package Auth

import (
	"encoding/json"
	"net/http"
	"time"

	"git.tovijaeschke.xyz/tovi/Envelope/Backend/Database"
	"git.tovijaeschke.xyz/tovi/Envelope/Backend/Models"

	"github.com/gofrs/uuid"
)

type Credentials struct {
	Username string `json:"username"`
	Password string `json:"password"`
}

type loginResponse struct {
	Status               string `json:"status"`
	Message              string `json:"message"`
	AsymmetricPublicKey  string `json:"asymmetric_public_key"`
	AsymmetricPrivateKey string `json:"asymmetric_private_key"`
}

func makeLoginResponse(w http.ResponseWriter, code int, message, pubKey, privKey string) {
	var (
		status     string = "error"
		returnJson []byte
		err        error
	)
	if code > 200 && code < 300 {
		status = "success"
	}

	returnJson, err = json.MarshalIndent(loginResponse{
		Status:               status,
		Message:              message,
		AsymmetricPublicKey:  pubKey,
		AsymmetricPrivateKey: privKey,
	}, "", "  ")
	if err != nil {
		http.Error(w, "Error", http.StatusInternalServerError)
		w.WriteHeader(http.StatusInternalServerError)
		return
	}

	// Return updated json
	w.WriteHeader(code)
	w.Write(returnJson)
}

func Login(w http.ResponseWriter, r *http.Request) {
	var (
		creds        Credentials
		userData     Models.User
		sessionToken uuid.UUID
		expiresAt    time.Time
		err          error
	)

	err = json.NewDecoder(r.Body).Decode(&creds)
	if err != nil {
		makeLoginResponse(w, http.StatusInternalServerError, "An error occurred", "", "")
		return
	}

	userData, err = Database.GetUserByUsername(creds.Username)
	if err != nil {
		makeLoginResponse(w, http.StatusUnauthorized, "An error occurred", "", "")
		return
	}

	if !CheckPasswordHash(creds.Password, userData.Password) {
		makeLoginResponse(w, http.StatusUnauthorized, "An error occurred", "", "")
		return
	}

	sessionToken, err = uuid.NewV4()
	if err != nil {
		makeLoginResponse(w, http.StatusInternalServerError, "An error occurred", "", "")
		return
	}

	expiresAt = time.Now().Add(1 * time.Hour)

	Sessions[sessionToken.String()] = Session{
		UserID:   userData.ID.String(),
		Username: userData.Username,
		Expiry:   expiresAt,
	}

	http.SetCookie(w, &http.Cookie{
		Name:    "session_token",
		Value:   sessionToken.String(),
		Expires: expiresAt,
	})

	makeLoginResponse(
		w,
		http.StatusOK,
		"Successfully logged in",
		userData.AsymmetricPublicKey,
		userData.AsymmetricPrivateKey,
	)
}