using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using Luneraria.Core;
using Luneraria.View;
using NUnit.Framework;
using UnityEngine;
using UnityEngine.UIElements;

namespace Luneraria.UI.Tests
{
    /// <summary>
    /// The real game for the U3 tests (port of the helpers of tools/luneraria/verify_g3.gd): the G1
    /// scene with its game controller, a human seat, the HUD and the camera rendering into textures
    /// of one size, so screen points of the camera and of the HUD agree. Input goes through the
    /// real paths: UI Toolkit pointer events for the HUD, LuneGame.Key and ClickField for keys and
    /// the field. Nothing sets HUD state directly; public match state (round, HP, gold, claims) is
    /// set like Godot's g3_views.gd did.
    /// </summary>
    public sealed class HudSession
    {
        public const int Human = 1;
        public LuneGame Game;
        public LuneHud Hud;
        public LuneMatchDriver Driver;
        public LuneMatchView View;
        public LuneCameraRig Rig;
        public Camera Camera;
        public RenderTexture Target;
        RenderTexture _sceneTarget;
        public int Width;
        public int Height;

        public LuneMatch Match { get { return Driver.Runner.Match; } }
        public LuneMatchRunner Runner { get { return Driver.Runner; } }
        public LuneHudModel Model { get { return Hud.Model; } }
        public Player Me { get { return Match.Players[Human]; } }

        public static string Root { get { return Path.GetDirectoryName(Application.dataPath); } }

        /// <summary>Loads the scene and starts a match with the human seat, HUD into a width×height texture.</summary>
        public IEnumerator Open(int width = 1920, int height = 1080, int seed = 4, float uiScale = 1f, bool reducedMotion = false, int startRound = 1, int extraGold = 0, string[] bunds = null, bool extended = false)
        {
            LunePreferences.ResetSession(uiScale, reducedMotion);
            yield return HudCaptureTests.LoadScene();
            Width = width;
            Height = height;
            Game = Object.FindAnyObjectByType<LuneGame>();
            Assert.IsNotNull(Game, "the scene has a game controller");
            Driver = Game.Driver;
            View = Game.View;
            Rig = Game.Rig;
            Camera = View.ViewCamera != null ? View.ViewCamera : Camera.main;
            Target = new RenderTexture(width, height, 0, RenderTextureFormat.ARGB32);
            // MSAA like the player (URP asset 4×); a camera target texture sets the sample count itself.
            _sceneTarget = new RenderTexture(width, height, 24, RenderTextureFormat.ARGB32) { antiAliasing = 4 };
            Camera.targetTexture = _sceneTarget;
            Game.Target = Target;
            Driver.HumanSlot = Human;
            Driver.Seed = seed;
            Driver.StartRound = startRound;
            Driver.ExtraGold = extraGold;
            Driver.Bunds = bunds;
            Driver.Extended = extended;
            Driver.Speed = 1f;
            Driver.Restart();
            yield return Frames(3);
            Hud = Game.Hud;
            Assert.AreSame(Driver.Runner.Match, Hud.Match, "the HUD shows the driver's match");
            Game.StartCamera(true);
            yield return Frames(2);
        }

        public void Close()
        {
            if (Camera != null)
                Camera.targetTexture = null;
            Target?.Release();
            _sceneTarget?.Release();
        }

        public static IEnumerator Frames(int count)
        {
            for (int index = 0; index < count; index++)
                yield return null;
        }

        /// <summary>The HUD rebuilds now (Godot sync()).</summary>
        public void Sync()
        {
            Hud.MarkDirty();
            Hud.Tick(0f);
        }

        /// <summary>HUD time passes (tooltips, feed, rates) without simulating the match.</summary>
        public void Tick(float seconds, float step = .02f)
        {
            for (float time = 0f; time < seconds - 1e-4f; time += step)
                Hud.Tick(step);
        }

        // ---------------------------------------------------------------- pointer input (UI Toolkit events)
        IPanel Panel { get { return Hud.Root.panel; } }

        public void Pointer(Vector2 at, EventType type)
        {
            var source = new Event { type = type, mousePosition = at, button = 0, clickCount = 1 };
            EventBase evt = type == EventType.MouseDown ? PointerDownEvent.GetPooled(source)
                : type == EventType.MouseUp ? PointerUpEvent.GetPooled(source)
                : (EventBase)PointerMoveEvent.GetPooled(source);
            using (evt)
                Panel.visualTree.SendEvent(evt);
        }

        public static Vector2 Center(VisualElement element)
        {
            return element.worldBound.center;
        }

        public void MoveTo(Vector2 at) { Pointer(at, EventType.MouseMove); }

        public void ClickAt(Vector2 at)
        {
            Pointer(at, EventType.MouseMove);
            Pointer(at, EventType.MouseDown);
            Pointer(at, EventType.MouseUp);
        }

