require 'sinatra'
require 'xmlrpc/marshal'
require 'discourse_api'
require 'json'
require 'pp'
require 'chronic'

CONFIG = YAML.load( 
  File.read(
    File.join(
      File.expand_path( File.join( File.dirname( __FILE__ ), ".." ) ), 
      "config.yml"
    )
  )
)

#use Rack::Session::Cookie, :key => "rack.session",
#  :domain => DOMAIN,
#  :path => "/",
#  :expire_after => 86400 * 7, # login every 7 days...
#  :secret => "change_me",     # change these
#  :old_secret => "change_me"


set :discourse_api, URI::parse( CONFIG.fetch( 'discourse_url' ) )
set :discourse_api_key, CONFIG.fetch( 'discourse_api_key' )

# For push notifications. TODO.
set :tapatalk_api, CONFIG.fetch( 'tapatalk_url', nil )
set :tapatalk_api_key, CONFIG.fetch( 'tapatalk_api_key', nil )


before do
  # Pass through all cookies to the discourse instance
  discourse( request.cookies )
end

helpers do

  # Use this as our entry point
  def dispatch
    xml = @request.body.read
    
    fixup_tapatalk_xml( xml )

    halt 400, "Empty XMLRPC request" if xml.empty?

    # Parse xml
    method, arguments = XMLRPC::Marshal.load_call(xml)

    method = "xmlrpc_#{method.gsub(/([A-Z])/, '_ ').downcase}"
    puts "method = #{method}, args = #{ method =~ /login/ ? "*REDACTED*" : arguments.inspect }"

    # Check if method exists
    if(respond_to?(method))
      content_type("text/xml", :charset => "utf-8")
      send(method, *arguments)
    else
      raise Sinatra::NotFound
    end
  end
  
  # Apparently, tapatalk formats booleans contrary to the XMLRPC standard.
  # https://github.com/svdgraaf/django-tapatalk/blob/master/tapatalk/dispatcher.py
  def fixup_tapatalk_xml( text )
    text.gsub( '<boolean>true</boolean>', '<boolean>1</boolean>' )
  end
  
  def make_xmlrpc_datetime( string )
    Chronic.parse( string )
  end
  
  def binary_xmlrpc( string )
    # assume it's utf-8 for now, wrap in base64 encoding
    XMLRPC::Base64.new( string )
  end
  
  def make_avatar_url( template_txt, size = 120 )
    template_txt.to_s.
      gsub(/\A\/\//, "http://"). # srsly wat, discourse? Well, it's probably for selection between HTTP or HTTPS more easily. But still.
      gsub( "{size}", size.to_s ) # url parameter
  end
  
  # Clean up the text, converting it to BBCode (TODO) unless use_html 
  
  def format_post_content_for_xmlrpc( html_text, use_html )
    raise NotImplementedError.new( "Can't convert to BBCode yet" ) unless
      use_html
      
    html_text
  end

  def build_tapatalk_topic( discourse_topic, extra = {} )
    result = {
      'forum_id' => discourse_topic["category_id"].to_s,
      'topic_id' => discourse_topic["id"].to_s,
      'topic_title' => binary_xmlrpc( discourse_topic["title"].to_s ),
      # 'prefix' => binary_xmlrpc( "" ), # optional
      'post_author_name' => binary_xmlrpc( "" ),
      # 'post_author_id' => 0, # required, Int (apparently), level 4
      # 'is_subscribed' => false, # optional
      # 'can_subscribe' => false, # optiona;
      # 'is_closed' => false, # optional
      # 'icon_url' => "" # optional
      # participated_uids # optional, level 4
      'post_time' => make_xmlrpc_datetime( discourse_topic['last_posted_at'] ),
      'reply_number' => discourse_topic['posts_count'].to_i, # reply_count ? 
      'new_post' => !!discourse_topic['unseen'],
      'view_number' => discourse_topic['views'].to_i,
      
      # 'short_content' => binary_xmlrpc( "" ) # api level 4, not provided by discourse in some calls
      
    }
    
    # Fill in some association-related data
    if extra[:categories] 
      category = extra[:categories].find {|hsh| hsh["id"] == discourse_topic["category_id"] } || {}
      result["forum_name"] = binary_xmlrpc( category.fetch( "name", "Uncategorised" ) )
    end
    
    if discourse_topic["posters"]
      orig_poster = discourse_topic["posters"].find {|hsh| hsh['description'].to_s =~ /Original Poster/i }
      
      result["post_author_id"] = orig_poster["user_id"] if orig_poster
      if extra[:users] && result["post_author_id"]
        user = extra[:users].find {|hsh| hsh["id"] == result["post_author_id"] }
        if user
          result["post_author_name"] = binary_xmlrpc( user["username"].to_s ) 
          result["icon_url"] = make_avatar_url( user["avatar_template"] )
        end
      end
      
