require "securerandom"
require "bcrypt"

class SettingsController < ApplicationController
  before_action :authenticate_user!
  before_action :set_main_nav_section
  before_action :set_settings_section, only: [:show, :update, :update_email, :reset_email_password]
  before_action :set_user, only: [:show, :update, :update_email, :reset_email_password]

  def index
    redirect_to setting_path(:profile)
  end

  def show
    case @settings_section
    when "lightning"
      @notifications_enabled = @user.preferences[:lightning_notify_sats_received] != "disabled" ||
                               @user.preferences[:lightning_notify_zap_received] != "disabled"
    when "nostr"
      session[:shared_secret] ||= SecureRandom.base64(12)
    end
  end

  # PUT /settings/:section
  def update
    @user.preferences.merge!(user_params[:preferences] || {})
    @user.display_name = user_params[:display_name]
    @user.avatar_new   = user_params[:avatar_new]
    @user.pgp_pubkey   = user_params[:pgp_pubkey]

    if @user.save
      if @user.display_name && (@user.display_name != @user.ldap_entry[:display_name])
        LdapManager::UpdateDisplayName.call(dn: @user.dn, display_name: @user.display_name)
      end

      if @user.avatar_new.present?
        if store_user_avatar
          LdapManager::UpdateAvatar.call(user: @user)
          XmppSetAvatarJob.perform_later(user: @user) if Setting.ejabberd_enabled?
        else
          @validation_errors = @user.errors
          render :show, status: :unprocessable_entity and return
        end
      end

      if @user.pgp_pubkey && (@user.pgp_pubkey != @user.ldap_entry[:pgp_key])
        UserManager::UpdatePgpKey.call(user: @user)
      end

      redirect_to setting_path(@settings_section), flash: {
        success: 'Settings saved.'
      }
    else
      @validation_errors = @user.errors
      render :show, status: :unprocessable_entity
    end
  end

  # POST /settings/update_email
  def update_email
    if @user.valid_ldap_authentication?(security_params[:current_password])
      if @user.update email: email_params[:email]
        redirect_to setting_path(:account), flash: {
          notice: 'Please confirm your new address using the confirmation link we just sent you.'
        }
      else
        @validation_errors = @user.errors
        render :show, status: :unprocessable_entity
      end
    else
      redirect_to setting_path(:account), flash: {
        error: 'Password did not match your current password. Try again.'
      }
    end
  end

  # POST /settings/reset_email_password
  def reset_email_password
    @user.current_password = security_params[:current_password]

    if @user.valid_ldap_authentication?(@user.current_password)
      @user.current_password = nil
      session[:new_email_password] = generate_email_password
      hashed_password = hash_email_password(session[:new_email_password])
      LdapManager::UpdateEmailPassword.call(dn: @user.dn, password_hash: hashed_password)

      if @user.ldap_entry[:email_maildrop] != @user.address
        LdapManager::UpdateEmailMaildrop.call(dn: @user.dn, address: @user.address)
      end

      redirect_to new_password_services_email_path
    else
      @validation_errors = {
        current_password: [ "Wrong password. Try again!" ]
      }
      render :show, status: :forbidden
    end
  end

  # POST /settings/reset_password
  def reset_password
    current_user.send_reset_password_instructions
    sign_out current_user
    msg = "We have sent you an email with a link to reset your password."
    redirect_to check_your_email_path, notice: msg
  end

  # POST /settings/set_nostr_pubkey
  def set_nostr_pubkey
    signed_event = Nostr::Event.new(**nostr_event_from_params)

    is_valid_sig  = signed_event.verify_signature
    is_valid_auth = NostrManager::VerifyAuth.call(
      event: signed_event,
      challenge: session[:shared_secret]
    )

    unless is_valid_sig && is_valid_auth
      flash[:alert] = "Public key could not be verified"
      http_status :unprocessable_entity and return
    end

    user_with_pubkey = LdapManager::FetchUserByNostrKey.call(pubkey: signed_event.pubkey)

    if user_with_pubkey.present? && (user_with_pubkey != current_user)
      flash[:alert] = "Public key already in use for a different account"
      http_status :unprocessable_entity and return
    end

    LdapManager::UpdateNostrKey.call(dn: current_user.dn, pubkey: signed_event.pubkey)
    session[:shared_secret] = nil

    flash[:success] = "Public key verification successful"
    http_status :ok
  end

  # DELETE /settings/nostr_pubkey
  def remove_nostr_pubkey
    # TODO require current pubkey or password to delete
    LdapManager::UpdateNostrKey.call(dn: current_user.dn, pubkey: nil)

    redirect_to setting_path(:nostr), flash: {
      success: 'Public key removed from account'
    }
  end

  private

    def set_main_nav_section
      @current_section = :settings
    end

    def set_settings_section
      @settings_section = params[:section]
      allowed_sections = [
        :profile, :account, :xmpp, :email,
        :lightning, :remotestorage, :nostr
      ]

      unless allowed_sections.include?(@settings_section.to_sym)
        redirect_to setting_path(:profile)
      end
    end

    def set_user
      @user = current_user
    end

    def user_params
      params.require(:user).permit(
        :display_name, :avatar_new, :pgp_pubkey,
        preferences: UserPreferences.pref_keys
      )
    end

    def email_params
      params.require(:user).permit(:email)
    end

    def security_params
      params.require(:user).permit(:current_password)
    end

    def generate_email_password
      characters = [('a'..'z'), ('A'..'Z'), (0..9)].map(&:to_a).flatten
      SecureRandom.random_bytes(16).each_byte.map { |b| characters[b % characters.length] }.join
    end

    def hash_email_password(password)
      salt = BCrypt::Engine.generate_salt
      BCrypt::Engine.hash_secret(password, salt)
    end

    def store_user_avatar
      io = @user.avatar_new.tempfile
      img_data = UserManager::ProcessAvatar.call(io: io)
      if img_data.blank?
        @user.errors.add(:avatar, "failed to process file")
        false
      end
      tempfile = Tempfile.create
      tempfile.binmode
      tempfile.write(img_data)
      tempfile.rewind

      hash = Digest::SHA256.hexdigest(img_data)
      ext = @user.avatar_new.content_type == "image/png" ? "png" : "jpg"
      filename = "#{hash}.#{ext}"

      if filename == @user.avatar.filename.to_s
        @user.errors.add(:avatar, "must be a new file/picture")
        false
      else
        key = "users/#{@user.cn}/avatars/#{filename}"
        @user.avatar.attach io: tempfile, key: key, filename: filename
        @user.save
      end
    end
end