process_set_realm_authority.rs

//! Program state processor

use borsh::BorshSerialize;
use solana_program::{
    account_info::{next_account_info, AccountInfo},
    entrypoint::ProgramResult,
    pubkey::Pubkey,
};

use crate::{
    error::GovernanceError,
    state::{governance::assert_governance_for_realm, realm::get_realm_data_for_authority},
};

/// Processes SetRealmAuthority instruction
pub fn process_set_realm_authority(
    program_id: &Pubkey,
    accounts: &[AccountInfo],
    remove_authority: bool,
) -> ProgramResult {
    let account_info_iter = &mut accounts.iter();

    let realm_info = next_account_info(account_info_iter)?; // 0
    let realm_authority_info = next_account_info(account_info_iter)?; // 1

    let mut realm_data =
        get_realm_data_for_authority(program_id, realm_info, realm_authority_info.key)?;

    if !realm_authority_info.is_signer {
        return Err(GovernanceError::RealmAuthorityMustSign.into());
    }

    let new_realm_authority = if remove_authority {
        None
    } else {
        // Ensure the new realm authority is one of the governances from the realm
        // Note: This is not a security feature because governance creation is only gated with min_community_tokens_to_create_governance
        //       The check is done to prevent scenarios where the authority could be accidentally set to a wrong or none existing account
        let new_realm_authority_info = next_account_info(account_info_iter)?; // 2
        assert_governance_for_realm(program_id, new_realm_authority_info, realm_info.key)?;

        Some(*new_realm_authority_info.key)
    };

    realm_data.authority = new_realm_authority;

    realm_data.serialize(&mut *realm_info.data.borrow_mut())?;

    Ok(())
}