// bulma hamburger menu
document.addEventListener('DOMContentLoaded', () => {
  // Get all "navbar-burger" elements
  const $navbarBurgers = Array.prototype.slice.call(document.querySelectorAll('.navbar-burger'), 0);
  // Add a click event on each of them
  $navbarBurgers.forEach(el => {
    el.addEventListener('click', () => {
      // Get the target from the "data-target" attribute
      const target = el.dataset.target;
      const $target = document.getElementById(target);
      // Toggle the "is-active" class on both the "navbar-burger" and the "navbar-menu"
      el.classList.toggle('is-active');
      $target.classList.toggle('is-active');
    });
  });
});

// language selector
document.getElementById("current-language").addEventListener("click", (e) => {
    e.preventDefault();
    document.getElementById("language-dropdown").classList.toggle("is-active");
});

const i18n = JSON.parse(document.getElementById("i18n-data").textContent);
const i18nSupported = Object.keys(i18n._flags)

// build language selector
const langSelector = document.getElementById("language-selector")
for (const l of i18nSupported) {
  const a = document.createElement("a");
  a.classList.add("navbar-item");
  a.innerHTML = `${i18n._flags[l]} ${l.toUpperCase()}`;
  a.href = "#";
  a.addEventListener("click", (e) => {
    changeLanguage(e.target.textContent.slice(-2).toLowerCase());
    document.getElementById("language-dropdown").classList.remove("is-active");
  });
  langSelector.appendChild(a);
}

changeLanguage = (l) => {
  const lang = i18nSupported.includes(l) ? l : "en";
  document.querySelectorAll("[data-i18n]").forEach(el => {
    el.innerHTML = i18n[el.dataset.i18n][lang];
  });
  document.getElementById("current-language").innerHTML = `${i18n._flags[lang]} ${lang.toUpperCase()}`;
  console.log(`Switching language to ${lang}`);
};

saveFormData = () => {
  localStorage.setItem("bezahlbrudiFormData", JSON.stringify({
    name: document.querySelector("#name input").value,
    iban: document.querySelector("#iban input").value.toUpperCase(),
    bic: document.querySelector("#bic input").value.toUpperCase(),
    amount: parseFloat(document.querySelector("#amount input").value).toFixed(2),
    purpose: document.querySelector("#purpose input").value,
    lang: document.getElementById("current-language").textContent.slice(-2).toLowerCase()
  }));
}

// Field data checks

validateName = (target) => {
  if (target.value.length == 0) return
  if (target.value.length > 0 && target.value.length <= 70) {
    target.classList.remove("is-danger")
    document.querySelector("#name div span").innerHTML = "&#x2705;";
    if (document.querySelector("#name p")) {
      document.querySelector("#name p").remove();
    }
  } else {
    target.classList.add("is-danger")
    document.querySelector("#name div span").innerHTML = "&#x274C;";

    if (!document.querySelector("#name p")) {
      const help = document.createElement("p");
      help.classList.add("help", "is-danger");
      help.textContent = "Name can only have 70 characters.";
      document.querySelector("#name").appendChild(help);
    }
  }
}

validateBic = (target) => {
  if (target.value.length == 0) return
  const re = /^[a-z]{6}[2-9a-z][0-9a-np-z]([a-z0-9]{3}|x{3})?$/i;

  if (re.test(target.value)) {
    target.classList.remove("is-danger")
    document.querySelector("#bic div span").innerHTML = "&#x2705;";
    if (document.querySelector("#bic p")) {
      document.querySelector("#bic p").remove();
    }
  } else {
    target.classList.add("is-danger")
    document.querySelector("#bic div span").innerHTML = "&#x274C;";

    if (!document.querySelector("#bic p")) {
      const help = document.createElement("p");
      help.classList.add("help", "is-danger");
      help.textContent = "BIC is invalid";
      document.querySelector("#bic").appendChild(help);
    }
  }
}

validateIban = (target) => {
  if (target.value.length == 0) return
  // IBANs are fucking complicated. this is a hugely simplified check
  // If you want to know more look here:
  // https://www.swift.com/standards/data-standards/iban-international-bank-account-number
  const re = /^[a-z]{2}[0-9a-z]+$/i;

  if (re.test(target.value)) {
    target.classList.remove("is-danger")
    document.querySelector("#iban div span").innerHTML = "&#x2705;";
    if (document.querySelector("#iban p")) {
      document.querySelector("#iban p").remove();
    }
  } else {
    target.classList.add("is-danger")
    document.querySelector("#iban div span").innerHTML = "&#x274C;";

    if (!document.querySelector("#iban p")) {
      const help = document.createElement("p");
      help.classList.add("help", "is-danger");
      help.textContent = "IBAN is invalid";
      document.querySelector("#iban").appendChild(help);
    }
  }
}

