import type Phaser from 'phaser';

const defaultFaceCropRatio = 0.6;
const defaultFaceCropTopRatio = 0.035;

export type DialogueFacePortraitLayout = {
  cropX: number;
  cropY: number;
  cropSize: number;
  originX: number;
  originY: number;
  scale: number;
};

export function calculateDialogueFacePortraitLayout(
  sourceWidth: number,
  sourceHeight: number,
  displaySize: number
): DialogueFacePortraitLayout {
  if (
    !Number.isFinite(sourceWidth) ||
    !Number.isFinite(sourceHeight) ||
    !Number.isFinite(displaySize) ||
    sourceWidth <= 0 ||
    sourceHeight <= 0 ||
    displaySize <= 0
  ) {
    throw new RangeError('Dialogue portrait dimensions must be finite positive numbers.');
  }

  const cropSize = Math.max(
    1,
    Math.round(
      Math.min(sourceWidth, sourceHeight) * defaultFaceCropRatio
    )
  );
  const cropX = Math.round((sourceWidth - cropSize) / 2);
  const cropY = Math.round(
    Math.min(
      Math.max(0, sourceHeight * defaultFaceCropTopRatio),
      sourceHeight - cropSize
    )
  );

  return {
    cropX,
    cropY,
    cropSize,
    originX: (cropX + cropSize / 2) / sourceWidth,
    originY: (cropY + cropSize / 2) / sourceHeight,
    scale: displaySize / cropSize
  };
}

export function fitDialogueFacePortrait(
  portrait: Phaser.GameObjects.Image,
  displaySize: number
) {
  const layout = calculateDialogueFacePortraitLayout(
    portrait.frame.realWidth,
    portrait.frame.realHeight,
    displaySize
  );

  portrait
    .setCrop(
      layout.cropX,
      layout.cropY,
      layout.cropSize,
      layout.cropSize
    )
    .setOrigin(layout.originX, layout.originY)
    .setScale(layout.scale);

  return layout;
}