cspj-application/server/internal/db/db.go

122 lines
3 KiB
Go

package db
import (
"context"
"fmt"
"log"
"net/http"
"github.com/jackc/pgx/v5/pgxpool"
)
// db connection info
// !MIGHT CHANGE
const (
host = "localhost"
port = 5432
user = "asdfuser"
password = "asdfpassword"
dbname = "asdfdb"
)
var DbPool *pgxpool.Pool
var allowedUsernames map[string]bool
// initialize connection to db
func ConnectToDb() (*pgxpool.Pool, error) {
// this server is intended to be ran on the same system as the db
dbUrl := fmt.Sprintf("postgresql://%s:%s@%s:%d/%s", user, password, host, port, dbname)
config, err := pgxpool.ParseConfig((dbUrl))
if err != nil {
return nil, fmt.Errorf("unable to parse data URL: %w", err)
}
pool, err := pgxpool.NewWithConfig(context.Background(), config)
if err != nil {
return nil, fmt.Errorf("unable to create connection pool: %w", err)
}
log.Println("Connected to DB :)")
return pool, nil
}
// setup demo db
func SetupDemoDb(w http.ResponseWriter, r *http.Request) {
// create table and insert demo data
createTableSQL := `
CREATE TABLE IF NOT EXISTS users (
id SERIAL PRIMARY KEY,
username VARCHAR(50) UNIQUE NOT NULL,
email VARCHAR(100) NOT NULL
);`
// also avoid duplicate entries
insertDataSQL := `
INSERT INTO users (username, email) VALUES
('alice', 'alice@example.com'),
('bob', 'bob@example.com'),
('charlie', 'charlie@example.com')
ON CONFLICT (username) DO NOTHING;`
// execute create table
_, err := DbPool.Exec(context.Background(), createTableSQL)
if err != nil {
http.Error(w, "Failed to create table", http.StatusInternalServerError)
log.Printf("Error creating table: %v", err)
return
}
// execute insert demo data
_, err = DbPool.Exec(context.Background(), insertDataSQL)
if err != nil {
http.Error(w, "Failed to insert demo data", http.StatusInternalServerError)
log.Printf("Error inserting demo data: %v", err)
return
}
// response back to client
w.WriteHeader(http.StatusOK)
w.Write([]byte("Database setup complete with demo data"))
log.Println("Demo database setup completed successfully")
}
// nuke the db
func NukeDb(w http.ResponseWriter, r *http.Request) {
// drop user table
dropTableSQL := `
DROP TABLE IF EXISTS users CASCADE;
`
// execute the command
_, err := DbPool.Exec(context.Background(), dropTableSQL)
if err != nil {
http.Error(w, "Failed to drop table", http.StatusInternalServerError)
log.Printf("Error dropping table: %v", err)
return
}
log.Println("Database nuked")
}
// fetch existing usernames from db
func FetchUsernames() (map[string]bool, error) {
usernames := make(map[string]bool)
rows, err := DbPool.Query(context.Background(), "SELECT username FROM users")
if err != nil {
return nil, fmt.Errorf("error querying users: %w", err)
}
defer rows.Close()
for rows.Next() {
var username string
if err := rows.Scan(&username); err != nil {
return nil, fmt.Errorf("error scanning username: %w", err)
}
usernames[username] = true
}
log.Println("Fetched usernames:", usernames)
return usernames, nil
}