<script setup lang="ts">
import { motion } from 'motion-v';
import { computed, nextTick, onMounted, onUnmounted, ref, watch } from 'vue';

interface TrueFocusProps {
  sentence?: string;
  manualMode?: boolean;
  blurAmount?: number;
  borderColor?: string;
  glowColor?: string;
  animationDuration?: number;
  pauseBetweenAnimations?: number;
}

const props = withDefaults(defineProps<TrueFocusProps>(), {
  sentence: 'True Focus',
  manualMode: false,
  blurAmount: 5,
  borderColor: 'green',
  glowColor: 'rgba(0, 255, 0, 0.6)',
  animationDuration: 0.5,
  pauseBetweenAnimations: 1
});

const words = computed(() => props.sentence.split(' '));
const currentIndex = ref(0);
const lastActiveIndex = ref<number | null>(null);
const containerRef = ref<HTMLDivElement>();
const wordRefs = ref<HTMLSpanElement[]>([]);
const focusRect = ref({ x: 0, y: 0, width: 0, height: 0 });

let interval: number | null = null;

watch(
  [() => props.manualMode, () => props.animationDuration, () => props.pauseBetweenAnimations, words],
  () => {
    if (interval) {
      clearInterval(interval);
      interval = null;
    }

    if (!props.manualMode) {
      interval = setInterval(
        () => {
          currentIndex.value = (currentIndex.value + 1) % words.value.length;
        },
        (props.animationDuration + props.pauseBetweenAnimations) * 1000
      );
    }
  },
  { immediate: true }
);

watch(
  [currentIndex, words.value.length],
  async () => {
    if (currentIndex.value === null || currentIndex.value === -1) return;
    if (!wordRefs.value[currentIndex.value] || !containerRef.value) return;

    await nextTick();

    const parentRect = containerRef.value.getBoundingClientRect();
    const activeRect = wordRefs.value[currentIndex.value].getBoundingClientRect();

    focusRect.value = {
      x: activeRect.left - parentRect.left,
      y: activeRect.top - parentRect.top,
      width: activeRect.width,
      height: activeRect.height
    };
  },
  { immediate: true }
);

const handleMouseEnter = (index: number) => {
  if (props.manualMode) {
    lastActiveIndex.value = index;
    currentIndex.value = index;
  }
};

const handleMouseLeave = () => {
  if (props.manualMode) {
    currentIndex.value = lastActiveIndex.value || 0;
  }
};

const setWordRef = (el: HTMLSpanElement | null, index: number) => {
  if (el) {
    wordRefs.value[index] = el;
  }
};

onMounted(async () => {
  await nextTick();

  if (wordRefs.value[0] && containerRef.value) {
    const parentRect = containerRef.value.getBoundingClientRect();
    const activeRect = wordRefs.value[0].getBoundingClientRect();

    focusRect.value = {
      x: activeRect.left - parentRect.left,
      y: activeRect.top - parentRect.top,
      width: activeRect.width,
      height: activeRect.height
    };
  }
});

onUnmounted(() => {
  if (interval) {
    clearInterval(interval);
  }
});
</script>

<template>
  <div class="relative flex flex-wrap justify-center items-center gap-[1em]" ref="containerRef">
    <span
      v-for="(word, index) in words"
      :key="index"
      :ref="el => setWordRef(el as HTMLSpanElement, index)"
      class="relative font-black text-5xl transition-[filter,color] duration-300 ease-in-out cursor-pointer"
      :style="{
        filter: index === currentIndex ? 'blur(0px)' : `blur(${blurAmount}px)`,
        '--border-color': borderColor,
        '--glow-color': glowColor,
        transition: `filter ${animationDuration}s ease`
      }"
      @mouseenter="handleMouseEnter(index)"
      @mouseleave="handleMouseLeave"
    >
      {{ word }}
    </span>

    <motion.div
      class="top-0 left-0 box-content absolute border-none pointer-events-none"
      :animate="{
        x: focusRect.x,
        y: focusRect.y,
        width: focusRect.width,
        height: focusRect.height,
        opacity: currentIndex >= 0 ? 1 : 0
      }"
      :transition="{
        duration: animationDuration
      }"
      :style="{
        '--border-color': borderColor,
        '--glow-color': glowColor
      }"
    >
      <span
        class="top-[-10px] left-[-10px] absolute [filter:drop-shadow(0_0_4px_var(--border-color,#fff))] border-[3px] border-[var(--border-color,#fff)] border-r-0 border-b-0 rounded-[3px] w-4 h-4 transition-none"
      ></span>

      <span
        class="top-[-10px] right-[-10px] absolute [filter:drop-shadow(0_0_4px_var(--border-color,#fff))] border-[3px] border-[var(--border-color,#fff)] border-b-0 border-l-0 rounded-[3px] w-4 h-4 transition-none"
      ></span>

      <span
        class="bottom-[-10px] left-[-10px] absolute [filter:drop-shadow(0_0_4px_var(--border-color,#fff))] border-[3px] border-[var(--border-color,#fff)] border-t-0 border-r-0 rounded-[3px] w-4 h-4 transition-none"
      ></span>

      <span
        class="right-[-10px] bottom-[-10px] absolute [filter:drop-shadow(0_0_4px_var(--border-color,#fff))] border-[3px] border-[var(--border-color,#fff)] border-t-0 border-l-0 rounded-[3px] w-4 h-4 transition-none"
      ></span>
    </motion.div>
  </div>
</template>
