module HelixVersioningEngine
  # 'counters' operations.
  #
  # The 'counter' resource is really just a key-value instance. We open up
  # the counters table to allow applications to basically use them for various
  # locking and unlocking operations.
  class App < Sinatra::Base
    # List all counters in the system
    #
    # Optional URL parameters:
    #
    # - `nameFilter` (-e)
    # - `max` (-m)
    # - `sideTable` (-u) UNDOCUMENTED
    #
    get '/p4/:api/counters' do |_|
      nameFilter = params['nameFilter'] if params.key?('nameFilter')
      max = params['max'] if params.key?('max')
      sideTable = true if params.key?('sideTable')

      require_p4
      p4 = env['p4']

      cmd = ["counters"]
      cmd.push('-e', nameFilter) if nameFilter
      cmd.push('-m', max) if max
      cmd.push('-u') if sideTable

      counters = p4.run(*cmd)

      counters = [] unless counters

      # I've noticed invalid UTF-8 characters coming from server keys on
      # non-unicode servers. Try to force the UTF-8 encoding, and replace
      # illegal characters.
      begin
        counters.to_json
      rescue JSON::GeneratorError
        converted = counters.map do |h|
          Hash[h.map do |key, value|
                 [key, value.encode('UTF-8', 'UTF-8', invalid: :replace, undef: :replace, replace: '?')]
               end]
        end
        converted.to_json
      end
    end

    get '/p4/:api/counters/:counter' do |_, counter|
      require_p4
      p4 = env['p4']

      results = p4.run_counter(counter)

      # If the counter doesn't exist, you just get a counter result with the
      # value 0
      results.first.to_json
    end

    put '/p4/:api/counters/:counter' do |_, counter|
      require_p4
      p4 = env['p4']

      results = p4.run_counter('-f', counter, params['value'])

      results.nil? ? '' : results.to_json
    end

    delete '/p4/:api/counters/:counter' do |_, counter|
      require_p4
      p4 = env['p4']

      r = p4.run_counter('-f', '-d', counter)

      r.nil? ? '' : r.to_json
    end

    post '/p4/:api/counters/:counter/increment' do |_, counter|
      require_p4
      p4 = env['p4']

      results = p4.run_counter('-f', '-i', counter)

      results.nil? ? '' : results.to_json
    end
  end
end