cdk/crates/cdk-cli/src/sub_commands/mint_blind_auth.rs

use std::path::Path;

use anyhow::{anyhow, Result};
use cdk::mint_url::MintUrl;
use cdk::nuts::MintInfo;
use cdk::wallet::MultiMintWallet;
use cdk::{Amount, OidcClient};
use clap::Args;
use serde::{Deserialize, Serialize};

use crate::token_storage;

#[derive(Args, Serialize, Deserialize)]
pub struct MintBlindAuthSubCommand {
    /// Mint url
    mint_url: MintUrl,
    /// Amount
    amount: Option<u64>,
    /// Cat (access token)
    #[arg(long)]
    cat: Option<String>,
}

pub async fn mint_blind_auth(
    multi_mint_wallet: &MultiMintWallet,
    sub_command_args: &MintBlindAuthSubCommand,
    work_dir: &Path,
) -> Result<()> {
    let mint_url = sub_command_args.mint_url.clone();

    // Ensure the mint exists
    if !multi_mint_wallet.has_mint(&mint_url).await {
        multi_mint_wallet.add_mint(mint_url.clone()).await?;
    }

    multi_mint_wallet.fetch_mint_info(&mint_url).await?;

    // Try to get the token from the provided argument or from the stored file
    let cat = match &sub_command_args.cat {
        Some(token) => token.clone(),
        None => {
            // Try to load from file
            match token_storage::get_token_for_mint(work_dir, &mint_url).await {
                Ok(Some(token_data)) => {
                    println!("Using access token from cashu_tokens.json");
                    token_data.access_token
                }
                Ok(None) => {
                    return Err(anyhow::anyhow!(
                        "No access token provided and no token found in cashu_tokens.json for this mint"
                    ));
                }
                Err(e) => {
                    return Err(anyhow::anyhow!(
                        "Failed to read token from cashu_tokens.json: {}",
                        e
                    ));
                }
            }
        }
    };

    // Try to set the access token
    if let Err(err) = multi_mint_wallet.set_cat(&mint_url, cat.clone()).await {
        tracing::error!("Could not set cat: {}", err);

        // Try to refresh the token if we have a refresh token
        if let Ok(Some(token_data)) = token_storage::get_token_for_mint(work_dir, &mint_url).await {
            println!("Attempting to refresh the access token...");

            // Get the mint info to access OIDC configuration
            if let Some(mint_info) = multi_mint_wallet.fetch_mint_info(&mint_url).await? {
                match refresh_access_token(&mint_info, &token_data.refresh_token).await {
                    Ok((new_access_token, new_refresh_token)) => {
                        println!("Successfully refreshed access token");

                        // Save the new tokens
                        if let Err(e) = token_storage::save_tokens(
                            work_dir,
                            &mint_url,
                            &new_access_token,
                            &new_refresh_token,
                        )
                        .await
                        {
                            println!("Warning: Failed to save refreshed tokens: {e}");
                        }

                        // Try setting the new access token
                        if let Err(err) =
                            multi_mint_wallet.set_cat(&mint_url, new_access_token).await
                        {
                            tracing::error!("Could not set refreshed cat: {}", err);
                            return Err(anyhow::anyhow!(
                                "Authentication failed even after token refresh"
                            ));
                        }

                        // Set the refresh token
                        multi_mint_wallet
                            .set_refresh_token(&mint_url, new_refresh_token)
                            .await?;
                    }
                    Err(e) => {
                        tracing::error!("Failed to refresh token: {}", e);
                        return Err(anyhow::anyhow!("Failed to refresh access token: {}", e));
                    }
                }
            }
        } else {
            return Err(anyhow::anyhow!(
                "Authentication failed and no refresh token available"
            ));
        }
    } else {
        // If we have a refresh token, set it
        if let Ok(Some(token_data)) = token_storage::get_token_for_mint(work_dir, &mint_url).await {
            tracing::info!("Attempting to use refresh access token to refresh auth token");
            multi_mint_wallet
                .set_refresh_token(&mint_url, token_data.refresh_token)
                .await?;
            multi_mint_wallet.refresh_access_token(&mint_url).await?;
        }
    }

    println!("Attempting to mint blind auth");

    let amount = match sub_command_args.amount {
        Some(amount) => amount,
        None => {
            let mint_info = multi_mint_wallet
                .fetch_mint_info(&mint_url)
                .await?
                .ok_or(anyhow!("Unknown mint info"))?;
            mint_info
                .bat_max_mint()
                .ok_or(anyhow!("Unknown max bat mint"))?
        }
    };

    let proofs = multi_mint_wallet
        .mint_blind_auth(&mint_url, Amount::from(amount))
        .await?;

    println!("Received {} auth proofs for mint {mint_url}", proofs.len());

    Ok(())
}

async fn refresh_access_token(
    mint_info: &MintInfo,
    refresh_token: &str,
) -> Result<(String, String)> {
    let openid_discovery = mint_info
        .nuts
        .nut21
        .clone()
        .ok_or_else(|| anyhow::anyhow!("OIDC discovery information not available"))?
        .openid_discovery;

    let oidc_client = OidcClient::new(openid_discovery, None);

    // Get the token endpoint from the OIDC configuration
    let token_url = oidc_client.get_oidc_config().await?.token_endpoint;

    // Create the request parameters for token refresh
    let params = [
        ("grant_type", "refresh_token"),
        ("refresh_token", refresh_token),
        ("client_id", "cashu-client"), // Using default client ID
    ];

    // Make the token refresh request
    let client = reqwest::Client::new();
    let response = client.post(token_url).form(&params).send().await?;

    if !response.status().is_success() {
        return Err(anyhow::anyhow!(
            "Token refresh failed with status: {}",
            response.status()
        ));
    }

    let token_response: serde_json::Value = response.json().await?;

    let access_token = token_response["access_token"]
        .as_str()
        .ok_or_else(|| anyhow::anyhow!("No access token in refresh response"))?
        .to_string();

    // Get the new refresh token or use the old one if not provided
    let new_refresh_token = token_response["refresh_token"]
        .as_str()
        .unwrap_or(refresh_token)
        .to_string();

    Ok((access_token, new_refresh_token))
}