import { existsSync, readFileSync } from "node:fs";
import path from "node:path";

/**
 * Lightweight liveness probe for Docker/Coolify healthchecks.
 * Returns 200 as soon as the Next.js Route Handler layer is up and able to
 * serve a request. We deliberately DO NOT touch the database here: a transient
 * DB hiccup should not make Coolify mark the container unhealthy and force a
 * restart (which would break in-flight requests against an otherwise healthy
 * web process). DB health is tracked separately by the Coolify-managed
 * PostgreSQL service.
 *
 * Path: GET /api/health
 */
export const dynamic = "force-dynamic";
export const runtime = "nodejs";

const startedAt = Date.now();

const HEADERS = {
  "Content-Type": "application/json",
  "Cache-Control": "no-store, no-transform",
} as const;

type VersionInfo = {
  version: string | null;
  tag: string | null;
  gitDescribe: string | null;
  commitHash: string | null;
  commitDate: string | null;
  commitSubject: string | null;
  lastUpdated: string | null;
  commitMessage: string | null;
  buildTime: string | null;
};

function readVersionInfo(): Partial<VersionInfo> {
  const versionInfoPath = path.join(
    process.cwd(),
    "src",
    "generated",
    "versionInfo.json",
  );
  try {
    if (!existsSync(versionInfoPath)) return {};
    const raw = readFileSync(versionInfoPath, "utf8");
    return JSON.parse(raw) as Partial<VersionInfo>;
  } catch {
    return {};
  }
}

export async function GET(): Promise<Response> {
  const version = readVersionInfo();
  return new Response(
    JSON.stringify({
      ok: true,
      uptime: Math.max(0, Math.round((Date.now() - startedAt) / 1000)),
      version: version.version ?? null,
      commit: version.commitHash ?? null,
      buildTime: version.buildTime ?? null,
    }),
    { status: 200, headers: HEADERS },
  );
}