use rusqlite::{Connection, OptionalExtension, params, Result, Row, Transaction};
use sha2::digest::typenum::op;
use crate::db::_external_id::{Id, AccountId, UserId};

use crate::db::_securities::Security;
use crate::db::_users::User;
use crate::db::external_id::SecurityId;

#[derive(PartialEq, Debug)]
pub enum AccountType {
    Checking,
    SecurityEmitter,
}

impl AccountType {
    pub fn from_row(row: &Row) -> Result<AccountType> {
        let s: String = row.get("acc_account_type")?;
        if s == "security_emitter" {
            Ok(AccountType::SecurityEmitter)
        } else {
            Ok(AccountType::Checking)
        }
    }
}

pub struct Account {
    id: u32,
    amount: u32,
    timestamp: i32,
    security: Security,
    account_type: AccountType,
}

impl Account {
    pub fn id(&self) -> AccountId {
        AccountId::from_id(self.id)
    }

    pub fn from_row(row: &Row) -> Result<Account> {
        return Ok(Account {
            id: row.get("acc_id")?,
            amount: row.get("acc_amount")?,
            timestamp: row.get("acc_timestamp")?,
            security: Security::from_row(row)?,
            account_type: AccountType::from_row(row)?,
        });
    }

    pub fn raw_amount(&self) -> u32 {
        self.amount
    }
}

pub fn list_accounts<'a>(conn: &Connection) -> Result<Vec<Account>> {
    let q = "SELECT acc.id AS acc_id,
                          acc.amount AS acc_amount,
                          UNIXEPOCH(acc.timestamp) AS acc_timestamp,
                          account_type AS acc_account_type,

                          sec.id AS sec_id,
                          sec.symbol AS sec_symbol,
                          sec.security_type AS sec_security_type
                   FROM accounts acc
                   JOIN securities sec ON acc.security = sec.id
                   ORDER BY acc.id ASC";
    let mut stmt = conn.prepare(q)?;
    let ret: Vec<Account> = stmt
        .query_map([], &Account::from_row)?
        .filter(Result::is_ok)
        .map(Result::unwrap)
        .collect();
    return Ok(ret);
}

pub fn get_account_by_id(tx: &Transaction, id: &AccountId) -> Result<Account> {
    let q = "SELECT acc.id AS acc_id,
                          acc.amount AS acc_amount,
                          UNIXEPOCH(acc.timestamp) AS acc_timestamp,
                          account_type AS acc_account_type,

                          sec.id AS sec_id,
                          sec.symbol AS sec_symbol,
                          sec.security_type AS sec_security_type
                  FROM accounts acc
                  JOIN securities sec ON acc.security = sec.id
                  WHERE acc.id = ?1";
    return tx.query_row(q, params![id], Account::from_row);
}

fn create_account(tx: &Transaction, sec: &SecurityId, user: &UserId, account_type: AccountType) -> Result<Account> {
    let q = "INSERT INTO accounts(security, owner, amount, timestamp, account_type)
                   VALUES (?1, ?2, 0, CURRENT_TIMESTAMP, ?3)";
    let account_type = match account_type {
        AccountType::Checking => "checking",
        AccountType::SecurityEmitter => "security_emitter",
    };
    tx.execute(q, (sec, user, account_type))?;
    let id = AccountId::from_id(tx.last_insert_rowid() as u32);
    return get_account_by_id(tx, &id);
}

pub fn create_checking_account(tx: &Transaction, sec: &SecurityId, user: &UserId) -> Result<Account> {
    create_account(tx, sec, user, AccountType::Checking)
}

pub fn create_security_emitter_account(tx: &Transaction, sec: &SecurityId, user: &UserId) -> Result<Account> {
    create_account(tx, sec, user, AccountType::SecurityEmitter)
}

pub fn is_owner(tx: &Transaction, account_id: &AccountId, user_id: &UserId) -> Result<bool> {
    let q = "SELECT id FROM accounts WHERE id = ?1 AND owner = ?2";
    let params = params![account_id, user_id];
    let ite = |row: &Row| row.get::<usize, u32>(0);
    let option = tx.query_row(q, params, ite).optional()?;
    Ok(option.is_some())
}

