require 'open3'

module DPL
  class Provider
    class Snap < Provider
      # Support installing snaps
      def self.snap(name, command = name, classic: false, channel: nil)
        install_command = "sudo snap install #{name}"

        if classic
          install_command += " --classic"
        end

        unless channel.nil?
          install_command += " --channel=#{channel}"
        end

        context.shell(install_command, retry: true) if `which #{command}`.chop.empty?
      end

      apt_get 'snapd', 'snap'
      snap 'snapcraft', classic: true

      def install_deploy_dependencies
        # Snapcraft may already be installed, but in case we installed
        # the snap, we need to add /snap/bin to the PATH.
        ENV["PATH"] += ':/snap/bin'
      end

      def check_auth
        log "Attemping to login"
        stdout, stderr, status = Open3.capture3(
          "snapcraft login --with -", stdin_data: login_token)

        if status == 0
          log stdout
        else
          error "Failed to authenticate: #{stderr}"
        end
      end

      # No SSH keys needed
      def needs_key?
        false
      end

      # Users must specify the path to the snap they want pushed (globbing is
      # supported).
      def snap
        option(:snap)
      end

      # Users can specify the channel into which they'd like to release this
      # snap. It defaults to the 'edge' channel.
      def channel
        options.fetch(:channel, 'edge')
      end

      # Users must specify their login token, either explicitly in the YAML or
      # via the $SNAP_TOKEN enironment variable.
      def login_token
        options[:token] || context.env['SNAP_TOKEN'] || error("Missing token")
      end

      def push_app
        snaps = Dir.glob(snap)
        case snaps.length
        when 0
          error "No snap found matching '#{snap}'"
        when 1
          snap_path = snaps.first
          context.fold("Pushing snap") do
            context.shell "snapcraft push #{snap_path} --release=#{channel}"
          end
        else
          snap_list = snaps.join(', ')
          error "Multiple snaps found matching '#{snap}': #{snap_list}"
        end
      end
    end
  end
end