import { readFileSync } from "node:fs";
import { runCommand } from "./command";
import { repoRoot, rootPath } from "./config";

const defaultManifest = "src/components/microservices/k3sctl-adapter/k3s/dev/unidesk-dev-foundation.k8s.yaml";
const devNamespace = "unidesk-dev";
const prodNamespace = "unidesk";
const requiredKinds = new Set([
  "Namespace/unidesk-dev",
  "Secret/unidesk-dev-runtime-secrets",
  "ConfigMap/unidesk-dev-runtime-config",
  "ConfigMap/unidesk-dev-db-guard",
  "ConfigMap/unidesk-dev-db-init",
  "Service/postgres-dev",
  "StatefulSet/postgres-dev",
  "Job/unidesk-dev-db-migrate",
]);

interface ManifestDocument {
  index: number;
  raw: string;
  kind: string;
  name: string;
  namespace: string | null;
}

interface DevEnvOptions {
  manifestPath: string;
  kubectlDryRun: boolean;
}

function isHelpArg(arg: string | undefined): boolean {
  return arg === "help" || arg === "--help" || arg === "-h";
}

function parseOptions(args: string[]): DevEnvOptions {
  const options: DevEnvOptions = { manifestPath: defaultManifest, kubectlDryRun: false };
  for (let index = 0; index < args.length; index += 1) {
    const arg = args[index];
    if (arg === "--manifest") {
      const value = args[index + 1];
      if (value === undefined || value.length === 0) throw new Error("--manifest requires a path");
      options.manifestPath = value;
      index += 1;
    } else if (arg === "--kubectl-dry-run") {
      options.kubectlDryRun = true;
    } else if (!isHelpArg(arg)) {
      throw new Error(`unknown dev-env option: ${arg}`);
    }
  }
  return options;
}

function scalarAfter(text: string, key: string): string | null {
  const match = text.match(new RegExp(`^\\s*${key}:\\s*"?([^"\\n#]+)"?\\s*(?:#.*)?$`, "mu"));
  return match?.[1]?.trim() ?? null;
}

function namespaceFromDoc(text: string): string | null {
  const metadataIndex = text.search(/^metadata:\s*$/mu);
  if (metadataIndex < 0) return null;
  const metadataBlock = text.slice(metadataIndex);
  const match = metadataBlock.match(/^ {2}namespace:\s*"?([^"\n#]+)"?\s*(?:#.*)?$/mu);
  return match?.[1]?.trim() ?? null;
}

function parseManifestDocuments(text: string): ManifestDocument[] {
  return text.split(/^---\s*$/mu)
    .map((raw, index) => ({ raw: raw.trim(), index }))
    .filter((doc) => doc.raw.length > 0)
    .map(({ raw, index }) => {
      const kind = scalarAfter(raw, "kind") ?? "";
      const name = (() => {
        const metadataIndex = raw.search(/^metadata:\s*$/mu);
        if (metadataIndex < 0) return "";
        const metadataBlock = raw.slice(metadataIndex);
        const match = metadataBlock.match(/^ {2}name:\s*"?([^"\n#]+)"?\s*(?:#.*)?$/mu);
        return match?.[1]?.trim() ?? "";
      })();
      return { index, raw, kind, name, namespace: namespaceFromDoc(raw) };
    });
}

function databaseUrls(text: string): string[] {
  const urls: string[] = [];
  const pattern = /postgres(?:ql)?:\/\/[^\s"']+/gu;
  for (const match of text.matchAll(pattern)) urls.push(match[0] ?? "");
  return urls.filter((url) => url.length > 0 && !url.includes("*") && !url.includes("$"));
}

function validateDatabaseUrl(url: string): { ok: boolean; url: string; reason: string | null } {
  if (url.includes("d601-tcp-egress-gateway") || url.includes("74.48.78.17:15432") || url.includes("database:5432/unidesk")) {
    return { ok: false, url, reason: "matches production database route" };
  }
  let parsed: URL;
  try {
    parsed = new URL(url);
  } catch {
    return { ok: false, url, reason: "invalid URL" };
  }
  const hostOk = [
    "postgres-dev",
    "postgres-dev.unidesk-dev",
    "postgres-dev.unidesk-dev.svc",
    "postgres-dev.unidesk-dev.svc.cluster.local",
  ].includes(parsed.hostname);
  const database = parsed.pathname.replace(/^\/+/u, "");
  if (!hostOk) return { ok: false, url, reason: `host ${parsed.hostname} is not postgres-dev` };
  if (database !== "unidesk_dev") return { ok: false, url, reason: `database ${database} is not unidesk_dev` };
  return { ok: true, url, reason: null };
}