validateAmount = (target) => {
  if (target.value == 0) return
  if (parseFloat(target.value) > 0 && target.value.toString() === parseFloat(target.value).toFixed(2).toString()) {
    target.value = parseFloat(target.value).toFixed(2);
    target.classList.remove("is-danger")
    document.querySelector("#amount div span.is-right").innerHTML = "&#x2705;";
  } else {
    target.classList.add("is-danger")
    document.querySelector("#amount div span.is-right").innerHTML = "&#x274C;";
  }
}

validatePurpose = (target) => {
  if (target.value.length == 0) return
  const re = /[a-zA-Z0-9\/?:().,'+\- ]{1,140}/i;

  if (re.test(target.value)) {
    target.classList.remove("is-danger")
    document.querySelector("#purpose div span").innerHTML = "&#x2705;";
    if (document.querySelector("#purpose p")) {
      document.querySelector("#purpose p").remove();
    }
  } else {
    target.classList.add("is-danger")
    document.querySelector("#purpose div span").innerHTML = "&#x274C;";

    if (!document.querySelector("#purpose p")) {
      const help = document.createElement("p");
      help.classList.add("help", "is-danger");
      help.textContent = "Purpose can only have 140 characters and only include A-Z, a-z, 0-9, /?:().,'+- and spaces.";
      document.querySelector("#purpose").appendChild(help);
    }
  }
}

document.querySelector("#name input").addEventListener("input", (event) => {
  validateName(event.target);
  regenerate();
});

document.querySelector("#iban input").addEventListener("input", (event) => {
  validateIban(event.target);
  regenerate();
});

document.querySelector("#bic input").addEventListener("input", (event) => {
  validateBic(event.target);
  regenerate();
});

document.querySelector("#amount input").addEventListener("input", (event) => {
  validateAmount(event.target);
  regenerate();
});

document.querySelector("#purpose input").addEventListener("input", (event) => {
  validatePurpose(event.target);
  regenerate();
});

// Remember inputs
document.querySelector("#rememberme").addEventListener("change", (event) => {
  if (event.target.checked) {
    saveFormData();
  } else {
    localStorage.clear();
  }
})

// Regenerate on color-scheme change
window.matchMedia('(prefers-color-scheme: dark)').addEventListener('change', (event) => {
  regenerate()
});

// qr code generator
regenerate = () => {
  document.querySelector('#qr-code').innerHTML = "";
  if (document.querySelector("#name input").classList.contains("is-danger")) {
    console.error("Error in name");
  }
  else if (document.querySelector("#iban input").classList.contains("is-danger")) {
    console.error("Error in IBAN");
  }
  else if (document.querySelector("#bic input").classList.contains("is-danger")) {
    console.error("Error in BIC");
  }
  else if (document.querySelector("#amount input").classList.contains("is-danger")) {
      console.error("Error in Amount");
  }
  else if (document.querySelector("#purpose input").classList.contains("is-danger")) {
    console.error("Error in Purpose");
  } else {
    console.log("Generating new QR code...");
    const data = `BCD
002
1
SCT
${document.querySelector("#bic input").value.toUpperCase()}
${document.querySelector("#name input").value}
${document.querySelector("#iban input").value.toUpperCase()}
EUR${document.querySelector("#amount input").value}


${document.querySelector("#purpose input").value}
`;

    if (window.matchMedia && window.matchMedia('(prefers-color-scheme: dark)').matches) {
      // dark mode
      QrCreator.render({
        text: data,
        radius: 0.25,
        ecLevel: "H",
        fill: "#fff",
        background: "#000",
        size: 512
      }, document.querySelector('#qr-code'));
    } else {
      // light mode
      QrCreator.render({
        text: data,
        radius: 0.25,
        ecLevel: "H",
        fill: "#000",
        background: "#fff",
        size: 512
      }, document.querySelector('#qr-code'));
    }

    if (document.querySelector("#rememberme").checked) {
      saveFormData();
    }
  }
}

// Fill in form from local storage
const savedData = localStorage.getItem("bezahlbrudiFormData");
if (savedData) {
  const formData = JSON.parse(savedData);
  document.querySelector("#name input").value = formData["name"];
  document.querySelector("#iban input").value = formData["iban"];
  document.querySelector("#bic input").value = formData["bic"];
  document.querySelector("#amount input").value = formData["amount"];
  document.querySelector("#purpose input").value = formData["purpose"];
  document.querySelector("#rememberme").checked = true;
  changeLanguage(formData["lang"]);
} else {
  // get browser language
  let lang = "en"; // default fallback
  for (const l of navigator.languages) {
    const base = l.split("-")[0];
    if (i18nSupported.includes(base)) {
      lang = base;
      break;
    }
  }
  changeLanguage(lang);
}

// Validate all fields to set css properties
validateName(document.querySelector("#name input"));
validateIban(document.querySelector("#iban input"));
validateBic(document.querySelector("#bic input"));
validateAmount(document.querySelector("#amount input"));
validatePurpose(document.querySelector("#purpose input"));

// generate qr code on first visit
regenerate();

if ('serviceWorker' in navigator) {
  navigator.serviceWorker.register('/js/service-worker.js')
    .catch(err => console.error('Service Worker registration failed:', err));
}