use rusqlite::{ffi, params, Connection, Savepoint, Transaction};

use crate::db::accounts;
use crate::db::accounts::AccountType;

use crate::db::cheques::{Cheque, WireTransferRequest};
use crate::db::external_id::AccountId;
use crate::util::*;

fn _transfer_securities_from_one_account_to_another(
    tx: &Savepoint,
    drawer_account_id: &AccountId,
    payee_account_id: &AccountId,
    amount: i64,
) -> CustomResult<(
    accounts::AccountChangeReceipt,
    accounts::AccountChangeReceipt,
)> {
    let drawer_receipt = accounts::add_to_account(tx, drawer_account_id, -amount)?;
    let payee_receipt = accounts::add_to_account(tx, payee_account_id, amount)?;
    if drawer_receipt.amount < 0 && drawer_receipt.account_type != AccountType::SecurityEmitter {
        let m = format!(
            "Drawer of {:} does not have sufficient amount in account.",
            drawer_account_id
        );
        return Err(Error::InvalidAmount(m));
    }
    if drawer_receipt.security_id != drawer_receipt.security_id {
        let m = format!(
            "Incompatible security type between accounts {:} (drawer) and {:} (payee).",
            drawer_account_id,
            payee_account_id
        );
        return Err(Error::InvalidAmount(m));

    }
    Ok((drawer_receipt, payee_receipt))
}

fn _transfer_cheque_securities(
    tx: &Savepoint,
    cheque: &Cheque,
    account_id: &AccountId,
) -> CustomResult<(
    accounts::AccountChangeReceipt,
    accounts::AccountChangeReceipt,
)> {
    _transfer_securities_from_one_account_to_another(tx, &cheque.drawer_account_id, account_id, cheque.amount)
}



fn _transfer_wire_transfer_securities(
    tx: &Savepoint,
    wire_transfer_request: &WireTransferRequest,
) -> CustomResult<(
    accounts::AccountChangeReceipt,
    accounts::AccountChangeReceipt,
)> {
    _transfer_securities_from_one_account_to_another(tx,
                                                     &wire_transfer_request.drawer_account_id,
                                                     &wire_transfer_request.payee_account_id,
                                                     wire_transfer_request.amount)
}

fn _add_wire_transfer_request_to_wire_transfers_log(tx: &Connection,
                                                    cheque: &WireTransferRequest,
                                                    drawer_receipt: &accounts::AccountChangeReceipt,
                                                    payee_receipt: &accounts::AccountChangeReceipt) -> Result<(), Error> {
    let q = "
        INSERT INTO cached_wire_transfers(
            drawer_account_id,
            drawer_account_version,
            payee_account_id,
            payee_account_version,
            wire_transfer_request_number,
            amount,
            underlying_security
        )
        VALUES(?1, ?2, ?3, ?4, ?5, ?6, ?7)
    ";
    let params = params![
        drawer_receipt.account_id,
        drawer_receipt.version,
        payee_receipt.account_id,
        payee_receipt.version,
        cheque.amount,
        cheque.amount,
        payee_receipt.security_id
    ];
    let ret = tx.execute(q, params).map_err(Error::SqlError);
    match ret {
        Ok(_) => Ok(()),
        Err(Error::SqlError(rusqlite::Error::SqliteFailure(
                                ffi::Error {
                                    code: _,
                                    extended_code: 2067,
                                },
                                _,
                            ))) => Err(Error::DoubleSpendingError(format!(
            "Wire transfer number {} has already been cached.",
            cheque.amount
        ))),
        Err(a) => Err(a),
    }
}

fn _add_cheque_to_cashed_cheques_log(
    tx: &Connection,
    cheque: &Cheque,
    drawer_receipt: &accounts::AccountChangeReceipt,
    payee_receipt: &accounts::AccountChangeReceipt,
) -> Result<(), Error> {
    let q = "
        INSERT INTO cashed_cheques(
            drawer_user_id,
            drawer_account_id,
            drawer_account_version,
            payee_user_id,
            payee_account_id,
            payee_account_version,
            cheque_number,
            amount,
            underlying_security
        )
        VALUES(?1, ?2, ?3, ?4, ?5, ?6, ?7, ?8, ?9)
    ";
    let params = params![
        cheque.drawer_user_id,
        cheque.drawer_account_id,
        drawer_receipt.version,
        cheque.payee_user_id,
        payee_receipt.account_id,
        payee_receipt.version,
        cheque.cheque_number,
        cheque.amount,
        cheque.security_id
    ];
    let ret = tx.execute(q, params).map_err(Error::SqlError);
    match ret {
        Ok(_) => Ok(()),
        Err(Error::SqlError(rusqlite::Error::SqliteFailure(
            ffi::Error {
                code: _,
                extended_code: 2067,
            },
            _,
        ))) => Err(Error::DoubleSpendingError(format!(
            "Cheque number {} from user {} has already been cached.",
            cheque.cheque_number, cheque.drawer_user_id
        ))),
        Err(a) => Err(a),
    }
}

