// ---------------------------------------------------------
// Tool tab navigation
// ---------------------------------------------------------

// Find all tool buttons and tool panels.
const toolTabs = document.querySelectorAll(".tool-tab");
const toolPanels = document.querySelectorAll(".tool-panel");

// Switch tools when a tab button is clicked.
toolTabs.forEach((tab) => {
  tab.addEventListener("click", () => {
    const selectedToolId = tab.dataset.tool;

    // Mark only the selected tab as active.
    toolTabs.forEach((currentTab) => {
      const isSelected = currentTab === tab;

      currentTab.classList.toggle("active", isSelected);

      if (isSelected) {
        currentTab.setAttribute("aria-current", "page");
      } else {
        currentTab.removeAttribute("aria-current");
      }
    });

    // Show only the selected tool panel.
    toolPanels.forEach((panel) => {
      panel.hidden = panel.id !== selectedToolId;
    });
  });
});


// ---------------------------------------------------------
// Website Status Checker
// ---------------------------------------------------------

const uptimeForm = document.getElementById("uptime-form");
const urlInput = document.getElementById("url-input");
const checkButton = document.getElementById("check-button");
const statusMessage = document.getElementById(
  "status-message"
);
const resultPanel = document.getElementById("result-panel");

const onlineBadge = document.getElementById("online-badge");
const statusCode = document.getElementById("status-code");
const responseTime = document.getElementById(
  "response-time"
);
const redirectCount = document.getElementById(
  "redirect-count"
);
const checkedAt = document.getElementById("checked-at");
const finalUrl = document.getElementById("final-url");

// Handle Website Status form submissions.
uptimeForm.addEventListener("submit", async (event) => {
  event.preventDefault();

  const url = urlInput.value.trim();

  // Reset the interface before checking.
  statusMessage.textContent = "Checking website...";
  statusMessage.className = "status-message";
  resultPanel.hidden = true;

  checkButton.disabled = true;
  checkButton.textContent = "Checking...";

  try {
    const response = await fetch("/api/uptime", {
      method: "POST",

      headers: {
        "Content-Type": "application/json",
      },

      body: JSON.stringify({ url }),
    });

    const result = await response.json();

    // Handle HTTP-level errors.
    if (!response.ok) {
      throw new Error(
        result.error || "The request failed."
      );
    }

    // Handle unreachable or blocked destinations.
    if (!result.online) {
      throw new Error(
        result.error ||
          "The website could not be reached."
      );
    }

    // Fill in the successful result.
    onlineBadge.textContent = "Online";
    onlineBadge.className = "status-badge online";

    statusCode.textContent = result.statusCode;
    responseTime.textContent =
      `${result.responseTimeMs} ms`;
    redirectCount.textContent = result.redirectCount;

    checkedAt.textContent =
      new Date(result.checkedAt).toLocaleString();

    finalUrl.textContent = result.finalUrl;
    finalUrl.href = result.finalUrl;

    statusMessage.textContent =
      "Website check completed.";

    resultPanel.hidden = false;
  } catch (error) {
    statusMessage.textContent = error.message;
    statusMessage.className = "status-message error";
  } finally {
    checkButton.disabled = false;
    checkButton.textContent = "Check Website";
  }
});


// ---------------------------------------------------------
// DNS Lookup
// ---------------------------------------------------------

const dnsForm = document.getElementById("dns-form");
const hostnameInput = document.getElementById(
  "hostname-input"
);
const dnsButton = document.getElementById("dns-button");
const dnsMessage = document.getElementById("dns-message");
const dnsResultPanel = document.getElementById(
  "dns-result-panel"
);
const dnsHostname = document.getElementById(
  "dns-hostname"
);
const dnsRecords = document.getElementById("dns-records");
const dnsCheckedAt = document.getElementById(
  "dns-checked-at"
);

