"use client";

import React from "react";
import NextImage from "next/image";
import { RotateCw } from "lucide-react";
import {
  CANVAS_HANDLE_BASE_SIZE,
  CANVAS_ROTATE_HANDLE_BASE_SIZE,
} from "../lib/editor-constants";
import { buildFaceLabelOverlays } from "../lib/canvas-geometry";
import { renderLayerWithEffects } from "../lib/effects/registry";
import { getToolUiDefinition } from "../lib/tools/registry";
import { getToolDefinition } from "@pien-studio/editor-core";
import { useCanvasInteractions } from "../hooks/use-canvas-interactions";
import { useTranslations } from "../hooks/use-translations";
import { createStroke, paintSegment, type BrushStroke, type BrushOptions } from "../lib/brush-painter";
import type { Layer, LayerEffect } from "@pien-studio/types";

interface CanvasRendererProps {
  layers: Layer[];
  canvasWidth: number;
  canvasHeight: number;
  selectedLayerId: string | null;
  onSelectLayer: (id: string | null) => void;
  onMoveLayer: (id: string, x: number, y: number) => void;
  onMoveLayerEnd?: (id: string, x: number, y: number) => void;
  onResizeLayer?: (id: string, width: number, height: number) => void;
  onResizeLayerEnd?: (id: string, width: number, height: number) => void;
  onRotateLayer?: (id: string, rotation: number) => void;
  onRotateLayerEnd?: (id: string, rotation: number) => void;
  onInteractionStart?: () => void;
  onInteractionEnd?: () => void;
  onContextMenu?: (x: number, y: number) => void;
  isDark: boolean;
  tool?: string;
  onFillLayer?: (layerId: string, x: number, y: number) => void;
  brushOptions?: BrushOptions;
  onBrushCommit?: (layerId: string, stroke: BrushStroke) => void;
  faceDetections?: {
    x: number;
    y: number;
    width: number;
    height: number;
    label?: string;
  }[];
  faceOverlayLayerId?: string | null;
  faceBlurPreview?: {
    layerId: string;
    effects: LayerEffect[];
  } | null;
}

function BrushOverlayCanvas({ stroke, width, height }: { stroke: HTMLCanvasElement; width: number; height: number }) {
  const canvasRef = React.useRef<HTMLCanvasElement | null>(null);

  React.useEffect(() => {
    const el = canvasRef.current;
    if (!el) return;
    const ctx = el.getContext("2d");
    if (!ctx) return;
    ctx.clearRect(0, 0, el.width, el.height);
    ctx.drawImage(stroke, 0, 0, el.width, el.height);
  });

  return (
    <canvas
      ref={canvasRef}
      width={Math.max(1, Math.round(width))}
      height={Math.max(1, Math.round(height))}
      className="pointer-events-none absolute inset-0 h-full w-full rounded"
    />
  );
}

function EffectImageLayer({
  layer,
  width,
  height,
  effectsOverride,
}: {
  layer: Layer;
  width: number;
  height: number;
  effectsOverride?: LayerEffect[] | null;
}) {
  const canvasRef = React.useRef<HTMLCanvasElement | null>(null);
  const imageRef = React.useRef<HTMLImageElement | null>(null);

  const activeEffects = effectsOverride ?? layer.effects;

  const draw = React.useCallback(() => {
    const canvas = canvasRef.current;
    const image = imageRef.current;
    if (!canvas || !image) return;
    const ctx = canvas.getContext("2d");
    if (!ctx) return;
    ctx.clearRect(0, 0, canvas.width, canvas.height);
    renderLayerWithEffects(ctx, image, activeEffects, canvas.width, canvas.height);
  }, [activeEffects]);

  React.useEffect(() => {
    if (!layer.sourceUri) return;
    let canceled = false;
    const image = new Image();
    image.crossOrigin = "anonymous";
    image.onload = () => {
      if (canceled) return;
      imageRef.current = image;
      draw();
    };
    image.src = layer.sourceUri;
    return () => {
      canceled = true;
    };
  }, [draw, layer.sourceUri]);