    end

    # FIXME: how do these differ from post_author_name/id ? most recent / original?
    result['topic_author_name'] = result['post_author_name']
    result['topic_author_id'] = result['post_author_id'].to_s

    result['last_reply_time'] = result["post_time"]
    
    result
  end
  
  # Try to keep this instance around for as long as possible...
  # TODO: To keep it around, push into Rack::Session, or cookies? Some sort of
  # long-lived store. Can go away with process restarts, of course.
  def discourse( cookies = {} )
    @discourse ||= begin
      uri = settings.discourse_api
      uri = URI.parse(uri) unless uri.is_a?( URI::Generic )
      client = DiscourseApi::Client.new( uri.host, uri.port, uri.scheme )
      client.api_key = settings.discourse_api_key
      client.cookies = cookies
      client
    end
  end

  def respond_xmlrpc( rsp )
    XMLRPC::Marshal.dump_response( rsp )
  end
  
  ## http://tapatalk.com/api/api_section.php ##
 

  # First function called by tapatalk, apparently we should always return the
  # whole hash.
  def xmlrpc_get_config( name = nil )
    result = {
    
      # Uncontroversial
      "sys_version"            => "0.1", # For now
      "version"                => "dev", # For now
      "api_level"              => "3",   # Maybe?
      "is_open"                => true,  # Set to false to stop working
      "guest_okay"             => true,

      # These are optional, and assume 1 if missing
      "mark_read"              => "0",   # TODO
      "subscribe_forum"        => "0",   # TODO
      "announcement"           => "0",   # Probably?

      # These are optional, and assume 0 if missing
      # "delete_reason"          => "0", # TODO
      # "m_approve"            => "0", # TODO
      # "m_delete"             => "0", # TODO
      # "m_report"             => "0", # TODO
      # "guest_search"           => "0", # TODO
      # "guest_whosonline"       => "0", # TODO
      # "emoji"                  => "0", # Probably?
      # "support_md5"            => "0", # TODO
      # "support_sha1"           => "0", # TODO
      # "conversation"           => "0", # TODO
      # "advanced_delete"        => "0", # TODO
      # "get_activity"           => "0", # TODO
      # "prefix_edit"            => "0", # TODO
      # "anonymous_login"        => "0", # TODO
      # "search_user"            => "0", # TODO
      # "user_recommend"         => "0", # TODO

      # Other optional params
      "min_search_length"      => 3,   # Boring default
      "alert"                  => "0", # TODO
      "direct_unsubscribe"     => "0", # TODO
      # "push_type"              => "",  # TODO - HIGH PRIORITY
      # "ban_delete_type"        => "none", # TODO    

      "inappreg"               => "0", # TODO
      "inappsignin"            => "1",
      "ignore_user"            => "0",  # TODO
      
      # These are API level 4 items. Ignore for now.
      # "goto_post"              => false, # TODO
      # "goto_unread"            => false, # TODO
      # "mark_forum"             => "0",   # TODO
      # "no_refresh_on_post"     => "0",   # TODO
      # "get_latest_topic"       => "0",   # TODO
      # "get_id_by_url"          => "0",   # TODO
      # "anonymous"              => "0", # TODO
      # "searchid"               => "0", # TODO
      # "avatar"                 => "0", # TODO
      # "pm_load"                => "0", # TODO
      # "subscribe_load"         => "0", # TODO
      # "inbox_stat"             => "0", # TODO
      # "multi_quote"            => "0", # TODO
      # "default_smilies"        => "1", # Probably?
      # "can_unread"             => "0", # Probably
      # "get_forum"              => "1", # No sub-forums in discourse but it needs this anyway
      # "get_topic_status"       => "0", # TODO
      # "get_participated_forum" => "0", # TODO
      # "get_forum_status"       => "1", # TODO
      # "get_smilies"            => "0", # TODO
      # "advanced_online_users"  => "0", # TODO
      # "mark_pm_unread"         => "0", # Probably?
      # "advanced_search"        => "0", # TODO
      # "mass_subscribe"         => "0", # TODO
      # "user_id"                => "0", # TODO
      # "mark_topic_read"        => "0", # TODO
      # "first_unread"           => "0", # TODO

      # These are returned by some other forums but aren't documented
      "key" => settings.tapatalk_api_key, # tapatalk API key, at a guess?
      "push" => "0",    
      # "allow_moderate", 
      # "charset" => "ISO-8859-1", 
      "disable_bbcode" => "0",
      # "disable_subscribe_forum" => "0",
      # "forum_signature" => 1,
      # "get_online_users" => "1",
      
