class ReportController < ApplicationController

  before_filter :admin_authorization, only: [:login_stat,:submission_stat]
  before_filter(only: [:problem_hof]) { |c|
    return false unless authenticate

    if GraderConfiguration["right.user_view_submission"]
      return true;
    end

    admin_authorization
  }

  def login_stat
    @logins = Array.new

    date_and_time = '%Y-%m-%d %H:%M'
    begin
      @since_time = DateTime.strptime(params[:since_datetime],date_and_time)
    rescue
      @since_time = DateTime.new(1000,1,1)
    end
    begin
      @until_time = DateTime.strptime(params[:until_datetime],date_and_time)
    rescue
      @until_time = DateTime.new(3000,1,1)
    end
    
    User.all.each do |user|
      @logins << { id: user.id,
                   login: user.login, 
                   full_name: user.full_name, 
                   count: Login.where("user_id = ? AND created_at >= ? AND created_at <= ?",
                                      user.id,@since_time,@until_time)
                          .count(:id),
                   min: Login.where("user_id = ? AND created_at >= ? AND created_at <= ?",
                                      user.id,@since_time,@until_time)
                          .minimum(:created_at),
                   max: Login.where("user_id = ? AND created_at >= ? AND created_at <= ?",
                                      user.id,@since_time,@until_time)
                          .maximum(:created_at)
                 }
    end
  end

  def submission_stat

    date_and_time = '%Y-%m-%d %H:%M'
    begin
      @since_time = DateTime.strptime(params[:since_datetime],date_and_time)
    rescue
      @since_time = DateTime.new(1000,1,1)
    end
    begin
      @until_time = DateTime.strptime(params[:until_datetime],date_and_time)
    rescue
      @until_time = DateTime.new(3000,1,1)
    end

    @submissions = {}

    User.find_each do |user|
      @submissions[user.id] = { login: user.login, full_name: user.full_name, count: 0, sub: { } }
    end

    Submission.where("submitted_at >= ? AND submitted_at <= ?",@since_time,@until_time).find_each do |s|
      if @submissions[s.user_id]
        if not @submissions[s.user_id][:sub].has_key?(s.problem_id)
          a = nil
          begin
            a = Problem.find(s.problem_id)
          rescue
            a = nil
          end
          @submissions[s.user_id][:sub][s.problem_id] = 
            { prob_name: (a ? a.full_name : '(NULL)'),
              sub_ids: [s.id] } 
        else
          @submissions[s.user_id][:sub][s.problem_id][:sub_ids] << s.id
        end
        @submissions[s.user_id][:count] += 1
      end
    end
  end

  def problem_hof
    # gen problem list
    @user = User.find(session[:user_id])
    @problems = @user.available_problems

    # get selected problems or the default
    if params[:id]
      begin
        @problem = Problem.available.find(params[:id])
      rescue
        redirect_to action: :problem_hof
        flash[:notice] = 'Error: submissions for that problem are not viewable.'
        return
      end
    end

    if @problem
      #aggregrate by language
      @by_lang = {}
      Submission.where(problem_id: @problem.id).find_each do |sub|
        lang = Language.find_by_id(sub.language_id)
        next unless lang
        next unless sub.points >= @problem.full_score

        #initialize
        unless @by_lang.has_key?(lang.pretty_name)
          @by_lang[lang.pretty_name] = {
            runtime: { avail: false, value: 2**30-1 },
            memory: { avail: false, value: 2**30-1 },
            length: { avail: false, value: 2**30-1 },
            first: { avail: false, value: DateTime.new(3000,1,1) }
          }
        end

        if sub.max_runtime and sub.max_runtime < @by_lang[lang.pretty_name][:runtime][:value]
          @by_lang[lang.pretty_name][:runtime] = {
            avail: true,
            user_id: sub.user_id,
            value: sub.max_runtime,
            sub_id: sub.id
          }
        end

        if sub.peak_memory and sub.peak_memory < @by_lang[lang.pretty_name][:memory][:value]
          @by_lang[lang.pretty_name][:memory] = {
            avail: true,
            user_id: sub.user_id,
            value: sub.peak_memory,
            sub_id: sub.id
          }
        end

        if sub.submitted_at and sub.submitted_at < @by_lang[lang.pretty_name][:first][:value] and
           !sub.user.admin?
          @by_lang[lang.pretty_name][:first] = {
            avail: true,
            user_id: sub.user_id,
            value: sub.submitted_at,
            sub_id: sub.id
          }
        end

        if @by_lang[lang.pretty_name][:length][:value] > sub.effective_code_length
          @by_lang[lang.pretty_name][:length] = {
            avail: true,
            user_id: sub.user_id,
            value: sub.effective_code_length,
            sub_id: sub.id
          }
        end
      end
      
      #process user_id
      @by_lang.each do |lang,prop|
        prop.each do |k,v|
          v[:user] = User.exists?(v[:user_id]) ? User.find(v[:user_id]).full_name : "(NULL)"
        end
      end

      #sum into best
      if @by_lang and @by_lang.first
        @best = @by_lang.first[1]
        @by_lang.each do |lang,prop|
          if @best[:runtime][:value] >= prop[:runtime][:value]
            @best[:runtime] = prop[:runtime]
            @best[:runtime][:lang] = lang
          end
          if @best[:memory][:value] >= prop[:memory][:value]
            @best[:memory] = prop[:memory]
            @best[:memory][:lang] = lang
          end
          if @best[:length][:value] >= prop[:length][:value]
            @best[:length] = prop[:length]
            @best[:length][:lang] = lang
          end
          if @best[:first][:value] >= prop[:first][:value]
            @best[:first] = prop[:first]
            @best[:first][:lang] = lang
          end
        end
      end
    end
  end
end