// Convert one DNS record into readable text.
function formatDnsRecord(recordType, record) {
  // MX records are objects containing an exchange and priority.
  if (
    recordType === "MX" &&
    typeof record === "object" &&
    record !== null
  ) {
    return `${record.exchange} (priority ${record.priority})`;
  }

  return String(record);
}

// Build one DNS record section.
function createDnsRecordGroup(recordType, records) {
  const group = document.createElement("section");
  group.className = "dns-record-group";

  const heading = document.createElement("h4");
  heading.textContent = recordType;

  group.appendChild(heading);

  // Show an empty state when no records exist.
  if (!Array.isArray(records) || records.length === 0) {
    const emptyMessage = document.createElement("p");
    emptyMessage.className = "empty-record";
    emptyMessage.textContent = "No records found.";

    group.appendChild(emptyMessage);

    return group;
  }

  const list = document.createElement("ul");
  list.className = "dns-record-list";

  records.forEach((record) => {
    const item = document.createElement("li");

    item.textContent = formatDnsRecord(
      recordType,
      record
    );

    list.appendChild(item);
  });

  group.appendChild(list);

  return group;
}

// Handle DNS form submissions.
dnsForm.addEventListener("submit", async (event) => {
  event.preventDefault();

  const hostname = hostnameInput.value.trim();

  // Reset the DNS interface before the request.
  dnsMessage.textContent = "Looking up DNS records...";
  dnsMessage.className = "status-message";
  dnsResultPanel.hidden = true;

  dnsButton.disabled = true;
  dnsButton.textContent = "Looking Up...";

  try {
    const response = await fetch("/api/dns", {
      method: "POST",

      headers: {
        "Content-Type": "application/json",
      },

      body: JSON.stringify({ hostname }),
    });

    const result = await response.json();

    if (!response.ok) {
      throw new Error(
        result.error || "The DNS lookup failed."
      );
    }

    dnsHostname.textContent = result.hostname;

    // Remove any records from the previous lookup.
    dnsRecords.replaceChildren();

    const recordOrder = [
      "A",
      "AAAA",
      "CNAME",
      "MX",
      "TXT",
      "NS",
    ];

    // Render each supported record type.
    recordOrder.forEach((recordType) => {
      const group = createDnsRecordGroup(
        recordType,
        result.records[recordType]
      );

      dnsRecords.appendChild(group);
    });

    dnsCheckedAt.textContent =
      `Checked ${new Date(
        result.checkedAt
      ).toLocaleString()}`;

    dnsMessage.textContent = "DNS lookup completed.";
    dnsResultPanel.hidden = false;
  } catch (error) {
    dnsMessage.textContent = error.message;
    dnsMessage.className = "status-message error";
  } finally {
    dnsButton.disabled = false;
    dnsButton.textContent = "Look Up DNS";
  }
});


// ---------------------------------------------------------
// SSL Certificate Checker
// ---------------------------------------------------------

const sslForm = document.getElementById("ssl-form");
const sslHostnameInput = document.getElementById(
  "ssl-hostname-input"
);
const sslButton = document.getElementById("ssl-button");
const sslMessage = document.getElementById("ssl-message");
const sslResultPanel = document.getElementById(
  "ssl-result-panel"
);

const sslStatusBadge = document.getElementById(
  "ssl-status-badge"
);
const sslHostname = document.getElementById(
  "ssl-hostname"
);
const sslDaysRemaining = document.getElementById(
  "ssl-days-remaining"
);
const sslValidFrom = document.getElementById(
  "ssl-valid-from"
);
const sslValidTo = document.getElementById("ssl-valid-to");
const sslProtocol = document.getElementById("ssl-protocol");
const sslCipher = document.getElementById("ssl-cipher");
const sslAddress = document.getElementById("ssl-address");
const sslCheckedAt = document.getElementById(
  "ssl-checked-at"
);

const sslSubject = document.getElementById("ssl-subject");
const sslIssuer = document.getElementById("ssl-issuer");
const sslFingerprint = document.getElementById(
  "ssl-fingerprint"
);

const sslAuthorizationErrorBlock =
  document.getElementById(
    "ssl-authorization-error-block"
  );

const sslAuthorizationError = document.getElementById(
  "ssl-authorization-error"
);

