"use client";

import { ArrowLeft, ArrowRight, ArrowUpLeft } from "lucide-react";
import { useEffect, useRef, useState } from "react";

import { Container } from "@/components/container";
import { MotionReveal } from "@/components/motion-reveal";
import { Button } from "@/components/ui/button";
import type { CarouselApi } from "@/components/ui/carousel";
import {
  Carousel,
  CarouselContent,
  CarouselItem,
} from "@/components/ui/carousel";
import { layout } from "@/lib/layout";
import { type, typeMeasure, typeSpacing } from "@/lib/typography";
import { cn } from "@/lib/utils";

const AUTOPLAY_MS = 4000;
const TWEEN_FACTOR_BASE = 0.84;
const SCALE_MIN = 0.8;
const SCALE_MAX = 1.05;
const OPACITY_MIN = 0.45;
const OPACITY_MAX = 1;

const projects17Prop = [
  {
    id: 1,
    title: "طراحی سایت سنگبری",
    profession: "سنگبری",
    image: "/assets/main-pic/100.jpg",
  },
  {
    id: 2,
    title: "طراحی سایت فروشگاهی کفش",
    profession: "فروشگاه کفش",
    image: "/assets/main-pic/101.jpg",
  },
  {
    id: 3,
    title: "طراحی سایت لوازم یدکی خودرو",
    profession: "لوازم یدکی خودرو",
    image: "/assets/main-pic/102.jpg",
  },
  {
    id: 4,
    title: "طراحی سایت لوازم یدکی",
    profession: "لوازم یدکی",
    image: "/assets/main-pic/103.jpg",
  },
  {
    id: 5,
    title: "طراحی سایت تجهیزات ساختمانی",
    profession: "تجهیزات ساختمانی",
    image: "/assets/main-pic/104.jpg",
  },
];

function numberWithinRange(value: number, min: number, max: number) {
  return Math.min(Math.max(value, min), max);
}

interface Projects17Props {
  className?: string;
}

export function Projects17({ className }: Projects17Props) {
  const [carouselApi, setCarouselApi] = useState<CarouselApi>();
  const [canScrollPrev, setCanScrollPrev] = useState(false);
  const [canScrollNext, setCanScrollNext] = useState(false);
  const [selectedIndex, setSelectedIndex] = useState(0);
  const [scrollSnaps, setScrollSnaps] = useState<number[]>([]);
  const tweenNodesRef = useRef<(HTMLElement | null)[]>([]);
  const tweenFactorRef = useRef(0);

  useEffect(() => {
    if (!carouselApi) return;

    const updateSelection = () => {
      setCanScrollPrev(carouselApi.canScrollPrev());
      setCanScrollNext(carouselApi.canScrollNext());
      setSelectedIndex(carouselApi.selectedScrollSnap());
      setScrollSnaps(carouselApi.scrollSnapList());
    };

    updateSelection();
    carouselApi.on("select", updateSelection);
    carouselApi.on("reInit", updateSelection);

    return () => {
      carouselApi.off("select", updateSelection);
      carouselApi.off("reInit", updateSelection);
    };
  }, [carouselApi]);

  // Continuous scale/opacity while scrolling (desktop only)
  useEffect(() => {
    if (!carouselApi) return;

    const desktop = window.matchMedia("(min-width: 768px)");

    const setTweenFactor = () => {
      tweenFactorRef.current =
        TWEEN_FACTOR_BASE * carouselApi.scrollSnapList().length;
    };

    const resetTween = () => {
      tweenNodesRef.current.forEach((node) => {
        if (!node) return;
        node.style.transform = "";
        node.style.opacity = "";
        node.style.zIndex = "";
      });
    };

    const tweenScale = () => {
      if (!desktop.matches) {
        resetTween();
        return;
      }

      const engine = carouselApi.internalEngine();
      const scrollProgress = carouselApi.scrollProgress();
      const slidesInView = carouselApi.slidesInView();

      carouselApi.scrollSnapList().forEach((scrollSnap, snapIndex) => {
        let diffToTarget = scrollSnap - scrollProgress;
        const slidesInSnap = engine.slideRegistry[snapIndex];

        slidesInSnap.forEach((slideIndex) => {
          const tweenNode = tweenNodesRef.current[slideIndex];
          if (!tweenNode) return;

          if (engine.options.loop) {
            engine.slideLooper.loopPoints.forEach((loopItem) => {
              const target = loopItem.target();
              if (slideIndex === loopItem.index && target !== 0) {
                const sign = Math.sign(target);
                if (sign === -1) {
                  diffToTarget = scrollSnap - (1 + scrollProgress);
                }
                if (sign === 1) {
                  diffToTarget = scrollSnap + (1 - scrollProgress);
                }
              }
            });
          }

