namespace GrossesMitainesAPI.Controllers;

#region Dependencies
using GrossesMitainesAPI.Data;
using GrossesMitainesAPI.Models;
using GrossesMitainesAPI.Services;
using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Cors;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using Microsoft.AspNet.Identity;
using System.Data;
using System.Linq;

#endregion

[EnableCors("_myAllowSpecificOrigins"), ApiController, Route("api/[controller]"),
 Authorize(AuthenticationSchemes = "Identity.Application", Roles = "Administrateur")]
public class InvoiceController : Controller {
    #region DI Fields
    private readonly ILogger<InvoiceController> _logger;
    private readonly InventoryContext _context;
    private readonly DatabaseCacheService _cache;
    private readonly SignInManager<InventoryUser> _signInMan;
    private readonly Microsoft.AspNetCore.Identity.UserManager<InventoryUser> _userMan;

    #endregion

    #region Ctor
    public InvoiceController(ILogger<InvoiceController> logger, 
                             InventoryContext context, 
                             DatabaseCacheService cache,
                             Microsoft.AspNetCore.Identity.UserManager<InventoryUser> userMan) { 
        _logger = logger;
        _context = context;
        _cache = cache;
        _userMan = userMan;
    }

    #endregion

    #region API Methods
    [HttpGet, Route("GetList"), Authorize(Roles = "Client, Administrateur")]
    public async Task<ActionResult<List<InvoiceModel>>> Get(bool? all = false) {
        IList<string> roles;
        string id;
        try { // Trouver les rôles de l'utilisateur, assumer non-admin si impossible à trouver.
            roles = await _userMan.GetRolesAsync(await _userMan.GetUserAsync(_signInMan.Context.User));
        } catch (Exception e) {
            _logger.LogError(10, e.Message);
            roles = new List<string>();
        }

        try {
            id = _signInMan.Context.User.Identity.GetUserId();
            if (all is not null && all == true && roles.Contains("Administrateur"))
                return _context.Invoices.Include("LinkedAccount, ShippingAddress").ToList();
            else return _context.Invoices.Include("ShippingAddress").Where(x => x.LinkedAccount != null &&
                                                x.LinkedAccount.Id == id).ToList();
        } catch (Exception e) {
            _logger.LogError(10, e.Message);
            return BadRequest();
        }
    }

    [HttpGet, Route("Get"), Authorize(Roles = "Client, Administrateur")]
    public async Task<ActionResult<InvoiceModel>> Get(int id) {
        IList<string> roles;
        InvoiceModel inv;

        try { // Trouver les rôles de l'utilisateur, assumer non-admin si impossible à trouver.
            roles = await _userMan.GetRolesAsync(await _userMan.GetUserAsync(_signInMan.Context.User));
        } catch (Exception e) {
            _logger.LogError(10, e.Message);
            roles = new List<string>();
        }

        try {
            inv = _context.Invoices.Where(x => x.Id == id).Include("ShippingAddress").First();
        } catch (Exception e) {
            _logger.LogError(10, e.Message);
            return BadRequest();
        }

        if (roles.Contains("Administrateur") ||
            (inv.LinkedAccount is not null &&
            inv.LinkedAccount.Id == _signInMan.Context.User.Identity.GetUserId()))
            return inv;
        else return Unauthorized();
    }

    [HttpPost, AllowAnonymous]
    public async Task<ActionResult<InvoiceModel>> Post(InvoiceModel inv) {
        var user = await _userMan.GetUserAsync(_signInMan.Context.User);
        List<ProductModel> prods;

        if (user is not null)
            inv.LinkedAccount = user;
        inv.PurchaseDate = DateTime.Now; // Pour forcer la date.

        var prodcom = inv.Products.ToList();

        try {
            prods = _context.Products.Where(x => inv.Products.Select(x => x.Product).Contains(x)).ToList();
        } catch (Exception e) {
            _logger.LogError(8, e.Message);
            return BadRequest();
        }

        foreach (var prod in prodcom) { // Update de quantités dans l'inventaire.
            ProductModel inventProd = prods.Where(x => x.Id == prod.Product.Id).First();
            if (inventProd.Quantity > prod.Quantity)
                return BadRequest(); // TODO: retourner le produit qui ne peut pas être vendu.
            if (inventProd.Quantity == prod.Quantity) {
                inventProd.Quantity = 0;
                inventProd.Status = inventProd.Status == ProductModel.States.Clearance ?
                                                         ProductModel.States.Discontinued :
                                                         ProductModel.States.BackOrder;
            } else inventProd.Quantity -= prod.Quantity;
        }

        try { // Faire les updates dans la BD.
            _context.Invoices.Add(inv);
            _context.Products.UpdateRange(prods);
            _context.SaveChanges();
        } catch (Exception e) {
            _logger.LogError(8, e.Message);
            return BadRequest();
        }

        _cache.askForRefresh();
        return Ok(inv);
    }

    [HttpPost, Authorize(Roles = "Client, Administrateur")]
    public async  Task<ActionResult<InvoiceModel>> Cancel(int id) {
        InvoiceModel inv;
        IList<string> roles;

        try { // Trouver la commande.
            inv = _context.Invoices.Where(x => x.Id == id)
                                   .Include("Product").First();
        } catch (Exception e) {
            _logger.LogError(8, e.Message);
            return BadRequest();
        }

        try { // Trouver les rôles de l'utilisateur, assumer non-admin si impossible à trouver.
            roles = await _userMan.GetRolesAsync(await _userMan.GetUserAsync(_signInMan.Context.User));
        } catch (Exception e) {
            _logger.LogError(10, e.Message);
            roles = new List<string>();
        }

        // Pour ne pas pouvoir arbitrairement annuler la commande d'un autre client en tant que client.
        if (!((inv.LinkedAccount is not null && 
             inv.LinkedAccount.Id == _signInMan.Context.User.Identity.GetUserId()) ||
             roles.Contains("Administrateur")))
            return Unauthorized();

        inv.Status = InvoiceModel.InStates.Cancelled;

        foreach (var prod in inv.Products) // Revert l'inventaire.
            prod.Product.Quantity = prod.Product.Quantity + prod.Quantity;

        try {
            _context.Update(inv);
            _context.SaveChanges();
        } catch (Exception e) {
            _logger.LogError(8, e.Message);
            return BadRequest();
        }

        _cache.askForRefresh();

        return Ok(inv);
    }

    #endregion
}