import { Cropper, ImageRestriction } from "react-advanced-cropper";
import type { Coordinates, CropperRef } from "react-advanced-cropper";
import "react-advanced-cropper/dist/style.css";
import { useRef, useState } from "react";

import { calculateCropOutputSize, createCroppedImageFile } from "@/shared/lib/crop-image";
import type { CropRenderRequest } from "@/shared/lib/crop-image";
import { useModalFocus } from "@/shared/ui/use-modal-focus";

export type CropSourceImage = {
  readonly file: File;
  readonly height: number;
  readonly previewUrl: string;
  readonly release?: () => void;
  readonly width: number;
};

export type ImageCropPolicy = {
  readonly aspect: number | "free";
  readonly maxWidth: number;
  readonly noUpscale: boolean;
};

export type ImageCropDialogProps = {
  readonly image: CropSourceImage;
  readonly onApply: (file: File) => void;
  readonly onCancel: () => void;
  readonly open: boolean;
  readonly policy: ImageCropPolicy;
  readonly renderCrop?: (request: CropRenderRequest) => Promise<File>;
};

const MOVE_STEP = 10;

export function ImageCropDialog({ image, onApply, onCancel, open, policy, renderCrop = createCroppedImageFile }: ImageCropDialogProps) {
  const [applyError, setApplyError] = useState<string | null>(null);
  const [coordinates, setCoordinates] = useState<Coordinates | null>(null);
  const [isApplying, setIsApplying] = useState(false);
  const cropperRef = useRef<CropperRef>(null);
  const { dialogRef, trapFocus } = useModalFocus<HTMLElement>(open);
  const sourceAspect = image.width / image.height;
  const resolvedAspect = policy.aspect === "free" ? sourceAspect : policy.aspect;
  const baseWidth = sourceAspect > resolvedAspect ? Math.round(image.height * resolvedAspect) : image.width;
  const baseHeight = sourceAspect > resolvedAspect ? image.height : Math.round(image.width / resolvedAspect);
  const zoom = coordinates === null ? 1 : baseWidth / coordinates.width;
  const outputSize = calculateCropOutputSize({
    aspect: policy.aspect,
    maxWidth: policy.maxWidth,
    noUpscale: policy.noUpscale,
    sourceHeight: image.height,
    sourceWidth: image.width,
    zoom,
  });

  if (!open) {
    return null;
  }

  function updateCoordinates(cropper: CropperRef) {
    setCoordinates(cropper.getCoordinates());
  }

  function handleDialogKeyDown(event: React.KeyboardEvent<HTMLElement>) {
    if (event.key === "Escape") {
      event.preventDefault();
      event.stopPropagation();
      if (isApplying) {
        return;
      }
      onCancel();
      return;
    }

    trapFocus(event);
  }

  function handleCropperKeyDown(event: React.KeyboardEvent<HTMLDivElement>) {
    const cropper = cropperRef.current;
    if (cropper === null) {
      return;
    }

    switch (event.key) {
      case "ArrowDown":
        event.preventDefault();
        cropper.moveImage(0, MOVE_STEP);
        return;
      case "ArrowLeft":
        event.preventDefault();
        cropper.moveImage(-MOVE_STEP, 0);
        return;
      case "ArrowRight":
        event.preventDefault();
        cropper.moveImage(MOVE_STEP, 0);
        return;
      case "ArrowUp":
        event.preventDefault();
        cropper.moveImage(0, -MOVE_STEP);
        return;
      case "+":
      case "=":
        event.preventDefault();
        cropper.zoomImage(1.1);
        return;
      case "-":
        event.preventDefault();
        cropper.zoomImage(0.9);
        return;
      default:
    }
  }

  function resetCrop() {
    cropperRef.current?.reset();
  }

  async function applyCrop() {
    if (isApplying) {
      return;
    }

    const freshCoordinates = cropperRef.current?.getCoordinates() ?? {
      height: baseHeight,
      left: (image.width - baseWidth) / 2,
      top: (image.height - baseHeight) / 2,
      width: baseWidth,
    };

