'use client';

import { useCallback, useEffect, useRef, type PointerEvent, type ReactNode } from 'react';
import { X } from 'lucide-react';
import { usePathname } from 'next/navigation';
import type { PublicPortfolio } from '@/server/content';
import { useDismissCaseStudy } from './PortfolioNavigation';
import { CaseStudyShare } from './CaseStudyShare';
import { useDrawerDrag } from './useDrawerDrag';
import styles from './CaseStudyDrawer.module.css';

export function CaseStudyDrawer({ children, portfolio }: { children: ReactNode; portfolio: PublicPortfolio }) {
  const copy = portfolio.messages.projects;
  const pathname = usePathname();
  const dismissRoute = useDismissCaseStudy();
  const dialogRef = useRef<HTMLDialogElement>(null);
  const sheetRef = useRef<HTMLDivElement>(null);
  const scrollRef = useRef<HTMLDivElement>(null);
  const backdropPressed = useRef(false);
  const closing = useRef(false);
  const returnFocusRef = useRef<HTMLElement | null>(null);
  const backgroundScrollY = useRef(0);

  const finishDismiss = useCallback(() => {
    const dialog = dialogRef.current;
    if (dialog?.open) dialog.close();
    returnFocusRef.current?.focus({ preventScroll: true });
    dismissRoute();
    requestAnimationFrame(() => {
      requestAnimationFrame(() => {
        window.scrollTo({ top: backgroundScrollY.current, behavior: 'instant' });
        returnFocusRef.current?.focus({ preventScroll: true });
      });
    });
  }, [dismissRoute]);

  const requestDismiss = useCallback((animate = true) => {
    if (closing.current) return;
    closing.current = true;
    const dialog = dialogRef.current;
    const sheet = sheetRef.current;
    const reduceMotion = window.matchMedia('(prefers-reduced-motion: reduce)').matches;

    if (!animate || reduceMotion || !dialog || !sheet) {
      finishDismiss();
      return;
    }

    dialog.dataset.state = 'closing';
    sheet.style.transition = 'transform 180ms var(--motion-ease-out)';
    sheet.style.transform = 'translateY(100%)';
    window.setTimeout(finishDismiss, 180);
  }, [finishDismiss]);

  const dragHandlers = useDrawerDrag({ sheetRef, onDismiss: requestDismiss });

  useEffect(() => {
    const dialog = dialogRef.current;
    if (!dialog) return;
    const root = document.documentElement;
    const previousOverflow = root.style.overflow;
    const skipMovement = root.dataset.caseStudyInput === 'keyboard';
    const recordedScrollY = Number(root.dataset.caseStudyScrollY);
    const activeElement = document.activeElement;
    returnFocusRef.current = activeElement instanceof HTMLElement && activeElement !== document.body
      ? activeElement
      : null;
    backgroundScrollY.current = Number.isFinite(recordedScrollY) ? recordedScrollY : window.scrollY;
    delete root.dataset.caseStudyInput;
    dialog.dataset.motion = skipMovement ? 'none' : 'standard';
    dialog.showModal();
    root.style.overflow = 'hidden';
    requestAnimationFrame(() => {
      dialog.dataset.state = 'open';
      dialog.querySelector<HTMLElement>('[data-case-study-initial-focus]')?.focus();
    });

    return () => {
      root.style.overflow = previousOverflow;
      if (dialog.open) dialog.close();
      if (returnFocusRef.current) {
        const restoreScroll = () => window.scrollTo({
          top: backgroundScrollY.current,
          behavior: 'instant',
        });
        restoreScroll();
        window.setTimeout(restoreScroll, 120);
        window.setTimeout(restoreScroll, 600);
      }
    };
  }, []);

  useEffect(() => {
    scrollRef.current?.scrollTo({ top: 0, behavior: 'auto' });
    requestAnimationFrame(() => {
      dialogRef.current?.querySelector<HTMLElement>('[data-case-study-initial-focus]')?.focus();
    });
  }, [pathname]);

  const handleBackdropDown = (event: PointerEvent<HTMLDialogElement>) => {
    backdropPressed.current = event.target === event.currentTarget;
  };

  const handleBackdropUp = (event: PointerEvent<HTMLDialogElement>) => {
    if (backdropPressed.current && event.target === event.currentTarget) requestDismiss();
    backdropPressed.current = false;
  };

  return (
    <dialog
      ref={dialogRef}
      className={styles.dialog}
      aria-labelledby="case-study-title"
      aria-describedby="case-study-introduction"
      data-state="opening"
      onCancel={(event) => {
        event.preventDefault();
        requestDismiss(false);
      }}
      onPointerDown={handleBackdropDown}
      onPointerUp={handleBackdropUp}
    >
      <div ref={sheetRef} className={styles.sheet}>
        <div className={styles.utilityHeader}>
          <div className={styles.dragTarget} aria-hidden="true" {...dragHandlers}>
            <span className={styles.dragHandle} />
          </div>
          <span className={styles.drawerLabel}>{copy.drawerLabel}</span>
          <div className={styles.actions}>
            <CaseStudyShare portfolio={portfolio} />
            <button
              type="button"
              className={styles.iconButton}
              onClick={(event) => requestDismiss(event.detail !== 0)}
              aria-label={copy.closeCaseStudy}
              data-case-study-initial-focus
              autoFocus
            >
              <X size={21} aria-hidden="true" />
            </button>
          </div>
        </div>
        <div ref={scrollRef} className={styles.scrollArea}>{children}</div>
      </div>
    </dialog>
  );
}