# frozen_string_literal: true

class ChannelsCdrSignalController < ApplicationController
  prepend_before_action -> { authentication_check && authorize! }, except: [:webhook]
  skip_before_action :verify_csrf_token, only: [:webhook]

  include CreatesTicketArticles

  def index
    assets = {}
    channel_ids = []
    Channel.where(area: 'Signal::Number').order(:id).each do |channel|
      assets = channel.assets(assets)
      channel_ids.push channel.id
    end
    render json: {
      assets: assets,
      channel_ids: channel_ids
    }
  end

  def add
    begin
      errors = {}
      errors['group_id'] = 'required' unless params[:group_id].present?

      if errors.present?
        render json: {
          errors: errors
        }, status: :bad_request
        return
      end
      channel = Channel.create(
        area: 'Signal::Number',
        options: {
          adapter: 'cdr_signal',
          phone_number: params[:phone_number],
          bot_token: params[:bot_token],
          bot_endpoint: params[:bot_endpoint],
          token: SecureRandom.urlsafe_base64(48),
          organization_id: params[:organization_id]
        },
        group_id: params[:group_id],
        active: true
      )
    rescue StandardError => e
      raise Exceptions::UnprocessableEntity, e.message
    end
    render json: channel
  end

  def update
    errors = {}
    errors['group_id'] = 'required' unless params[:group_id].present?

    if errors.present?
      render json: {
        errors: errors
      }, status: :bad_request
      return
    end
    channel = Channel.find_by(id: params[:id], area: 'Signal::Number')
    begin
      channel.options[:phone_number] = params[:phone_number]
      channel.options[:bot_token] = params[:bot_token]
      channel.options[:bot_endpoint] = params[:bot_endpoint]
      channel.options[:organization_id] = params[:organization_id]
      channel.group_id = params[:group_id]
      channel.save!
    rescue StandardError => e
      raise Exceptions::UnprocessableEntity, e.message
    end
    render json: channel
  end

  def rotate_token
    channel = Channel.find_by(id: params[:id], area: 'Signal::Number')
    channel.options[:token] = SecureRandom.urlsafe_base64(48)
    channel.save!
    render json: {}
  end

  def enable
    channel = Channel.find_by(id: params[:id], area: 'Signal::Number')
    channel.active = true
    channel.save!
    render json: {}
  end

  def disable
    channel = Channel.find_by(id: params[:id], area: 'Signal::Number')
    channel.active = false
    channel.save!
    render json: {}
  end

  def destroy
    channel = Channel.find_by(id: params[:id], area: 'Signal::Number')
    channel.destroy
    render json: {}
  end

  def channel_for_token(token)
    return false unless token

    Channel.where(area: 'Signal::Number').each do |channel|
      return channel if channel.options[:token] == token
    end
    false
  end

  def webhook
    token = params['token']
    return render json: {}, status: 401 unless token

    channel = channel_for_token(token)
    return render json: {}, status: 401 if !channel || !channel.active
    # Use constant-time comparison to prevent timing attacks
    return render json: {}, status: 401 unless ActiveSupport::SecurityUtils.secure_compare(
      channel.options[:token].to_s,
      token.to_s
    )

    # Handle group creation events
    if params[:event] == 'group_created'
      return update_group
    end

    # Handle group member joined events
    if params[:event] == 'group_member_joined'
      return handle_group_member_joined
    end

    channel_id = channel.id

    # validate input
    errors = {}

    #    %i[to
    #       from
    #       message_id
    #       sent_at].each | field |
    #      (errors[field] = 'required' if params[field].blank?)

    if errors.present?
      render json: {
        errors: errors
      }, status: :bad_request
      return
    end

    message_id = params[:message_id]

    return if Ticket::Article.exists?(message_id: "cdr_signal.#{message_id}")

    receiver_phone_number = params[:to].strip
    sender_phone_number = params[:from].present? ? params[:from].strip : nil
    sender_user_id = params[:user_id].present? ? params[:user_id].strip : nil

