package main

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

// RegistrationRequest represents the incoming registration request.
type RegistrationRequest struct {
	Email   string `json:"email"`
	Captcha string `json:"captcha"`
}

func registerHandler(w http.ResponseWriter, r *http.Request) {
	// Allow only POST requests
	if r.Method != http.MethodPost {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

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

	// Validate email
	if !validateEmailDomain(req.Email) {
		http.Error(w, "Email domain is not allowed", http.StatusBadRequest)
		return
	}

	// Validate reCAPTCHA token
	valid, err := validateRecaptcha(req.Captcha)
	if err != nil {
		http.Error(w, fmt.Sprintf("CAPTCHA validation failed: %v", err), http.StatusInternalServerError)
		return
	}
	if !valid {
		http.Error(w, "Invalid CAPTCHA", http.StatusUnauthorized)
		return
	}

	// Initialize Overleaf instance
	baseURL := os.Getenv("OL_INSTANCE")
	if baseURL == "" {
		http.Error(w, "OL_INSTANCE is not set", http.StatusInternalServerError)
		return
	}
	overleaf := NewOverleaf(baseURL)

	// Admin login using environment variables
	adminEmail := os.Getenv("OL_ADMIN_EMAIL")
	adminPassword := os.Getenv("OL_ADMIN_PASSWORD")
	if adminEmail == "" || adminPassword == "" {
		http.Error(w, "OL_ADMIN_EMAIL or OL_ADMIN_PASSWORD is not set", http.StatusInternalServerError)
		return
	}

	if err := overleaf.Login(adminEmail, adminPassword); err != nil {
		http.Error(w, fmt.Sprintf("Admin login failed: %v", err), http.StatusInternalServerError)
		return
	}

	// Create the user in Overleaf
	if err := overleaf.RegisterUser(req.Email); err != nil {
		http.Error(w, fmt.Sprintf("Failed to create user: %v", err), http.StatusInternalServerError)
		return
	}

	// Respond with success
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(http.StatusOK)
	json.NewEncoder(w).Encode(map[string]string{
		"message": "User registered successfully. Please check your email to set your password.",
	})
}