import { useMemo } from "react";
import type { AvatarExpression, AvatarState } from "./persona";

export type RasterVariant = "neutral" | "sad" | "tired" | "anxious" | "warm" | "startled";

const VARIANT_FOR_EXPRESSION: Record<AvatarExpression, RasterVariant> = {
  neutral: "neutral",
  calm: "neutral",
  bored: "neutral",
  determined: "neutral",
  warm: "warm",
  joy: "warm",
  delight: "warm",
  relief: "warm",
  hopeful: "warm",
  sad: "sad",
  grief: "sad",
  lonely: "sad",
  ashamed: "sad",
  guilty: "sad",
  overwhelmed: "sad",
  anxious: "anxious",
  confused: "anxious",
  conflicted: "anxious",
  embarrassed: "anxious",
  resistant: "anxious",
  guarded: "anxious",
  skeptical: "anxious",
  irritated: "anxious",
  angry: "anxious",
  rage: "anxious",
  startled: "startled",
  panic: "startled",
  tired: "tired",
};

export function rasterVariantFor(expression: AvatarExpression): RasterVariant {
  return VARIANT_FOR_EXPRESSION[expression];
}

export interface RasterBustProps {
  artSet: string;
  affect: AvatarExpression;
  state: AvatarState;
  breath: number;
  blink: number;
  mouth: number;
  gazeX: number;
  gazeY: number;
  headTilt: number;
  reduced: boolean;
}

const TX = "opacity 220ms cubic-bezier(0.22,0.61,0.36,1), transform 220ms cubic-bezier(0.22,0.61,0.36,1)";

function clamp01(value: number): number {
  return Math.min(1, Math.max(0, value));
}

function layerTransform(extra = ""): string {
  return `translateX(-50%)${extra ? ` ${extra}` : ""}`;
}

function mouthPartFor(variant: RasterVariant): string {
  return variant === "startled" ? "mouth-startled" : `mouth-${variant}`;
}

function browPoseFor(variant: RasterVariant): { y: number; rotate: number } {
  switch (variant) {
    case "sad":
      return { y: 1.4, rotate: -0.35 };
    case "tired":
      return { y: 1.8, rotate: -0.2 };
    case "anxious":
      return { y: -1.1, rotate: 0.25 };
    case "warm":
      return { y: -0.7, rotate: 0.12 };
    case "startled":
      return { y: -3.2, rotate: 0.1 };
    default:
      return { y: 0, rotate: 0 };
  }
}

export function RasterBust({
  artSet,
  affect,
  state,
  breath,
  blink,
  mouth,
  gazeX,
  gazeY,
  headTilt,
  reduced,
}: RasterBustProps) {
  const variant = rasterVariantFor(affect);
  const speaking = state === "speaking" && !reduced;
  const blinkClosed = reduced ? 0 : clamp01((1 - blink) / 0.92);
  const speakOverlay = speaking ? clamp01(mouth) : 0;
  const browPose = browPoseFor(variant);

  const stackTransform = `translate(${gazeX.toFixed(2)}px, ${(gazeY - breath).toFixed(
    2,
  )}px) rotate(${headTilt.toFixed(2)}deg)`;

  const part = useMemo(
    () => (name: string) => `${import.meta.env.BASE_URL}avatar/${artSet}/parts/${name}.png`,
    [artSet],
  );

  const hairPhase = reduced ? 0 : breath;
  const hairLeftTransform = layerTransform(
    `translate(${(hairPhase * 0.36).toFixed(2)}px, ${(hairPhase * -0.05).toFixed(
      2,
    )}px) rotate(${(hairPhase * -0.16).toFixed(2)}deg)`,
  );
  const hairRightTransform = layerTransform(
    `translate(${(hairPhase * -0.32).toFixed(2)}px, ${(hairPhase * -0.04).toFixed(
      2,
    )}px) rotate(${(hairPhase * 0.15).toFixed(2)}deg)`,
  );
  const bangsTransform = layerTransform(
    `translate(${(hairPhase * 0.12).toFixed(2)}px, ${(hairPhase * 0.08).toFixed(
      2,
    )}px) rotate(${(hairPhase * 0.08).toFixed(2)}deg)`,
  );
  const eyesTransform = layerTransform(
    `translate(${(gazeX * 0.22).toFixed(2)}px, ${(gazeY * 0.16).toFixed(2)}px)`,
  );
  const browTransform = layerTransform(
    `translate(${(gazeX * 0.08).toFixed(2)}px, ${(browPose.y + gazeY * 0.05).toFixed(
      2,
    )}px) rotate(${browPose.rotate.toFixed(2)}deg)`,
  );