      # No idea what this does
      # "hide_forum_id" => "",

      # "reg_url" => "register.php",
      "sign_in" => "0", # what does this do?
      # "stats" =>  {"user"=>320812, "topic"=>233040, "post"=>2389071}
    }    
    respond_xmlrpc( result )
  end

  # TODO! Very important
  def xmlrpc_login( user = nil, pass = nil, anonymous = false, push = '1' )

    return respond_xmlrpc(
      'result' => false,
      'result_text' => binary_xmlrpc( 'Anonymous login not supported' )
    ) if anonymous
    
    # We need to send on the cookies we received from discourse, and ensure they're
    # passed in for future API requests
    
    # we need one of these to play with the session API
    if discourse.csrf_token.nil?
      discourse.csrf_token = discourse.session_csrf({}).fetch("csrf")
    end
    
    # We raise if session creation fails
    user_info = begin
      rsp = discourse.session_create( :login => user, :password => pass )
      return respond_xmlrpc( 'result' => false, 'result_text' => binary_xmlrpc( rsp['error'] ) ) if rsp['error']
      
      rsp
    rescue => err
      puts err.inspect
      puts err.backtrace.join("\n")
      return respond_xmlrpc( 'result' => false )
    end
    
    # We can just proxy the entire cookie over untouched
    headers "Set-Cookie" => discourse.last_response['Set-Cookie']
    
    # user = user_info.fetch("user")
    
    respond_xmlrpc(
      'result' => true,
      # 'user_id' => user["id"], # api level 4
      # 'username' => binary_xmlrpc( "username" ), # api level 4
      # 'usergroup_id' => [], # api level 4
      # 'email' => binary_xmlrpc( "" ) # api level 4 # not sent by discourse
      # 'icon_url' => make_avatar_url( user["avatar_template"] ), # api level 4
      # 'post_count' => , # api level 4 # discourse gives back stats with action_type and count members
      'can_pm' => false, # TODO!
      'can_send_pm' => false, # TODO! # can_send_private_message_to_user is always false...?
      'can_moderate' => false, # TODO! user["moderator"]
      # can_search => true, # api level 4
      # can_whosonline => true, # api level 4
      # can_profile => true, # api level 4
      'can_upload_avatar' => false, # TODO
      # push_type ...
    )
  end
  
  # also TODO
  def xmlrpc_logout_user
    discourse.session_destroy({})
    respond_xmlrpc( 'result' => true )
  end
  
  # Ignore forum_id for now. Naughty naughty.
  def xmlrpc_get_forum( return_description = nil, forum_id = nil)
   
    forum_info = discourse.categories({})
    category_list = forum_info.fetch( "category_list" )
    categories = category_list.fetch( "categories" )
    
    result = categories.collect {|hsh|
      tmp = { 
        'forum_id' => hsh['id'].to_s,
        'forum_name' => binary_xmlrpc( hsh['name'].to_s ), # FIXME: python encodes this to UTF8. Can't be nil
        'parent_id' => "-1", # no such thing as sub-categories in Discourse
        'sub_only' => false,
        # 'child' => [], # Don't return this if we have no children
        # 'is_protected' => false, # ?
        'is_subscribed' => false, # TODO
        'can_subscribe' => false, # TODO
        'can_post' => !!category_list["can_create_topic"] # FIXME: this may not be correct!
      }

      # FIXME: may not be right?
      # if return_description
      #   tmp['description'] = binary_xmlrpc( hsh['description'].to_s )
      # end
      
      tmp
    }

    respond_xmlrpc( result )
  end
  
  # FIXME: STUB.
  # In API level 4, we can say this doesn't exist and force tapatalk to use get_topic
  def xmlrpc_get_unread_topic( start_num = 0, last_num = 0, search_id = nil, filters = nil )
    result = {
      'result' => true,
      # optional
      # 'result_text' => binary_xmlrpc( '' ),
      # 'search_id' => '',
    }
    
    result['topics'] = [].collect {|hsh| build_tapatalk_topic( hsh ) }
    result['total_topic_num'] = result['topics'].count
    
    respond_xmlrpc( result )
  end
  
  def xmlrpc_get_latest_topic( start_num = 0, last_num = 0, search_id = nil, filters = nil )

    result = { 'result' => true }

    latest_topics = discourse.topics_latest({})
    topic_list = latest_topics.fetch( "topic_list" )
    topics = topic_list.fetch( "topics" )
    
    result['topics'] = topics.collect {|hsh|
      build_tapatalk_topic( hsh, :users => latest_topics["users"], :categories => latest_topics["categories"] )
    }
    result['total_topic_num'] = result['topics'].count # api level 4
    
    respond_xmlrpc( result )
  end
  
  def xmlrpc_get_topic( forum_id, start_num = 0, last_num = 0, mode = "DATE" )

    if forum_id == "0" # && %w|ANN TOP|.include?(mode)
      # In these cases, we're not interested in a particular forum
      # TODO! This is for announcements (mode = "ANN")! FIXME!
      # TODO: also for latest, like xmlrpc_get_latest_topic! FIXME!
      return respond_xmlrpc( 'result' => false )
    end
    
