using System.IO;
using ADOFAIRenderer.Core;
using ADOFAIRenderer.Util;
using HarmonyLib;
using UnityEngine;

namespace ADOFAIRenderer.Patch.Game;

/// <summary>
/// Patches of <c>scnGame</c> (custom level scene controller, also used by the editor's play mode): hides tiles and planets
/// for the "non-tile" render option and replaces the background video player during a render.
/// </summary>
[HarmonyPatch(typeof(scnGame))]
// ReSharper disable once InconsistentNaming
public static class scnGamePatch
{
    /// <summary>
    /// Postfix of <c>scnGame.Play(int seqID, bool remakeFloors)</c>, which starts (or restarts) play of the custom level:
    /// it resets the conductor, camera and controller state for the given start tile.
    /// <para>
    /// Active from stage Load when <c>AdvancedConfig.NonTile</c> is enabled. Disables the renderers of every floor in
    /// <c>scrLevelMaker.listFloors</c> (floor mesh, legacy sprite, icon, outline, top/bottom glow, multi-planet line,
    /// hold mesh, dummy planets) and of every planet of every player (sprite mesh, core/tail/sparks particles, ring, glow,
    /// face, samurai sprite), so only the background and decorations remain in the rendered video. The renderers are only
    /// disabled; the objects keep running. Hold meshes re-enable themselves, so <c>RenderManager.OnLastUpdate</c> disables
    /// them again every frame.
    /// </para>
    /// </summary>
    [HarmonyPostfix]
    [HarmonyPatch("Play")]
    public static void ProcessFloors()
    {
        if (RenderManager.Instance &&
            RenderManager.Instance.stage >= RenderStage.Load &&
            RenderManager.Instance.Configuration.AdvancedConfig.DisableTileCulling)
        {
            foreach (var floor in scrLevelMaker.instance.listFloors)
            {
                if (floor) floor.enabled = true;
            }
        }

        DecorationPatch.ProcessDecorations();

        var nonTile = RenderManager.Instance &&
                      RenderManager.Instance.stage >= RenderStage.Load &&
                      RenderManager.Instance.Configuration?.AdvancedConfig?.NonTile == true;

        if (!nonTile) return;
        foreach (var floor in scrLevelMaker.instance.listFloors)
        {
            DisableRenderers(
                floor.floorRenderer.renderer, floor.legacyFloorSpriteRenderer,
                floor.iconsprite, floor.outlineSprite, 
                floor.topGlow, floor.bottomGlow,
                floor.multiplanetLine
            );
                
            if (floor.holdRenderer) DisableRenderer(floor.holdRenderer.m_meshRenderer);
                
            if (floor.dummyPlanets == null) continue;
            foreach (var planet in floor.dummyPlanets)
                DisablePlanetRenderer(planet);
        }

        var players = scrPlayerManager.instance.players;
        if (players == null) return;
            
        foreach (var player in players)
        {
            var planets = player.planetarySystem?.planetList;
            if (planets == null) continue;

            foreach (var planet in planets)
                DisablePlanetRenderer(planet.planetRenderer);
        }
        return;

        // Disables every renderer that draws one planet (fire, ice, extra planets and floor dummy planets).
        void DisablePlanetRenderer(PlanetRenderer planet)
        {
            if (planet.sprite) DisableRenderer(planet.sprite.meshRenderer);
            DisableRenderers(
                planet.coreParticles.GetRenderer(), planet.tailParticles.GetRenderer(), 
                planet.tailParticlesCoop.GetRenderer(), planet.sparks.GetRenderer(), planet.ring, planet.glow, 
                planet.faceSprite, planet.faceDetails, planet.samuraiSprite
            );
        }

        void DisableRenderers(params Renderer?[] renderers)
        {
            foreach (var renderer in renderers) DisableRenderer(renderer);
        }

        // Sets Renderer.enabled = false; null or destroyed renderers are skipped (Unity null check).
        void DisableRenderer(Renderer? renderer)
        {
            if (renderer) renderer.enabled = false;
        }
    }
        