function kubectlDryRun(manifestPath: string): unknown {
  const result = runCommand(["kubectl", "apply", "--dry-run=client", "--validate=false", "-f", manifestPath], repoRoot, { timeoutMs: 60_000 });
  return {
    command: result.command,
    exitCode: result.exitCode,
    signal: result.signal,
    timedOut: result.timedOut,
    ok: result.exitCode === 0,
    stdoutTail: result.stdout.slice(-4000),
    stderrTail: result.stderr.slice(-4000),
  };
}

function devEnvHelp(): Record<string, unknown> {
  return {
    ok: true,
    command: "dev-env validate",
    usage: "bun scripts/cli.ts dev-env validate [--manifest path] [--kubectl-dry-run]",
    defaultManifest,
    checks: [
      "all namespaced resources must target unidesk-dev",
      "required dev namespace, postgres-dev, secret/config, guard, migration resources must exist",
      "dev DATABASE_URL values must target postgres-dev/unidesk_dev and not production routes",
      "--kubectl-dry-run optionally asks kubectl to client-dry-run the manifest without applying it",
    ],
  };
}

export function runDevEnvCommand(args: string[]): unknown {
  const action = args[0];
  if (action === undefined || isHelpArg(action)) return devEnvHelp();
  if (action !== "validate") throw new Error("dev-env usage: bun scripts/cli.ts dev-env validate [--manifest path] [--kubectl-dry-run]");

  const options = parseOptions(args.slice(1));
  const manifestPath = rootPath(options.manifestPath);
  const manifestText = readFileSync(manifestPath, "utf8");
  const docs = parseManifestDocuments(manifestText);
  const resources = docs.map((doc) => `${doc.kind}/${doc.name}`);
  const namespacedViolations = docs
    .filter((doc) => doc.kind !== "Namespace")
    .filter((doc) => doc.namespace !== devNamespace)
    .map((doc) => ({ index: doc.index, kind: doc.kind, name: doc.name, namespace: doc.namespace }));
  const namespaceObjectViolations = docs
    .filter((doc) => doc.kind === "Namespace")
    .filter((doc) => doc.name !== devNamespace)
    .map((doc) => ({ index: doc.index, kind: doc.kind, name: doc.name }));
  const productionNamespaceTouches = docs
    .filter((doc) => doc.namespace === prodNamespace || (doc.kind === "Namespace" && doc.name === prodNamespace))
    .map((doc) => ({ kind: doc.kind, name: doc.name }));
  const missingRequiredResources = Array.from(requiredKinds).filter((resource) => !resources.includes(resource));
  const urlChecks = databaseUrls(manifestText).map(validateDatabaseUrl);
  const badUrls = urlChecks.filter((check) => !check.ok);
  const forbiddenProductionTextHits = [
    "namespace: unidesk\n",
    "d601-tcp-egress-gateway.unidesk.svc.cluster.local:15432/unidesk",
    "74.48.78.17:15432/unidesk",
  ].filter((needle) => manifestText.includes(needle));

  const staticOk = namespacedViolations.length === 0
    && namespaceObjectViolations.length === 0
    && productionNamespaceTouches.length === 0
    && missingRequiredResources.length === 0
    && badUrls.length === 0
    && forbiddenProductionTextHits.length === 0;
  const kubectl = options.kubectlDryRun ? kubectlDryRun(manifestPath) : { skipped: true, enableWith: "--kubectl-dry-run" };
  const kubectlOk = typeof kubectl === "object" && kubectl !== null && "ok" in kubectl ? (kubectl as { ok: boolean }).ok : true;

  return {
    ok: staticOk && kubectlOk,
    manifest: options.manifestPath,
    namespace: devNamespace,
    staticChecks: {
      ok: staticOk,
      resources,
      namespacedViolations,
      namespaceObjectViolations,
      productionNamespaceTouches,
      missingRequiredResources,
      databaseUrlChecks: urlChecks,
      forbiddenProductionTextHits,
    },
    kubectlDryRun: kubectl,
  };
}