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

function statusString() {
  const now = Date.now();
  const elapsedSeconds = Math.floor((now - window.started) / 1000);
  const minutes = Math.floor(elapsedSeconds / 60);
  const seconds = elapsedSeconds % 60;
  const pad = (n) => n < 10 ? '0' + n : n;
  return `Card ${window.index + 1} of ${window.cards.length} scheduled for review, ${window.allCards.length} total
Current session: ${pad(minutes)}:${pad(seconds)}`;
}

function loadCard(card) {
  window.card.revealed = false;
  window.card.front.innerHTML = card.front;
  window.card.front.style.display = "block";
  window.card.back.innerHTML = card.back;
  window.card.back.style.display = "none";
  window.buttons.style.display = "none";
}

function flipCard() {
  window.card.revealed = true;

  // Reveal the "back".
  if (window.card.front.style.display !== "block") {
    window.card.front.style.display = "block";
    window.card.back.style.display = "none";
  } else {
    window.card.front.style.display = "none";
    window.card.back.style.display = "block";
  }

  // Reveal the buttons.
  window.buttons.style.display = "flex";
}

function rateCard(difficulty) {
  if (!window.card.revealed) {
    return;
  }
  // if (difficulty === "forgot") {

  // }
  if (++window.index < window.cards.length) {
    loadCard(window.cards[window.index]);
  } else {
    clearInterval(window.updateInterval);
    window.statusInfo.innerHTML = "Session complete!";
    window.flashcard.style.display = "none";
    window.buttons.style.display = "none";
  }
}

// Todo: check if card is revealed before allowing button inpt.

function loadCards(data) {
  document.getElementById('flashcard').style.display = "block";

  window.allCards = data;
  window.index = 0;
  window.started = Date.now();
  window.statusInfo = document.getElementById('status-info');
  window.buttons = document.getElementById('button-container');
  window.card = {
    front: document.getElementById('flashcard-front'),
    back: document.getElementById('flashcard-back')
  };

  document.getElementById('rating-button-forgot')
    .addEventListener('click', () => rateCard('forgot'));
  document.getElementById('rating-button-hard')
    .addEventListener('click', () => rateCard('hard'));
  document.getElementById('rating-button-medium')
    .addEventListener('click', () => rateCard('medium'));
  document.getElementById('rating-button-easy')
    .addEventListener('click', () => rateCard('easy'));

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

  // Temporary
  loadCard(window.cards[0]);

  window.updateInterval = setInterval(() => {
    window.statusInfo.innerText = statusString()
  }, 1000);
}

/***********************************************************************
 * 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
  });
});

window.addEventListener('keydown', (event) => {
  // console.log(event.code);
  if (event.code === 'Space') {
    flipCard();
  } else if (event.code === 'Digit1' || event.code === "Numpad1") {
    rateCard('forgot')
  } else if (event.code === 'Digit2' || event.code === "Numpad2") {
    rateCard('easy')
  } else if (event.code === 'Digit3' || event.code === "Numpad3") {
    rateCard('medium')
  } else if (event.code === 'Digit4' || event.code === "Numpad4") {
    rateCard('hard')
  }
});