# Gemfile
gem "httpx"

# app/services/deckle.rb
require "httpx"
require "json"

class Deckle
  BASE_URL = "https://api.getdeckle.dev"

  def initialize(api_key = ENV["DECKLE_API_KEY"])
    @api_key = api_key
  end

  def generate(html:, options: {})
    response = HTTPX.post(
      "#{BASE_URL}/v1/generate",
      headers: {
        "Authorization" => "Bearer #{@api_key}",
        "Content-Type" => "application/json"
      },
      body: { html: html, options: options }.to_json
    )
    JSON.parse(response.body, symbolize_names: true)
  end

  def from_template(template:, data:, options: {})
    response = HTTPX.post(
      "#{BASE_URL}/v1/generate",
      headers: {
        "Authorization" => "Bearer #{@api_key}",
        "Content-Type" => "application/json"
      },
      body: { template: template, data: data, options: options }.to_json
    )
    JSON.parse(response.body, symbolize_names: true)
  end
end

# app/controllers/invoices_controller.rb
class InvoicesController < ApplicationController
  def generate_pdf
    df = Deckle.new

    result = df.from_template(
      template: "tmpl_invoice_v2",
      data: {
        company: @invoice.customer_name,
        items: @invoice.line_items.map { |li|
          { description: li.description, qty: li.quantity, rate: li.rate }
        },
        total: @invoice.total.to_s
      }
    )

    render json: result
  end

  def download
    df = Deckle.new
    @invoice = Invoice.find(params[:id])

    result = df.from_template(
      template: "tmpl_invoice_v2",
      data: invoice_data(@invoice),
      options: { output: "base64" }
    )

    pdf_data = Base64.decode64(result[:data])
    send_data pdf_data,
      filename: "invoice-#{@invoice.id}.pdf",
      type: "application/pdf",
      disposition: "attachment"
  end

  private

  def invoice_data(invoice)
    {
      company: invoice.customer_name,
      items: invoice.line_items.as_json(only: [:description, :qty, :rate]),
      total: invoice.total.to_s
    }
  end
end

# config/routes.rb
Rails.application.routes.draw do
  resources :invoices do
    member do
      post :generate_pdf
      get :download
    end
  end
end