    # Check if this is a group message using the is_group flag from bridge-worker
    # This flag is set when:
    # 1. The original message came from a Signal group
    # 2. Bridge-worker created a new group for the conversation
    is_group_message = params[:is_group].to_s == 'true'

    # Lookup customer with fallback chain:
    # 1. Phone number in phone/mobile fields (preferred)
    # 2. Signal user ID in signal_user_id field
    # 3. User ID in phone/mobile fields (legacy - we used to store UUIDs there)
    customer = nil
    if sender_phone_number.present?
      customer = User.find_by(phone: sender_phone_number)
      customer ||= User.find_by(mobile: sender_phone_number)
    end
    if customer.nil? && sender_user_id.present?
      customer = User.find_by(signal_user_id: sender_user_id)
      # Legacy fallback: user ID might be stored in phone field
      customer ||= User.find_by(phone: sender_user_id)
      customer ||= User.find_by(mobile: sender_user_id)
    end

    unless customer
      role_ids = Role.signup_role_ids
      customer = User.create(
        firstname: '',
        lastname: '',
        email: '',
        password: '',
        phone: sender_phone_number.presence || sender_user_id,
        signal_user_id: sender_user_id,
        note: 'CDR Signal',
        active: true,
        role_ids: role_ids,
        updated_by_id: 1,
        created_by_id: 1
      )
    end

    # Update signal_user_id if we have it and customer doesn't
    if sender_user_id.present? && customer.signal_user_id.blank?
      customer.update(signal_user_id: sender_user_id)
    end
    # Update phone if we have it and customer only has user_id in phone field
    if sender_phone_number.present? && customer.phone == sender_user_id
      customer.update(phone: sender_phone_number)
    end

    # set current user
    UserInfo.current_user_id = customer.id
    current_user_set(customer, 'token_auth')

    group = Group.find_by(id: channel.group_id)
    if group.blank?
      Rails.logger.error "Signal channel #{channel_id} paired with Group #{channel.group_id}, but group does not exist!"
      return render json: { error: 'There was an error during Signal submission' }, status: 500
    end

    organization_id = channel.options['organization_id']
    if organization_id.present?
      organization = Organization.find_by(id: organization_id)
      unless organization.present?
        Rails.logger.error "Signal channel #{channel_id} paired with Organization #{organization_id}, but organization does not exist!"
        return render json: { error: 'There was an error during Signal submission' }, status: 500
      end
      unless customer.organization_id.present?
        customer.organization_id = organization.id
        customer.save!
      end
    end

    message = params[:message] ||= 'No text content'
    sent_at = params[:sent_at]
    attachment_data_base64 = params[:attachment]
    attachment_filename = params[:filename]
    attachment_mimetype = params[:mime_type]
    sender_display = sender_phone_number.presence || sender_user_id
    title = "Message from #{sender_display} at #{sent_at}"
    body = message

    # find ticket or create one
    state_ids = Ticket::State.where(name: %w[closed merged removed]).pluck(:id)

    if is_group_message
      Rails.logger.info "=== SIGNAL GROUP TICKET LOOKUP ==="
      Rails.logger.info "Looking for ticket with group_id: #{receiver_phone_number}"
      Rails.logger.info "Customer ID: #{customer.id}"
      Rails.logger.info "Customer Phone: #{sender_display}"
      Rails.logger.info "Channel ID: #{channel.id}"

      begin
        # Use text search on preferences YAML to efficiently find tickets without loading all into memory
        # This prevents DoS attacks from memory exhaustion
        ticket = Ticket.where.not(state_id: state_ids)
                      .where("preferences LIKE ?", "%channel_id: #{channel.id}%")
                      .where("preferences LIKE ?", "%chat_id: #{receiver_phone_number}%")
                      .order(updated_at: :desc)
                      .first

