app.rb

require 'sinatra'
require 'sequel'
require 'sinatra/sequel'
require 'sinatra/respond_with'
require 'json'

# added this to make the Model.order(:symbol.desc) syntax work. May want to not use the core extensions long-term.
Sequel.extension :core_extensions

class Link < Sequel::Model
  def hit!
    self.hits += 1
    self.save(:validate => false)
  end

  def validate
    super
    errors.add(:name, 'cannot be empty') if !name || name.empty?
    errors.add(:url, 'cannot be empty') if !url || url.empty?
  end

  def to_json
    {
      name: self.name,
      url: self.url,
      description: self.description,
      hits: self.hits,
    }
  end

end

# Configuration

configure do
  set :erb, :escape_html => false
  set :public_folder, Proc.new { File.join(root, "static") }
end

# Actions

get '/' do
  @links = Link.order(:hits.desc).all
  respond_with :index do |f|
    f.html { erb :index, params: params }
    f.json { @links.map(&:to_json).to_json }
  end
end

get '/links' do
  redirect '/'
end

post '/links' do
  begin
    Link.create(
      :name => params[:name].strip,
      :url  => params[:url].strip,
      :description  => params[:description].strip,
    )
    redirect '/'
  rescue Sequel::ValidationFailed,
         Sequel::DatabaseError => e
    halt "Error: #{e.message}"
  end
end

get '/links/suggest' do
  query = params[:q]

  results = Link.filter(:name.like("#{query}%")).or(:url.like("%#{query}%"))
  results = results.all.map {|r| r.name }

  content_type :json
  results.to_json
end

get '/links/search' do
  query = params[:q]
  @links = Link.filter(:name.like("#{query}%")).order(:hits.desc).all

  respond_with :index do |f|
    f.html { erb :index, params: params }
    f.json { @links.map(&:to_json).to_json }
  end
end

post '/links/:id/remove' do
  link = Link.find(:id => params[:id])
  halt 404 unless link
  link.destroy
  redirect '/'
end

post '/links/:id/update' do
  link = Link.find(:id => params[:id])
  halt 404 unless link

  begin
    link.name = params[:name]
    link.description = params[:description]
    link.url = params[:url]
    link.save
    redirect '/'
  rescue Sequel::ValidationFailed,
         Sequel::DatabaseError => e
    halt "Error: #{e.message}"
  end
end

get '/:name/?*?' do
  link = Link[:name => [params[:name], params[:splat].first].join('/')]
  params[:splat] = [''] if link # remove the splat so we don't reuse it

  # Just try the straight link if we didn't find a matching link
  link ||= Link[:name => params[:name]]

  if link
    link.hit!

    parts = params[:splat].first.split('/')
    parts = nil if parts.empty?

    url = link.url
    url %= parts

    redirect url
  else
    # try to list sub-links of the namespace
    filtered_links = Link.filter(:name.like("#{params[:name]}%")).order(:hits.desc).all
    if filtered_links.empty?
      @links = Link.order(:hits.desc).all
      params[:not_found] = params[:name]
    else
      @links = filtered_links
      params[:links_filter] = params[:name]
    end
    respond_with :index do |f|
      f.html { erb(:index, params: params) }
    end
  end
end