          const tweenValue = 1 - Math.abs(diffToTarget * tweenFactorRef.current);
          const progress = numberWithinRange(tweenValue, 0, 1);
          const scale = SCALE_MIN + progress * (SCALE_MAX - SCALE_MIN);
          const opacity = OPACITY_MIN + progress * (OPACITY_MAX - OPACITY_MIN);

          if (slidesInView.includes(slideIndex) || progress > 0.01) {
            tweenNode.style.transform = `scale(${scale})`;
            tweenNode.style.opacity = String(opacity);
            tweenNode.style.zIndex = progress > 0.85 ? "1" : "0";
          }
        });
      });
    };

    const onReInit = () => {
      setTweenFactor();
      tweenScale();
    };

    const onDesktopChange = () => {
      setTweenFactor();
      tweenScale();
    };

    setTweenFactor();
    tweenScale();
    carouselApi.on("reInit", onReInit);
    carouselApi.on("scroll", tweenScale);
    carouselApi.on("slideFocus", tweenScale);
    desktop.addEventListener("change", onDesktopChange);

    return () => {
      carouselApi.off("reInit", onReInit);
      carouselApi.off("scroll", tweenScale);
      carouselApi.off("slideFocus", tweenScale);
      desktop.removeEventListener("change", onDesktopChange);
      resetTween();
    };
  }, [carouselApi]);

  // Desktop autoplay — paused on hover/focus; skipped for reduced motion & mobile
  useEffect(() => {
    if (!carouselApi) return;

    const reducedMotion = window.matchMedia("(prefers-reduced-motion: reduce)");
    const desktop = window.matchMedia("(min-width: 768px)");
    let timer: ReturnType<typeof setInterval> | undefined;
    let paused = false;

    const clear = () => {
      if (timer) {
        clearInterval(timer);
        timer = undefined;
      }
    };

    const tick = () => {
      clear();
      if (paused || reducedMotion.matches || !desktop.matches) return;
      timer = setInterval(() => {
        carouselApi.scrollNext();
      }, AUTOPLAY_MS);
    };

    const pause = () => {
      paused = true;
      clear();
    };

    const resume = () => {
      paused = false;
      tick();
    };

    const onPointerDown = () => clear();
    const onSettle = () => {
      if (!paused) tick();
    };
    const onChange = () => tick();

    const root = carouselApi.rootNode();
    root.addEventListener("mouseenter", pause);
    root.addEventListener("mouseleave", resume);
    root.addEventListener("focusin", pause);
    root.addEventListener("focusout", resume);
    reducedMotion.addEventListener("change", onChange);
    desktop.addEventListener("change", onChange);
    carouselApi.on("pointerDown", onPointerDown);
    carouselApi.on("settle", onSettle);
    tick();

    return () => {
      clear();
      root.removeEventListener("mouseenter", pause);
      root.removeEventListener("mouseleave", resume);
      root.removeEventListener("focusin", pause);
      root.removeEventListener("focusout", resume);
      reducedMotion.removeEventListener("change", onChange);
      desktop.removeEventListener("change", onChange);
      carouselApi.off("pointerDown", onPointerDown);
      carouselApi.off("settle", onSettle);
    };
  }, [carouselApi]);

  return (
    <section
      id="projects"
      className={cn(
        "section-shell bg-section-muted",
        layout.scrollMargin,
        layout.sectionY,
        className
      )}
    >
      <Container className="section-content">
        <MotionReveal>
          <div className="mb-10 flex flex-col gap-6 md:mb-12 md:flex-row md:items-end md:justify-between md:gap-8">
            <div className={cn(typeSpacing.sectionStack, "min-w-0 max-w-2xl")}>
              <p className={cn(type.eyebrow, "text-primary")}>پورتفولیو</p>
              <h2 className={type.h2}>نمونه کارها</h2>
              <p className={cn(type["section-intro"], typeMeasure.prose)}>
                نگاهی به وب‌سایت‌هایی که برای کسب‌وکارهای مختلف طراحی و پیاده‌سازی
                کرده‌ایم.
              </p>
            </div>

            <div className="hidden shrink-0 items-center gap-2 md:flex">
              <Button
                size="icon"
                variant="secondary"
                onClick={() => carouselApi?.scrollPrev()}
                disabled={!canScrollPrev}
                aria-label="پروژه قبلی"
                className="size-10 border-surface bg-background/90 shadow-surface-sm backdrop-blur-sm disabled:opacity-40"
              >
                <ArrowRight />
              </Button>
              <Button
                size="icon"
                variant="secondary"
                onClick={() => carouselApi?.scrollNext()}
                disabled={!canScrollNext}
                aria-label="پروژه بعدی"
                className="size-10 border-surface bg-background/90 shadow-surface-sm backdrop-blur-sm disabled:opacity-40"
              >
                <ArrowLeft />
              </Button>
            </div>
          </div>

          <div className="relative overflow-hidden">
            <div className="local-highlight local-highlight--soft" aria-hidden />