  React.useEffect(() => {
    draw();
  }, [draw, width, height]);

  return (
    <canvas
      ref={canvasRef}
      width={Math.max(1, Math.round(width))}
      height={Math.max(1, Math.round(height))}
      className="pointer-events-none h-full w-full rounded object-cover"
    />
  );
}

export function CanvasRenderer({
  layers,
  canvasWidth,
  canvasHeight,
  selectedLayerId,
  onSelectLayer,
  onMoveLayer,
  onMoveLayerEnd,
  onResizeLayer,
  onResizeLayerEnd,
  onRotateLayer,
  onRotateLayerEnd,
  onInteractionStart,
  onInteractionEnd,
  onContextMenu,
  onFillLayer,
  brushOptions,
  onBrushCommit,
  isDark,
  tool = "pointer",
  faceDetections = [],
  faceOverlayLayerId = null,
  faceBlurPreview = null,
}: CanvasRendererProps) {
  const { t } = useTranslations();

  const brushStrokeRef = React.useRef<BrushStroke | null>(null);
  const brushLastPosRef = React.useRef<{ x: number; y: number } | null>(null);
  const [brushOverlay, setBrushOverlay] = React.useState<{ layerId: string; canvas: HTMLCanvasElement } | null>(null);

  const handleBrushStrokeStart = React.useCallback((layerId: string, x: number, y: number, layerWidth: number, layerHeight: number): void => {
    if (!brushOptions) return;
    const stroke = createStroke(layerWidth, layerHeight);
    brushStrokeRef.current = stroke;
    brushLastPosRef.current = { x, y };
    paintSegment(stroke, x, y, x, y, brushOptions);
    setBrushOverlay({ layerId, canvas: stroke.canvas });
  }, [brushOptions]);

  const handleBrushStrokeMove = React.useCallback((_layerId: string, x: number, y: number) => {
    if (!brushStrokeRef.current || !brushLastPosRef.current || !brushOptions) return;
    const { x: lx, y: ly } = brushLastPosRef.current;
    paintSegment(brushStrokeRef.current, lx, ly, x, y, brushOptions);
    brushLastPosRef.current = { x, y };
    setBrushOverlay((prev) => prev ? { ...prev } : prev);
  }, [brushOptions]);

  const handleBrushStrokeEnd = React.useCallback((layerId: string) => {
    const stroke = brushStrokeRef.current;
    brushStrokeRef.current = null;
    brushLastPosRef.current = null;
    setBrushOverlay(null);
    if (stroke && onBrushCommit) onBrushCommit(layerId, stroke);
  }, [onBrushCommit]);

  const {
    containerRef,
    viewport,
    isSpacePan,
    onContainerPointerDown,
    onContainerPointerMove,
    onContainerPointerUp,
    onLayerPointerDown,
    onResizeHandleDown,
    onRotateHandleDown,
    onTouchStart,
    onTouchMove,
    onTouchEnd,
    onContextMenuOpen,
  } = useCanvasInteractions({
    canvasWidth,
    canvasHeight,
    tool,
    onSelectLayer,
    onMoveLayer,
    onMoveLayerEnd,
    onResizeLayer,
    onResizeLayerEnd,
    onRotateLayer,
    onRotateLayerEnd,
    onInteractionStart,
    onInteractionEnd,
    onContextMenu,
    onFillLayer,
    onBrushStrokeStart: handleBrushStrokeStart,
    onBrushStrokeMove: handleBrushStrokeMove,
    onBrushStrokeEnd: handleBrushStrokeEnd,
  });

  const faceLabelOverlays = React.useMemo(() => {
    if (tool !== "face" || !faceOverlayLayerId || faceDetections.length === 0)
      return [];
    return buildFaceLabelOverlays(
      layers,
      faceOverlayLayerId,
      faceDetections,
      viewport,
    );
  }, [
    faceDetections,
    faceOverlayLayerId,
    layers,
    tool,
    viewport.scale,
    viewport.x,
    viewport.y,
  ]);

