# frozen_string_literal: true

require 'roda'
require 'securerandom'
require 'json'
require 'sequel'
require 'open-uri'

# URL Shortener App class
class App < Roda
  plugin :sessions, secret: ENV.delete('APP_SESSION_SECRET')
  plugin :render, escape: true
  plugin :flash
  plugin :json_parser
  plugin :request_headers

  DB = Sequel.sqlite("db/#{ENV.fetch('DB_NAME', nil)}")
  links = DB[:links]

  route do |r|
    r.root do
      @message = flash['message'] || 'Enter a URL'
      view :home
    end

    r.get String do |url_code|
      link = links.filter(code: url_code)
      r.redirect link.first[:url] unless link.first.nil?
      @message = "Link #{url_code} doesn't exist"
      response.status = 404
      view :home
    end

    r.post 'create' do
      url = r.params['url']
      if url.nil? || url.empty?
        flash['message'] = 'Please enter a valid URL'
        r.redirect '/'
      end

      begin
        OpenURI.open_uri(url)
      rescue URI::BadURIError
        flash['message'] = 'Invalid URL'
        r.redirect '/'
      rescue OpenURI::HTTPError
        flash['message'] = 'URL not found'
        r.redirect '/'
      rescue SocketError
        flash['message'] = 'URL does not resolve'
        r.redirect '/'
      end

      if links.filter(url:).first.nil?
        code = SecureRandom.urlsafe_base64 4
        links.insert(url:, code:)
        @message = 'Link created'
      end
      code = links.filter(url:).first[:code]
      @message ||= 'Link exists'
      @new_link = "http://#{request.env['HTTP_HOST']}/#{code}"
      view :create
    end
    r.on 'links' do
      r.post do
        if r.headers['CONTENT_TYPE'] != 'application/json'
          response.status = 400
          return { message: 'not a valid json request' }.to_json
        end

        url = r.params['url']
        if url.nil?
          response.status = 400
          return { message: 'missing url parameter' }.to_json
        end

        if url.empty?
          response.status = 400
          return { message: 'invalid url parameter' }.to_json
        end

        begin
          OpenURI.open_uri(url)
        rescue URI::BadURIError
          response.status = 400
          return { message: 'invalid url parameter' }.to_json
        rescue OpenURI::HTTPError
          response.status = 400
          return { message: 'url not found' }.to_json
        rescue SocketError
          response.status = 400
          return { message: 'url does not resolve' }.to_json
        end

        if links.filter(url:).first.nil?
          code = SecureRandom.urlsafe_base64 4
          links.insert(url:, code:)
        end

        code = links.filter(url:).first[:code]
        @new_link = "http://#{request.env['HTTP_HOST']}/#{code}"
        return { url:, code:, link: @new_link }.to_json
      end
    end
  end
end