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

    use crate::db::_test_utils::{setup_users_and_securities};
    use crate::db::_securities;
    use crate::db::_users;
    use crate::migration;

    use super::*;

    fn setup() -> (Connection, Vec<User>, Vec<Security>) {
        let mut conn = Connection::open_in_memory().unwrap();
        migration::apply_migrations(&mut conn).unwrap();

        let tx = conn.transaction().unwrap();
        let (users, securities) = setup_users_and_securities(&tx).unwrap();

        tx.commit().unwrap();
        return (conn, users, securities);
    }

    fn create_all_accounts(tx: &Transaction, users: &Vec<User>, secs: &Vec<Security>) -> Result<Vec<Account>> {
        let mut ret: Vec<Account> = Vec::new();
        for sec in secs.iter() {
            for user in users.iter() {
                ret.push(create_checking_account(&tx, &sec.id(), &user.id())?);
            }
        }
        return Ok(ret);
    }

    #[test]
    fn test_simplest_checking_account() -> Result<()> {
        let (mut conn, users, secs) = setup();
        let user = users.get(0).unwrap();
        let not_owner = users.get(1).unwrap();
        let sec = secs.get(0).unwrap();
        let tx = conn.transaction()?;

        let acc = create_checking_account(&tx, &sec.id(), &user.id())?;
        assert_eq!(acc.account_type, AccountType::Checking);
        assert_eq!(0, acc.raw_amount());

        assert!(is_owner(& tx, & acc.id(), &user.id())?);
        assert!(!is_owner(& tx, & acc.id(), &not_owner.id())?);
        Ok(())
    }

    #[test]
    fn test_simplest_security_emitter_account() -> Result<()> {
        let (mut conn, users, secs) = setup();
        let user = users.get(0).unwrap();
        let not_owner = users.get(1).unwrap();
        let sec = secs.get(0).unwrap();
        let tx = conn.transaction()?;

        let acc = create_security_emitter_account(&tx, &sec.id(), &user.id())?;
        assert_eq!(acc.account_type, AccountType::SecurityEmitter);
        assert_eq!(0, acc.raw_amount());

        assert!(is_owner(& tx, & acc.id(), &user.id())?);
        assert!(!is_owner(& tx, & acc.id(), &not_owner.id())?);
        Ok(())
    }

    #[test]
    fn test_happy_path() -> Result<()> {
        let (mut conn, users, secs) = setup();
        let tx = conn.transaction()?;
        create_all_accounts(&tx, &users, &secs)?;
        tx.commit()?;
        let accs = list_accounts(&conn)?;
        assert_eq!(4, accs.len());
        assert_eq!(1, accs.get(0).unwrap().id);
        return Ok(());
    }

    #[test]
    fn test_happy_path_no_commit() -> Result<()> {
        let (mut conn, users, secs) = setup();
        create_all_accounts(&conn.transaction()?, &users, &secs)?;
        let accs = list_accounts(&conn)?;
        assert_eq!(0, accs.len());
        return Ok(());
    }

    #[test]
    fn test_is_owner() -> Result<()> {
        let (mut conn, users, secs) = setup();
        let tx = &conn.transaction()?;
        let accounts = create_all_accounts(tx, &users, &secs)?;
        let user_1 = users.get(0).unwrap();
        let user_2 = users.get(1).unwrap();
        let sec = secs.get(0).unwrap();

        let acc = create_checking_account(&tx, &sec.id(), &user_1.id())?;

        assert!(is_owner(tx, &acc.id(), &user_1.id())?);
        assert!(!is_owner(tx, &acc.id(), &user_2.id())?);

        Ok(())
    }
}