using Raylib_cs;
using System.Numerics;

namespace Sand.App;

internal static partial class SandApp
{
    private static void HandleSidebar(AppState state, Vector2 mouse)
    {
        if (mouse.X >= SidebarWidth)
        {
            return;
        }

        var y = 60;
        foreach (var category in state.Categories.Keys.Skip(state.CategoryScrollOffset).Take(GetVisibleCategoryRows()))
        {
            var rect = new Rectangle(12, y, 196, 32);
            if (Raylib.CheckCollisionPointRec(mouse, rect))
            {
                state.CurrentCategory = category;
                state.ParticleScrollOffset = 0;
                if (state.Categories[state.CurrentCategory].Count > 0)
                {
                    state.CurrentParticle = state.Categories[state.CurrentCategory][0].Id;
                }
                return;
            }

            y += 38;
        }

        y = 240;
        var visibleRows = GetVisibleParticleRows();
        foreach (var particle in state.Categories[state.CurrentCategory].Skip(state.ParticleScrollOffset).Take(visibleRows))
        {
            var rect = new Rectangle(12, y, 196, 24);
            if (Raylib.CheckCollisionPointRec(mouse, rect))
            {
                state.CurrentParticle = particle.Id;
                return;
            }

            y += 28;
        }

        var clearRect = new Rectangle(12, Raylib.GetScreenHeight() - 96, 196, 32);
        if (Raylib.CheckCollisionPointRec(mouse, clearRect))
        {
            state.Simulation.Clear();
            return;
        }

        var settingsRect = new Rectangle(12, Raylib.GetScreenHeight() - 54, 196, 32);
        if (Raylib.CheckCollisionPointRec(mouse, settingsRect))
        {
            state.SettingsVisible = !state.SettingsVisible;
            state.Settings.EnableDebug = state.SettingsVisible || state.Settings.EnableDebug;
        }
    }

    private static void HandleSettingsPanel(AppState state, Rectangle panelRect, Vector2 mouse)
    {
        if (!Raylib.CheckCollisionPointRec(mouse, panelRect))
        {
            return;
        }

        var y = panelRect.Y + 18;
        foreach (var item in state.SettingItems.Skip(state.SettingsScrollOffset).Take(GetVisibleSettingsRows(panelRect)))
        {
            var rowRect = new Rectangle(panelRect.X + 12, y, panelRect.Width - 24, 26);
            if (Raylib.CheckCollisionPointRec(mouse, rowRect))
            {
                item.Toggle();
                state.Simulation.RefreshSettingsState();
                return;
            }

            y += 34;
        }

        var speedDownRect = new Rectangle(panelRect.X + 12, panelRect.Y + panelRect.Height - 36, 48, 24);
        var speedUpRect = new Rectangle(panelRect.X + 72, panelRect.Y + panelRect.Height - 36, 48, 24);
        if (Raylib.CheckCollisionPointRec(mouse, speedDownRect))
        {
            state.Simulation.Settings.TimeScale = MathF.Max(0.1f, state.Simulation.Settings.TimeScale - 0.1f);
            state.SimulationAccumulator = 0f;
            return;
        }

        if (Raylib.CheckCollisionPointRec(mouse, speedUpRect))
        {
            state.Simulation.Settings.TimeScale = MathF.Min(4f, state.Simulation.Settings.TimeScale + 0.1f);
            state.SimulationAccumulator = 0f;
        }
    }

    private static int GetVisibleParticleRows()
    {
        return Math.Max(1, (Raylib.GetScreenHeight() - 404) / 28);
    }

    private static int GetVisibleCategoryRows()
    {
        return Math.Max(1, (240 - 60) / 38);
    }
}