fn cash_cheque_unsafe(
    savepoint: &Savepoint,
    cheque: &Cheque,
    payee_account_id: &AccountId,
) -> CustomResult<()> {
    if cheque.amount < 0 {
        return Err(Error::InvalidAmount(format!(
            "The cheque {:?} has a negative amount.",
            cheque
        )));
    }
    if !accounts::is_owner(
        &savepoint,
        &cheque.drawer_account_id,
        &cheque.drawer_user_id,
    )? {
        return Err(Error::InvalidDrawer(format!(
            "The drawer is the security owner: {:?}",
            cheque
        )));
    }

    if !accounts::is_owner(&savepoint, payee_account_id, &cheque.payee_user_id)? {
        return Err(Error::InvalidPayee(format!(
            "Trying to cash the cheque {:?} in \
        an account {:} that is not owned by the payee.",
            cheque, payee_account_id
        )));
    }

    let drawer_account_sec = accounts::get_account_by_id(&savepoint, &cheque.drawer_account_id)?.security().id();
    if drawer_account_sec != cheque.security_id{
        return Err(Error::InvalidDrawer(format!(
            "Impossible to use an account containing {:} to emit a cheque in {:}",
            drawer_account_sec, cheque.security_id
        )));
    }

    let payee_account_sec = accounts::get_account_by_id(&savepoint, &payee_account_id)?.security().id();
    if payee_account_sec != cheque.security_id{
        return Err(Error::InvalidPayee(format!(
            "Impossible to cache a {:} cheque in {:} account .",
            cheque.security_id, payee_account_sec
        )));
    }

    let (drawer_receipt, payee_receipt) = _transfer_cheque_securities(&savepoint, cheque, payee_account_id)?;
    _add_cheque_to_cashed_cheques_log(&savepoint, cheque, &drawer_receipt, &payee_receipt)?;
    Ok(())
}

fn cash_wire_transfer_request_unsafe(
    savepoint: &Savepoint,
    wire_transfer: &WireTransferRequest,
) -> CustomResult<()> {
    // if wire_transfer.amount < 0 {
    //     return Err(Error::InvalidAmount(format!(
    //         "The cheque {:?} has a negative amount.",
    //         wire_transfer
    //     )));
    // }
    let (drawer_receipt, payee_receipt) = _transfer_wire_transfer_securities(&savepoint, wire_transfer)?;
    _add_wire_transfer_request_to_wire_transfers_log(&savepoint, wire_transfer, &drawer_receipt, &payee_receipt)?;
    Ok(())
}

fn cash_cheque(
    tx: &mut Transaction,
    cheque: &Cheque,
    payee_account_id: &AccountId,
) -> CustomResult<()> {
    let mut savepoint = tx.savepoint().map_err(Error::SqlError)?;
    let ret = cash_cheque_unsafe(&savepoint, cheque, payee_account_id);
    match ret {
        Err(_) => {
            savepoint.rollback().map_err(Error::SqlError)?;
            ret
        }
        Ok(_) => savepoint.commit().map_err(Error::SqlError),
    }
}

pub fn cash_wire_transfer_request(
    tx: &mut Transaction,
    wire_transfer: &WireTransferRequest,
) -> CustomResult<()> {
    let mut savepoint = tx.savepoint().map_err(Error::SqlError)?;
    let ret = cash_wire_transfer_request_unsafe(& savepoint, wire_transfer);
    match ret {
        Err(_) => {
            savepoint.rollback().map_err(Error::SqlError)?;
            ret
        }
        Ok(_) => savepoint.commit().map_err(Error::SqlError),
    }
}