            <div className="relative z-[1]">
              <Carousel
                setApi={setCarouselApi}
                opts={{
                  align: "start",
                  loop: true,
                  direction: "rtl",
                  breakpoints: {
                    "(min-width: 768px)": {
                      align: "center",
                    },
                  },
                }}
                className="w-full"
              >
                <CarouselContent
                  className="-mr-3 ml-0 sm:-mr-4 md:-mr-5"
                  viewportClassName="overflow-hidden py-1 sm:py-2 md:py-6"
                >
                  {projects17Prop.map((project, index) => {
                    const isActive = index === selectedIndex;

                    return (
                      <CarouselItem
                        key={project.id}
                        className="basis-[85%] pr-3 pl-0 sm:basis-[70%] sm:pr-4 md:basis-[52%] md:pr-5 lg:basis-[40%]"
                      >
                        <a
                          ref={(node) => {
                            tweenNodesRef.current[index] = node;
                          }}
                          href="#"
                          aria-current={isActive ? "true" : undefined}
                          className={cn(
                            "media-frame group relative block aspect-[4/3] overflow-hidden rounded-xl",
                            "md:origin-center md:will-change-transform",
                            isActive && "md:shadow-glow-media"
                          )}
                        >
                          {/* eslint-disable-next-line @next/next/no-img-element */}
                          <img
                            src={project.image}
                            alt={project.title}
                            className={cn(
                              "absolute inset-0 size-full object-cover transition-transform duration-500 ease-out",
                              isActive && "md:group-hover:scale-105"
                            )}
                          />
                          <div
                            className={cn(
                              "absolute inset-0 bg-linear-to-t from-brand-neutral/90 via-brand-neutral/35 to-transparent transition-opacity duration-300",
                              isActive && "md:group-hover:opacity-95"
                            )}
                            aria-hidden
                          />
                          <div className="absolute inset-0 flex flex-col justify-end gap-1.5 p-4 sm:gap-2 sm:p-5">
                            <p className={cn(type.caption, "text-white/75")}>
                              {project.profession}
                            </p>
                            <h3
                              className={cn(
                                type.h3,
                                "text-base text-white transition-[font-size] duration-500 ease-out sm:text-lg",
                                isActive && "md:text-xl"
                              )}
                            >
                              {project.title}
                            </h3>
                          </div>
                          <span
                            className={cn(
                              "absolute start-3 top-3 flex size-8 items-center justify-center rounded-full border border-white/20 bg-white/10 text-white backdrop-blur-sm transition-all duration-200 sm:start-4 sm:top-4 sm:size-9",
                              isActive
                                ? "opacity-100 md:opacity-0 md:group-hover:opacity-100"
                                : "opacity-0"
                            )}
                            aria-hidden
                          >
                            <ArrowUpLeft className="size-4 transition-transform duration-200 group-hover:scale-110 sm:size-5" />
                          </span>
                        </a>
                      </CarouselItem>
                    );
                  })}
                </CarouselContent>
              </Carousel>
            </div>

            <div className="pointer-events-none absolute inset-x-0 top-0 z-10 flex aspect-[4/3] items-center justify-between md:hidden">
              <Button
                size="icon"
                variant="secondary"
                onClick={() => carouselApi?.scrollPrev()}
                disabled={!canScrollPrev}
                aria-label="پروژه قبلی"
                className="pointer-events-auto size-10 border-surface bg-background/90 shadow-surface-sm backdrop-blur-sm disabled:opacity-40"
              >
                <ArrowRight />
              </Button>
              <Button
                size="icon"
                variant="secondary"
                onClick={() => carouselApi?.scrollNext()}
                disabled={!canScrollNext}
                aria-label="پروژه بعدی"
                className="pointer-events-auto size-10 border-surface bg-background/90 shadow-surface-sm backdrop-blur-sm disabled:opacity-40"
              >
                <ArrowLeft />
              </Button>
            </div>
          </div>

          {scrollSnaps.length > 1 ? (
            <div
              className="mt-6 flex items-center justify-center gap-2 md:mt-8"
              role="tablist"
              aria-label="اسلایدهای نمونه کار"
            >
              {scrollSnaps.map((_, index) => (
                <button
                  key={index}
                  type="button"
                  role="tab"
                  aria-selected={index === selectedIndex}
                  aria-label={`اسلاید ${index + 1}`}
                  onClick={() => carouselApi?.scrollTo(index)}
                  className={cn(
                    "h-1.5 rounded-full transition-all duration-200",
                    index === selectedIndex
                      ? "w-6 bg-primary"
                      : "w-1.5 bg-muted-foreground/30 hover:bg-muted-foreground/50"
                  )}
                />
              ))}
            </div>
          ) : null}

          <div className="mt-10 flex justify-center md:mt-12">
            <Button asChild size="lg">
              <a href="#">
                مشاهده نمونه کارها
                <ArrowLeft />
              </a>
            </Button>
          </div>
        </MotionReveal>
      </Container>
    </section>
  );
}