export async function getCurrentGitHash(): Promise<string | null> {
  try {
    const process = Deno.run({
      cmd: ["git", "rev-parse", "HEAD"],
      stdout: "piped",
      stderr: "piped",
    });

    const output = await process.output();
    const decoder = new TextDecoder();
    const hash = decoder.decode(output).trim();

    await process.status();

    return hash;
  } catch (error) {
    console.error("Error getting git hash:", error);
    return null;
  }
}

export function getEnvvar(value: string, defaultValue: string | undefined = undefined): string | null {
    const prefix = "DPG_";
    let envvarValue = Deno.env.get(`${prefix}${value.toUpperCase()}`);

    if(envvarValue !== undefined)
        return envvarValue
    else
        if(defaultValue !== undefined)
            return defaultValue
        else
            return null
}

export function getEnvvarAsBool(value: string, defaultValue: string | undefined = undefined): Boolean {
    const envvar = getEnvvar(value, defaultValue);
    
    if(envvar === "1" || envvar === "true")
        return true;
    else
        return false;
}

export async function getUAS(progName: string = "unknown-prog"): Promise<string> {
    let version = await getCurrentGitHash();
    version = version !== null ? version.substring(0,7) : "0000000";
    return `dpg.${progName}/${version}`;
}