#[cfg(test)]
mod test_utils {
    use rusqlite::Connection;

    use crate::db::accounts::{
        create_checking_account, create_security_emitter_account, get_account_by_id,
    };
    use crate::db::cheques::{Drawer, Payee};
    use crate::db::external_id::{Id, UserId};
    use crate::db::test_utils;
    use crate::migration;

    use super::*;

    pub fn setup_conn() -> Connection {
        let mut conn = Connection::open_in_memory().unwrap();
        migration::apply_migrations(&mut conn).unwrap();
        return conn;
    }

    pub fn setup_security_emitter() -> (Connection, Drawer, Payee, AccountId) {
        let mut conn = setup_conn();
        let tx = conn.transaction().unwrap();
        let (users, securities, _accounts) = test_utils::setup_basic_environment(&tx).unwrap();
        let sec = securities.get(0).unwrap();
        let drawer = users.get(0).unwrap();
        let payee = users.get(1).unwrap();
        let security_emitter_account =
            create_security_emitter_account(&tx, &sec.id(), &drawer.id()).unwrap();
        let payee_account = create_checking_account(&tx, &sec.id(), &payee.id()).unwrap();

        tx.commit().unwrap();
        let security_emitter: Drawer = (drawer.id(), security_emitter_account.id(), sec.id());
        let payee: Payee = (payee.id(), sec.id());
        (conn, security_emitter, payee, payee_account.id())
    }

    pub fn setup_security_emitter_mismatched_accounts() -> (Connection, Drawer, Payee, AccountId) {
        let mut conn = setup_conn();
        let tx = conn.transaction().unwrap();
        let (users, securities, _accounts) = test_utils::setup_basic_environment(&tx).unwrap();
        let sec_1 = securities.get(0).unwrap();
        let sec_2 = securities.get(1).unwrap();
        let drawer = users.get(0).unwrap();
        let payee = users.get(1).unwrap();
        let security_emitter_account =
            create_security_emitter_account(&tx, &sec_1.id(), &drawer.id()).unwrap();
        let payee_account = create_checking_account(&tx, &sec_2.id(), &payee.id()).unwrap();

        tx.commit().unwrap();
        let security_emitter: Drawer = (drawer.id(), security_emitter_account.id(), sec_1.id());
        let payee: Payee = (payee.id(), sec_1.id());
        (conn, security_emitter, payee, payee_account.id())

    }

    pub fn create_100_security_units_in_payee_account(
        tx: &mut Transaction,
        security_emitter: &Drawer,
        payee: &Payee,
        payee_account: &AccountId,
    ) {
        let cheque = Cheque::new(security_emitter.clone(), payee.clone(), 100, 99);

        cash_cheque(tx, &cheque, &payee_account).unwrap();
    }

    fn _create_drawer(payee: Payee, payee_account: AccountId) -> Drawer {
        (payee.0, payee_account, payee.1)
    }

    pub fn setup_basic() -> (Connection, Drawer, Payee, AccountId) {
        let (mut conn, security_emitter, payee, payee_account) = setup_security_emitter();

        let mut tx = conn.transaction().unwrap();

        create_100_security_units_in_payee_account(&mut tx, &security_emitter, &payee, &payee_account);
        let reg_account =
            create_checking_account(&tx, &security_emitter.2, &security_emitter.0).unwrap();

        tx.commit().unwrap();

        let drawer: Drawer = _create_drawer(payee, payee_account);
        let new_payee: Payee = (security_emitter.0, security_emitter.2);

        return (conn, drawer, new_payee, reg_account.id());
    }
}

#[cfg(test)]
mod test_caching_cheques {
    use rusqlite::Connection;

    use crate::db::accounts::{
        create_checking_account, create_security_emitter_account, get_account_by_id,
    };
    use crate::db::cheques::{Drawer, Payee};
    use crate::db::external_id::{Id, UserId};
    use crate::db::test_utils;
    use crate::migration;

    use super::*;
    use super::test_utils::*;

    #[test]
    fn test_happy_path_currency_emitter() -> CustomResult<()> { // done
        let (mut conn, security_emitter, payee, payee_account) = setup_security_emitter();
        let mut tx = conn.transaction().unwrap();

        let cheque = Cheque::new(security_emitter, payee, 1000, 99);

        cash_cheque(&mut tx, &cheque, &payee_account)?;
        tx.commit().unwrap();

        let tx = conn.transaction().unwrap();
        let acc = get_account_by_id(&tx, &payee_account).unwrap();
        assert_eq!(acc.raw_amount(), 1000);