// Convert a certificate date into local readable text.
function formatCertificateDate(value) {
  if (!value) {
    return "Unknown";
  }

  const date = new Date(value);

  if (Number.isNaN(date.getTime())) {
    return value;
  }

  return date.toLocaleString();
}

// Convert days remaining into readable text.
function getExpirationText(daysRemaining) {
  if (
    daysRemaining === null ||
    daysRemaining === undefined
  ) {
    return "Unknown";
  }

  if (daysRemaining < 0) {
    return `${Math.abs(daysRemaining)} days expired`;
  }

  if (daysRemaining === 0) {
    return "Expires today";
  }

  return `${daysRemaining} days`;
}

// Handle SSL certificate form submissions.
sslForm.addEventListener("submit", async (event) => {
  event.preventDefault();

  const hostname = sslHostnameInput.value.trim();

  // Reset the SSL interface before the request.
  sslMessage.textContent = "Checking certificate...";
  sslMessage.className = "status-message";
  sslResultPanel.hidden = true;

  sslButton.disabled = true;
  sslButton.textContent = "Checking...";

  try {
    const response = await fetch("/api/ssl", {
      method: "POST",

      headers: {
        "Content-Type": "application/json",
      },

      body: JSON.stringify({ hostname }),
    });

    const result = await response.json();

    if (!response.ok) {
      throw new Error(
        result.error ||
          "The SSL certificate check failed."
      );
    }

    // Show whether Node trusted the certificate.
    if (result.authorized) {
      sslStatusBadge.textContent = "Valid";
      sslStatusBadge.className =
        "status-badge online";
    } else {
      sslStatusBadge.textContent = "Not trusted";
      sslStatusBadge.className =
        "status-badge offline";
    }

    sslHostname.textContent = result.hostname;

    sslDaysRemaining.textContent =
      getExpirationText(result.daysRemaining);

    sslValidFrom.textContent =
      formatCertificateDate(result.validFrom);

    sslValidTo.textContent =
      formatCertificateDate(result.validTo);

    sslProtocol.textContent =
      result.protocol || "Unknown";

    sslCipher.textContent =
      result.cipher || "Unknown";

    sslAddress.textContent = result.resolvedAddress
      ? `${result.resolvedAddress} (IPv${result.addressFamily})`
      : "Unknown";

    sslCheckedAt.textContent =
      formatCertificateDate(result.checkedAt);

    sslSubject.textContent =
      result.subject || "Unknown";

    sslIssuer.textContent =
      result.issuer || "Unknown";

    sslFingerprint.textContent =
      result.fingerprint256 || "Unavailable";

    // Only show the authorization error when one exists.
    if (result.authorizationError) {
      sslAuthorizationError.textContent =
        result.authorizationError;

      sslAuthorizationErrorBlock.hidden = false;
    } else {
      sslAuthorizationError.textContent = "";
      sslAuthorizationErrorBlock.hidden = true;
    }

    sslMessage.textContent =
      "Certificate check completed.";

    sslResultPanel.hidden = false;
  } catch (error) {
    sslMessage.textContent = error.message;
    sslMessage.className = "status-message error";
  } finally {
    sslButton.disabled = false;
    sslButton.textContent = "Check Certificate";
  }
});


// ---------------------------------------------------------
// HTTP Headers Checker
// ---------------------------------------------------------

const headersForm = document.getElementById(
  "headers-form"
);
const headersUrlInput = document.getElementById(
  "headers-url-input"
);
const headersButton = document.getElementById(
  "headers-button"
);
const headersMessage = document.getElementById(
  "headers-message"
);
const headersResultPanel = document.getElementById(
  "headers-result-panel"
);

const headersScoreBadge = document.getElementById(
  "headers-score-badge"
);
const headersStatus = document.getElementById(
  "headers-status"
);
const headersRedirects = document.getElementById(
  "headers-redirects"
);
const headersScore = document.getElementById(
  "headers-score"
);
const headersCheckedAt = document.getElementById(
  "headers-checked-at"
);
const headersFinalUrl = document.getElementById(
  "headers-final-url"
);

const securityHeaderResults = document.getElementById(
  "security-header-results"
);
const allHeaderResults = document.getElementById(
  "all-header-results"
);