    # TODO: Need to respect pagination, restrict to just one category
    forum_info = discourse.category(:category_id => forum_id)
      
    categories = forum_info.fetch( "categories" )
    users = forum_info["users"]
    
    categories.each {|hsh| hsh["can_create_topic"] =  forum_info["topic_list"]["can_create_topic"] }
    
    category = categories.find {|hsh| hsh["id"].to_s == forum_id }

    # Null category to handle failure-to-find cases above
    category ||= {
      'topic_count' => 0,
      'id' => forum_id.to_i,
      "name" => "",
      'can_create_topic' => false,
      'topics' => []
    }
  
    result = {
      'total_topic_num' => category['topic_count'].to_i,
      'forum_id' => category['id'].to_s,
      'forum_name' => binary_xmlrpc( category['name'].to_s ),
      # 'unread_sticky_count' => 0, # TODO - api level 4
      # 'unread_announce_count' => 0,
      # 'can_subscribe' => false, # TODO - api level 4
      # 'is_subscribed' => false, # TODO - api level 4
      # 'require_prefix' => false, # TODO - api level 4
      'prefixes' => [], 
      'prefix_id' => "",
      'prefix_display_name' => binary_xmlrpc( "" ),
      'can_post' => !!category['can_create_topic'], # FIXME: may not be correct!
      'can_upload' => false,
      # 'require_prefix' => false, # api level 4
    }
    
    topic_list = forum_info.fetch( "topic_list" )
    
    result['topics'] = topic_list.fetch( "topics" ).collect {|hsh|
      build_tapatalk_topic( hsh, :users => users, :categories => categories )
    }
    
    respond_xmlrpc( result )
  end
  
 # def xmlrpc_get_id_by_url( url ) # TODO
 # end
  
  def xmlrpc_get_thread( topic_id, start_num = 0, end_num = 0, return_html = false )

    topic_info = discourse.topic(:topic_id => topic_id.to_i)
    post_stream = topic_info.fetch( "post_stream" )
    posts = post_stream.fetch( "posts" )
    
    result = {
      "forum_id" => topic_info["category_id"].to_s,
      "forum_name" => binary_xmlrpc( "Unknown" ), # FIXME: not returned in topic info, need to pull from cache with forum_id
      "forum_title" => binary_xmlrpc( "Unknown" ), # django insists it's called this
      "topic_id" => topic_info["id"].to_s,
      "topic_title" => binary_xmlrpc( topic_info["title"].to_s ),
      "prefix" => "",
      "is_subscribed" => false,
      "can_subscribe" => false,
      "can_reply" => true, # FIXME: ensure this is accurate
      "is_approved" => true, # FIXME: wat is das?
      "can_upload" => false,
      "is_poll" => false,
      "is_closed" => !!topic_info["closed"],
      "can_report" => false, # TODO
      "breadcrumb" => [], # TODO ?
    }

    result["posts"] = posts.collect {|hsh|
      { "post_id"          => hsh["id"].to_s,
        "post_title"       => binary_xmlrpc( hsh["user_title"].to_s  ),
        "post_content"     => binary_xmlrpc( format_post_content_for_xmlrpc( hsh["cooked"], return_html ) ),
        "forum_name"       => result["forum_name"], # django says we need this
        "forum_id"         => result["forum_id"],
        "post_author_id"   => hsh["user_id"].to_s,
        "post_author_name" => binary_xmlrpc( hsh["display_username"].to_s ), # FIXME: display username or real username?
        "is_online"        => !!hsh["yours"], # TODO: not included in discourse output?
        "can_edit"         => !!hsh["can_edit"], # TODO
        "is_approved"      => true, # django again
        "icon_url"         => make_avatar_url( hsh["avatar_template"] ), # TODO: this is a template, may need formatting
        "post_time"        => make_xmlrpc_datetime( hsh["updated_at"] ),
        "allow_smilies"    => true,
        "reply_number"     => hsh["post_number"].to_i,
        "view_count"       => hsh["reads"].to_i,
#        "attachments"      => [], # TODO!
#        "thanks_info"      => [], # TODO # Probably not needed anyway
#        "likes_info"       => [], # TODO!
      }
    }
    result["total_post_num"] = result["posts"].count.to_i
    
    respond_xmlrpc( result )
  end
  
 # def get_smilies # TODO - not a priority
 # end
  
end

post "/" do
  dispatch
end

post "/mobiquo/mobiquo.php" do
  dispatch
end