How to get the AccountId of the contract instantiated in the contract in Substrate ink

Question

• I want to instantiate another contract inside a contract and get the AccountId of that contract.

• Can anyone tell me how to do that?

  • Instantiate SampleContract2 in the add_contract function of SampleContract1.
  • I want to get the AccountId of the instantiated SampleContract2, manage it in a list, and use the AccountId later to be able to access SmapleContract2.
  • In the future, I would like to increase the types of contracts, so I would like to use AccountId, which can be used for general purposes, instead of the SmapleContract2 type for the list.

• Why does "sample_contract_2.env().account_id()" return the address of SampleContract1?

-- snip --
    #[ink(storage)]
    pub struct SampleContract1 {
      next_id:u128,
      account_id_list:Mapping<u128, AccountId>
    }
-- snip --
    impl SampleContract1 {
        #[ink(constructor)]
        pub fn new() -> Self {
            Self { 
                account_id_list: Mapping::default(),
                next_id:0,
            }
        }

        #[ink(message)]
        pub fn add_contract(&mut self ) -> Result<()> {
            let sample_contract_2 = SampleContract2::new();
            let contract_address = sample_contract_2.env().account_id(); <- ###### Address of SampleContract1 is obtained.
            self.token_list.insert(&self.next_id, &contract_address );
            self.next_id = self.next_id + 1;

            Ok(())
        }

Thank you.