        if ticket
          Rails.logger.info "=== FOUND MATCHING TICKET BY GROUP ID: ##{ticket.number} ==="
          # Update customer if different (handles duplicate phone numbers)
          if ticket.customer_id != customer.id
            Rails.logger.info "Updating ticket customer from #{ticket.customer_id} to #{customer.id}"
            ticket.customer_id = customer.id
          end
        else
          Rails.logger.info "=== NO MATCHING TICKET BY GROUP ID - CHECKING BY PHONE NUMBER ==="
        end
      rescue => e
        Rails.logger.error "Error during group ticket lookup: #{e.message}"
        Rails.logger.error e.backtrace.join("\n")
      end
    else
      Rails.logger.info "Not a group message or no group_id, finding most recent ticket"
      ticket = Ticket.where(customer_id: customer.id).where.not(state_id: state_ids).order(:updated_at).first
    end

    if ticket
      # check if title need to be updated
      ticket.title = title if ticket.title == '-'
      new_state = Ticket::State.find_by(default_create: true)
      ticket.state = Ticket::State.find_by(default_follow_up: true) if ticket.state_id != new_state.id
    else
      # Set up chat_id based on whether this is a group message
      chat_id = is_group_message ? receiver_phone_number : (sender_phone_number.presence || sender_user_id)

      # Build preferences with group_id included if needed
      cdr_signal_prefs = {
        bot_token: channel.options[:bot_token],
        chat_id: chat_id,
        user_id: sender_user_id
      }

      Rails.logger.info "=== CREATING NEW TICKET ==="
      Rails.logger.info "Preferences to be stored:"
      Rails.logger.info "  - channel_id: #{channel.id}"
      Rails.logger.info "  - cdr_signal: #{cdr_signal_prefs.inspect}"

      ticket = Ticket.new(
        group_id: channel.group_id,
        title: title,
        customer_id: customer.id,
        preferences: {
          channel_id: channel.id,
          cdr_signal: cdr_signal_prefs
        }
      )
    end

    ticket.save!

    article_params = {
      from: sender_display,
      to: receiver_phone_number,
      sender_id: Ticket::Article::Sender.find_by(name: 'Customer').id,
      subject: title,
      body: body,
      content_type: 'text/plain',
      message_id: "cdr_signal.#{message_id}",
      ticket_id: ticket.id,
      internal: params[:internal] == true,
      preferences: {
        cdr_signal: {
          timestamp: sent_at,
          message_id: message_id,
          from: sender_phone_number,
          user_id: sender_user_id
        }
      }
    }

    if attachment_data_base64.present?
      article_params[:attachments] = [
        # i don't even...
        # this is necessary because of what's going on in controllers/concerns/creates_ticket_articles.rb
        # we need help from the ruby gods
        {
          'filename' => attachment_filename,
          :filename => attachment_filename,
          :data => attachment_data_base64,
          'data' => attachment_data_base64,
          'mime-type' => attachment_mimetype
        }
      ]
    end

    ticket.with_lock do
      ta = article_create(ticket, article_params)
      ta.update!(type_id: Ticket::Article::Type.find_by(name: 'cdr_signal').id)
    end

    ticket.update!(create_article_type_id: Ticket::Article::Type.find_by(name: 'cdr_signal').id)

    result = {
      ticket: {
        id: ticket.id,
        number: ticket.number
      }
    }

    render json: result, status: :ok
  end

  # Webhook endpoint for receiving group creation notifications from bridge-worker
  # This is called when a Signal group is created for a conversation
  # Expected payload:
  # {
  #   "event": "group_created",
  #   "conversation_id": "ticket_id_or_number",
  #   "original_recipient": "+1234567890",
  #   "group_id": "uuid-of-signal-group",
  #   "timestamp": "ISO8601 timestamp"
  # }
  def update_group
    # Validate required parameters
    errors = {}
    errors['event'] = 'required' unless params[:event].present?
    errors['conversation_id'] = 'required' unless params[:conversation_id].present?
    errors['group_id'] = 'required' unless params[:group_id].present?

    if errors.present?
      render json: {
        errors: errors
      }, status: :bad_request
      return
    end

