MyNSB/API

package db

import (
    "database/sql"
    "errors"
    "fmt"
    _ "github.com/lib/pq"
    "mynsb-api/internal/filesint"
    "strings"
)

// Whole thing is pre much just an abstraction

// Connection struct is a struct that defines the connection details required for DB authentication
type Connection struct {
    Host         string
    Port         string
    User         string
    Password     string
    DatabaseName string
}

// Database pointer
var DB *sql.DB




// CONNECTION FUNCTIONS


// connect takes a connection configuration and connects to the psql database with it, the database connection is reflected within the db.DB object
func (connection Connection) connect() error {

    var err error

    // connect to the database
    DB, err = sql.Open("postgres", fmt.Sprintf("host=%s port=%s user=%s password=%s dbname=%s sslmode=disable",
        connection.Host, connection.Port, connection.User, connection.Password, connection.DatabaseName))
    if err != nil {
        return errors.New("could not connect to the database")
    }

    if err = DB.Ping(); err != nil {
        return errors.New("could not connect to the database")
    }

    return nil
}










// UTILITY FUNCTIONS

// getConnectionDetails returns a connection configuration based off the current database config in database/details.txt
func getConnectionDetails() (Connection, error) {

    connectionDetails, err := filesint.DataDump("database", "/details.txt")
    if err != nil {
        return Connection{}, err
    }

    // Attain the configuration through separation of delimiters
    detailsArray := strings.Split(string(connectionDetails), ",")
    host := strings.Split(detailsArray[0], ":")[1]
    port := strings.Split(detailsArray[1], ":")[1]


    return Connection{
        Host: host,
        Port: port,
    }, nil
}


// getUserPswd returns the pswd of the user inputted, this password is read off the /user pass/student.txt file
func getUserPswd(user string) string {
    if pwd, err := filesint.DataDump("sensitive", fmt.Sprintf("/user pass/%s.txt", user)); err == nil {
        return string(pwd)
    }

    return ""
}


// Conn takes a string signifying the type of user you wish to authenticate as and connects to it via the .connect() function
func Conn(user string) error {
    // connect to database as user
    connectionDetails, _ := getConnectionDetails()
    connectionDetails.User = user
    connectionDetails.Password = getUserPswd(user)
    connectionDetails.DatabaseName = "mynsb"

    err := connectionDetails.connect()
    if err != nil {
        return errors.New("could not connect to database")
    }

    return nil
}