  return (
    <div
      ref={containerRef}
      className="relative overflow-hidden"
      style={{
        width: "100%",
        height: "100%",
        touchAction: "none",
        userSelect: "none",
        cursor: isSpacePan ? "grab" : (getToolUiDefinition(tool)?.cursor ?? "default"),
      }}
      onPointerDown={(e) => {
        if (getToolDefinition(tool)?.interactionMode === "select" && e.button === 0) onSelectLayer(null);
        onContainerPointerDown(e);
      }}
      onMouseDown={(e) => e.preventDefault()}
      onPointerMove={onContainerPointerMove}
      onPointerUp={onContainerPointerUp}
      onPointerCancel={onContainerPointerUp}
      onDoubleClick={(e) => {
        e.preventDefault();
        e.stopPropagation();
      }}
      onContextMenu={onContextMenuOpen}
      onTouchStart={onTouchStart}
      onTouchMove={onTouchMove}
      onTouchEnd={onTouchEnd}
    >
      <div
        style={{
          position: "absolute",
          top: 0,
          left: 0,
          width: canvasWidth,
          height: canvasHeight,
          willChange: "transform",
          transform: `translate(${viewport.x}px, ${viewport.y}px) scale(${viewport.scale})`,
          transformOrigin: "0 0",
          outline: `${2 / viewport.scale}px solid var(--color-accent-strong)`,
          background:
            "linear-gradient(45deg, #d0d0d0 25%, transparent 25%), linear-gradient(-45deg, #d0d0d0 25%, transparent 25%), linear-gradient(45deg, transparent 75%, #d0d0d0 75%), linear-gradient(-45deg, transparent 75%, #d0d0d0 75%)",
          backgroundSize: "16px 16px",
          backgroundPosition: "0 0, 0 8px, 8px -8px, -8px 0px",
        }}
      >
        {layers.map((layer, idx) => {
          const isSelected = layer.id === selectedLayerId;
          const isImage = layer.type === "raster";
          const layerWidth =
            layer.width ??
            (isImage ? Math.round(200 * layer.scale) : undefined);
          const layerHeight =
            layer.height ??
            (isImage ? Math.round(150 * layer.scale) : undefined);
          const handleSize = CANVAS_HANDLE_BASE_SIZE / viewport.scale;
          const handleSizePx = `${handleSize}px`;
          const largeHandleSize =
            CANVAS_ROTATE_HANDLE_BASE_SIZE / viewport.scale;
          const largeHandleSizePx = `${largeHandleSize}px`;