    # Only handle group_created events for now
    unless params[:event] == 'group_created'
      render json: { error: 'Unsupported event type' }, status: :bad_request
      return
    end

    # Find the ticket by ID or number
    # Try to find by both ID and number since ticket numbers can be numeric
    ticket = Ticket.find_by(id: params[:conversation_id]) ||
             Ticket.find_by(number: params[:conversation_id])

    unless ticket
      Rails.logger.error "Signal group update: Ticket not found for conversation_id #{params[:conversation_id]}"
      render json: { error: 'Ticket not found' }, status: :not_found
      return
    end

    # Update ticket preferences with the group information
    ticket.preferences ||= {}
    ticket.preferences[:cdr_signal] ||= {}
    ticket.preferences[:cdr_signal][:chat_id] = params[:group_id]
    ticket.preferences[:cdr_signal][:original_recipient] = params[:original_recipient] if params[:original_recipient].present?
    ticket.preferences[:cdr_signal][:group_created_at] = params[:timestamp] if params[:timestamp].present?

    # Track whether user has joined the group (initially false)
    # This will be updated to true when we receive a group join event from Signal
    ticket.preferences[:cdr_signal][:group_joined] = params[:group_joined] if params.key?(:group_joined)

    ticket.save!

    Rails.logger.info "Signal group #{params[:group_id]} associated with ticket #{ticket.id}"

    render json: {
      success: true,
      ticket_id: ticket.id,
      ticket_number: ticket.number
    }, status: :ok
  end

  # Webhook endpoint for receiving group member joined notifications from bridge-worker
  # This is called when a user accepts the Signal group invitation
  # Expected payload:
  # {
  #   "event": "group_member_joined",
  #   "group_id": "group.base64encodedid",
  #   "member_phone": "+1234567890",
  #   "timestamp": "ISO8601 timestamp"
  # }
  def handle_group_member_joined
    # Validate required parameters
    errors = {}
    errors['event'] = 'required' unless params[:event].present?
    errors['group_id'] = 'required' unless params[:group_id].present?
    errors['member_phone'] = 'required' unless params[:member_phone].present?

    if errors.present?
      render json: {
        errors: errors
      }, status: :bad_request
      return
    end

    # Find ticket(s) with this group_id in preferences
    # Use text search on preferences YAML for efficient lookup (prevents DoS from loading all tickets)
    state_ids = Ticket::State.where(name: %w[closed merged removed]).pluck(:id)

    ticket = Ticket.where.not(state_id: state_ids)
                  .where("preferences LIKE ?", "%chat_id: #{params[:group_id]}%")
                  .order(updated_at: :desc)
                  .first

    unless ticket
      Rails.logger.warn "Signal group member joined: Ticket not found for group_id #{params[:group_id]}"
      render json: { error: 'Ticket not found for this group' }, status: :not_found
      return
    end

    # Idempotency check: if already marked as joined, skip update and return success
    # This prevents unnecessary database writes when the cron job sends duplicate notifications
    if ticket.preferences.dig('cdr_signal', 'group_joined') == true
      Rails.logger.debug "Signal group member #{params[:member_phone]} already marked as joined for group #{params[:group_id]} ticket #{ticket.id}, skipping update"
      render json: {
        success: true,
        ticket_id: ticket.id,
        ticket_number: ticket.number,
        group_joined: true,
        already_joined: true
      }, status: :ok
      return
    end

    # Update group_joined flag
    member_phone = params[:member_phone]
    ticket.preferences[:cdr_signal][:group_joined] = true
    ticket.preferences[:cdr_signal][:group_joined_at] = params[:timestamp] if params[:timestamp].present?
    ticket.preferences[:cdr_signal][:group_joined_by] = member_phone

    ticket.save!

    Rails.logger.info "Signal group member #{member_phone} joined group #{params[:group_id]} for ticket #{ticket.id}"

    render json: {
      success: true,
      ticket_id: ticket.id,
      ticket_number: ticket.number,
      group_joined: true
    }, status: :ok
  end
end