
                AttributeValues = _.AttributeValues.Select(x => new InventoryAttributeValueDto
                {
                    Id = x.Id,
                    AttributeDefinitionId = (int)x.AttributeDefinitionId!,
                    AttributeDefinition = new InventoryAttributeDefinitionDto()
                    {
                        Id = x.AttributeDefinitionId,
                        Name = x.AttributeDefinition.Name,
                        DataType = x.AttributeDefinition.DataType
                    },
                    StringValue = x.StringValue,
                    IntValue = x.IntValue,
                    DecimalValue = x.DecimalValue,
                    BoolValue = x.BoolValue,
                    DateTimeValue = x.DateTimeValue
                }).ToList(),
                Type = new InventoryTypeDto()
                {
                    Id = _.TypeId,
                    Name = _.Type.Name,
                }
            })
            .ToList<InventoryItemDto>();
    }

    public async Task<(int created, int updated)> UpsertAsync(List<InventoryItemRequest> items)
    {
        var created = 0;
        var updated = 0;

        var itemsToCreate = items
            .Where(_ => _.Id is null or 0)
            .Select(_ => new InventoryItem
            {
                Name = _.Name,
                AttributeValues = _.AttributeValues?.Select(x => new InventoryAttributeValue
                {
                    Id = x.Id,
                    AttributeDefinitionId = x.AttributeDefinitionId,
                    BoolValue = x.BoolValue,
                    DateTimeValue = x.DateTimeValue,
                    DecimalValue = x.DecimalValue,
                    IntValue = x.IntValue,
                    StringValue = x.StringValue
                }).ToList(),
                TypeId =  _.TypeId
            })
            .ToList();

        var itemsToUpdate = items
            .Where(_ => _.Id is not null and not 0)
            .Select(_ => new InventoryItem
            {
                Id = _.Id,
                Name = _.Name,
                AttributeValues = _.AttributeValues?.Select(x => new InventoryAttributeValue
                {
                    Id = x.Id,
                    AttributeDefinitionId = x.AttributeDefinitionId,
                    BoolValue = x.BoolValue,
                    DateTimeValue = x.DateTimeValue,
                    DecimalValue = x.DecimalValue,
                    IntValue = x.IntValue,
                    StringValue = x.StringValue
                }).ToList(),
                TypeId =  _.TypeId
            })
            .ToList();

        if (itemsToCreate.Count > 0)
        {
            _dbContext.InventoryItems.AddRange(itemsToCreate);
            created = itemsToCreate.Count;
        }

        if (itemsToUpdate.Count > 0)
        {
            List<int> idList = itemsToUpdate.Select(_ =>
            {
                if (_.Id != null) return (int)_.Id;
                throw new NullReferenceException();
            }).ToList<int>();

            var existingItems = _dbContext.InventoryItems.ToList()
                .Where(_ => idList.Contains((int)_.Id!))
                .ToDictionary(_ => (int)_.Id!);

            foreach (var incoming in itemsToUpdate)
            {
                if (!existingItems.TryGetValue(incoming.Id!.Value, out var existing))
                    continue;

                existing.Name = incoming.Name;
                existing.AttributeValues = incoming.AttributeValues;

                updated++;
            }
        }
        
        await _dbContext.SaveChangesAsync();

        return (created, updated);
    }

    public async Task<int> DeleteAsync(List<InventoryItemRequest> items)
    {
        var itemsToDelete = _dbContext.InventoryItems.Where(_ => items.Select(_ => _.Id).Contains(_.Id)).ToList();
        
        _dbContext.InventoryItems.RemoveRange(itemsToDelete);
        
        return await _dbContext.SaveChangesAsync();
    }
}