          return (
            <div
              key={layer.id}
              className="absolute"
              style={{
                left: layer.x,
                top: layer.y,
                width: layerWidth,
                height: layerHeight,
                transform: `rotate(${layer.rotation}deg)`,
                opacity: layer.opacity,
                display: layer.visible === false ? "none" : undefined,
                cursor: getToolUiDefinition(tool)?.cursor ?? "move",
                border: isSelected
                  ? "2px solid var(--color-accent-strong)"
                  : "1px dashed transparent",
                outline: isSelected
                  ? "2px solid var(--color-accent-strong)"
                  : "none",
                outlineOffset: "2px",
                zIndex: idx,
              }}
              onPointerDown={(e) => onLayerPointerDown(e, layer)}
              onClick={() => onSelectLayer(layer.id)}
            >
              {isImage && layer.sourceUri ? (
                layer.effects.length > 0 || (faceBlurPreview && faceBlurPreview.layerId === layer.id) ? (
                  <EffectImageLayer
                    layer={layer}
                    width={layerWidth ?? 1}
                    height={layerHeight ?? 1}
                    effectsOverride={
                      faceBlurPreview && faceBlurPreview.layerId === layer.id
                        ? faceBlurPreview.effects
                        : null
                    }
                  />
                ) : (
                  <NextImage
                    src={layer.sourceUri}
                    alt={layer.name ?? t("editor.layer")}
                    width={layerWidth ?? 1}
                    height={layerHeight ?? 1}
                    unoptimized
                    className="pointer-events-none h-full w-full rounded object-cover"
                    draggable={false}
                  />
                )
              ) : (
                <div
                  className={`flex items-center justify-center rounded border px-2 py-1 text-xs font-semibold ${
                    isSelected
                      ? "border-[var(--color-accent-strong)] bg-[var(--color-accent-strong)] text-white"
                      : isDark
                        ? "border-white/20 bg-[#2d3036] text-[#d7dae0]"
                        : "border-black/15 bg-white text-[#1f2430]"
                  }`}
                >
                  {layer.type}
                </div>
              )}
              {brushOverlay && brushOverlay.layerId === layer.id ? (
                <BrushOverlayCanvas stroke={brushOverlay.canvas} width={layerWidth ?? 1} height={layerHeight ?? 1} />
              ) : null}
              {tool === "face" && faceOverlayLayerId === layer.id
                ? faceDetections.map((face, index) => (
                    <div
                      key={`${layer.id}-face-${index}`}
                      className="absolute pointer-events-none border-2 border-[#00d2ff]"
                      style={{
                        left: face.x,
                        top: face.y,
                        width: face.width,
                        height: face.height,
                        zIndex: layers.length + 20 + index,
                        boxShadow: "0 0 0 1px rgba(0,0,0,0.35)",
                      }}
                    />
                  ))
                : null}
              {isSelected && tool === "pointer" && isImage && onResizeLayer ? (
                <>
                  <button
                    type="button"
                    className="absolute rounded-full border-2 border-white/80 bg-[var(--color-accent-strong)] shadow"
                    style={{
                      width: handleSizePx,
                      height: handleSizePx,
                      top: -handleSize / 2,
                      left: -handleSize / 2,
                    }}
                    onPointerDown={(e) => onResizeHandleDown(e, layer, "tl")}
                    title={t("editor.resize")}
                  />
                  <button
                    type="button"
                    className="absolute rounded-full border-2 border-white/80 bg-[var(--color-accent-strong)] shadow"
                    style={{
                      width: handleSizePx,
                      height: handleSizePx,
                      top: -handleSize / 2,
                      right: -handleSize / 2,
                    }}
                    onPointerDown={(e) => onResizeHandleDown(e, layer, "tr")}
                    title={t("editor.resize")}
                  />
                  <button
                    type="button"
                    className="absolute rounded-full border-2 border-white/80 bg-[var(--color-accent-strong)] shadow"
                    style={{
                      width: handleSizePx,
                      height: handleSizePx,
                      bottom: -handleSize / 2,
                      left: -handleSize / 2,
                    }}
                    onPointerDown={(e) => onResizeHandleDown(e, layer, "bl")}
                    title={t("editor.resize")}
                  />
                  <button
                    type="button"
                    className="absolute rounded-full border-2 border-white/80 bg-[var(--color-accent-strong)] shadow"
                    style={{
                      width: handleSizePx,
                      height: handleSizePx,
                      bottom: -handleSize / 2,
                      right: -handleSize / 2,
                    }}
                    onPointerDown={(e) => onResizeHandleDown(e, layer, "br")}
                    title={t("editor.resize")}
                  />
                  <div
                    className="absolute pointer-events-none"
                    style={{
                      top: -largeHandleSize,
                      left: "50%",
                      transform: "translateX(-50%)",
                      height: largeHandleSize,
                    }}
                  >
                    <div
                      className="w-px bg-[var(--color-accent-strong)]"
                      style={{
                        width: "1px",
                        height: "100%",
                        marginLeft: "0px",
                      }}
                    />
                    <button
                      type="button"
                      className="pointer-events-auto absolute top-0 left-1/2 -translate-x-1/2 rounded-full border-2 border-white/90 bg-[var(--color-accent-strong)] shadow flex items-center justify-center"
                      style={{
                        width: largeHandleSizePx,
                        height: largeHandleSizePx,
                      }}
                      onPointerDown={(e) => onRotateHandleDown(e, layer)}
                      title={t("editor.rotate")}
                    >
                      <RotateCw
                        className="text-white"
                        style={{
                          width: handleSize * 0.6,
                          height: handleSize * 0.6,
                        }}
                      />
                    </button>
                  </div>
                </>
              ) : null}
            </div>
          );
        })}
      </div>
      {faceLabelOverlays.map((label) => (
        <span
          key={label.id}
          className="pointer-events-none absolute rounded px-1.5 py-0.5 text-[10px] font-semibold whitespace-nowrap text-white"
          style={{
            left: label.left,
            top: label.top,
            background: "rgba(0, 210, 255, 0.9)",
            boxShadow: "0 2px 6px rgba(0,0,0,0.35), 0 0 0 1px rgba(0,0,0,0.22)",
            textShadow: "0 1px 1px rgba(0,0,0,0.35)",
            zIndex: layers.length + 100,
          }}
        >
          {label.text}
        </span>
      ))}
    </div>
  );
}