using System;
using System.Collections.Generic;
using System.Linq;
using System.Web.Mvc;
using AutoMapper;
using AutoMapper.QueryableExtensions;
using InventoryTraker.Web.ActionResults;
using InventoryTraker.Web.Core;
using InventoryTraker.Web.Data;
using InventoryTraker.Web.Models;

namespace InventoryTraker.Web.Controllers
{
	public class InventoryController : ControllerBase
	{
		private readonly AppDbContext _context;

		public InventoryController(AppDbContext context)
		{
			_context = context;
		}

		public ActionResult Index()
		{
			return View();
		}

		public JsonResult All()
		{
			var viewModels =
				AllInventory()
				.ProjectTo<InventoryViewModel>()
				.ToArray();

			return BetterJson(viewModels);
		}

		private IQueryable<Inventory> AllInventory()
		{
			return _context
				.Inventories
				.Where(x => x.Quantity > 0)
				.OrderBy(x => x.InventoryType.Name);
		}

		public JsonResult Add(InventoryAddForm form)
		{
			if (!ModelState.IsValid)
				return GetModelStateErrorListJson();

			var inventory = Mapper.Map<Inventory>(form);
			inventory.InventoryType = _context.InventoryTypes.Find(form.InventoryTypeId);
			_context.Inventories.Add(inventory);
			inventory.Transactions = new List<Transaction>
			{
				new Transaction
				{
					TransactionType = TransactionType.Added,
					AddedQuantity = inventory.Quantity,
					CurrentQuantity = inventory.Quantity,
					Memo = "Arrival",
					Timestamp = DateTime.Now,
					TransactionDate = inventory.AddedDate
				}
			};
			_context.SaveChanges();

			var model = Mapper.Map<InventoryViewModel>(inventory);
			return BetterJson(model);
		}

		public JsonResult Distribute(InventoryDistributeForm form)
		{
			if (!ModelState.IsValid)
				return GetModelStateErrorListJson();

			foreach (var quantityForm in form.InventoryQuantities)
			{
				var inventory = _context.Inventories.Find(quantityForm.InventoryId);
				
				// check if it's really there
				if (inventory == null)
					return BetterJsonResult.Error($"Inventory {quantityForm.InventoryId} not found");
				
				if (inventory.Quantity < quantityForm.Quantity)
					return BetterJsonResult.Error(
						$"Inventory {inventory.InventoryType.Name} has only {inventory.Quantity}, trying to remove {quantityForm.Quantity}");
				inventory.Quantity -= quantityForm.Quantity;

				inventory.Transactions.Add(new Transaction
				{
					TransactionType = TransactionType.Distributed,
					RemovedQuantity = quantityForm.Quantity,
					CurrentQuantity = inventory.Quantity,
					Memo = "Distributed to " + form.Destination,
					Timestamp = DateTime.Now,
					TransactionDate = form.DistributedDate
				});
			}
			
			_context.SaveChanges();

			return BetterJson(AllInventory()
				.ProjectTo<InventoryViewModel>()
				.ToArray());
		}
	}
}