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

namespace GrossesMitainesAPI.Controllers;

[EnableCors("_myAllowSpecificOrigins"), ApiController, Route("api/[controller]")]
public class SearchController : Controller {
    private readonly ILogger<SearchController> _logger;
    private readonly InventoryContext _context;
    private readonly DatabaseCacheService _cache;
    private Product[]? _searchCache = null;
    private const int PREVIEW = 4;

    public SearchController(ILogger<SearchController> logger, InventoryContext context, DatabaseCacheService cache) {
        _logger = logger;
        _context = context;
        _cache = cache;
        if (_cache.isOk()) // Se fait une copie de la cache si elle est fonctionnelle.
            _searchCache = _cache.GetCacheCopy();
    }

    [EnableCors("_myAllowSpecificOrigins"), HttpPost(Name = "Search")]
    public IEnumerable<Product> Post(string query, bool? preview, bool? deep) {
        if (_searchCache is not null)
            return SearchCached(query, preview, deep);
        else return Search(query, preview, deep);
    }

    private List<Product> Search(string query, bool? preview, bool? deep) {
        List<Product> products = new();
        query = query.Trim();
        try { // Pour faire une liste priorisée.
            if (preview.HasValue && preview == true)
                products = _context.Products.Where(x => x.Title.Contains(query)).Take(PREVIEW).ToList();
            else {
                if (deep.HasValue && deep == true) {
                    List<Product> title = new(), desc = new(), cat = new();
                    query = query.ToLower();
                    foreach (Product prod in _context.Products.ToList()) {
                        string sTitle = prod.Title.Replace(",", " ").ToLower(),
                               sCat = prod.Category.ToLower(),
                               sDesc = prod.Description.Replace(".", " ").Replace(",", " ").ToLower();
                        if (sTitle.StartsWith(query))
                            products.Add(prod);
                        else if (sTitle.Contains(" " + query + " "))
                            title.Add(prod);
                        else if (sDesc.StartsWith(query) || sDesc.Contains(" " + query + " "))
                            desc.Add(prod);
                        else if (sCat.Contains(query))
                            cat.Add(prod);
                    }
                    products.AddRange(title);
                    products.AddRange(desc);
                    products.AddRange(cat);
                } else {
                    products = _context.Products.Where(x => x.Title.Contains(query)).ToList();
                    foreach (Product prod in _context.Products.Where(x => x.Description.Contains(query)).ToArray())
                        if (!products.Contains(prod))
                            products.Add(prod);
                    foreach (Product prod in _context.Products.Where(x => x.Category.Contains(query)).ToArray())
                        if (!products.Contains(prod))
                            products.Add(prod);
                }
            }
        } catch (Exception e) {
            _logger.LogError(8, e.Message);
        }
        return products;
    }

    private List<Product> SearchCached(string query, bool? preview, bool? deep) {
        List<Product> products = new();
        query = query.Trim();
        if (_searchCache is null) {
            _logger.LogError(8, "Erreur de cache.");
            return Search(query, preview, deep); // Fallback vers version non-cached en cas d'erreur.
        }
        try { // Pour faire une liste priorisée.
            if (preview.HasValue && preview == true)
                products = _searchCache.Where(x => x.Title.Contains(query)).Take(PREVIEW).ToList();
            else {
                if (deep.HasValue && deep == true) {
                    List<Product> title = new(), desc = new(), cat = new();
                    query = query.ToLower();
                    foreach (Product prod in _searchCache) {
                        string sTitle = prod.Title.Replace(",", " ").ToLower(),
                               sCat = prod.Category.ToLower(),
                               sDesc = prod.Description.Replace(".", " ").Replace(",", " ").ToLower();
                        if (sTitle.StartsWith(query))
                            products.Add(prod);
                        else if (sTitle.Contains(" " + query + " "))
                            title.Add(prod);
                        else if (sDesc.StartsWith(query) || sDesc.Contains(" " + query + " "))
                            desc.Add(prod);
                        else if (sCat.Contains(query))
                            cat.Add(prod);
                    }
                    products.AddRange(title);
                    products.AddRange(desc);
                    products.AddRange(cat);
                } else {
                    products = _searchCache.Where(x => x.Title.Contains(query)).ToList();
                    foreach (Product prod in _searchCache.Where(x => x.Description.Contains(query)).ToArray())
                        if (!products.Contains(prod))
                            products.Add(prod);
                    foreach (Product prod in _searchCache.Where(x => x.Category.Contains(query)).ToArray())
                        if (!products.Contains(prod))
                            products.Add(prod);
                }
            }
        } catch (Exception e) {
            _logger.LogError(8, e.Message);
            return Search(query, preview, deep); // Fallback vers version non-cached en cas d'erreur.
        }
        return products;
    }
}