/
database.go
227 lines (192 loc) · 6.39 KB
/
database.go
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package database
import (
"context"
"database/sql"
"log"
"github.com/gurbaaz27/iitk-coin/models"
_ "github.com/mattn/go-sqlite3"
"golang.org/x/crypto/bcrypt"
)
var MyDB *sql.DB
var WalletDB *sql.DB
var TransactionHistoryDB *sql.DB
func checkErr(err error) {
if err != nil {
panic(err)
}
}
func InitialiseDB() {
MyDB, err := sql.Open("sqlite3", "./user-database-190349.db")
checkErr(err)
WalletDB, err := sql.Open("sqlite3", "./wallet-database-190349.db")
checkErr(err)
TransactionHistoryDB, err := sql.Open("sqlite3", "./transaction-database-190349.db")
checkErr(err)
defer MyDB.Close()
defer WalletDB.Close()
defer TransactionHistoryDB.Close()
statement, err := MyDB.Prepare("CREATE TABLE IF NOT EXISTS User (rollno TEXT, name TEXT, password TEXT)")
checkErr(err)
log.Println("User Database opened and table created (if not existed) successfully!")
statement.Exec()
statement, err = WalletDB.Prepare("CREATE TABLE IF NOT EXISTS Wallet (rollno TEXT, coins INTEGER)")
checkErr(err)
log.Println("Wallet Database opened and table created (if not existed) successfully!")
statement.Exec()
statement, err = TransactionHistoryDB.Prepare("CREATE TABLE IF NOT EXISTS TransactionHistory (sender TEXT, receiver TEXT, coins INTEGER, remarks TEXT)")
checkErr(err)
log.Println("Wallet Database opened and table created (if not existed) successfully!")
statement.Exec()
}
func AddUser(user models.User) bool {
MyDB, err := sql.Open("sqlite3", "./user-database-190349.db")
checkErr(err)
WalletDB, err := sql.Open("sqlite3", "./wallet-database-190349.db")
checkErr(err)
defer MyDB.Close()
defer WalletDB.Close()
if !UserExists(user) {
statement, err := MyDB.Prepare("INSERT INTO User (rollno, name, password) VALUES (?, ?, ?)")
checkErr(err)
statement.Exec(user.Rollno, user.Name, HashPwd(user.Password))
statement, err = WalletDB.Prepare("INSERT INTO Wallet (rollno, coins) VALUES (?, ?)")
checkErr(err)
statement.Exec(user.Rollno, 0)
log.Printf("New user details : rollno = %s, name = %s added in database user-database-190349.db\n", user.Rollno, user.Name)
log.Printf("Wallet for user initiated in database wallet-database-190349.db\n")
return true
} else {
log.Println("User with same roll no. already exists!")
return false
}
}
func UserValid(user models.LoginRequest) bool {
MyDB, err := sql.Open("sqlite3", "./user-database-190349.db")
checkErr(err)
defer MyDB.Close()
rows, err := MyDB.Query("SELECT * from User")
checkErr(err)
defer rows.Close()
for rows.Next() {
var rollno string
var name string
var password string
err = rows.Scan(&rollno, &name, &password)
checkErr(err)
if user.Rollno == rollno && CheckPasswords(password, user.Password) {
return true
}
}
return false
}
func UserExists(user models.User) bool {
MyDB, err := sql.Open("sqlite3", "./user-database-190349.db")
checkErr(err)
defer MyDB.Close()
err = MyDB.QueryRow("SELECT rollno FROM User WHERE rollno = ?", user.Rollno).Scan(&user.Rollno)
if err != nil {
if err != sql.ErrNoRows {
log.Print(err)
}
return false
}
return true
}
func HashPwd(password string) string {
hashedPassword, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
if err != nil {
panic(err)
}
return string(hashedPassword)
}
func CheckPasswords(hashedPwd string, pwd string) bool {
byteHash := []byte(hashedPwd)
bytePwd := []byte(pwd)
err := bcrypt.CompareHashAndPassword(byteHash, bytePwd)
if err != nil {
log.Println(err)
return false
}
return true
}
func ReturnBalance(rollno string) int64 {
WalletDB, err := sql.Open("sqlite3", "./wallet-database-190349.db")
checkErr(err)
defer WalletDB.Close()
var coins int64
err = WalletDB.QueryRow("SELECT coins FROM Wallet WHERE rollno = ?", rollno).Scan(&coins)
if err != nil {
if err != sql.ErrNoRows {
log.Print(err)
}
return -1
}
return coins
}
func RewardMoney(user models.RewardPayload) bool {
WalletDB, err := sql.Open("sqlite3", "./wallet-database-190349.db")
checkErr(err)
defer WalletDB.Close()
log.Printf("Updating the balance!")
statement, err := WalletDB.Prepare("UPDATE Wallet SET coins = coins + ? WHERE rollno = ?")
if err != nil {
return false
}
statement.Exec(user.Coins, user.Rollno)
TransactionHistoryDB, err := sql.Open("sqlite3", "./transaction-database-190349.db")
checkErr(err)
defer TransactionHistoryDB.Close()
statement, err = TransactionHistoryDB.Prepare("INSERT INTO TransactionHistory (sender, receiver, coins, remarks) VALUES (?, ?, ?, ?)")
checkErr(err)
statement.Exec("000007", user.Rollno, user.Coins, "Reward")
return true
}
func TransferCoins(user models.TransferPayload) bool {
WalletDB, err := sql.Open("sqlite3", "./wallet-database-190349.db")
checkErr(err)
defer WalletDB.Close()
ctx := context.Background()
tx, err := WalletDB.BeginTx(ctx, nil)
checkErr(err)
user.Coins = DeductTax(user)
res, err := tx.ExecContext(ctx, "UPDATE Wallet SET coins = coins - ? WHERE rollno=? AND coins - ? >= 0", user.Coins, user.SenderRollno, user.Coins)
checkErr(err)
rows_affected, err := res.RowsAffected()
checkErr(err)
if rows_affected != 1 {
tx.Rollback()
return false
}
res, err = tx.ExecContext(ctx, "UPDATE Wallet SET coins = coins + ? WHERE rollno=?", user.Coins, user.ReceiverRollno, user.Coins)
checkErr(err)
rows_affected, err = res.RowsAffected()
checkErr(err)
if rows_affected != 1 {
tx.Rollback()
return false
}
err = tx.Commit()
checkErr(err)
TransactionHistoryDB, err := sql.Open("sqlite3", "./transaction-database-190349.db")
checkErr(err)
defer TransactionHistoryDB.Close()
statement, err := TransactionHistoryDB.Prepare("INSERT INTO TransactionHistory (sender, receiver, coins, remarks) VALUES (?, ?, ?, ?)")
checkErr(err)
statement.Exec(user.SenderRollno, user.ReceiverRollno, user.Coins, "Transfer")
return true
}
func DeductTax(user models.TransferPayload) int64 {
if (user.SenderRollno[0:2] == user.ReceiverRollno[0:2]) && (len(user.SenderRollno) == len(user.ReceiverRollno)) {
return int64(float64(user.Coins) * 0.98)
} else {
return int64(float64(user.Coins) * 0.67)
}
}
// func UpdateTransactionHistory() {
// TransactionHistoryDB, err := sql.Open("sqlite3", "./transaction-database-190349.db")
// checkErr(err)
// defer TransactionHistoryDB.Close()
// statement, err := TransactionHistoryDB.Prepare("INSERT INTO Transaction (sender, receiver, amount, status) VALUES (?, ?, ?, ?)")
// checkErr(err)
// statement.Exec(000007, user.Rollno, user.Coins, 0)
// }