/***********************************************************************
 * State file processing                                               *
 ***********************************************************************/

function makeDeck(cards) {
  let today = new Date();
  // Granularity only at the day level.
  today.setHours(0, 0, 0, 0);
  return cards.filter((card) => {
    return (new Date(card.scheduled)) <= today;
  });
}

function pad(n) {
  return n < 10 ? '0' + n : n;
}

function statusString() {
  const now = Date.now();
  const elapsedSeconds = Math.floor((now - window.started) / 1000);
  const minutes = Math.floor(elapsedSeconds / 60);
  const seconds = elapsedSeconds % 60;
  return `Card ${window.index + 1} of ${window.deck.length} scheduled for review, ${window.cards.length} total
Current session: ${pad(minutes)}:${pad(seconds)}`;
}

function showCard(card) {
  const front = document.getElementById('flashcard-front');
  const back = document.getElementById('flashcard-back');

  front.innerHTML = card.front;
  back.innerHTML = card.back;
}

function toggleCard() {
  const front = document.getElementById('flashcard-front');
  const back = document.getElementById('flashcard-back');

  if (front.style.display === "block") {
    front.style.display = "none";
    back.style.display = "block";
  } else {
    back.style.display = "none";
    front.style.display = "block";
  }
}

function loadCards(data) {
  const statusInfo = document.getElementById('status-info');

  window.cards = data;
  window.deck = makeDeck(window.cards);
  window.index = 0;
  window.started = Date.now();

  // Temporary
  showCard(window.cards[0]);
  
  setInterval(() => { statusInfo.innerText = statusString() }, 1000);
  // Add an event listener for the spacebar press
  window.addEventListener('keydown', (event) => {
    if (event.code === 'Space') {
      toggleCard();
    }
  });
}

/***********************************************************************
 * Status display                                                      *
 ***********************************************************************/

function showToast(message, duration = 3000) {
  const toast = document.getElementById("toast");
  toast.textContent = message;

  // Show the toast
  toast.classList.add("show");

  // Hide the toast after specified time
  setTimeout(() => {
    toast.classList.remove("show");
  }, duration);
}

window.addEventListener("load", (event) => {
  document.getElementById('cards-input').addEventListener('change', function(event) {
    const file = event.target.files[0];
    if (!file) return;

    const reader = new FileReader();
    reader.onload = function(e) {
      try {
        const content = e.target.result;
        loadCards(JSON.parse(content));
      } catch (error) {
        console.error("JSON Parsing Error:", error);
      }
    };

    reader.onerror = function(error) {
      document.getElementById('result').textContent = "Error reading file: " + error;
      console.error("File Reading Error:", error);
    };

    reader.readAsText(file); // Read the file as text
  });
});