type Tokens = record {
     e8s : nat64;
};

type Duration = record {
    secs: nat64;
    nanos: nat32;
};

// Number of nanoseconds from the UNIX epoch in UTC timezone.
type TimeStamp = record {
    timestamp_nanos: nat64;
};

type ArchiveOptions = record {
    trigger_threshold : nat64;
    num_blocks_to_archive : nat64;
    node_max_memory_size_bytes: opt nat64;
    max_message_size_bytes: opt nat64;
    controller_id: principal;
    cycles_for_archive_creation: opt nat64;
};

// Height of a ledger block.
type BlockHeight = nat64;

// A number associated with a transaction.
// Can be set by the caller in `send` call as a correlation identifier.
type Memo = nat64;

// Account identifier encoded as a 64-byte ASCII hex string.
type AccountIdentifier = text;

// Subaccount is an arbitrary 32-byte byte array.
type SubAccount = blob;

type Transfer = variant {
    Burn: record {
        from: AccountIdentifier;
        amount: Tokens;
    };
    Mint: record {
        to: AccountIdentifier;
        amount: Tokens;
    };
    Send: record {
        from: AccountIdentifier;
        to: AccountIdentifier;
        amount: Tokens;
    };
};

type Transaction = record {
    transfer: Transfer;
    memo: Memo;
    created_at: BlockHeight;
};

// Arguments for the `send_dfx` call.
type SendArgs = record {
    memo: Memo;
    amount: Tokens;
    fee: Tokens;
    from_subaccount: opt SubAccount;
    to: AccountIdentifier;
    created_at_time: opt TimeStamp;
};

// Arguments for the `notify` call.
type NotifyCanisterArgs = record {
    // The of the block to send a notification about.
    block_height: BlockHeight;
    // Max fee, should be 10000 e8s.
    max_fee: Tokens;
    // Subaccount the payment came from.
    from_subaccount: opt SubAccount;
    // Canister that received the payment.
    to_canister: principal;
    // Subaccount that received the payment.
    to_subaccount: opt SubAccount;
};

type AccountBalanceArgs = record {
    account: AccountIdentifier;
};

type LedgerCanisterInitPayload = record {
    minting_account: AccountIdentifier;
    initial_values: vec record {AccountIdentifier; Tokens};
    max_message_size_bytes: opt nat64;
    transaction_window: opt Duration;
    archive_options: opt ArchiveOptions;
    send_whitelist: vec principal;
    transfer_fee: opt Tokens;
    token_symbol: opt text;
    token_name: opt text;
};

service: (LedgerCanisterInitPayload) -> {
  send_dfx : (SendArgs) -> (BlockHeight);
  notify_dfx: (NotifyCanisterArgs) -> ();
  account_balance_dfx : (AccountBalanceArgs) -> (Tokens) query;
}