        Ok(())
    }

    #[test]
    fn test_happy_path_regular_cheque() -> CustomResult<()> {  // done
        let (mut conn, drawer, payee, payee_account) = setup_basic();
        let mut tx = conn.transaction().unwrap();

        let cheque = Cheque::new(drawer.clone(), payee, 25, 10001);

        cash_cheque(&mut tx, &cheque, &payee_account)?;

        let payee_acc = get_account_by_id(&tx, &payee_account).unwrap();
        assert_eq!(payee_acc.raw_amount(), 25);

        let drawer_acc = get_account_by_id(&tx, &drawer.1).unwrap();
        assert_eq!(drawer_acc.raw_amount(), 75);

        Ok(())
    }

    fn test_negative_cheque(
        conn: &mut Connection,
        drawer: Drawer,
        payee: Payee,
        payee_account: AccountId,
    ) -> CustomResult<()> {
        let mut tx = conn.transaction().unwrap();

        let cheque = Cheque::new(drawer, payee, -1, 99);

        let ret = cash_cheque(&mut tx, &cheque, &payee_account);
        match ret {
            Err(Error::InvalidAmount(_)) => Ok(()),
            _ => Err(Error::Testing(
                "Expected invalid amount error here.".to_string(),
            )),
        }
    }

    #[test]
    fn test_unfounded_cheque() -> CustomResult<()> {
        let (mut conn, drawer, payee, payee_account) = setup_basic();
        let mut tx = conn.transaction().unwrap();

        let cheque = Cheque::new(drawer, payee, 1_000_000, 99);

        let ret = cash_cheque(&mut tx, &cheque, &payee_account);
        match ret {
            Err(Error::InvalidAmount(_)) => Ok(()),
            _ => Err(Error::Testing(
                "Expected invalid amount error here.".to_string(),
            )),
        }
    }

    #[test]
    fn test_negative_security_emitter_cheque() -> CustomResult<()> {
        let (mut conn, security_emitter, payee, payee_account) = setup_security_emitter();
        test_negative_cheque(&mut conn, security_emitter, payee, payee_account)
    }

    #[test]
    fn test_negative_regular_cheque() -> CustomResult<()> {
        let (mut conn, drawer, payee, payee_account) = setup_basic();
        test_negative_cheque(&mut conn, drawer, payee, payee_account)
    }

    fn _test_double_spend(
        conn: &mut Connection,
        drawer: Drawer,
        payee: Payee,
        payee_account: AccountId,
    ) -> CustomResult<()> {
        let mut tx = conn.transaction().unwrap();

        let cheque = Cheque::new(drawer, payee, 10, 99);

        cash_cheque(&mut tx, &cheque, &payee_account)?;
        tx.commit().unwrap();
        let mut tx = conn.transaction().unwrap();

        let ret = cash_cheque(&mut tx, &cheque, &payee_account);
        match ret {
            Err(Error::DoubleSpendingError(_)) => Ok(()),
            _ => Err(Error::Testing(
                "Expected double spending error here.".to_string(),
            )),
        }
    }

    #[test]
    fn test_double_spend_security_emitter_cheque() -> CustomResult<()> {
        let (mut conn, security_emitter, payee, payee_account) = setup_security_emitter();
        _test_double_spend(&mut conn, security_emitter, payee, payee_account)
    }

    #[test]
    fn test_double_spend_regular_emitter_cheque() -> CustomResult<()> {
        let (mut conn, drawer, payee, payee_account) = setup_basic();
        _test_double_spend(&mut conn, drawer, payee, payee_account)
    }

    fn _test_invalid_drawer(
        conn: &mut Connection,
        drawer: Drawer,
        payee: Payee,
        payee_account: AccountId,
    ) -> CustomResult<()> {
        let mut tx = conn.transaction().unwrap();
        let not_currency_owner_user_id = UserId::from_id(drawer.0.get_id() + 72623);
        let not_currency_owner: Drawer = (not_currency_owner_user_id, drawer.1, drawer.2);
        let cheque = Cheque::new(not_currency_owner, payee, 100, 99);

        let ret = cash_cheque(&mut tx, &cheque, &payee_account);
        match ret {
            Err(Error::InvalidDrawer(_)) => Ok(()),
            _ => Err(Error::Testing("Expected invalid drawer here.".to_string())),
        }
    }

