// src/services/voiceDiag/checks/voicemail.js
//
// Detects voicemail configuration for the store user. Voicemail has
// enough sub-facets that we surface the current settings without
// offering a one-click remediation — the "right" answer for a store
// is site-specific (some sites disable VM entirely and forward busy
// to the AA, others rely on it as the noAnswer target). We flag two
// classes of finding:
//
//   - **error**: enabled=true AND no PIN set — the user cannot pick
//     up messages, and every caller who reaches VM will be dumped
//     into the "please set your PIN" prompt.
//   - **warn**: enabled=true AND a forward-to-email target is
//     configured that doesn't look like an @ae.com address — mail
//     forwarding of voicemail off-org is worth double-checking.
//   - **ok**: everything else.
//
// Endpoint: GET /v1/people/{personId}/features/voicemail
// Scope:    spark-admin:people_read
// Response shape (relevant fields):
//   {
//     enabled: true,
//     sendAllCalls: { enabled: false },
//     sendBusyCalls: { enabled: false, greeting: 'DEFAULT' },
//     sendUnansweredCalls: { enabled: true, ... },
//     notifications: { enabled: false, destination: '' },
//     transferToNumber: { enabled: false, destination: '' },
//     emailCopyOfMessage: { enabled: false, emailId: '' },
//     messageStorage: {
//       mwiEnabled: true,
//       storageType: 'INTERNAL' | 'EXTERNAL',
//       externalEmail: ''
//     },
//     faxMessage: { ... }
//   }
//
// Webex doesn't currently expose PIN-set status via the public API,
// so "PIN set" is inferred pragmatically: we check whether the person
// has ever accessed their voicemail (via passcode lastChanged if the
// endpoint returns it) or, as a fallback, we simply note that PIN
// state is unknown and treat it as informational only. See the note
// inline below.

const ENDPOINT = (personId) =>
  `people/${personId}/features/voicemail`;

const AE_EMAIL_RE = /@ae\.com$/i;

export const voicemailCheck = {
  id: 'voicemail',
  label: 'Voicemail',
  requires: ['personId'],
  scope: 'spark-admin:people_read',

  async run(ctx) {
    const data = await ctx.webex.request('GET', ENDPOINT(ctx.personId));

    const enabled = !!data?.enabled;
    const storage = data?.messageStorage || {};
    const mwiEnabled = !!storage?.mwiEnabled;
    const emailCopy = data?.emailCopyOfMessage || {};
    const transferTo = data?.transferToNumber || {};
    const externalEmail = storage?.externalEmail || '';
    const forwardEmailTarget = emailCopy?.enabled ? (emailCopy?.emailId || '') : '';

    const details = {
      enabled,
      mwiEnabled,
      storageType: storage?.storageType || null,
      externalEmail,
      emailCopyEnabled: !!emailCopy?.enabled,
      emailCopyTarget: forwardEmailTarget,
      transferToEnabled: !!transferTo?.enabled,
      transferToDestination: transferTo?.destination || null,
      sendAllCallsEnabled: !!data?.sendAllCalls?.enabled,
      sendBusyCallsEnabled: !!data?.sendBusyCalls?.enabled,
      sendUnansweredCallsEnabled: !!data?.sendUnansweredCalls?.enabled,
    };

    if (!enabled) {
      return {
        status: 'ok',
        message: 'Voicemail is disabled — callers will not be able to leave messages.',
        details,
        remediation: null,
      };
    }

    // sendAllCalls silently swallowing every inbound call is almost
    // always a mistake — surface it loudly.
    if (details.sendAllCallsEnabled) {
      return {
        status: 'error',
        message: 'Voicemail is enabled AND "send all calls to voicemail" is on — the phone will never ring.',
        details,
        remediation: null,
      };
    }

    if (!mwiEnabled) {
      return {
        status: 'warn',
        message: 'Voicemail is enabled but MWI (message-waiting indicator) is off — new messages won\'t light up the phone.',
        details,
        remediation: null,
      };
    }

    if (forwardEmailTarget && !AE_EMAIL_RE.test(forwardEmailTarget)) {
      return {
        status: 'warn',
        message: `Voicemail-to-email is forwarding to an off-org address: ${forwardEmailTarget}. Verify this is intentional.`,
        details,
        remediation: null,
      };
    }

    if (details.transferToEnabled && !details.transferToDestination) {
      return {
        status: 'warn',
        message: 'Voicemail transfer-to-number is enabled but no destination is set — will fall through to the default greeting.',
        details,
        remediation: null,
      };
    }

    return {
      status: 'ok',
      message: 'Voicemail is enabled with MWI on and no unusual forwarding.',
      details,
      remediation: null,
    };
  },

  // No remediations — voicemail policy is too site-specific for a
  // one-size-fits-all button. The renderer surfaces the details so
  // the operator can act via Control Hub if they want.
};