/**
 * Authentication-related tools for the Outlook MCP server
 */
const config = require('../config');
const tokenManager = require('./token-manager');
const { analyzeTokenScopes, expectedSharedScopes } = require('../utils/mailbox');

async function handleAbout() {
  const sharedLine = config.ENABLE_SHARED_MAILBOXES
    ? 'Shared mailbox support: enabled (optional mailbox param + list-mailboxes). Requires Mail.*.Shared scopes and re-auth after upgrade.'
    : 'Shared mailbox support: disabled (OUTLOOK_ENABLE_SHARED_MAILBOXES=false).';
  return {
    content: [{
      type: "text",
      text: `Outlook Assistant MCP Server v${config.SERVER_VERSION}\n\nProvides access to Microsoft Outlook email, calendar, folders, and rules through Microsoft Graph API.\n${sharedLine}`
    }]
  };
}

/**
 * Initiates device code flow via MSAL. Returns the code and URL to the user
 * immediately; MSAL polls internally until the user completes sign-in.
 */
async function handleAuthenticate(args) {
  if (config.USE_TEST_MODE) {
    tokenManager.createTestTokens();
    return {
      content: [{ type: "text", text: 'Successfully authenticated with Microsoft Graph API (test mode)' }]
    };
  }

  let flowResult;
  try {
    flowResult = await tokenManager.initiateDeviceCodeFlow();
  } catch (err) {
    console.error('[authenticate] Failed to initiate device code flow:', err.message);
    return {
      content: [{ type: "text", text: `Failed to start authentication: ${err.message}` }]
    };
  }

  const { deviceCodeInfo, tokenPromise } = flowResult;
  const { userCode, verificationUri, expiresIn } = deviceCodeInfo;
  const minutesRemaining = Math.floor(expiresIn / 60);

  // MSAL polls internally — just log completion when it resolves
  tokenPromise
    .then(result => {
      if (result) console.error('[authenticate] Sign-in completed — MSAL cached tokens.');
    })
    .catch(err => {
      console.error(`[authenticate] Device code flow ended: ${err.message}`);
    });

  const scopeHint = config.ENABLE_SHARED_MAILBOXES
    ? `\nThis login requests shared-mailbox scopes: ${expectedSharedScopes().join(', ')}.\nAfter signing in, call check-auth-status and confirm those scopes are present.`
    : '';

  return {
    content: [{
      type: "text",
      text: [
        `To sign in to Microsoft, please:`,
        ``,
        `  1. Open: ${verificationUri}`,
        `  2. Enter code: ${userCode}`,
        ``,
        `You have ${minutesRemaining} minutes to complete sign-in.`,
        `After signing in, call check-auth-status to confirm.`,
        scopeHint
      ].filter(Boolean).join('\n')
    }]
  };
}

async function handleCheckAuthStatus() {
  console.error(`[CHECK-AUTH-STATUS] Checking for valid token...`);
  try {
    const token = await tokenManager.getAccessToken();
    if (!token) {
      console.error('[CHECK-AUTH-STATUS] No valid token found');
      return { content: [{ type: "text", text: "Not authenticated" }] };
    }
    console.error('[CHECK-AUTH-STATUS] Valid token acquired');

    const lines = ['Authenticated and ready'];

    if (config.ENABLE_SHARED_MAILBOXES) {
      const analysis = analyzeTokenScopes(token);
      if (analysis.missing.length === 0) {
        lines.push('Shared mailbox scopes: OK (' + analysis.present.join(', ') + ')');
      } else if (analysis.present.length === 0) {
        lines.push('Shared mailbox scopes: MISSING (' + analysis.missing.join(', ') + ')');
        lines.push('Re-run authenticate (device code) after adding these delegated permissions in Entra and granting admin consent.');
      } else {
        lines.push('Shared mailbox scopes: PARTIAL');
        lines.push('  present: ' + analysis.present.join(', '));
        lines.push('  missing: ' + analysis.missing.join(', '));
        lines.push('Re-run authenticate so the token picks up the missing scopes.');
      }
      if (analysis.scp) {
        lines.push('Token scp: ' + analysis.scp);
      }
    } else {
      lines.push('Shared mailbox feature disabled (OUTLOOK_ENABLE_SHARED_MAILBOXES=false).');
    }

    return { content: [{ type: "text", text: lines.join('\n') }] };
  } catch (e) {
    console.error('[CHECK-AUTH-STATUS] Error:', e.message);
    return { content: [{ type: "text", text: "Not authenticated" }] };
  }
}

const authTools = [
  {
    name: "about",
    description: "Returns information about this Outlook Assistant server",
    inputSchema: { type: "object", properties: {}, required: [] },
    handler: handleAbout
  },
  {
    name: "authenticate",
    description: "Authenticate with Microsoft Graph API using device code flow. Returns a short code and URL. IMPORTANT: Show the user the code and URL — they must visit the URL on any device and enter the code to complete sign-in. After they sign in, call check-auth-status to confirm. After upgrading to shared-mailbox support, re-authenticate so Mail.*.Shared scopes appear on the token.",
    inputSchema: {
      type: "object",
      properties: {
        force: {
          anyOf: [{ type: "boolean" }, { type: "string" }],
          description: "Force re-authentication even if already authenticated"
        }
      },
      required: []
    },
    handler: handleAuthenticate
  },
  {
    name: "check-auth-status",
    description: "Check the current authentication status with Microsoft Graph API, including whether shared-mailbox scopes are present on the access token",
    inputSchema: { type: "object", properties: {}, required: [] },
    handler: handleCheckAuthStatus
  }
];

module.exports = { authTools, handleAbout, handleAuthenticate, handleCheckAuthStatus };