/**
 * Build-time CLI: рендерит канонический серверный конфиг HY2XS тем же кодом,
 * который работает на target-сервере.
 *
 * Используется compatibility gate: получившийся YAML скармливается реальному
 * upstream-бинарнику Hysteria до того, как будет создан release package.
 *
 *   bun run tools/render-canonical-config.ts \
 *     --package-dir . --obfs gecko --tls-mode file \
 *     --cert /tmp/x.crt --key /tmp/x.key --out /tmp/config.yaml
 */

import { parseRuntimeEnv } from "../src/config/env";
import { HYSTERIA_OBFS_TYPES } from "../src/config/profile";
import { readText } from "../src/lib/fs";
import { hysteriaConfigTemplatePath, renderHysteriaConfig } from "../src/steps/config";
import type { RuntimeContext } from "../src/types/context";

type Options = {
  packageDir: string;
  configPath: string;
  templatePath: string;
  obfs: string;
  tlsMode: string;
  certPath: string;
  keyPath: string;
  hysteriaPort: string;
  trafficStatsPort: string;
  outPath: string;
};

function fail(message: string): never {
  console.error(`[hy2xs-build] ERROR: ${message}`);
  process.exit(1);
}

function parseArgs(argv: string[]): Options {
  const options: Options = {
    packageDir: "",
    configPath: "",
    templatePath: "",
    obfs: "gecko",
    tlsMode: "file",
    certPath: "",
    keyPath: "",
    hysteriaPort: "",
    trafficStatsPort: "",
    outPath: ""
  };

  const flags: Record<string, keyof Options> = {
    "--package-dir": "packageDir",
    "--config": "configPath",
    "--template": "templatePath",
    "--obfs": "obfs",
    "--tls-mode": "tlsMode",
    "--cert": "certPath",
    "--key": "keyPath",
    "--port": "hysteriaPort",
    "--traffic-stats-port": "trafficStatsPort",
    "--out": "outPath"
  };

  for (let i = 0; i < argv.length; i += 1) {
    const key = flags[argv[i]];
    if (!key) {
      fail(`unknown argument: ${argv[i]}`);
    }
    const value = argv[i + 1];
    if (value === undefined || value.startsWith("--")) {
      fail(`missing value for ${argv[i]}`);
    }
    options[key] = value;
    i += 1;
  }

  if (!options.packageDir) {
    fail("missing --package-dir");
  }
  if (!options.outPath) {
    fail("missing --out");
  }
  if (!(HYSTERIA_OBFS_TYPES as readonly string[]).includes(options.obfs)) {
    fail(`unsupported --obfs value: ${options.obfs}`);
  }

  options.configPath ||= `${options.packageDir}/config/hy2xs.env`;
  options.templatePath ||= hysteriaConfigTemplatePath(options.packageDir);

  return options;
}

function overrideEnv(source: string, overrides: Record<string, string>): string {
  const pending = new Map(Object.entries(overrides));
  const lines = source.split(/\r?\n/).map((line) => {
    const trimmed = line.trim();
    if (!trimmed || trimmed.startsWith("#")) {
      return line;
    }
    const key = trimmed.slice(0, trimmed.indexOf("="));
    if (pending.has(key)) {
      const value = pending.get(key) as string;
      pending.delete(key);
      return `${key}=${value}`;
    }
    return line;
  });

  for (const [key, value] of pending) {
    lines.push(`${key}=${value}`);
  }

  return lines.join("\n");
}

async function main(): Promise<void> {
  const options = parseArgs(Bun.argv.slice(2));

  const overrides: Record<string, string> = {
    HY2XS_HYSTERIA_OBFS_TYPE: options.obfs,
    HY2XS_TLS_MODE: options.tlsMode,
    // Compatibility gate работает офлайн и не должен зависеть от секретов пакета.
    HY2XS_HYSTERIA_OBFS_PASSWORD: "hy2xs-compat-gate-obfs-password",
    HY2XS_HYSTERIA_TRAFFIC_STATS_SECRET: "hy2xs-compat-gate-traffic-secret",
    HY2XS_ADMIN_INITIAL_PASSWORD: "hy2xs-compat-gate-admin-password",
    HY2XS_ADMIN_CON_PASS: "hy2xs-compat-gate-con-password"
  };

  if (options.certPath) {
    overrides.HY2XS_TLS_CERT_PATH = options.certPath;
  }
  if (options.keyPath) {
    overrides.HY2XS_TLS_KEY_PATH = options.keyPath;
  }
  if (options.hysteriaPort) {
    overrides.HY2XS_HYSTERIA_PORT = options.hysteriaPort;
  }
  if (options.trafficStatsPort) {
    overrides.HY2XS_HYSTERIA_TRAFFIC_STATS_PORT = options.trafficStatsPort;
  }

  const sourceEnv = await readText(options.configPath);
  const config = parseRuntimeEnv(overrideEnv(sourceEnv, overrides));

  const context = {
    mode: "install",
    options: {
      packageDir: options.packageDir,
      sourceConfigPath: options.configPath,
      runtimeConfigPath: "/etc/hy2xs/hy2xs.env",
      nonInteractive: true,
      skipFirewall: true,
      skipServiceStart: true,
      skipSmoke: true
    },
    config,
    packageVersion: "compat-gate",
    packageBuildId: "compat-gate",
    installDate: new Date().toISOString(),
    hysteriaVersion: "compat-gate",
    hysteriaResolution: "compat-gate"
  } satisfies RuntimeContext;

  const template = await readText(options.templatePath);
  await Bun.write(options.outPath, renderHysteriaConfig(context, template));
}

try {
  await main();
} catch (error) {
  fail(error instanceof Error ? error.message : String(error));
}