using Microsoft.AspNetCore.Mvc;
using GrossesMitainesAPI.Models;
using System.Linq;
using GrossesMitainesAPI.Data;
using Microsoft.Extensions.Logging;

namespace GrossesMitainesAPI.Controllers;

[ApiController, Route("api/[controller]")]
public class InventoryController : Controller {
    private readonly ILogger<InventoryController> _logger;
    private readonly InventoryContext _context;

    public InventoryController(ILogger<InventoryController> logger, InventoryContext context) {
        _context = context;
        _logger = logger;
    }

    [HttpGet(Name = "Inventory")] // Pour faire des calls async par paquet de AMOUNT (5) (pour du loading en scrollant)
    public IEnumerable<Product> Get(int? lastId, string? order, string? filterPrice, string? filterState) {
        const int AMOUNT = 5;

        var ret = _context.Products.AsQueryable();

        switch (filterPrice) {
            case "PriceUnder20":
                ret = ret.Where(x => x.Price < 20);
                break;
            case "Price20to49":
                ret = ret.Where(x => x.Price >= 20 && x.Price < 50);
                break;
            case "Price50to99":
                ret = ret.Where(x => x.Price >= 50 && x.Price < 100);
                break;
            case "PriceOver100":
                ret = ret.Where(x => x.Price >= 100);
                break;
            default: break;
        }

        switch (filterState) {
            case "isAvailable":
                ret = ret.Where(x => x.Status == Product.States.Available);
                break;
            case "isUnavailable":
                ret = ret.Where(x => x.Status == Product.States.Unavailable);
                break;
            case "isBackOrder":
                ret = ret.Where(x => x.Status == Product.States.BackOrder);
                break; ;
            case "isClearance":
                ret = ret.Where(x => x.Status == Product.States.Clearance);
                break;
            case "isDiscontinued":
                ret = ret.Where(x => x.Status == Product.States.Discontinued);
                break;
            default: break;
        }

        switch (order) {
            case "Price":
                ret = ret.OrderBy(x => x.Status == Product.States.Promotion? x.PromoPrice: x.Price);
                break;
            case "PriceDesc":
                ret = ret.OrderByDescending(x => x.Status == Product.States.Promotion ? x.PromoPrice : x.Price);
                break;
            case "Title":
                ret = ret.OrderBy(x => x.Title);
                break;
            case "TitleDesc":
                ret = ret.OrderByDescending(x => x.Title);
                break;
            case "Category":
                ret = ret.OrderBy(x => x.Category);
                break;
            case "CategoryDesc":
                ret = ret.OrderByDescending(x => x.Category);
                break;
            default: break;
        }

        List<Product> lst = new();
        bool yup = false;
        int add = 0;

        if (lastId.HasValue)
            foreach (Product prod in new List<Product>(ret.ToList())) {
                if (yup && add < AMOUNT) {
                    lst.Add(prod);
                    add++;
                }
                if (prod.Id == lastId)
                    yup = true;
            }

        return lst;
    }

    // Inventory/Delete => Décrémenter un produit.
    [HttpDelete(Name = "Inventory")]
    public void Delete(int? id) {
        if (!id.HasValue) {
            _logger.LogError(8, "Delete sans Id.");
            return;
        }

        try {
            Product prod = _context.Products.First(x => x.Id == id);
            if (prod.Quantity > 0) { 
                prod.Quantity = prod.Quantity - 1;
                if (prod.Quantity == 0)
                    prod.Status = prod.Status == Product.States.Clearance? 
                                                 Product.States.Discontinued: 
                                                 Product.States.Unavailable;
            }
            else {
                _logger.LogError(8, "Vente de produit pas en stock.");
                return;
            }
            _context.Products.Update(prod);
            _context.SaveChanges();
        } catch (Exception e) {
            _logger.LogError(8, e.Message);
        }
    }
}