// Copyright 2019-2023 Parity Technologies (UK) Ltd.
// This file is dual-licensed as Apache-2.0 or GPL-3.0.
// see LICENSE for license details.

use clap::Args;
use color_eyre::eyre;
use std::{fs, io::Read, path::PathBuf};
use subxt_codegen::utils::Uri;

/// The source of the metadata.
#[derive(Debug, Args)]
pub struct FileOrUrl {
    /// The url of the substrate node to query for metadata for codegen.
    #[clap(long, value_parser)]
    url: Option<Uri>,
    /// The path to the encoded metadata file.
    #[clap(long, value_parser)]
    file: Option<PathBuf>,
}

impl FileOrUrl {
    /// Fetch the metadata bytes.
    pub async fn fetch(&self) -> color_eyre::Result<Vec<u8>> {
        match (&self.file, &self.url) {
            // Can't provide both --file and --url
            (Some(_), Some(_)) => {
                eyre::bail!("specify one of `--url` or `--file` but not both")
            }
            // Load from --file path
            (Some(path), None) => {
                let mut file = fs::File::open(path)?;
                let mut bytes = Vec::new();
                file.read_to_end(&mut bytes)?;
                Ok(bytes)
            }
            // Fetch from --url
            (None, Some(uri)) => Ok(subxt_codegen::utils::fetch_metadata_bytes(uri).await?),
            // Default if neither is provided; fetch from local url
            (None, None) => {
                let uri = Uri::from_static("http://localhost:9933");
                Ok(subxt_codegen::utils::fetch_metadata_bytes(&uri).await?)
            }
        }
    }
}