import { fileExists, readText, writeTextAtomic } from "../lib/fs";
import { info, setOperationContext } from "../lib/log";
import { redactEnv, redactYaml } from "../lib/redaction";

export type RedactConfigFormat = "auto" | "env" | "yaml";

export type RedactConfigOptions = {
  configPath: string;
  outPath: string;
  inPlace: boolean;
  format: RedactConfigFormat;
};

function detectFormat(path: string): Exclude<RedactConfigFormat, "auto"> | null {
  const p = path.toLowerCase();
  if (p.endsWith(".env") || p.endsWith("hy2xs.env") || p.endsWith("post-install.env")) {
    return "env";
  }
  if (p.endsWith(".yaml") || p.endsWith(".yml")) {
    return "yaml";
  }
  return null;
}

function resolveFormat(format: RedactConfigFormat, path: string): Exclude<RedactConfigFormat, "auto"> {
  if (format !== "auto") {
    return format;
  }
  const detected = detectFormat(path);
  if (!detected) {
    throw new Error(`unable to auto-detect format for ${path}; use --format env|yaml`);
  }
  return detected;
}

export async function redactConfig(options: RedactConfigOptions): Promise<void> {
  setOperationContext(`redact-config-${Date.now().toString(36)}`);

  if (!(await fileExists(options.configPath))) {
    throw new Error(`config file not found: ${options.configPath}`);
  }

  const targetPath = options.inPlace ? options.configPath : options.outPath;
  if (!targetPath) {
    throw new Error("target path is empty");
  }

  const input = await readText(options.configPath);
  const format = resolveFormat(options.format, options.configPath);
  const output = format === "env" ? redactEnv(input) : redactYaml(input);

  await writeTextAtomic(targetPath, output, {
    mode: 0o600,
    owner: "root",
    group: "root"
  });

  info(`redact-config done: source=${options.configPath} target=${targetPath} format=${format} in_place=${options.inPlace}`);
}