import {
  InteractionRequiredAuthError,
  PublicClientApplication,
} from "@azure/msal-browser";

let msalInstance = null;
let apiScope = "";

function requireInstance() {
  if (!msalInstance) {
    throw new Error("MSAL n'est pas initialise.");
  }

  return msalInstance;
}

function activeAccount() {
  const instance = requireInstance();
  return instance.getActiveAccount() ?? instance.getAllAccounts()[0] ?? null;
}

async function initialize(tenantId, clientId, scope, redirectUri) {
  if (msalInstance) {
    return;
  }

  if (!tenantId || !clientId || !scope || !redirectUri) {
    throw new Error("La configuration Azure du frontend est incomplete.");
  }

  apiScope = scope;
  msalInstance = await PublicClientApplication.createPublicClientApplication({
    auth: {
      clientId,
      authority: `https://login.microsoftonline.com/${tenantId}`,
      redirectUri,
      postLogoutRedirectUri: redirectUri,
    },
    cache: {
      cacheLocation: "sessionStorage",
    },
  });

  const account = activeAccount();
  if (account) {
    msalInstance.setActiveAccount(account);
  }
}

async function signIn() {
  const instance = requireInstance();
  const result = await instance.loginPopup({
    scopes: ["openid", "profile", "email", apiScope],
  });

  instance.setActiveAccount(result.account);
}

async function getAccessToken() {
  const instance = requireInstance();
  const account = activeAccount();
  if (!account) {
    throw new Error("Aucun compte Microsoft connecte.");
  }

  try {
    const result = await instance.acquireTokenSilent({
      account,
      scopes: [apiScope],
    });
    return result.accessToken;
  } catch (error) {
    if (!(error instanceof InteractionRequiredAuthError)) {
      throw error;
    }

    const result = await instance.acquireTokenPopup({
      account,
      scopes: [apiScope],
    });
    return result.accessToken;
  }
}

function hasAccount() {
  return activeAccount() !== null;
}

async function signOut() {
  const instance = requireInstance();
  const account = activeAccount();
  if (!account) {
    return;
  }

  await instance.logoutPopup({ account });
}

globalThis.emeMsal = {
  getAccessToken,
  hasAccount,
  initialize,
  signIn,
  signOut,
};