lssa/nssa/test_program_methods/guest/src/bin/chain_caller.rs

use nssa_core::program::{
    ChainedCall, PdaSeed, ProgramId, ProgramInput, read_nssa_inputs,
    write_nssa_outputs_with_chained_call,
};
use risc0_zkvm::serde::to_vec;

type Instruction = (u128, ProgramId, u32, Option<PdaSeed>);

/// A program that calls another program `num_chain_calls` times.
/// It permutes the order of the input accounts on the subsequent call
/// The `ProgramId` in the instruction must be the program_id of the authenticated transfers program
fn main() {
    let ProgramInput {
        pre_states,
        instruction: (balance, auth_transfer_id, num_chain_calls, pda_seed),
    } = read_nssa_inputs::<Instruction>();

    let [recipient_pre, sender_pre] = match pre_states.try_into() {
        Ok(array) => array,
        Err(_) => return,
    };

    let instruction_data = to_vec(&balance).unwrap();

    let mut running_recipient_pre = recipient_pre.clone();
    let mut running_sender_pre = sender_pre.clone();

    if pda_seed.is_some() {
        running_sender_pre.is_authorized = true;
    }

    let mut chained_calls = Vec::new();
    for _i in 0..num_chain_calls {
        let new_chained_call = ChainedCall {
            program_id: auth_transfer_id,
            instruction_data: instruction_data.clone(),
            pre_states: vec![running_sender_pre.clone(), running_recipient_pre.clone()], // <- Account order permutation here
            pda_seeds: pda_seed.iter().cloned().collect(),
        };
        chained_calls.push(new_chained_call);

        running_sender_pre.account.balance -= balance;
        running_recipient_pre.account.balance += balance;
    }

    write_nssa_outputs_with_chained_call(
        vec![recipient_pre.clone(), sender_pre.clone()],
        vec![recipient_pre.account, sender_pre.account],
        chained_calls,
    );
}