package auth

import (
	"database/sql"
	"encoding/json"
	"fmt"
	"git.minhas.io/asara/sudoscientist-go-backend/packages/middleware"
	"git.minhas.io/asara/sudoscientist-go-backend/packages/users"
	"github.com/badoux/checkmail"
	"github.com/dgrijalva/jwt-go"
	"github.com/go-chi/chi"
	"github.com/go-chi/jwtauth"
	"github.com/go-chi/render"
	"golang.org/x/crypto/bcrypt"
	"net/http"
	"os"
	"strings"
	"time"
)

var (
	DB            *sql.DB
	TokenAuth     *jwtauth.JWTAuth
	PostalEnabled bool
	PostalKey     string
	PostalAPI     string
)

func Init() {
	if postal_key, ok := os.LookupEnv("POSTAL_KEY"); ok {
		PostalKey = postal_key
		if postal_api, ok := os.LookupEnv("POSTAL_API"); ok {
			PostalAPI = postal_api
			PostalEnabled = true
		}
	}
}

type ReturnError struct {
	Message string `json:"error"`
}

type SignUpCredentials struct {
	Username string `json:"username", db:"username"`
	Email    string `json:"email", db:"email"`
	Password string `json:"password", db:"password"`
}

type SignInCredentials struct {
	Username string `json:"username", db:"username"`
	Password string `json:"password", db:"password"`
}

type Claims struct {
	Username string `json:"username"`
	jwt.StandardClaims
}

type JWT struct {
	JWT string `json:"jwt"`
}

func Routes() *chi.Mux {
	r := chi.NewRouter()
	r.Post("/signin", signin)
	r.Post("/register", register)
	r.Group(func(r chi.Router) {
		r.Use(jwtauth.Verify(TokenAuth, auth_middleware.TokenFromSplitCookie))
		r.Use(jwtauth.Authenticator)
		r.Post("/refresh", refresh)
	})
	return r
}

func register(w http.ResponseWriter, r *http.Request) {
	returnError := ReturnError{}
	creds := &SignUpCredentials{}
	err := json.NewDecoder(r.Body).Decode(creds)
	if err != nil {
		w.WriteHeader(http.StatusBadRequest)
		fmt.Println(err)
		return
	}
	if creds.Username == "" {
		returnError.Message = "username is required"
		w.WriteHeader(http.StatusBadRequest)
		render.JSON(w, r, returnError)
		return
	}
	if creds.Password == "" {
		returnError.Message = "password is required"
		w.WriteHeader(http.StatusBadRequest)
		render.JSON(w, r, returnError)
		return
	}
	if creds.Email == "" {
		returnError.Message = "email is required"
		w.WriteHeader(http.StatusBadRequest)
		render.JSON(w, r, returnError)
		return
	}
	err = checkmail.ValidateFormat(creds.Email)
	if err != nil {
		returnError.Message = "email not valid"
		w.WriteHeader(http.StatusBadRequest)
		render.JSON(w, r, returnError)
		return
	}

	hashedPassword, err := bcrypt.GenerateFromPassword([]byte(creds.Password), 10)
	s := `INSERT INTO users (username, email, password, admin)
          VALUES ($1, $2, $3, $4)`
	if _, err = DB.Exec(s, creds.Username, creds.Email, string(hashedPassword), false); err != nil {
		w.WriteHeader(http.StatusInternalServerError)
		fmt.Println(err)
		return
	}
	users.CreateProfile(creds.Username, creds.Email)
	w.WriteHeader(http.StatusCreated)
	expirationTime := time.Now().Add(6 * time.Hour)
	claims := &Claims{
		Username: creds.Username,
		StandardClaims: jwt.StandardClaims{
			ExpiresAt: expirationTime.Unix(),
		},
	}
	_, tokenString, _ := TokenAuth.Encode(claims)
	token := setCookies(w, tokenString, expirationTime)
	w.WriteHeader(http.StatusOK)
	render.JSON(w, r, token)
}

func signin(w http.ResponseWriter, r *http.Request) {
	creds := &SignInCredentials{}
	err := json.NewDecoder(r.Body).Decode(creds)
	if err != nil {
		w.WriteHeader(http.StatusBadRequest)
		return
	}
	result := DB.QueryRow("SELECT password FROM users WHERE username=$1", creds.Username)
	storedCreds := &SignInCredentials{}
	err = result.Scan(&storedCreds.Password)
	if err != nil {
		if err == sql.ErrNoRows {
			w.WriteHeader(http.StatusUnauthorized)
			return
		}
		w.WriteHeader(http.StatusInternalServerError)
		return
	}
	if err = bcrypt.CompareHashAndPassword([]byte(storedCreds.Password), []byte(creds.Password)); err != nil {
		w.WriteHeader(http.StatusUnauthorized)
	}
	expirationTime := time.Now().Add(5 * time.Hour)
	claims := &Claims{
		Username: creds.Username,
		StandardClaims: jwt.StandardClaims{
			ExpiresAt: expirationTime.Unix(),
		},
	}
	_, tokenString, _ := TokenAuth.Encode(claims)
	token := setCookies(w, tokenString, expirationTime)
	w.WriteHeader(http.StatusOK)
	render.JSON(w, r, token)
}

func refresh(w http.ResponseWriter, r *http.Request) {
	_, claims, _ := jwtauth.FromContext(r.Context())
	w.WriteHeader(http.StatusOK)
	expirationTime := time.Now().Add(5 * time.Hour)
	newClaims := &Claims{
		Username: claims["username"].(string),
		StandardClaims: jwt.StandardClaims{
			ExpiresAt: expirationTime.Unix(),
		},
	}
	_, tokenString, _ := TokenAuth.Encode(newClaims)
	token := setCookies(w, tokenString, expirationTime)
	w.WriteHeader(http.StatusOK)
	render.JSON(w, r, token)
}

func setCookies(w http.ResponseWriter, jwt string, expiration time.Time) string {
	splitToken := strings.Split(jwt, ".")
	dataCookie := http.Cookie{Name: "DataCookie", Value: strings.Join(splitToken[:2], "."), Expires: expiration, HttpOnly: false, Path: "/", Domain: ".sudoscientist.com", MaxAge: 360, Secure: true}
	http.SetCookie(w, &dataCookie)
	signatureCookie := http.Cookie{Name: "SignatureCookie", Value: splitToken[2], Expires: expiration, HttpOnly: true, Path: "/", Domain: ".sudoscientist.com", MaxAge: 360, Secure: true}
	http.SetCookie(w, &signatureCookie)
	return strings.Join(splitToken[:2], ".")
}