<script setup>
import { ref, unref, onMounted, nextTick } from 'vue';
import axios from 'axios';
import { Readability } from '@mozilla/readability';
import Modal from './modal/AddUrl.vue';

const showMessage = ref(false)
const feeds = ref([]);
const message = ref('')
const showModal = ref(false)

async function getReadable(feed, index) {
  try {
    const response = await axios.post("/api/v1/article/read", {
      url: feed.url
    },
      {
        headers: {
          'Content-Type': 'application/json',
          'user-token': localStorage.getItem("user-token")
        }
      })

    const doc = new DOMParser().parseFromString(response.data.content, 'text/html');
    // Scraped articles often contain image/link URLs that are relative to the
    // source site. A <base> tag makes the browser (and Readability) resolve
    // them against the article's original URL instead of our own origin.
    const base = doc.createElement('base');
    base.setAttribute('href', feed.url);
    doc.head.prepend(base);
    const article = new Readability(doc).parse();
    feeds.value[index].content = article.content;
  } catch (error) {
    console.error('Error fetching data:', error)
    showMessageForXSeconds(error, 5)
  }
}

async function markRead(id) {
  try {
    const response = await axios.put("/api/v1/article/read/" + id,
      null,
      {
        headers: {
          'Content-Type': 'application/json',
          'user-token': localStorage.getItem("user-token")
        }
      }
    )
    console.log(response.status)
  } catch (error) {
    console.log(error)
  }
}

function showMessageForXSeconds(text, seconds) {
  message.value = text;
  showMessage.value = true;

  // Set a timeout to hide the message after x seconds
  setTimeout(() => {
    showMessage.value = false;
    message.value = '';
  }, seconds * 1000); // Convert seconds to milliseconds
}

const fetchData = async () => {
  const user_id = localStorage.getItem("user-id")
  try {
    const response = await axios.get("/api/v1/article/get/" + user_id, {
      headers: {
        'Content-Type': 'application/json',
        'user-token': localStorage.getItem("user-token")
      }
    });
    const items = [];
    response.data.feeds.forEach(feed => {
      feed.items.forEach(item => items.push({ ...item, feedTitle: feed.title }));
    });
    // timestamps are zero-padded "YYYY-MM-DD HH:MM:SS" strings, so a plain
    // lexicographic comparison sorts them chronologically.
    items.sort((a, b) => b.timestamp.localeCompare(a.timestamp));
    feeds.value = items;
    await nextTick();
    setupIntersectionObserver();
  } catch (error) {
    console.error('Error fetching data:', error)
    showMessageForXSeconds(error, 5)
  }
};

async function sync() {
  try {
    const response = await axios.post('/api/v1/article/sync', {
      user_id: parseInt(localStorage.getItem("user-id"))
    },
      {
        headers: {
          'Content-Type': 'application/json',
          'user-token': localStorage.getItem("user-token")
        }
      })

    if (response.status == 200) {
      showMessageForXSeconds('Sync successful.', 5)
    }
    fetchData();
  } catch (error) {
    console.error('Error sync', error)
    showMessageForXSeconds(error, 5)
  }
}

let observer; // Declare observer outside the setup function

function setupIntersectionObserver() {
  if (observer) {
    observer.disconnect();
  }

  observer = new IntersectionObserver(handleIntersection, {
    root: null, // Use the viewport as the root
    rootMargin: '0px',
    // threshold: 0.5, // Fire the callback when at least 50% of the element is visible
  });

  const observedDivs = document.querySelectorAll(".observe");
  if (observedDivs.length > 0) {
    observedDivs.forEach(observedDiv => {
      observer.observe(observedDiv);
    })
  }
}

async function handleIntersection(entries) {
  // The callback function for when the target element enters or exits the viewport
  for (const entry of entries) {
    // An article that has scrolled above the viewport (not intersecting,
    // bounding box above the top edge) has been read — mark it and remove it.
    if (initialLoad === true && !entry.isIntersecting && entry.boundingClientRect.y < 0) {
      await markRead(feeds.value[entry.target.id].id)
      removeFeed(entry.target.id)
      document.getElementById(0)?.scrollIntoView()
    }
  }
}

function removeFeed(index) {
  const array = unref(feeds);
  array.splice(index, 1);
}

let initialLoad = false
onMounted(async () => {
  initialLoad = false
  await fetchData()
  setTimeout(function () {
    initialLoad = true
    console.log('set to true')
  }, 2000);
});
</script>

<template>
  <div class="feed-actions">
    <p @click="sync">Sync</p>
    <p @click="showModal = true">Add RSS</p>
  </div>
  <Teleport to="body">
    <modal :show="showModal" @close="showModal = false">
      <template #header>
        <h3>Add RSS Feed</h3>
      </template>
    </modal>
  </Teleport>
  <div>
    <h1>Feeds</h1>
    <div v-if="showMessage" class="message">{{ message }}</div>
    <div id='article' class='article'>
      <p v-if="feeds.length == 0">No unread articles.</p>
      <template v-for="(   feed, index   ) in    feeds   ">
        <div v-bind:id="index" class="observe">
          <p class="feed-source">{{ feed.feedTitle }}</p>
          <h2 @click="getReadable(feed, index)" class="feed-title">{{ feed.title }}</h2>
          <h3>{{ feed.timestamp }}</h3>
          <p class="feed-content" v-html='feed.content'></p>
        </div>
      </template>
    </div>
  </div>
</template>
