/**
 * Admin router — role-gated admin API surface (ADMIN-01/02/03).
 *
 * Security contract:
 *   - adminRouter.use('*', requireAdmin) is the FIRST statement (Pitfall 9 / T-10-08).
 *     This guard runs before ANY route handler, so no admin route is reachable by non-admins.
 *   - POST /credentials uses noEchoHook: NEVER returns Zod's result.error (which contains
 *     .received = the submitted password). Returns { error: 'Invalid request' } only (T-10-09).
 *   - validateEncryptAndStoreCredential from credentialSync.ts is the ONLY place
 *     createFastmailClient + fetchCalendars + encryptPassword + upsert live (D-07).
 *   - No console.log of request bodies or passwords in any handler (T-10-10).
 *
 * Routes:
 *   GET  /api/admin/members             → list members + credential status (UI-SPEC Surface 2)
 *   POST /api/admin/credentials         → validate+encrypt+store for any member (ADMIN-01)
 *   GET  /api/admin/calendars           → list synced calendars (UI-SPEC Surface 5)
 *   PUT  /api/admin/calendars/:id/shared → exclusive is_shared designation (ADMIN-02)
 *
 * Mounted in index.ts: app.route('/api/admin', adminRouter)
 */

import { Hono } from 'hono';
import type { Context } from 'hono';
import { zValidator } from '@hono/zod-validator';
import { z } from 'zod';
import { eq } from 'drizzle-orm';
import { db } from '../db/client.js';
import { users, memberCredentials, calendars } from '../db/schema.js';
import { requireAdmin } from '../lib/requireAdmin.js';
import {
  validateEncryptAndStoreCredential,
  CredentialValidationError,
} from '../broker/credentialSync.js';
// Side-effect import: brings in the ContextVariableMap augmentation for c.get('user')
import '../auth/devBypass.js';

export const adminRouter = new Hono();

// Pitfall 9: requireAdmin MUST be the first statement on the router.
// All sub-routes are protected — no path can be reached without passing this guard.
adminRouter.use('*', requireAdmin);

// ---------------------------------------------------------------------------
// Zod schema + no-echo hook for credential routes (T-10-09 / Pitfall 7)
// ---------------------------------------------------------------------------

const credentialSchema = z.object({
  userId: z.number().int().positive(),
  providerType: z.literal('caldav'),
  fastmailEmail: z.string().email().max(256),
  appPassword: z.string().min(1).max(500),
});

/**
 * noEchoHook: NEVER return result.error from zValidator for credential routes.
 * Zod's error object contains issues[].received which echoes the submitted value
 * (the app password) — returning it would violate T-10-09 (Pitfall 7).
 * Always return { error: 'Invalid request' } 400, no other fields.
 */
const noEchoHook = (result: { success: boolean }, c: Context) => {
  if (!result.success) {
    return c.json({ error: 'Invalid request' }, 400);
  }
};

// ---------------------------------------------------------------------------
// GET /api/admin/members
//
// Returns all household members with their credential status.
// Feeds UI-SPEC Surface 2 (member list with rotate-credential affordance).
// ---------------------------------------------------------------------------

adminRouter.get('/members', async (c) => {
  const rows = await db
    .select({
      id: users.id,
      displayName: users.displayName,
      color: users.color,
      credentialId: memberCredentials.id,
    })
    .from(users)
    .leftJoin(memberCredentials, eq(memberCredentials.userId, users.id));

  const members = rows.map((row) => ({
    id: row.id,
    displayName: row.displayName,
    color: row.color,
    hasCredential: row.credentialId !== null,
  }));

  return c.json({ members });
});

// ---------------------------------------------------------------------------
// POST /api/admin/credentials
//
// Admin rotates (or sets for the first time) a member's Fastmail app password.
// Validates against CalDAV (PROPFIND) before storing.
// Uses the shared validateEncryptAndStoreCredential helper — no duplicated logic here.
// ---------------------------------------------------------------------------

adminRouter.post('/credentials', zValidator('json', credentialSchema, noEchoHook), async (c) => {
  const { userId, fastmailEmail, appPassword, providerType } = c.req.valid('json');
  // T-10-10: NEVER log appPassword or c.req.valid('json') here

  try {
    await validateEncryptAndStoreCredential(userId, fastmailEmail, appPassword, providerType);
  } catch (err) {
    if (err instanceof CredentialValidationError) {
      // T-10-09: map validation failure to generic 400 — no echo of password or Zod details
      return c.json({ error: 'Invalid request' }, 400);
    }
    // Unexpected errors (DB failure, etc.) — log message only, no credential data
    console.error(
      '[admin/POST /credentials] Unexpected error:',
      err instanceof Error ? err.message : String(err),
    );
    return c.json({ error: 'Service unavailable' }, 503);
  }

  return c.json({ ok: true }, 200);
});

// ---------------------------------------------------------------------------
// GET /api/admin/calendars
//
// Lists all synced calendars. Feeds UI-SPEC Surface 5 (shared-calendar picker).
// ---------------------------------------------------------------------------

adminRouter.get('/calendars', async (c) => {
  const rows = await db
    .select({
      id: calendars.id,
      displayName: calendars.displayName,
      isShared: calendars.isShared,
    })
    .from(calendars);

  return c.json({ calendars: rows });
});

// ---------------------------------------------------------------------------
// PUT /api/admin/calendars/:id/shared
//
// Exclusively marks one calendar as is_shared=true (ADMIN-02).
// Clears is_shared on any prior shared calendar first (D-06 single-select).
// Pattern 7: two sequential UPDATE statements.
// ---------------------------------------------------------------------------

adminRouter.put('/calendars/:id/shared', async (c) => {
  const targetId = parseInt(c.req.param('id'), 10);
  if (isNaN(targetId)) {
    return c.json({ error: 'Invalid calendar id' }, 400);
  }

  // CR-01: verify the target exists and flip the shared lane atomically.
  // Without the existence check + transaction, a bad/stale id would clear the
  // current shared calendar in step 1 and update 0 rows in step 2 — silently
  // leaving the household with NO shared calendar while still returning ok.
  const found = await db.transaction(async (tx) => {
    const [target] = await tx
      .select({ id: calendars.id })
      .from(calendars)
      .where(eq(calendars.id, targetId))
      .limit(1);
    if (!target) return false;

    // Step 1: Clear is_shared on any currently-shared calendar
    await tx.update(calendars).set({ isShared: false }).where(eq(calendars.isShared, true));
    // Step 2: Set is_shared on the target calendar (D-06 single-select)
    await tx.update(calendars).set({ isShared: true }).where(eq(calendars.id, targetId));
    return true;
  });

  if (!found) {
    return c.json({ error: 'Calendar not found' }, 404);
  }

  return c.json({ ok: true }, 200);
});