namespace :load do
  task :defaults do
    set :nginx_sudo_paths,          -> { [:nginx_log_path, :nginx_sites_enabled_dir, :nginx_sites_available_dir] }
    set :nginx_sudo_tasks,          -> { ['nginx:start', 'nginx:stop', 'nginx:restart', 'nginx:reload', 'nginx:configtest', 'nginx:site:add', 'nginx:site:disable', 'nginx:site:enable', 'nginx:site:remove' ] }
    set :nginx_log_path,            -> { "#{shared_path}/log" }
    set :nginx_service_path,        -> { 'service nginx' }
    set :nginx_static_dir,          -> { "public" }
    set :nginx_application_name,    -> { fetch(:application) }
    set :nginx_sites_enabled_dir,   -> { "/etc/nginx/sites-enabled" }
    set :nginx_sites_available_dir, -> { "/etc/nginx/sites-available" }
    set :nginx_roles,               -> { :web }
    set :nginx_template,            -> { :default }
    set :nginx_use_ssl,             -> { false }
    set :nginx_ssl_certificate,          -> { "#{fetch(:application)}.crt" }
    set :nginx_ssl_certificate_path,     -> { '/etc/ssl/certs' }
    set :nginx_ssl_certificate_key,      -> { "#{fetch(:application)}.key" }
    set :nginx_ssl_certificate_key_path, -> { '/etc/ssl/private' }
    set :app_server,                     -> { true }
  end
end

namespace :nginx do

  # prepend :sudo to list if arguments if :key is in :nginx_use_sudo_for list
  def add_sudo_if_required argument_list, *keys
    keys.each do | key |
      if use_sudo? key
        argument_list.unshift(:sudo)
        break
      end
    end
  end

  def use_sudo? key
    return (fetch(:nginx_sudo_tasks).include?(key) || fetch(:nginx_sudo_paths).include?(key))
  end

  def valid_nginx_config?
    test_sudo = use_sudo?('nginx:configtest') ? 'sudo ' : ''
    nginx_service = fetch(:nginx_service_path)
    test "[ $(#{test_sudo}#{nginx_service} configtest | grep -c 'fail') -eq 0 ]"
  end

  task :load_vars do
    set :sites_available,       -> { fetch(:nginx_sites_available_dir) }
    set :sites_enabled,         -> { fetch(:nginx_sites_enabled_dir) }
    set :enabled_application,   -> { File.join(fetch(:sites_enabled),   fetch(:nginx_application_name)) }
    set :available_application, -> { File.join(fetch(:sites_available), fetch(:nginx_application_name)) }
  end

  # validate_sudo_settings
  task :validate_user_settings do
    path_and_dir_keys = [:nginx_log_path, :nginx_sites_enabled_dir, :nginx_sites_available_dir]
    nginx_task_keys   = ['nginx:start', 'nginx:stop', 'nginx:restart', 'nginx:reload', 'nginx:configtest', 'nginx:site:add', 'nginx:site:disable', 'nginx:site:enable', 'nginx:site:remove' ]

    fetch(:nginx_sudo_paths).each do | path |
      abort("Invalid value in :nginx_sudo_paths, Unknown symbol '#{path}'") unless path_and_dir_keys.include? path
    end
    fetch(:nginx_sudo_tasks).each do | task |
      abort("Invalid symbol in :nginx_tasks! Unknown symbol '#{task}'") unless nginx_task_keys.include? task
    end
  end

  desc "Configtest nginx service"
  task :configtest do
    on release_roles fetch(:nginx_roles) do
      abort("nginx configuration is invalid! (Make sure nginx configuration files are readable and correctly formated.)") unless valid_nginx_config?
    end
  end

  %w[start stop restart reload].each do |command|
    desc "#{command.capitalize} nginx service"
    task command => ['nginx:validate_user_settings'] do
      on release_roles fetch(:nginx_roles) do
        arguments = fetch(:nginx_service_path), command
        add_sudo_if_required arguments, "nginx:#{command}"
        execute *arguments
      end
    end
    before "nginx:#{command}", 'nginx:configtest' unless command == 'stop'
  end

  task :create_log_paths do
    on release_roles fetch(:nginx_roles) do
      arguments = :mkdir, '-pv', fetch(:nginx_log_path)
      add_sudo_if_required arguments, :nginx_log_path
      execute *arguments
    end
  end
  after 'deploy:check', 'nginx:create_log_paths'

  desc 'Compress JS and CSS with gzip'
  task :gzip_static => ['nginx:load_vars'] do
    on release_roles fetch(:nginx_roles) do
      within release_path do
        execute :find, "'#{fetch(:nginx_static_dir)}' -type f -name '*.js' -o -name '*.css' -exec gzip -v -9 -f -k {} \\;"
      end
    end
  end

  namespace :site do
    desc 'Creates the site configuration and upload it to the available folder'
    task :add => ['nginx:load_vars', 'nginx:validate_user_settings'] do
      on release_roles fetch(:nginx_roles) do
        within fetch(:sites_available) do
          config_file = fetch(:nginx_template)
          if config_file == :default
              config_file = File.expand_path('../../../../templates/nginx.conf.erb', __FILE__)
          end
          config = ERB.new(File.read(config_file)).result(binding)
          upload! StringIO.new(config), '/tmp/nginx.conf'
          arguments = :mv, '/tmp/nginx.conf', fetch(:nginx_application_name)
          add_sudo_if_required arguments, 'nginx:sites:add', :nginx_sites_available_dir
          execute *arguments
        end
      end
    end

    desc 'Enables the site creating a symbolic link into the enabled folder'
    task :enable => ['nginx:load_vars', 'nginx:validate_user_settings'] do
      on release_roles fetch(:nginx_roles) do
        if test "! [ -h #{fetch(:enabled_application)} ]"
          within fetch(:sites_enabled) do
            arguments = :ln, '-nfs', fetch(:available_application), fetch(:enabled_application)
            add_sudo_if_required arguments, 'nginx:sites:enable', :nginx_sites_enabled_dir
            execute *arguments
          end
        end
      end
    end

    desc 'Disables the site removing the symbolic link located in the enabled folder'
    task :disable => ['nginx:load_vars', 'nginx:validate_user_settings'] do
      on release_roles fetch(:nginx_roles) do
        if test "[ -f #{fetch(:enabled_application)} ]"
          within fetch(:sites_enabled) do
            arguments = :rm, '-f', fetch(:nginx_application_name)
            add_sudo_if_required arguments, 'nginx:sites:disable', :nginx_sites_enabled_dir
            execute *arguments
          end
        end
      end
    end

    desc 'Removes the site by removing the configuration file from the available folder'
    task :remove => ['nginx:load_vars', 'nginx:validate_user_settings'] do
      on release_roles fetch(:nginx_roles) do
        if test "[ -f #{fetch(:available_application)} ]"
          within fetch(:sites_available) do
            arguments = :rm, fetch(:nginx_application_name)
            add_sudo_if_required arguments, 'nginx:sites:remove', :nginx_sites_available_dir
            execute *arguments
          end
        end
      end
    end
  end
end