import { randomBytes } from "node:crypto";
import type { InstallContext, InstallOptions } from "../types/context";
import { exists, readText, writeText } from "../lib/fs";
import { runVisible } from "../lib/process";
import { step } from "../lib/log";
import { parseRuntimeEnv, renderRuntimeEnv } from "../config/env";
import { preflight } from "../steps/preflight";
import { installDeps } from "../steps/deps";
import { prepareFilesystem } from "../steps/filesystem";
import { deployUi } from "../steps/ui";
import { installHysteria } from "../steps/hysteria";
import { generateConfig } from "../steps/config";
import { deploySystemd } from "../steps/systemd";
import { applyFirewall } from "../steps/firewall";
import { writePostInstallEnv } from "../steps/env";
import { smoke } from "../steps/smoke";

async function readPackageValue(packageDir: string, file: string, fallback: string): Promise<string> {
  try {
    return (await readText(`${packageDir}/metadata/${file}`)).trim();
  } catch {
    return fallback;
  }
}

function secret(): string {
  return randomBytes(24).toString("base64url");
}

export async function install(options: InstallOptions): Promise<void> {
  const hasConfig = await exists(options.configPath);
  const sourceConfigPath = hasConfig ? options.configPath : `${options.packageDir}/config/hy2xs.env`;
  const sourceConfigRaw = await readText(sourceConfigPath);
  const config = parseRuntimeEnv(sourceConfigRaw);

  const context: InstallContext = {
    options,
    config,
    packageVersion: await readPackageValue(options.packageDir, "package.version", "unknown"),
    packageBuildId: await readPackageValue(options.packageDir, "package.build_id", "unknown"),
    installDate: new Date().toISOString(),
    hysteriaAuthPassword: secret(),
    hysteriaVersion: "unknown"
  };

  step("preflight");
  await preflight(context);
  step("system dependencies");
  await installDeps(context);
  step("filesystem");
  await prepareFilesystem(context);
  if (!hasConfig) {
    step("write runtime env");
    await runVisible`mkdir -p /etc/hy2xs`;
    await writeText(options.configPath, renderRuntimeEnv(config), 0o600);
  }
  step("bundled UI");
  await deployUi(context);
  step("Hysteria2 upstream install");
  await installHysteria(context);
  step("config generation");
  await generateConfig(context);
  step("systemd units");
  await deploySystemd(context);
  step("firewall");
  await applyFirewall(context);
  step("post-install env");
  await writePostInstallEnv(context);
  step("smoke checks");
  await smoke(context);
}