require 'openai'

class AiPrdService
  def initialize(user_prompt)
    @client = OpenAI::Client.new(access_token: ENV['OPENAI_API_KEY'])
    @user_prompt = user_prompt
  end

  def generate_prd_json
    response = @client.chat(
      parameters: {
        model: "gpt-4o-mini",
        messages: [
          { role: "system", content: "You are an AI assistant that generates structured PRDs." },
          { role: "user", content: @user_prompt }
        ],
        temperature: 0.7
      }
    )
    prd_content = JSON.parse(response.dig("choices", 0, "message", "content"))
    prd_content
  rescue JSON::ParserError => e
    Rails.logger.error "Failed to parse AI response: #{e.message}"
    nil
  end
end

require 'caracal'

class DocxGenerator
  def initialize(prd_json)
    @prd_json = prd_json
  end

  def generate_docx(output_path)
    Caracal::Document.save(output_path) do |docx|
      docx.h1 @prd_json['title']
      @prd_json['sections'].each do |section|
        docx.h2 section['heading']
        docx.p section['content']
      end
    end
  end
end

require 'erb'

class MarkdownGenerator
  TEMPLATE = <<~MD
    # <%= @prd_json['title'] %>

    <% @prd_json['sections'].each do |section| %>
    ## <%= section['heading'] %>

    <%= section['content'] %>

    <% end %>
  MD

  def initialize(prd_json)
    @prd_json = prd_json
  end

  def generate_markdown
    ERB.new(TEMPLATE).result(binding)
  end
end

require 'yaml'

class YamlGenerator
  def initialize(prd_json)
    @prd_json = prd_json
  end

  def generate_yaml(output_path)
    File.write(output_path, @prd_json.to_yaml)
  end
end

require 'odf-report'

class OdtGenerator
  def initialize(prd_json)
    @prd_json = prd_json
  end

  def generate_odt(output_path)
    report = ODFReport::Report.new("template.odt") do |r|
      r.add_field("TITLE", @prd_json['title'])
      @prd_json['sections'].each_with_index do |section, index|
        r.add_field("HEADING#{index+1}", section['heading'])
        r.add_field("CONTENT#{index+1}", section['content'])
      end
    end
    report.generate(output_path)
  end
end

require 'prawn'

class PdfGenerator
  def initialize(prd_json)
    @prd_json = prd_json
  end

  def generate_pdf(output_path)
    Prawn::Document.generate(output_path) do |pdf|
      pdf.text @prd_json['title'], size: 24, style: :bold
      @prd_json['sections'].each do |section|
        pdf.move_down 10
        pdf.text section['heading'], size: 18, style: :bold
        pdf.text section['content'], size: 12
      end
    end
  end
end

class TxtGenerator
  def initialize(prd_json)
    @prd_json = prd_json
  end

  def generate_txt(output_path)
    content = []
    content << @prd_json['title']
    @prd_json['sections'].each do |section|
      content << "\n#{section['heading']}\n"
      content << "#{section['content']}\n"
    end
    File.write(output_path, content.join("\n"))
  end
end