import { execSync } from "child_process";
import { writeFileSync, mkdirSync, rmSync } from "fs";
import { tmpdir } from "os";
import { join } from "path";
import { config } from "../lib/config";

export async function getLatestChartVersion(): Promise<string> {
  // Query backend image tags instead of Helm chart tags — DO API is unreliable for OCI helm artifacts
  const res = await fetch("https://api.digitalocean.com/v2/registry/lunarfront/repositories/lunarfront-app/tags?page=1&per_page=100", {
    headers: { Authorization: `Bearer ${config.doToken}` },
  });
  const data = await res.json() as { tags: { tag: string }[] };
  const versions = (data.tags ?? [])
    .map(t => t.tag)
    .filter(t => /^\d+\.\d+\.\d+$/.test(t))
    .sort((a, b) => {
      const [aMaj, aMin, aPat] = a.split(".").map(Number);
      const [bMaj, bMin, bPat] = b.split(".").map(Number);
      return bMaj - aMaj || bMin - aMin || bPat - aPat;
    });
  if (!versions.length) throw new Error("No chart versions found in DOCR");
  return versions[0];
}

function withRepo<T>(fn: (dir: string, env: NodeJS.ProcessEnv) => T): T {
  const keyPath = join(tmpdir(), `manager-ssh-key-${Date.now()}`);
  const dir = join(tmpdir(), `lunarfront-charts-${Date.now()}`);

  const keyContent = config.gitSshKey.endsWith("\n") ? config.gitSshKey : config.gitSshKey + "\n";
  writeFileSync(keyPath, keyContent, { mode: 0o600 });

  const env = {
    ...process.env,
    GIT_SSH_COMMAND: `ssh -i ${keyPath} -o StrictHostKeyChecking=no`,
  };

  try {
    execSync(`git clone ${config.gitRepoUrl} ${dir}`, { env, stdio: "pipe" });
    execSync(`git -C ${dir} config user.email "manager@lunarfront.tech"`, { env });
    execSync(`git -C ${dir} config user.name "lunarfront-manager"`, { env });
    const result = fn(dir, env);
    const unpushed = execSync(`git -C ${dir} log origin/main..HEAD --oneline`, { env }).toString().trim();
    if (unpushed) execSync(`git -C ${dir} push origin main`, { env, stdio: "pipe" });
    return result;
  } finally {
    rmSync(dir, { recursive: true, force: true });
    rmSync(keyPath, { force: true });
  }
}

export async function addCustomerChart(slug: string, appVersion: string) {
  const version = (appVersion === "*" || appVersion === "latest") ? await getLatestChartVersion() : appVersion;
  withRepo((dir, env) => {
    const manifest = buildArgoCDApp(slug, version);
    writeFileSync(join(dir, "customers", `${slug}.yaml`), manifest);
    execSync(`git -C ${dir} add customers/${slug}.yaml`, { env });
    execSync(`git -C ${dir} commit -m "feat: provision customer ${slug}"`, { env });
  });
}

export async function upgradeCustomerChart(slug: string, version: string) {
  withRepo((dir, env) => {
    const manifest = buildArgoCDApp(slug, version);
    writeFileSync(join(dir, "customers", `${slug}.yaml`), manifest);
    execSync(`git -C ${dir} add customers/${slug}.yaml`, { env });
    const diff = execSync(`git -C ${dir} diff --cached --name-only`, { env }).toString().trim();
    if (!diff) return;
    execSync(`git -C ${dir} commit -m "chore: upgrade customer ${slug} to chart ${version}"`, { env });
  });
}

export async function upgradeAllCustomerCharts(slugs: string[], version: string) {
  withRepo((dir, env) => {
    for (const slug of slugs) {
      const manifest = buildArgoCDApp(slug, version);
      writeFileSync(join(dir, "customers", `${slug}.yaml`), manifest);
      execSync(`git -C ${dir} add customers/${slug}.yaml`, { env });
    }
    const diff = execSync(`git -C ${dir} diff --cached --name-only`, { env }).toString().trim();
    if (!diff) return;
    execSync(`git -C ${dir} commit -m "chore: upgrade all customers to chart ${version}"`, { env });
  });
}

export function removeCustomerChart(slug: string) {
  withRepo((dir, env) => {
    const filePath = join(dir, "customers", `${slug}.yaml`);
    const tracked = execSync(`git -C ${dir} ls-files customers/${slug}.yaml`, { env }).toString().trim();
    if (!tracked) return;
    rmSync(filePath, { force: true });
    execSync(`git -C ${dir} add customers/${slug}.yaml`, { env });
    execSync(`git -C ${dir} commit -m "chore: deprovision customer ${slug}"`, { env });
  });
}

function buildArgoCDApp(slug: string, version: string): string {
  const revision = version;
  return `apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: customer-${slug}
  namespace: argocd
spec:
  project: default
  source:
    repoURL: registry.digitalocean.com/lunarfront
    chart: lunarfront
    targetRevision: "${revision}"
    helm:
      parameters:
        - name: ingress.host
          value: ${slug}.lunarfront.tech
  destination:
    server: https://kubernetes.default.svc
    namespace: customer-${slug}
  syncPolicy:
    automated:
      prune: true
      selfHeal: true
    syncOptions:
      - CreateNamespace=true
`;
}