main.go

package main

import (
	"database/sql"
	"encoding/json"
	"log"
	"net/http"
	"time"

	"github.com/gorilla/mux"
	_ "github.com/lib/pq"
)

type User struct {
	ID       string `json:"id,omitempty"`
	Username string `json:"username"`
	Password string `json:"password,omitempty"`
	Avatar   string `json:"avatar,omitempty"`
}

// Global variable to hold the database connection
var db *sql.DB

func createUser(w http.ResponseWriter, r *http.Request) {
	var user User
	if err := json.NewDecoder(r.Body).Decode(&user); err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}

	_, err := db.Exec("INSERT INTO users (username, password, avatar) VALUES ($1, $2, $3)",
		user.Username, user.Password, user.Avatar)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}

	w.WriteHeader(http.StatusCreated)
	json.NewEncoder(w).Encode(user)
}

func getUsers(w http.ResponseWriter, r *http.Request) {
    rows, err := db.Query("SELECT * FROM users")
    if err != nil {
        http.Error(w, err.Error(), http.StatusInternalServerError)
        return
    }
    defer rows.Close()

    var users []User
    for rows.Next() {
        var user User
        var createdAt time.Time
        if err := rows.Scan(&user.ID, &user.Username, &user.Password, &user.Avatar, &createdAt); err != nil {
            http.Error(w, err.Error(), http.StatusInternalServerError)
            return
        }
        users = append(users, user)
    }

    json.NewEncoder(w).Encode(users)
}

func enableCors(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		// Set headers for CORS
		w.Header().Set("Access-Control-Allow-Origin", "*") // In production, replace * with your frontend's address
		w.Header().Set("Access-Control-Allow-Methods", "POST, GET, OPTIONS, PUT, DELETE") 
		w.Header().Set("Access-Control-Allow-Headers", "Content-Type, Authorization") 

		// Handle preflight requests
		if r.Method == "OPTIONS" {
			w.WriteHeader(http.StatusOK)
			return // Preflight does not require further handling
		}

		next.ServeHTTP(w, r)
	})
}


func main() {
	var err error
	db, err = connectDB() 
	if err != nil {
		log.Fatalf("Error connecting to the database: %v", err)
	}
	defer db.Close()

	initAndSeedDB() 

	router := mux.NewRouter()
	router.HandleFunc("/users", createUser).Methods("POST")
	router.HandleFunc("/users", getUsers).Methods("GET")

	handler := enableCors(router)
    log.Fatal(http.ListenAndServe(":8080", handler))
}