    const requestZoom = baseWidth / freshCoordinates.width;
    const renderedWidth = Math.round(baseWidth / requestZoom);
    const renderedHeight = Math.round(baseHeight / requestZoom);
    const centeredX = (image.width - renderedWidth) / 2;
    const centeredY = (image.height - renderedHeight) / 2;
    const requestOutputSize = calculateCropOutputSize({
      aspect: policy.aspect,
      maxWidth: policy.maxWidth,
      noUpscale: policy.noUpscale,
      sourceHeight: image.height,
      sourceWidth: image.width,
      zoom: requestZoom,
    });
    setApplyError(null);
    setIsApplying(true);

    try {
      const file = await renderCrop({
        aspect: policy.aspect,
        file: image.file,
        offsetX: (centeredX - freshCoordinates.left) * requestZoom,
        offsetY: (centeredY - freshCoordinates.top) * requestZoom,
        outputHeight: requestOutputSize.height,
        outputWidth: requestOutputSize.width,
        previewFrameHeight: baseHeight,
        previewFrameWidth: baseWidth,
        previewUrl: image.previewUrl,
        sourceHeight: image.height,
        sourceWidth: image.width,
        zoom: requestZoom,
      });
      onApply(file);
    } catch (error: unknown) {
      if (!(error instanceof Error)) {
        throw error;
      }
      setApplyError("이미지 crop을 적용하지 못했습니다.");
    } finally {
      setIsApplying(false);
    }
  }

  return (
    <div className="fixed inset-0 z-modal grid place-items-center bg-background/80 p-4">
      <section aria-label="이미지 crop" aria-modal="true" className="flex max-h-[calc(100dvh-2rem)] w-full max-w-lg flex-col gap-4 overflow-y-auto rounded-lg border border-border bg-card p-4 sm:p-6" onKeyDown={handleDialogKeyDown} ref={dialogRef} role="dialog">
        <div className="flex flex-col gap-2">
          <h2 className="text-xl font-semibold">이미지 crop</h2>
          <p className="text-sm text-muted-foreground">이미지를 이동하거나 확대해 사용할 영역을 선택한 뒤 적용합니다.</p>
        </div>
        <div aria-label="이미지 crop viewport" className="overflow-hidden rounded-lg border border-border bg-muted p-2 sm:p-4" onKeyDown={handleCropperKeyDown} role="application" tabIndex={0}>
          <Cropper
            canvas={false}
            checkOrientation={false}
            className="h-[min(56vh,28rem)] min-h-64 w-full rounded-md bg-muted"
            disabled={isApplying}
            imageRestriction={ImageRestriction.stencil}
            onChange={updateCoordinates}
            onReady={updateCoordinates}
            ref={cropperRef}
            src={image.previewUrl}
            stencilProps={{ aspectRatio: resolvedAspect, grid: true }}
          />
        </div>
        <p className="text-sm font-semibold text-info">예상 결과 {outputSize.width} × {outputSize.height}px</p>
        {applyError === null ? null : <p className="rounded-md border border-destructive bg-card p-3 text-sm font-semibold text-destructive" role="alert">{applyError}</p>}
        {isApplying ? <p className="rounded-md border border-border bg-card p-3 text-sm font-semibold" role="status">이미지 crop을 적용하는 중</p> : null}
        <div className="flex flex-wrap justify-end gap-2">
          <button className="min-h-11 rounded-md border border-input bg-card px-4 py-2 font-semibold hover:bg-accent disabled:opacity-60" disabled={isApplying} onClick={resetCrop} type="button">초기화</button>
          <button className="min-h-11 rounded-md border border-input bg-card px-4 py-2 font-semibold hover:bg-accent disabled:opacity-60" disabled={isApplying} onClick={onCancel} type="button">취소</button>
          <button className="min-h-11 rounded-md border border-input bg-primary px-4 py-2 font-semibold text-primary-foreground hover:bg-[var(--button-bg-hover)] active:bg-[var(--button-bg-active)] disabled:opacity-60" disabled={isApplying} onClick={() => void applyCrop()} type="button">적용</button>
        </div>
      </section>
    </div>
  );
}