    /// <summary>
    /// Prefix of <c>scnGame.UpdateVideo()</c>, which sets up the level's background video on the native Unity
    /// <c>VideoPlayer</c> (<c>scnGame.videoBG</c>): it reads <c>miscSettings.bgVideo</c>, loads a <c>VideoClip</c> for internal
    /// (Resources / Addressables) and bundle levels or sets <c>videoBG.url</c> to the file next to the custom level, then calls
    /// <c>Stop()</c>, <c>Prepare()</c> and sets <c>isLooping</c> from <c>loopVideo</c>. The game calls it from
    /// <c>scnGame.FinishCustomLevelLoading</c> and from <c>scnGame.ReloadAssets</c> when <c>force</c> is true.
    /// <para>
    /// While <see cref="RenderManager.IsActive"/> (stage &gt;= OnScene), an external video file of a custom level is played by
    /// <see cref="VideoBGPlayer"/> (FFmpeg decoder), which shows the frame for the render time of each frame. The native
    /// <c>VideoPlayer</c> plays in real time and would drift from the offline render clock, so it is disabled for that case.
    /// Internal and bundle levels (built-in <c>VideoClip</c> assets, not files) and a missing file use the original method.
    /// </para>
    /// <para>Outside a render, any <see cref="VideoBGPlayer"/> left on the video object is destroyed and the native player re-enabled.</para>
    /// </summary>
    /// <param name="__instance">The scene controller.</param>
    /// <returns>True to run the original UpdateVideo; false when the mod handled the video (or there is none).</returns>
    [HarmonyPrefix]
    [HarmonyPatch("UpdateVideo")]
    // ReSharper disable once InconsistentNaming
    public static bool ReplaceVideo(scnGame __instance)
    {
        // Only replace when rendering is active
        if (!RenderManager.IsActive)
        {
            // Remove FFmpeg player if it was attached previously
            var oldPlayer = __instance.videoBG.gameObject.GetComponent<VideoBGPlayer>();
            if (oldPlayer) Object.Destroy(oldPlayer);
            
            // Re-enable native player component
            __instance.videoBG.enabled = true;
            return true; // Execute original
        }

        string text = __instance.levelData.miscSettings.GetString("bgVideo");
        if (string.IsNullOrEmpty(text))
        {
            __instance.videoBG.gameObject.SetActive(false);
            return false; // Skip original
        }

        __instance.videoBG.gameObject.SetActive(true);

        // We can only play external video files via FFmpegNativeDecoder.
        // Internal/Bundle level background videos are built-in VideoClips, so we fall back to native Unity VideoPlayer.
        if (ADOBase.isInternalLevel || ADOBase.isBundleLevel)
        {
            __instance.videoBG.enabled = true;
            return true; // Execute original
        }

        // Custom level video path
        var videoPath = Path.Combine(Path.GetDirectoryName(ADOBase.levelPath) ?? "", text);
        if (!File.Exists(videoPath))
        {
            return true; // Let the original print error
        }

        // Camera for the CameraFarPlane render mode: the VideoPlayer's target camera, or the "BGStaticCam" scene object
        // when none is assigned.
        var targetCamera = __instance.videoBG.targetCamera;
        if (!targetCamera)
        {
            var camGo = GameObject.Find("BGStaticCam");
            if (camGo != null)
            {
                targetCamera = camGo.GetComponent<Camera>();
            }
        }

        // Disable the native VideoPlayer so it does not play the video in real time alongside VideoBGPlayer.
        __instance.videoBG.enabled = false;

        // Add or retrieve our custom FFmpeg video background player
        if (!__instance.videoBG.gameObject.TryGetComponent<VideoBGPlayer>(out var player))
        {
            player = __instance.videoBG.gameObject.AddComponent<VideoBGPlayer>();
        }

        var isLooping = __instance.levelData.miscSettings.GetBool("loopVideo");
            
        // Initialize player. If targetTexture is null (CameraFarPlane mode), it will build a quad in front of targetCamera.
        player.Init(videoPath, __instance.videoBG.targetTexture, isLooping, targetCamera, __instance.videoBG.gameObject);

        return false; // Skip original UpdateVideo
    }
}