using System;
using System.Linq;
using System.Configuration;

namespace Website.DataAccess
{
    public class SqlContentProvider : IContentProvider
    {
        private readonly WebsiteDataContext _context;

        private static bool _ShouldRecreateDatabase = Parse.AppSetting<bool>("SqlContentProvider.RecreateDB");
        public static bool ShouldRecreateDatabase
        {
            get { return _ShouldRecreateDatabase; }
            set { _ShouldRecreateDatabase = value; }
        }

        protected IQueryable<Content> ContentTable
        {
            get { return _context.Contents; }
        }

        #region Constructors

        public SqlContentProvider(string connectionName)
        {
            var connString = ConfigurationManager.ConnectionStrings[connectionName];
            _context = new WebsiteDataContext(connString.ConnectionString);
            EnsureDatabase();
        }
        public SqlContentProvider(WebsiteDataContext context)
        {
            _context = context;
            EnsureDatabase();
        }

        #endregion

        protected void EnsureDatabase()
        {
            if (_context.DatabaseExists() && ShouldRecreateDatabase)
            {
                _context.DeleteDatabase();
                ShouldRecreateDatabase = false;
            }

            if (!_context.DatabaseExists())
                _context.CreateDatabase();
        }

        public IContent GetById(int id)
        {
            var content = ContentTable.FirstOrDefault(c => c.ID == id);
            return content;
        }

        public IContent GetByName(string url)
        {
            if (string.IsNullOrEmpty(url))
                return null;

            var lowerUrl = url.ToLowerInvariant();
            var content = ContentTable.FirstOrDefault(c => c.PageName.ToLower() == lowerUrl);
            return content;
        }

        public void Save(IContent content)
        {
            if (content == null)
                throw new ArgumentNullException("content");

            if(string.IsNullOrEmpty(content.PageName))
                throw new ArgumentNullException("content.PageName");

            if (content.ID == default(int))
                Insert(content);
            else
                Update(content);
        }

        protected void Update(IContent content)
        {
            if (!(content is Content))
                throw new NotImplementedException();
                
            _context.SubmitChanges();
        }

        protected void Insert(IContent content)
        {
            if (content == null)
                throw new ArgumentNullException("content");

            var dbContent = Content.FromIContent(content);
            _context.Contents.InsertOnSubmit(dbContent);
            _context.SubmitChanges();

            content.ID = dbContent.ID;
        }
    }

}