package funkin.play.character;

import flixel.graphics.frames.FlxFramesCollection;
import funkin.modding.events.ScriptEvent;
import funkin.util.assets.FlxAnimationUtil;
import funkin.play.character.CharacterData.CharacterRenderType;

/**
 * For some characters which use Sparrow atlases, the spritesheets need to be split
 * into multiple files. This character renderer handles by showing the appropriate sprite.
 *
 * Examples in base game include BF Holding GF (most of the sprites are in one file
 * but the death animation is in a separate file).
 * Only example I can think of in mods is Tricky (which has a separate file for each animation).
 *
 * BaseCharacter has game logic, SparrowCharacter has only rendering logic.
 * KEEP THEM SEPARATE!
 *
 * TODO: Rewrite this to use a single frame collection.
 * @see https://github.com/HaxeFlixel/flixel/issues/2587#issuecomment-1179620637
 */
class MultiSparrowCharacter extends BaseCharacter
{
  /**
   * The actual group which holds all spritesheets this character uses.
   */
  var members:Map<String, FlxFramesCollection> = new Map<String, FlxFramesCollection>();

  /**
   * A map between animation names and what frame collection the animation should use.
   */
  var animAssetPath:Map<String, String> = new Map<String, String>();

  /**
   * The current frame collection being used.
   */
  var activeMember:String;

  public function new(id:String)
  {
    super(id, CharacterRenderType.MultiSparrow);
  }

  override function onCreate(event:ScriptEvent):Void
  {
    trace('Creating Multi-Sparrow character: ' + this.characterId);

    buildSprites();
    super.onCreate(event);
  }

  function buildSprites():Void
  {
    buildSpritesheets();
    buildAnimations();

    if (_data.isPixel)
    {
      this.isPixel = true;
      this.antialiasing = false;
    }
    else
    {
      this.isPixel = false;
      this.antialiasing = true;
    }
  }

  function buildSpritesheets():Void
  {
    // TODO: This currently works by creating like 5 frame collections and switching between them.
    // It would be better to refactor this to simply concatenate the frame collections together.

    // Build the list of asset paths to use.
    // Ignore nulls and duplicates.
    var assetList = [_data.assetPath];
    for (anim in _data.animations)
    {
      if (anim.assetPath != null && !assetList.contains(anim.assetPath))
      {
        assetList.push(anim.assetPath);
      }
      animAssetPath.set(anim.name, anim.assetPath);
    }

    // Load the Sparrow atlas for each path and store them in the members map.
    for (asset in assetList)
    {
      var texture:FlxFramesCollection = Paths.getSparrowAtlas(asset, 'shared');
      // If we don't do this, the unused textures will be removed as soon as they're loaded.

      if (texture == null)
      {
        trace('Multi-Sparrow atlas could not load texture: ${asset}');
      }
      else
      {
        trace('Adding multi-sparrow atlas: ${asset}');
        texture.parent.destroyOnNoUse = false;
        members.set(asset, texture);
      }
    }

    // Use the default frame collection to start.
    loadFramesByAssetPath(_data.assetPath);
  }

  /**
   * Replace this sprite's animation frames with the ones at this asset path.
   */
  function loadFramesByAssetPath(assetPath:String):Void
  {
    if (_data.assetPath == null)
    {
      trace('[ERROR] Multi-Sparrow character has no default asset path!');
      return;
    }
    if (assetPath == null)
    {
      // trace('Asset path is null, falling back to default. This is normal!');
      loadFramesByAssetPath(_data.assetPath);
      return;
    }

    if (this.activeMember == assetPath)
    {
      // trace('Already using this asset path: ${assetPath}');
      return;
    }

    if (members.exists(assetPath))
    {
      // Switch to a new set of sprites.
      // trace('Loading frames from asset path: ${assetPath}');
      this.frames = members.get(assetPath);
      this.activeMember = assetPath;
      this.setScale(_data.scale);
    }
    else
    {
      trace('[WARN] MultiSparrow character ${characterId} could not find asset path: ${assetPath}');
    }
  }

  /**
   * Replace this sprite's animation frames with the ones needed to play this animation.
   */
  function loadFramesByAnimName(animName)
  {
    if (animAssetPath.exists(animName))
    {
      loadFramesByAssetPath(animAssetPath.get(animName));
    }
    else
    {
      trace('[WARN] MultiSparrow character ${characterId} could not find animation: ${animName}');
    }
  }

  function buildAnimations()
  {
    trace('[MULTISPARROWCHAR] Loading ${_data.animations.length} animations for ${characterId}');

    // We need to swap to the proper frame collection before adding the animations, I think?
    for (anim in _data.animations)
    {
      loadFramesByAnimName(anim.name);
      FlxAnimationUtil.addAtlasAnimation(this, anim);

      if (anim.offsets == null)
      {
        setAnimationOffsets(anim.name, 0, 0);
      }
      else
      {
        setAnimationOffsets(anim.name, anim.offsets[0], anim.offsets[1]);
      }
    }

    var animNames = this.animation.getNameList();
    trace('[MULTISPARROWCHAR] Successfully loaded ${animNames.length} animations for ${characterId}');
  }

  public override function playAnimation(name:String, restart:Bool = false, ?ignoreOther:Bool = false, ?reverse:Bool = false):Void
  {
    // Make sure we ignore other animations if we're currently playing a forced one,
    // unless we're forcing a new animation.
    if (!this.canPlayOtherAnims && !ignoreOther) return;

    loadFramesByAnimName(name);
    super.playAnimation(name, restart, ignoreOther, reverse);
  }

  override function set_frames(value:FlxFramesCollection):FlxFramesCollection
  {
    // DISABLE THIS SO WE DON'T DESTROY OUR HARD WORK
    // WE WILL MAKE SURE TO LOAD THE PROPER SPRITESHEET BEFORE PLAYING AN ANIM
    // if (animation != null)
    // {
    // 	animation.destroyAnimations();
    // }

    if (value != null)
    {
      graphic = value.parent;
      this.frames = value;
      this.frame = value.getByIndex(0);
      this.numFrames = value.numFrames;
      resetHelpers();
      this.bakedRotationAngle = 0;
      this.animation.frameIndex = 0;
      graphicLoaded();
    }
    else
    {
      this.frames = null;
      this.frame = null;
      this.graphic = null;
    }

    return this.frames;
  }
}