require "prawn"
require "prawn/qrcode"
require "rqrcode"

# PDF ticket generator service using Prawn
#
# Generates simple, compact PDF tickets with QR codes for event entry validation
# Clean, minimalist design that fits on a single page
class TicketPdfGenerator
  # Suppress Prawn's internationalization warning for built-in fonts
  Prawn::Fonts::AFM.hide_m17n_warning = true
  attr_reader :ticket

  def initialize(ticket)
    @ticket = ticket
  end

  def generate
    Prawn::Document.new(page_size: "A4", margin: 40) do |pdf|
      # Simple header
      create_simple_header(pdf)
      
      # Event and ticket info in compact layout
      create_ticket_info(pdf)
      
      # QR code section
      create_qr_section(pdf)
      
      # Simple footer
      create_simple_footer(pdf)
      
    end.render
  end

  private

  def create_simple_header(pdf)
    # Brand name
    pdf.fill_color "6366F1"
    pdf.font "Helvetica", style: :bold, size: 24
    pdf.text "AperoNight", align: :center
    
    pdf.move_down 5
    pdf.font "Helvetica", size: 10
    pdf.fill_color "64748B"
    pdf.text "Billet d'entree", align: :center
    
    pdf.move_down 20
    
    # Simple divider line
    pdf.stroke_color "E5E7EB"
    pdf.horizontal_line 0, pdf.bounds.width
    pdf.move_down 20
  end

  def create_ticket_info(pdf)
    # Event name - prominent
    pdf.fill_color "1F2937"
    pdf.font "Helvetica", style: :bold, size: 18
    pdf.text ticket.event.name, align: :center
    pdf.move_down 15
    
    # Two-column layout for ticket details
    pdf.bounding_box([0, pdf.cursor], width: pdf.bounds.width, height: 120) do
      # Left column
      pdf.bounding_box([0, pdf.cursor], width: pdf.bounds.width / 2 - 20, height: 120) do
        create_info_item(pdf, "Date", ticket.event.start_time.strftime("%d %B %Y"))
        create_info_item(pdf, "Heure", ticket.event.start_time.strftime("%H:%M"))
        create_info_item(pdf, "Lieu", ticket.event.venue_name)
      end
      
      # Right column
      pdf.bounding_box([pdf.bounds.width / 2 + 20, pdf.cursor], width: pdf.bounds.width / 2 - 20, height: 120) do
        create_info_item(pdf, "Type", ticket.ticket_type.name)
        create_info_item(pdf, "Prix", "#{sprintf('%.2f', ticket.price_euros)} EUR")
        create_info_item(pdf, "Titulaire", "#{ticket.first_name} #{ticket.last_name}")
      end
    end
    
    pdf.move_down 30
  end

  def create_info_item(pdf, label, value)
    pdf.font "Helvetica", style: :bold, size: 9
    pdf.fill_color "64748B"
    pdf.text label.upcase
    
    pdf.move_down 2
    pdf.font "Helvetica", size: 11
    pdf.fill_color "1F2937"
    pdf.text value
    pdf.move_down 12
  end

  def create_qr_section(pdf)
    # Center the QR code horizontally
    qr_size = 120
    x_position = (pdf.bounds.width - qr_size) / 2
    
    pdf.bounding_box([x_position, pdf.cursor], width: qr_size, height: qr_size + 40) do
      # QR Code title
      pdf.font "Helvetica", style: :bold, size: 12
      pdf.fill_color "1F2937"
      pdf.text "Code d'entree", align: :center
      pdf.move_down 10
      
      # Generate QR code
      generate_simple_qr_code(pdf, qr_size)
      
      pdf.move_down 10
      
      # QR code ID
      pdf.font "Helvetica", size: 8
      pdf.fill_color "64748B"
      pdf.text "ID: #{ticket.qr_code[0..15]}...", align: :center
    end
    
    pdf.move_down 40
  end

  def generate_simple_qr_code(pdf, size)
    # Ensure all required data is present before generating QR code
    if ticket.qr_code.blank?
      raise "Ticket QR code is missing"
    end

    # Build QR code data with safe association loading
    qr_code_data = build_qr_code_data(ticket)

    # Validate QR code data before creating QR code
    if qr_code_data.blank? || qr_code_data == "{}"
      Rails.logger.error "QR code data is empty: ticket_id=#{ticket.id}, qr_code=#{ticket.qr_code}, event_id=#{ticket.ticket_type&.event_id}, user_id=#{ticket.order&.user_id}"
      raise "QR code data is empty or invalid"
    end

    # Ensure qr_code_data is a proper string for QR code generation
    unless qr_code_data.is_a?(String) && qr_code_data.length > 2
      Rails.logger.error "QR code data is not a valid string: #{qr_code_data.inspect} (class: #{qr_code_data.class})"
      raise "QR code data must be a valid string"
    end

    # Generate QR code
    pdf.print_qr_code(qr_code_data, extent: size, align: :center)
  end

  def create_simple_footer(pdf)
    # Security notice
    pdf.font "Helvetica", size: 8
    pdf.fill_color "64748B"
    pdf.text "Ce billet est valable pour une seule entree.", align: :center
    pdf.text "Presentez ce code QR a l'entree de l'evenement.", align: :center
    
    pdf.move_down 10
    
    # Divider line
    pdf.stroke_color "E5E7EB"
    pdf.horizontal_line 0, pdf.bounds.width
    pdf.move_down 5
    
    # Generation timestamp
    pdf.font "Helvetica", size: 7
    pdf.fill_color "9CA3AF"
    timestamp = "Genere le #{Time.current.strftime('%d/%m/%Y a %H:%M')}"
    pdf.text timestamp, align: :center
  end

  def build_qr_code_data(ticket)
    # Try multiple approaches to get valid QR code data
    begin
      # Primary approach: full JSON with all data
      data = {
        ticket_id: ticket.id,
        qr_code: ticket.qr_code,
        event_id: ticket.ticket_type&.event_id,
        user_id: ticket.order&.user_id
      }.compact

      # Ensure we have the minimum required data
      if data[:ticket_id] && data[:qr_code]
        return data.to_json
      end
    rescue StandardError => e
      Rails.logger.warn "Failed to build complex QR data: #{e.message}"
    end

    # Fallback approach: just use the ticket's QR code string
    begin
      return ticket.qr_code.to_s if ticket.qr_code.present?
    rescue StandardError => e
      Rails.logger.warn "Failed to use ticket QR code: #{e.message}"
    end

    # Final fallback: simple ticket identifier
    "TICKET-#{ticket.id}"
  end
end