slackernews.rb

require 'sinatra'
require 'dm-core'
require 'dm-migrations'
require 'dm-timestamps'
require 'dm-aggregates'
require 'hpricot'
require 'open-uri'
require 'coderay'
require 'rdiscount'
require 'haml'

class User 
    include DataMapper::Resource
    property :id, Serial
    property :username, String
    has n, :discussions
    has n, :comments
end

class Discussion 
    include DataMapper::Resource
    property :id, Serial
    property :title, String, :required=>false
    property :url, String, :required=>false
    property :points, Integer, :default=>0
    property :created_at, DateTime
    property :content, Text

    belongs_to :user
    has n, :comments

    def popularity 
        t = Date.day_fraction_to_time(DateTime.now - @created_at)[0]
        (@points-1) / (t+2)**1.8
    end

    def self.most_popular 
        Discussion.all.sort{|a,b| b.popularity <=> a.popularity }
    end
end

class Comment 
    include DataMapper::Resource
    property :id, Serial
    property :created_at, DateTime
    property :content, Text

    belongs_to :user
    belongs_to :discussion
end

enable :sessions
configure do 
    DataMapper.setup(:default, (ENV["DATABASE_URL"] || "sqlite3:///#{Dir.pwd}/development.sqlite3"))
    DataMapper.auto_upgrade!
end
helpers do 
    def logged_in? 
        !!session[:user_id]
    end
    def current_user 
        User.get(session[:user_id])
    end
    def get_title(uri)
       begin
           doc = Hpricot open(uri).read
           title = doc.search("title").inner_text
           title.strip.empty? ? uri : title
       rescue
           uri
       end
    end

    def display_formatted(raw_markdown) 
        #convert to html
        md = RDiscount.new raw_markdown
        #examine with hpricot
        html = Hpricot md.to_html
        #search for code and highlight it
        html.search "pre" do |code| 
            lang = ""
            lines = code.innerText.split "\n"
            lines.each do |line|
                if line[0..2] == "@@@"
                    lang = line.gsub "@@@", '' 
                    break
                end
            end
            #ok, we have the lang, now, color it
            newhtml = Hpricot CodeRay.scan(lines[1..-1].join("\n"), lang.to_sym).div :line_numbers => :inline, :css => :class
            html.replace_child code, newhtml
        end
        #return the string representation of the note
        html.to_s
    end
end

get '/' do 
    #return hottest news
    @news = Discussion.most_popular
    haml :index
end

get '/newest' do 
    @news = Discussion.all :order => [:created_at.desc]
    haml :index
end

get '/submit' do 
    #submit, validate and shit
    redirect '/' unless logged_in?
    haml :submit
end

get '/discussions/:id' do |thread_id|
    #view comments on a thread
    @thread = Discussion.get thread_id
    redirect '/' if @thread.nil?
    haml :thread
end

get '/users/:user' do |username|
    #get threads submitted by user
    #TODO: valid user
    u = User.first :username=>username
    redirect '/' if u.nil?
    @news = u.discussions.all
    haml :index
end

get '/login' do 
    #get login form
    redirect '/' if logged_in?
    haml :login
end

post '/comments' do 
    #assign a comment to a thread
    thread = Discussion.get params[:thread]
    Comment.create :content=>params[:content], :discussion=>thread, :user => User.get(session[:user_id])
    thread.points += 1
    thread.save
    redirect "/discussions/#{params[:thread]}"
end

post '/discussions/vote/:id' do |thread_id| 
    t = Discussion.get(thread_id)
    t.points += 1
    t.save
    session[:voted] ||= []
    session[:voted] << t.id
    redirect request.referer
end

post '/discussions' do 
    #create a thread, validate stuff
    @errors = []
    @errors << "Tenés que proveer o un título o una url" if params[:title].strip.empty? && params[:url].strip.empty?
    return haml :submit unless @errors.empty?
    t = Discussion.new
    t.title = !params[:title].empty? ? params[:title] : get_title(params[:url])
    t.user = User.get session[:user_id]
    t.content= params[:content] || " "
    t.url = params[:url]
    t.save
    unless !params[:url].empty?
        t.update :url=>"/discussions/#{t.id}"
    end
    redirect '/newest'
end

post '/login' do 
    #login the user
    u = User.first_or_create :username => params["username"]
    session[:user_id] = u.id
    session[:voted] = []
    redirect '/'
end
get '/logout' do 
    session.clear
    redirect '/'
end