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

namespace GrossesMitainesAPI.Controllers;

[EnableCors("_myAllowSpecificOrigins"), ApiController, Route("api/[controller]")]
public class InventoryController : Controller {
    private readonly ILogger<InventoryController> _logger;
    private readonly InventoryContext _context;
    private readonly DatabaseCacheService _cache;
    private static object _lock = new object();
    private const int AMOUNT_SCROLL = 5;

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

    [EnableCors("_myAllowSpecificOrigins"), 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, bool? all) {
        bool islock = false;
        IQueryable<Product> ret;
        if (_cache.isOk()) { 
            ret = _cache.queryCache();
            islock = true;
        }
        else 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;
            case "isPromoted":
                ret = ret.Where(x => x.Status == Product.States.Clearance || x.Status == Product.States.Promotion);
                break;
            default: break;
        }
        switch (order) {
            case "Price":
                ret = ret.OrderBy(x => x.Status == Product.States.Promotion || x.Status == Product.States.Clearance? x.PromoPrice: x.Price);
                break;
            case "PriceDesc":
                ret = ret.OrderByDescending(x => x.Status == Product.States.Promotion || x.Status == Product.States.Clearance ? 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;
        try {
            if (lastId.HasValue) { // Pour avoir les prochains peu importe l'ordre.
                List<Product> prods;
                if (islock)
                    lock (_lock) {
                        prods = ret.ToList();
                    }
                else prods = ret.ToList();
                foreach (Product prod in prods) {
                    if (yup && add < AMOUNT_SCROLL) {
                        lst.Add(prod);
                        add++;
                    }
                    if (prod.Id == lastId)
                        yup = true;
                }
            } else if (all.HasValue && all == true) {
                if (islock)
                    lock (_lock) {
                        lst = ret.ToList();
                    }
                else lst = ret.ToList();
            } else if (islock)
                lock (_lock) {
                    lst = ret.Take(AMOUNT_SCROLL).ToList();
                }
            else lst = ret.Take(AMOUNT_SCROLL).ToList();
            return lst;
        } catch (Exception e) {
            if (islock)
                _logger.LogError(e, "Erreur d'appel de cache.");
            else _logger.LogError(e, "Erreur d'appel d'API.");
            return new List<Product>();
        }
    }
    // Inventory/Delete => Décrémenter un produit. Va aller chercher directement dans la BD.
    [EnableCors("_myAllowSpecificOrigins"), HttpDelete(Name = "Inventory")]
    public ActionResult<int> Delete(int? id) {
        int rid = 0;
        if (!id.HasValue) {
            _logger.LogError(8, "Delete sans Id.");
            return BadRequest();
        }
        try {
            Product prod = _context.Products.First(x => x.Id == id);
            rid = prod.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.BackOrder;
            }
            else {
                _logger.LogError(8, "Vente de produit pas en stock.");
                return BadRequest();
            }
            _context.Products.Update(prod);
            _context.SaveChanges();
        } catch (Exception e) {
            _logger.LogError(8, e.Message);
            return BadRequest();
        }
        _cache.askForRefresh();
        return rid;
    }
}