using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Website.Data;
using Website.ViewModels;

namespace Website.Controllers
{
	public class BlogController : Controller
	{
		const int MaxPostsPerPage = 10;
		private readonly BlogRepository _repo;

		public BlogController(BlogRepository repo)
		{
			_repo = repo;
		}

		public async Task<IActionResult> Page(int page)
		{
			var offset = (page - 1) * MaxPostsPerPage;
			var posts = (await _repo.GetLatestPostsAsync(MaxPostsPerPage, offset)).Select(p => new BlogPostPreviewViewModel(p));
			var maxPages = (await _repo.GetCountAsync()) / MaxPostsPerPage;
			var model = new BlogViewModel(posts, page, maxPages);
			return View(model);
		}

		public async Task<IActionResult> Entry(string url)
		{
			try {
				var post = await _repo.GetPostByUrlAsync(url);
				var model = new BlogPostViewModel(post);
				return View(model);
			} catch (InvalidOperationException) {
				return NotFound();
			}
		}
	}
}