    #[test]
    fn test_invalid_drawer_security_emitter() -> CustomResult<()> {
        let (mut conn, security_emitter, payee, payee_account) = setup_security_emitter();
        _test_invalid_drawer(&mut conn, security_emitter, payee, payee_account)
    }

    #[test]
    fn test_invalid_drawer_regular_cheque() -> CustomResult<()> {
        let (mut conn, drawer, payee, payee_account) = setup_basic();
        _test_invalid_drawer(&mut conn, drawer, payee, payee_account)
    }

    fn test_invalid_payee(
        conn: &mut Connection,
        security_emitter: Drawer,
        payee: Payee,
    ) -> CustomResult<()> {
        let mut tx = conn.transaction().unwrap();
        let wrong_payee_account = &security_emitter.1;

        let cheque = Cheque::new(security_emitter.clone(), payee.clone(), 1000, 99);

        let ret = cash_cheque(&mut tx, &cheque, wrong_payee_account);
        match ret {
            Err(Error::InvalidPayee(_)) => Ok(()),
            _ => Err(Error::Testing("Expected invalid payee here.".to_string())),
        }
    }

    #[test]
    fn test_invalid_payee_security_emitter_cheque() -> CustomResult<()> {
        let (mut conn, security_emitter, payee, _payee_account) = setup_security_emitter();
        test_invalid_payee(&mut conn, security_emitter, payee)
    }

    #[test]
    fn test_invalid_payee_regular_cheque() -> CustomResult<()> {
        let (mut conn, drawer, payee, _payee_account) = setup_basic();
        test_invalid_payee(&mut conn, drawer, payee)
    }

    #[test]
    fn test_mismatch_securities() -> CustomResult<()>{
        let (mut conn, drawer, payee, payee_account) = setup_security_emitter_mismatched_accounts();
        let cheque = Cheque::new(drawer.clone(), payee.clone(), 1000, 99);
        let mut tx = conn.transaction().unwrap();

        match cash_cheque(&mut tx, &cheque, & payee_account) {
            Err(Error::InvalidPayee(_)) => Ok(()),
            _ => Err(Error::Testing("Expected invalid payee here.".to_string()))
        }
    }
}


#[cfg(test)]
mod test_wire_transfers {
    use crate::db::accounts::get_account_by_id;
    use super::*;
    use super::test_utils::*;

    #[test]
    fn test_happy_path_currency_emitter() -> CustomResult<()> {
        let (mut conn, security_emitter, payee, payee_account) = setup_security_emitter();
        let mut tx = conn.transaction().unwrap();

        // let cheque = Cheque::new(security_emitter, payee, 1000, 99);
        let wire_transfer = WireTransferRequest::new(security_emitter, &payee_account, 1000, 777);;

        cash_wire_transfer_request(&mut tx, &wire_transfer)?;
        tx.commit().unwrap();

        let tx = conn.transaction().unwrap();
        let acc = get_account_by_id(&tx, &payee_account).unwrap();
        assert_eq!(acc.raw_amount(), 1000);

        Ok(())
    }

    #[test]
    fn test_happy_path_regular_wire_transfer() -> CustomResult<()> {
        let (mut conn, drawer, payee, payee_account) = setup_basic();
        let mut tx = conn.transaction().unwrap();

        let wire_transfer = WireTransferRequest::new(drawer.clone(), &payee_account, 25, 989);

        cash_wire_transfer_request(&mut tx, &wire_transfer)?;

        let payee_acc = get_account_by_id(&tx, &payee_account).unwrap();
        assert_eq!(payee_acc.raw_amount(), 25);

        let drawer_acc = get_account_by_id(&tx, &drawer.1).unwrap();
        assert_eq!(drawer_acc.raw_amount(), 75);

        Ok(())
    }

    #[test]
    fn test_wire_transfer_double_spending() -> CustomResult<()> {
        let (mut conn, drawer, payee, payee_account) = setup_basic();
        let wire_transfer = WireTransferRequest::new(drawer.clone(), &payee_account, 25, 989);

        let mut tx = conn.transaction().unwrap();
        cash_wire_transfer_request(&mut tx, &wire_transfer)?;
        tx.commit().unwrap();

        let mut tx = conn.transaction().unwrap();
        let ret = cash_wire_transfer_request(&mut tx, &wire_transfer);
        match ret {
            Err(Error::DoubleSpendingError(_)) => Ok(()),
            _ => Err(Error::Testing("Expected DoubleSpendingError error".to_string()))
        }
    }
}