// Build one visible security-header result.
function createSecurityHeaderItem(header) {
  const item = document.createElement("article");
  item.className = "security-header-item";

  const heading = document.createElement("div");
  heading.className = "security-header-heading";

  const name = document.createElement("strong");
  name.textContent = header.name;

  const status = document.createElement("span");

  status.className = header.present
    ? "header-status present"
    : "header-status missing";

  status.textContent = header.present
    ? "Present"
    : "Missing";

  heading.append(name, status);

  const purpose = document.createElement("p");
  purpose.className = "security-header-purpose";
  purpose.textContent = header.purpose;

  item.append(heading, purpose);

  // Show the raw header value when present.
  if (header.present && header.value) {
    const value = document.createElement("p");
    value.className = "security-header-value";

    const code = document.createElement("code");
    code.textContent = header.value;

    value.appendChild(code);
    item.appendChild(value);
  }

  return item;
}

// Build one raw response-header row.
function createResponseHeaderItem(name, value) {
  const item = document.createElement("div");
  item.className = "response-header-item";

  const nameElement = document.createElement("div");
  nameElement.className = "response-header-name";
  nameElement.textContent = name;

  const valueElement = document.createElement("div");
  valueElement.className = "response-header-value";
  valueElement.textContent = value;

  item.append(nameElement, valueElement);

  return item;
}

// Handle HTTP header form submissions.
headersForm.addEventListener("submit", async (event) => {
  event.preventDefault();

  const url = headersUrlInput.value.trim();

  // Reset the interface before checking.
  headersMessage.textContent =
    "Checking response headers...";

  headersMessage.className = "status-message";
  headersResultPanel.hidden = true;

  headersButton.disabled = true;
  headersButton.textContent = "Checking...";

  try {
    const response = await fetch("/api/headers", {
      method: "POST",

      headers: {
        "Content-Type": "application/json",
      },

      body: JSON.stringify({ url }),
    });

    const result = await response.json();

    if (!response.ok) {
      throw new Error(
        result.error ||
          "The HTTP header check failed."
      );
    }

    // Fill in the summary information.
    headersStatus.textContent =
      `${result.statusCode} ${
        result.statusText || ""
      }`.trim();

    headersRedirects.textContent =
      result.redirectCount;

    headersScore.textContent =
      `${result.presentSecurityHeaderCount} of ` +
      `${result.totalSecurityHeaderCount}`;

    headersScoreBadge.textContent =
      `${result.presentSecurityHeaderCount}/` +
      `${result.totalSecurityHeaderCount}`;

    headersCheckedAt.textContent =
      new Date(result.checkedAt).toLocaleString();

    headersFinalUrl.textContent = result.finalUrl;
    headersFinalUrl.href = result.finalUrl;

    // Remove old security header results.
    securityHeaderResults.replaceChildren();

    result.securityHeaders.forEach((header) => {
      securityHeaderResults.appendChild(
        createSecurityHeaderItem(header)
      );
    });

    // Remove old raw response headers.
    allHeaderResults.replaceChildren();

    // Render all response headers alphabetically.
    Object.entries(result.headers)
      .sort(([nameA], [nameB]) =>
        nameA.localeCompare(nameB)
      )
      .forEach(([name, value]) => {
        allHeaderResults.appendChild(
          createResponseHeaderItem(name, value)
        );
      });

    headersMessage.textContent =
      "Header check completed.";

    headersResultPanel.hidden = false;
  } catch (error) {
    headersMessage.textContent = error.message;
    headersMessage.className = "status-message error";
  } finally {
    headersButton.disabled = false;
    headersButton.textContent = "Check Headers";
  }
});