using System.Collections.Generic;
using System.Linq;
using System.Web.Mvc;
using Portoa.Web;

namespace VideoGameQuotes.Web.Models {
	public class BrowseModelBinder : IModelBinder {
		public object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext) {
			var model = new BrowseModel {
				SortMethod = SortMethod.Alphabetical,
				SortOrder = SortOrder.Ascending
			};

			var qualifierText = (controllerContext.RouteData.Values["qualifiers"] ?? string.Empty).ToString();
			if (string.IsNullOrEmpty(qualifierText)) {
				return model;
			}

			var segments = qualifierText.Split('/').ToArray();
			for (var i = 0; i < segments.Length; i++) {
				switch (segments[i]) {
					case "game":
					case "system":
					case "category":
					case "publisher":
						if (i < segments.Length - 1) {
							var ids = ParseCommaSeparatedIntegers(segments[i + 1]);
							switch (segments[i]) {
								case "game":
									model.GameIds = ids;
									break;
								case "system":
									model.SystemIds = ids;
									break;
								case "category":
									model.CategoryIds = ids;
									break;
								case "publisher":
									model.PublisherIds = ids;
									break;
							}

							i++; //loop unroll ftw
						}

						break;
					case "alphabetical":
						model.SortMethod = SortMethod.Alphabetical;
						break;
					case "date":
						model.SortMethod = SortMethod.Date;
						break;
					case "rating":
						model.SortMethod = SortMethod.Rating;
						break;
					case "asc":
						model.SortOrder = SortOrder.Ascending;
						break;
					case "desc":
						model.SortOrder = SortOrder.Descending;
						break;
					default:
						controllerContext.AddModelError("qualifiers", "Unknown qualifier: " + segments[i]);
						break;
				}
			}

			return model;
		}

		private static IEnumerable<int> ParseCommaSeparatedIntegers(string value) {
			foreach (var id in value.Split(',')) {
				int result;
				if (int.TryParse(id, out result)) {
					yield return result;
				}
			}
		}
	}
}