module EyeManager

# File lib/eyemanager.rb, line 24
def destroy
  cmd = "eye q -s"
  output = `#{cmd}`
  raise "Eye destroy failed. " +
            "Command: #{cmd}. Output: #{output}." unless
      /^Eye quit|socket\(.+\) not found/.match(output)
end

# File lib/eyemanager.rb, line 32
def list_apps
  eye_status_apps_filtered_by.map{|a| a['name']}
end

# File lib/eyemanager.rb, line 8
def start params={}
  validate_start_params params
  load_config_and_verify params[:config] if params[:config]
  start_and_verify params[:application]
end

# File lib/eyemanager.rb, line 19
def status params={}
  validate_status_params params
  eye_status_filtered_by params
end

# File lib/eyemanager.rb, line 14
def stop params={}
  validate_stop_params params
  stop_and_verify params
end

# File lib/eyemanager.rb, line 77
def build_eye_process_key_with params={}
  "#{params[:application]}:" +
      "#{(params[:group] ? "#{params[:group]}:" : "")}" +
      "#{params[:process]}"
end

# File lib/eyemanager.rb, line 98
def eye_status_apps_filtered_by app=nil
  status_apps = JSON.parse(`eye i -j`)['subtree']
  app.to_s.length > 0 ?
      status_apps
          .select{|a| a["name"] == "#{app}" &&
          a["type"] == "application"} :
      status_apps
rescue JSON::ParserError => e
      []
end

# File lib/eyemanager.rb, line 83
def eye_status_filtered_by params={}
  process_status = 'unknown'
  eye_status_apps_filtered_by(params[:application]).each do |app|
    eye_status_groups_filtered_by(params[:group], app["subtree"])
        .each do |group|
      process_status = eye_status_process_status_filtered_by(
          params[:process], group["subtree"])
      break unless process_status == 'unknown'
    end
  end
  process_status
rescue JSON::ParserError => e
  'unknown'
end

# File lib/eyemanager.rb, line 109
def eye_status_groups_filtered_by group, app_groups
  the_group = group.to_s.length > 0 ? group : '__default__'
  app_groups.select{|grp| grp["name"] == "#{the_group}" &&
      grp["type"] == "group"}
end

# File lib/eyemanager.rb, line 115
def eye_status_process_status_filtered_by process, group_processes
  the_process =
      group_processes.select{|prc| prc["name"] == "#{process}" &&
          prc["type"] == "process"}
  the_process[0] && the_process[0]["state"] ?
      the_process[0]["state"] : 'unknown'
end

# File lib/eyemanager.rb, line 51
def load_config_and_verify config
  cmd = "eye load #{config}"
  output = `#{cmd}`
  raise EyeLoadFailed,
        "Eye load failed to load config. " +
            "Command: #{cmd}. Output: #{output}." unless
      /Config loaded/.match(output)
end

# File lib/eyemanager.rb, line 60
def start_and_verify application
  cmd = "eye start #{application}"
  output = `#{cmd}`
  raise "Eye start failed. " +
            "Command: #{cmd}. Output: #{output}." unless
      /command :start sent to \[#{Regexp.escape(application)}\]/.match(output)
end

# File lib/eyemanager.rb, line 68
def stop_and_verify params
  eye_process_key = build_eye_process_key_with(params)
  cmd = "eye stop #{eye_process_key}"
  output = `#{cmd}`
  raise "Eye stop failed. " +
            "Command: #{cmd}. Output: #{output}." unless
      /command :stop sent to \[#{Regexp.escape(eye_process_key)}\]/.match(output)
end

# File lib/eyemanager.rb, line 38
def validate_start_params params={}
  raise ":application is required" unless params[:application]
end

# File lib/eyemanager.rb, line 47
def validate_status_params params={}
  raise ":process is required" unless params[:process]
end

# File lib/eyemanager.rb, line 42
def validate_stop_params params={}
  raise ":application is required" unless params[:application]
  raise ":process is required" unless params[:process]
end