import { NextResponse } from "next/server";
import { prisma } from "@capakraken/db";
import { createNotificationsForUsers } from "@capakraken/api";
import { logger } from "@capakraken/api/lib/logger";
import { readFileSync } from "fs";
import { join } from "path";
import { verifyCronSecret } from "~/lib/cron-auth.js";

export const dynamic = "force-dynamic";
export const runtime = "nodejs";

/**
 * Known CVEs / minimum safe versions for critical dependencies.
 * Update this map when new advisories are published.
 */
const MINIMUM_SAFE_VERSIONS: Record<string, { minVersion: string; advisory?: string }> = {
  next: { minVersion: "15.0.0", advisory: "Keep Next.js on latest 15.x" },
  prisma: { minVersion: "6.0.0", advisory: "Prisma 6.x for latest security patches" },
  "@sentry/nextjs": { minVersion: "8.0.0", advisory: "Sentry v8 for latest fixes" },
  ioredis: { minVersion: "5.4.0", advisory: "ioredis 5.4+ for connection security" },
  "next-auth": { minVersion: "5.0.0", advisory: "Auth.js v5 for security hardening" },
};

interface Finding {
  package: string;
  currentVersion: string;
  minimumVersion: string;
  severity: "high" | "medium" | "low";
  advisory: string;
}

/**
 * Simple semver comparison: returns true if `current` >= `minimum`.
 * Handles standard x.y.z versions and beta/rc suffixes.
 */
function isVersionSafe(current: string, minimum: string): boolean {
  const normalize = (v: string) =>
    v
      .replace(/^[~^>=<]*/, "")
      .split("-")[0]!
      .split(".")
      .map((n) => parseInt(n, 10) || 0);

  const cur = normalize(current);
  const min = normalize(minimum);

  for (let i = 0; i < 3; i++) {
    const c = cur[i] ?? 0;
    const m = min[i] ?? 0;
    if (c > m) return true;
    if (c < m) return false;
  }
  return true; // equal
}

function scanPackageJson(): Finding[] {
  const findings: Finding[] = [];

  try {
    // Read root package.json and web app package.json
    const paths = [
      join(process.cwd(), "package.json"),
      join(process.cwd(), "../../package.json"), // monorepo root from apps/web
    ];

    const allDeps: Record<string, string> = {};

    for (const p of paths) {
      try {
        const content = JSON.parse(readFileSync(p, "utf-8"));
        Object.assign(allDeps, content.dependencies ?? {}, content.devDependencies ?? {});
      } catch {
        // File not found — skip
      }
    }

    for (const [pkg, rule] of Object.entries(MINIMUM_SAFE_VERSIONS)) {
      const installed = allDeps[pkg];
      if (!installed) continue;

      if (!isVersionSafe(installed, rule.minVersion)) {
        findings.push({
          package: pkg,
          currentVersion: installed,
          minimumVersion: rule.minVersion,
          severity: "high",
          advisory: rule.advisory ?? "Update recommended",
        });
      }
    }
  } catch (error) {
    logger.error(
      { error, route: "/api/cron/security-audit" },
      "Failed to scan package manifests for security audit",
    );
  }

  return findings;
}

/**
 * GET /api/cron/security-audit
 *
 * Checks installed dependency versions against known minimum safe versions.
 * Creates a CRITICAL notification for ADMIN users if high-severity issues found.
 *
 * Protected by CRON_SECRET environment variable.
 * When set, requests must include `Authorization: Bearer <secret>`.
 */
export async function GET(request: Request) {
  const deny = verifyCronSecret(request);
  if (deny) return deny;

  try {
    const findings = scanPackageJson();
    const highSeverity = findings.filter((f) => f.severity === "high");

    // Alert admins if high-severity findings exist
    if (highSeverity.length > 0) {
      const adminUsers = await prisma.user.findMany({
        where: { systemRole: "ADMIN" },
        select: { id: true },
      });

      if (adminUsers.length > 0) {
        const details = highSeverity
          .map((f) => `${f.package}@${f.currentVersion} (need >=${f.minimumVersion})`)
          .join(", ");

        await createNotificationsForUsers({
          db: prisma,
          userIds: adminUsers.map((u) => u.id),
          type: "SYSTEM_ALERT",
          title: `Security Audit: ${highSeverity.length} high-severity finding(s)`,
          body: `Outdated packages detected: ${details}. Run \`pnpm update\` and review advisories.`,
          category: "system",
          priority: "CRITICAL",
          link: "/admin/settings",
        });
      }
    }

    return NextResponse.json({
      ok: highSeverity.length === 0,
      totalFindings: findings.length,
      highSeverity: highSeverity.length,
      findings,
      scannedAt: new Date().toISOString(),
    });
  } catch (error) {
    logger.error({ error, route: "/api/cron/security-audit" }, "Security audit cron failed");
    return NextResponse.json({ ok: false, error: "Internal error" }, { status: 500 });
  }
}