package api

import (
	"crypto/rand"
	"encoding/json"
	"fmt"
	"math/big"
	"net/http"

	"git.freecumextremist.com/grumbulon/pomme/internal"
	"golang.org/x/crypto/bcrypt"
	"gorm.io/gorm"
)

// NewUser takes a POST request and user form and creates a user in the database.
func NewUser(w http.ResponseWriter, r *http.Request) {
	db, ok := r.Context().Value(keyPrincipalContextID).(*gorm.DB)
	if !ok {
		http.Error(w, "internal server error", http.StatusInternalServerError)
	}

	var result internal.User

	err := r.ParseForm()
	if err != nil {
		http.Error(w, "Unable to parse request", http.StatusInternalServerError)

		return
	}

	username := r.Form.Get("username")

	if username == "" {
		username = autoUname()
	}

	password := r.Form.Get("password")

	if password == "" {
		http.Error(w, "No password entered", http.StatusInternalServerError)
	}

	db.Where("username = ?", username).First(&result)

	if result.Username != "" {
		http.Error(w, "User already exists", http.StatusInternalServerError)

		return
	}

	hashedPassword, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
	}

	db.Create(&internal.User{Username: username, HashedPassword: string(hashedPassword)})

	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(http.StatusCreated)
	err = json.NewEncoder(w).Encode(
		internal.Response{
			Username:     username,
			HTTPResponse: http.StatusCreated,
		})

	if err != nil {
		http.Error(w, "internal server error", http.StatusInternalServerError)

		return
	}
}

func autoUname() string {
	n, err := rand.Int(rand.Reader, big.NewInt(1000))
	if err != nil {
		return ""
	}

	return fmt.Sprintf("user%d", n.Int64())
}