        /// <summary>A real click on an element (pointer move, down and up at its centre).</summary>
        public void Click(VisualElement element)
        {
            Assert.IsNotNull(element);
            Assert.IsTrue(Visible(element), "click on a hidden element: " + element.name + " " + element.GetType().Name);
            ClickAt(Center(element));
            Sync();
        }

        /// <summary>
        /// A real click on an element that may just have been rebuilt: one layout frame first (a
        /// player can only click what is drawn), then pointer move, down and up, then a sync.
        /// </summary>
        public IEnumerator Tap(System.Func<VisualElement> find)
        {
            yield return null;
            VisualElement element = find();
            Assert.IsNotNull(element, "nothing to tap");
            Assert.IsTrue(Visible(element), "tap on a hidden element: " + element.GetType().Name);
            Rect bound = element.worldBound;
            Assert.IsFalse(float.IsNaN(bound.width) || bound.width <= 0f, "tap on an element without layout: " + element.GetType().Name);
            ClickAt(bound.center);
            Sync();
            yield return null;
        }

        public LuneTooltip Hover(VisualElement element, float wait = .35f)
        {
            MoveTo(Center(element));
            Tick(wait);
            return Hud.Tooltip;
        }

        public void Leave()
        {
            MoveTo(new Vector2(-50f, -50f));
            Tick(.05f);
        }

        // ---------------------------------------------------------------- queries
        public static bool Visible(VisualElement element)
        {
            for (VisualElement node = element; node != null; node = node.parent)
            {
                if (node.style.display == DisplayStyle.None)
                    return false;
            }
            return element.panel != null;
        }

        /// <summary>All visible text of the HUD (Godot texts(root)).</summary>
        public string Texts(VisualElement root = null)
        {
            var parts = new List<string>();
            root = root ?? Hud.Root;
            root.Query<TextElement>().ForEach(text =>
            {
                if (Visible(text) && !string.IsNullOrEmpty(text.text))
                    parts.Add(text.text);
            });
            return string.Join("\n", parts);
        }

        public T First<T>(System.Func<T, bool> where = null) where T : VisualElement
        {
            return Hud.Root.Query<T>().ToList().FirstOrDefault(e => Visible(e) && (where == null || where(e)));
        }

        public LuneButton ButtonWithText(string text, VisualElement root = null)
        {
            return (root ?? Hud.Root).Query<LuneButton>().ToList().FirstOrDefault(b => Visible(b) && b.Text == text);
        }

        // ---------------------------------------------------------------- match helpers (public state, like g3_views.gd)
        public IEnumerator Starter()
        {
            yield return Tap(() => ButtonWithText("Startaufstellung"));
        }

        /// <summary>Plays the running combat to its end through the host loop (no HUD shortcuts).</summary>
        public IEnumerator FinishCombat(int maxFrames = 20000)
        {
            int frames = 0;
            while (Runner.Current == LuneMatchRunner.Stage.Combat && frames++ < maxFrames)
            {
                Runner.Advance(.25);
                if (frames % 20 == 0)
                    yield return null;
            }
            Runner.Advance(.02);
            yield return Frames(2);
            Sync();
        }

        /// <summary>Steps the combat for some simulated seconds.</summary>
        public IEnumerator Fight(double seconds)
        {
            double done = 0.0;
            while (done < seconds && Runner.Current == LuneMatchRunner.Stage.Combat)
            {
                Runner.Advance(.05);
                done += .05;
            }
            yield return Frames(2);
            Sync();
        }

        // ---------------------------------------------------------------- screenshots
        public void Capture(string relative)
        {
            LunePortraits.Shared?.Flush();
            Camera.Render();
            Texture2D scene = LuneHudCapture.Read(_sceneTarget);
            Texture2D overlay = LuneHudCapture.Read(Target);
            Texture2D image = LuneHudCapture.Compose(scene, overlay);
            LuneHudCapture.Save(image, Path.Combine(Root, relative));
            Object.Destroy(scene);
            Object.Destroy(overlay);
            Object.Destroy(image);
        }

        /// <summary>Waits until portraits and the HUD have caught up, then captures.</summary>
        public IEnumerator Shot(string relative)
        {
            Sync();
            LunePortraits.Shared?.Flush();
            yield return Frames(3);
            Capture(relative);
        }
    }
}