/**
 * OIDC authentication middleware wiring.
 *
 * Configures @hono/oidc-auth for the generic OIDC identity provider (D-06).
 *
 * Required env vars:
 *   OIDC_AUTH_SECRET          — 32+ char random string for JWT cookie signing (T-02-03)
 *   OIDC_ISSUER               — OIDC issuer URL (middleware fetches /.well-known/openid-configuration)
 *   OIDC_CLIENT_ID            — registered client ID at the OIDC provider
 *   OIDC_CLIENT_SECRET        — PLAIN text secret (NOT the pbkdf2 hash — see Pitfall 7)
 *   OIDC_REDIRECT_URI         — https://familysync.<domain>/callback
 *   OIDC_AUTH_EXTERNAL_URL    — https://familysync.<domain> — MANDATORY behind Pangolin (Pitfall 1)
 *
 * Phase 12 — env-OR-app_config fallback (D-02 / D-03 / Recommendation a):
 *   OIDC_ISSUER, OIDC_CLIENT_ID, OIDC_AUTH_EXTERNAL_URL may be absent from env on a
 *   fresh unconfigured instance or when the wizard has written them to app_config but
 *   the container has not yet been restarted. oidcAuthMiddlewareWithFallback() reads
 *   the process.env value first; when absent, reads the app_config DB value and injects
 *   it via process.env for the duration of the request. This avoids a crash on fresh
 *   boot and allows wizard-configured values to work before a container restart.
 *
 *   A2 CONFIRMED: @hono/oidc-auth reads OIDC_ISSUER etc. at per-request call time
 *   (inside setOidcAuthEnv → env(c) → process.env). NOT at import time. A fresh instance
 *   without these env vars boots cleanly; the HTTP 500 only occurs if a request hits
 *   /api/* OIDC-protected routes before setup is complete — which is acceptable since
 *   /api/setup/* is pre-auth and is the only pre-setup surface.
 *
 * Session persistence (AUTH-02):
 *   @hono/oidc-auth stores the refresh token in the signed JWT cookie.
 *   Every OIDC_AUTH_REFRESH_INTERVAL (default 15 min) the middleware calls
 *   the token endpoint with the stored refresh token — no iframe required (D-12).
 *   Session lifespan is governed by OIDC_AUTH_EXPIRES (default 1 day) and
 *   the OIDC provider's refresh_token_lifespan.
 *
 * Scopes: openid, profile, email only — no 'groups' scope (D-11).
 *
 * Source: https://github.com/honojs/middleware/tree/main/packages/oidc-auth
 */

import type { Context, Next } from 'hono';
import { eq } from 'drizzle-orm';
import { db } from '../db/client.js';
import { appConfig } from '../db/schema.js';

export { oidcAuthMiddleware, processOAuthCallback, getAuth } from '@hono/oidc-auth';

// ---------------------------------------------------------------------------
// env-OR-app_config fallback middleware (D-02 / D-03 / Recommendation a)
//
// OIDC_ISSUER, OIDC_CLIENT_ID, OIDC_AUTH_EXTERNAL_URL are non-secret config
// (D-01) that the wizard writes to app_config. When the env var is absent,
// this middleware reads the app_config value and sets it into process.env so
// that the downstream oidcAuthMiddleware() picks it up from its env(c) read.
//
// Env floor vars that stay in env only (never in app_config):
//   OIDC_AUTH_SECRET, OIDC_CLIENT_SECRET — secrets; must be in Docker env (D-01)
//
// Called once per /api/* request that reaches the OIDC guard.
// Reading 3 app_config rows adds negligible overhead for a 2-person household app.
// ---------------------------------------------------------------------------

export async function oidcConfigFallbackMiddleware(c: Context, next: Next): Promise<void> {
  const needsIssuer = !process.env.OIDC_ISSUER;
  const needsClientId = !process.env.OIDC_CLIENT_ID;
  const needsExternalUrl = !process.env.OIDC_AUTH_EXTERNAL_URL;

  if (needsIssuer || needsClientId || needsExternalUrl) {
    // Build a minimal list of keys to read — only the absent ones
    const keysToRead: string[] = [];
    if (needsIssuer) keysToRead.push('oidc_issuer');
    if (needsClientId) keysToRead.push('oidc_client_id');
    if (needsExternalUrl) keysToRead.push('app_external_url');

    // Read from app_config (written by POST /api/setup/config)
    for (const key of keysToRead) {
      const [row] = await db
        .select({ value: appConfig.value })
        .from(appConfig)
        .where(eq(appConfig.key, key))
        .limit(1);

      if (row?.value) {
        // Inject into process.env so oidcAuthMiddleware()'s env(c) picks it up.
        // This is safe: these are non-secret, app-config-owned values (D-01).
        //
        // WR-03 — single-write semantics: once written, process.env is NOT re-read
        // from DB on subsequent requests (the needsXxx guard above is false once set).
        // Consequence: if the operator changes these values via the wizard after the
        // container is already running, the in-process value is stale until restart.
        // A container restart is required to pick up any changed OIDC config values.
        if (key === 'oidc_issuer') {
          console.info(
            '[oidcFallback] Writing OIDC_ISSUER from app_config — container restart required to update this value',
          );
          process.env.OIDC_ISSUER = row.value;
        }
        if (key === 'oidc_client_id') {
          console.info(
            '[oidcFallback] Writing OIDC_CLIENT_ID from app_config — container restart required to update this value',
          );
          process.env.OIDC_CLIENT_ID = row.value;
        }
        if (key === 'app_external_url') {
          console.info(
            '[oidcFallback] Writing OIDC_AUTH_EXTERNAL_URL from app_config — container restart required to update this value',
          );
          process.env.OIDC_AUTH_EXTERNAL_URL = row.value;
        }
      }
    }
  }

  await next();
}