using System;
using System.Diagnostics.Contracts;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Windows.Forms;
using Newtonsoft.Json;

namespace IPCamAppBar
{
    public partial class MainForm : Form
    {
        private readonly Config config;
        private readonly AppBar appBar;


        public MainForm()
        {
            InitializeComponent();

            // ReSharper disable once PossibleNullReferenceException
            // ReSharper disable once AssignNullToNotNullAttribute
            using (var file = File.OpenText(Path.Combine(Path.GetDirectoryName(Assembly.GetEntryAssembly().Location), "config.json")))
            {
                var serializer = new JsonSerializer();
                config = (Config)serializer.Deserialize(file, typeof(Config));
            }

            var monitor = GetMonitor(config.AppBar.Monitor);
            var position = GetAppBarPosition(config.AppBar.Side);

            appBar = new AppBar(Handle);
            appBar.SetPosition(monitor, position, config.AppBar.Size);

            config.Cameras?.ForEach(AddCamera);
        }


        protected override void WndProc(ref Message m)
        {
            appBar?.HandleMessage(m);
            base.WndProc(ref m);
        }


        private static Screen GetMonitor(int number)
        {
            // Since I could not find any way to get the numbers as assigned in the
            // display control panel, we'll just order them left-to-right.
            var orderedScreens = Screen.AllScreens.OrderBy(s => s.Bounds.Left).ToList();

            // 0 means primary. Yeah. Totally not losing geek-creds for using a 1-based
            // index here. No sir. 'tis a feature!
            return number > 0 && number <= orderedScreens.Count
                ? orderedScreens[number - 1]
                : Screen.PrimaryScreen;
        }


        private static AppBarPosition GetAppBarPosition(ConfigSide side)
        {
            switch (side)
            {
                case ConfigSide.Top: return AppBarPosition.Top;
                case ConfigSide.Bottom: return AppBarPosition.Bottom;
                case ConfigSide.Left: return AppBarPosition.Left;
                case ConfigSide.Right: return AppBarPosition.Right;
                default:
                    throw new ArgumentOutOfRangeException(nameof(side), side, @"Invalid side value");
            }
        }


        private void AddCamera(ConfigCamera camera)
        {
            var view = new CameraView(camera.URL)
            {
                Width = camera.Width, 
                Height = camera.Height
            };

            CameraViewContainer.Controls.Add(view);
        }


        private void MainForm_FormClosed(object sender, FormClosedEventArgs e)
        {
            appBar.Dispose();
        }


        private void CloseToolStripMenuItem_Click(object sender, EventArgs e)
        {
            Close();
        }
    }
}