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

# PDF ticket generator service using Prawn
#
# Generates PDF tickets with QR codes for event entry validation
# Includes event details, venue information, and unique QR code for each ticket
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: [400, 650], margin: 0) do |pdf|
      # Main container with modern gradient background
      create_background(pdf)

      # Header section with brand and visual hierarchy
      create_header(pdf)

      # Event information card
      create_event_card(pdf)

      # Ticket holder information
      create_holder_section(pdf)

      # QR Code section with modern styling
      create_qr_section(pdf)

      # Footer with security elements
      create_footer(pdf)

    end.render
  end

  private

  def create_background(pdf)
    # Gradient background effect
    pdf.fill_color "F8FAFC"
    pdf.fill_rectangle [0, pdf.bounds.height], pdf.bounds.width, pdf.bounds.height

    # Top decorative band
    pdf.fill_color "6366F1"
    pdf.fill_rectangle [0, pdf.bounds.height], pdf.bounds.width, 120

    # Subtle gradient effect
    pdf.fill_color "8B5CF6"
    pdf.fill_rectangle [0, pdf.bounds.height], pdf.bounds.width, 80
  end

  def create_header(pdf)
    pdf.move_cursor_to(pdf.bounds.height - 30)

    # ApéroNight logo/brand
    pdf.fill_color "FFFFFF"
    pdf.font "Helvetica", style: :bold, size: 32
    pdf.text "AperoNight", align: :center

    pdf.move_down 8
    pdf.font "Helvetica", size: 12
    pdf.fill_color "E2E8F0"
    pdf.text "EVENEMENT TICKET", align: :center, character_spacing: 2
  end

  def create_event_card(pdf)
    pdf.move_cursor_to(480)

    # Main event card with shadow effect
    card_y = pdf.cursor

    # Shadow effect
    pdf.fill_color "E2E8F0"
    pdf.rounded_rectangle [22, card_y - 2], 356, 152, 15
    pdf.fill

    # Main card
    pdf.fill_color "FFFFFF"
    pdf.stroke_color "E5E7EB"
    pdf.line_width 1
    pdf.rounded_rectangle [20, card_y], 360, 150, 15
    pdf.fill_and_stroke

    # Event name with accent
    pdf.bounding_box([40, card_y - 20], width: 320, height: 110) do
      pdf.fill_color "1F2937"
      pdf.font "Helvetica", style: :bold, size: 20
      pdf.text ticket.event.name, align: :center

      pdf.move_down 15

      # Event details grid
      create_event_details_grid(pdf)
    end
  end

  def create_event_details_grid(pdf)
    details = [
      { label: "DATE", value: ticket.event.start_time.strftime("%d %B %Y"), icon: "[CAL]" },
      { label: "HEURE", value: ticket.event.start_time.strftime("%H:%M"), icon: "[TIME]" },
      { label: "LIEU", value: ticket.event.venue_name, icon: "[LOC]" },
      { label: "TYPE", value: ticket.ticket_type.name, icon: "[TICK]" }
    ]

    pdf.font "Helvetica", size: 10

    details.each_slice(2).with_index do |row, row_index|
      y_offset = row_index * 35

      row.each_with_index do |detail, col_index|
        x_offset = col_index * 160

        pdf.bounding_box([x_offset, pdf.cursor - y_offset], width: 150, height: 30) do
          # Icon and label
          pdf.fill_color "6B7280"
          pdf.font "Helvetica", style: :bold, size: 8
          pdf.text "#{detail[:icon]} #{detail[:label]}", character_spacing: 1

          pdf.move_down 3

          # Value
          pdf.fill_color "1F2937"
          pdf.font "Helvetica", style: :bold, size: 11
          pdf.text detail[:value]
        end
      end
    end
  end

  def create_holder_section(pdf)
    pdf.move_cursor_to(280)

    # Ticket holder section
    pdf.bounding_box([20, pdf.cursor], width: 360, height: 60) do
      # Section header with accent line
      pdf.fill_color "6366F1"
      pdf.fill_rectangle [0, pdf.cursor], 60, 2

      pdf.move_down 10

      pdf.fill_color "1F2937"
      pdf.font "Helvetica", style: :bold, size: 12
      pdf.text "DETENTEUR DU BILLET", character_spacing: 1

      pdf.move_down 8

      # Holder name with elegant styling
      pdf.font "Helvetica", style: :bold, size: 18
      pdf.fill_color "374151"
      pdf.text "#{ticket.first_name.upcase} #{ticket.last_name.upcase}"

      pdf.move_down 5

      # Price badge
      create_price_badge(pdf)
    end
  end

  def create_price_badge(pdf)
    price_text = "€#{sprintf('%.2f', ticket.price_euros)}"

    # Price badge background
    pdf.fill_color "10B981"
    pdf.rounded_rectangle [0, pdf.cursor], 80, 25, 12
    pdf.fill

    # Price text
    pdf.fill_color "FFFFFF"
    pdf.font "Helvetica", style: :bold, size: 12
    pdf.text_box price_text, at: [0, pdf.cursor],
                 width: 80, height: 25,
                 align: :center, valign: :center
  end

  def create_qr_section(pdf)
    pdf.move_cursor_to(190)

    # QR Code section with modern card design
    pdf.bounding_box([20, pdf.cursor], width: 360, height: 140) do
      # QR background card
      pdf.fill_color "F1F5F9"
      pdf.stroke_color "E2E8F0"
      pdf.rounded_rectangle [0, pdf.cursor], 360, 130, 15
      pdf.fill_and_stroke

      # QR Code title
      pdf.move_down 15
      pdf.fill_color "475569"
      pdf.font "Helvetica", style: :bold, size: 12
      pdf.text "CODE D'ENTREE", align: :center, character_spacing: 2

      pdf.move_down 10

      # Generate and place QR code
      generate_qr_code(pdf)

      pdf.move_down 10

      # QR code ID
      pdf.font "Helvetica", size: 8
      pdf.fill_color "64748B"
      pdf.text "ID: #{ticket.qr_code[0..11]}...", align: :center, character_spacing: 0.5
    end
  end

  def generate_qr_code(pdf)
    # 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

    # Create QR code with white background
    pdf.bounding_box([130, pdf.cursor], width: 100, height: 100) do
      pdf.fill_color "FFFFFF"
      pdf.rounded_rectangle [0, pdf.cursor], 100, 100, 8
      pdf.fill

      # Generate QR code
      pdf.print_qr_code(qr_code_data, extent: 85, align: :center)
    end
  end

  def create_footer(pdf)
    pdf.move_cursor_to(40)

    # Security notice
    pdf.font "Helvetica", size: 8
    pdf.fill_color "6B7280"
    pdf.text "[!] Ce billet est valable pour une seule entree", align: :center
    pdf.text "Presentez ce billet a l'entree de l'evenement", align: :center

    pdf.move_down 8

    # Generation timestamp with modern styling
    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, character_spacing: 0.3
  end

  private

  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