  return (
    <div
      className="vg-raster"
      data-raster-art-set={artSet}
      data-raster-variant={variant}
      data-raster-speaking={speaking ? "true" : "false"}
      style={{ transform: stackTransform, transformOrigin: "50% 86%" }}
      aria-hidden="true"
    >
      <img
        className="vg-raster__layer vg-raster__layer--base"
        src={part("base-faceless")}
        alt=""
        loading="eager"
        decoding="async"
        draggable={false}
      />

      <img
        className="vg-raster__layer vg-raster__layer--hair"
        src={part("hair-left")}
        alt=""
        loading="eager"
        decoding="async"
        draggable={false}
        style={{
          opacity: reduced ? 0 : 0.16,
          transform: hairLeftTransform,
          transformOrigin: "34% 28%",
          transition: TX,
        }}
      />
      <img
        className="vg-raster__layer vg-raster__layer--hair"
        src={part("hair-right")}
        alt=""
        loading="eager"
        decoding="async"
        draggable={false}
        style={{
          opacity: reduced ? 0 : 0.16,
          transform: hairRightTransform,
          transformOrigin: "66% 28%",
          transition: TX,
        }}
      />
      <img
        className="vg-raster__layer vg-raster__layer--bangs"
        src={part("hair-bangs")}
        alt=""
        loading="eager"
        decoding="async"
        draggable={false}
        style={{
          opacity: reduced ? 0 : 0.2,
          transform: bangsTransform,
          transformOrigin: "50% 22%",
          transition: TX,
        }}
      />

      <img
        className="vg-raster__layer vg-raster__layer--brow"
        src={part(`brow-${variant}`)}
        alt=""
        loading="eager"
        decoding="async"
        draggable={false}
        style={{ opacity: 1, transform: browTransform, transformOrigin: "50% 30%", transition: TX }}
      />
      <img
        className="vg-raster__layer vg-raster__layer--eyes"
        src={part(`eyes-${variant}`)}
        alt=""
        loading="eager"
        decoding="async"
        draggable={false}
        style={{
          opacity: 1 - blinkClosed * 0.95,
          transform: eyesTransform,
          transformOrigin: "50% 32%",
          transition: TX,
        }}
      />
      <img
        className="vg-raster__layer vg-raster__layer--eyelid"
        src={part("eyelid-closed")}
        alt=""
        loading="eager"
        decoding="async"
        draggable={false}
        style={{ opacity: blinkClosed, transform: layerTransform(), transition: TX }}
      />
      <img
        className="vg-raster__layer vg-raster__layer--nose"
        src={part("nose-neutral")}
        alt=""
        loading="eager"
        decoding="async"
        draggable={false}
        style={{ transform: layerTransform() }}
      />
      <img
        className="vg-raster__layer vg-raster__layer--mouth"
        src={part(mouthPartFor(variant))}
        alt=""
        loading="eager"
        decoding="async"
        draggable={false}
        style={{
          opacity: 1 - speakOverlay * 0.78,
          transform: layerTransform(),
          transition: TX,
        }}
      />
      <img
        className="vg-raster__layer vg-raster__layer--mouthopen"
        src={part("mouth-open")}
        alt=""
        loading="eager"
        decoding="async"
        draggable={false}
        style={{
          opacity: speakOverlay,
          transform: layerTransform(`translateY(${(speakOverlay * 1.2).toFixed(2)}px)`),
          transformOrigin: "50% 40%",
          transition: TX,
        }}
      />
    </div>
  );
}