package main

import (
	"encoding/json"
	"net/http"
	"os"
	"strings"
)

type RegisterRequest struct {
	Email    string `json:"email"`
	Password string `json:"password"`
	Captcha  string `json:"captcha"`
}

func RegisterHandler(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

	// Parse the request
	var req RegisterRequest
	err := json.NewDecoder(r.Body).Decode(&req)
	if err != nil {
		http.Error(w, "Invalid request body", http.StatusBadRequest)
		return
	}

	// Validate email domain
	allowedDomains := strings.Split(os.Getenv("ALLOWED_DOMAINS"), ",")
	if !isDomainAllowed(req.Email, allowedDomains) {
		http.Error(w, "Email domain not allowed", http.StatusForbidden)
		return
	}

	// Validate CAPTCHA
	if !ValidateCaptcha(req.Captcha) {
		http.Error(w, "Invalid CAPTCHA", http.StatusUnauthorized)
		return
	}

	// Register user
	overleaf := NewOverleaf(os.Getenv("OL_INSTANCE"))
	err = overleaf.Login(os.Getenv("OL_ADMIN_EMAIL"), os.Getenv("OL_ADMIN_PASSWORD"))
	if err != nil {
		http.Error(w, "Failed to log in as admin", http.StatusInternalServerError)
		return
	}

	err = overleaf.RegisterUser(req.Email, req.Password)
	if err != nil {
		http.Error(w, "Failed to register user: "+err.Error(), http.StatusInternalServerError)
		return
	}

	w.WriteHeader(http.StatusCreated)
	json.NewEncoder(w).Encode(map[string]string{"message": "User registered successfully"})
}

func isDomainAllowed(email string, allowedDomains []string) bool {
	parts := strings.Split(email, "@")
	if len(parts) != 2 {
		return false
	}
	domain := parts[1]
	for _, allowed := range allowedDomains {
		if domain == allowed {
			return true
		}
	}
	return false
}