require "./funko.cr"
require "commander"
require "docr"
require "docr/utils.cr"
require "file_utils"
require "uuid"

# Functions as a Service, Ops!
module Faaso
  VERSION = "0.1.0"

  # Ensure the faaso-net network exists
  def self.setup_network
    docker_api = Docr::API.new(Docr::Client.new)
    docker_api.networks.create(Docr::Types::NetworkConfig.new(
      name: "faaso-net",
      check_duplicate: false,
      driver: "bridge"
    ))
  rescue ex : Docr::Errors::DockerAPIError
    raise ex if ex.status_code != 409 # Network already exists

  end

  module Commands
    class Build
      @arguments : Array(String) = [] of String
      @options : Commander::Options

      def initialize(options, arguments)
        @options = options
        @arguments = arguments
      end

      def run
        funkos = Funko.from_paths(@arguments)
        funkos.each do |funko|
          # Create temporary build location
          tmp_dir = Path.new("tmp", UUID.random.to_s)
          Dir.mkdir_p(tmp_dir) unless File.exists? tmp_dir

          # Copy runtime if requested
          if !funko.runtime.nil?
            runtime_dir = Path.new("runtimes", funko.runtime.to_s)
            if !File.exists? runtime_dir
              puts "Error: runtime #{funko.runtime} not found"
              next
            end
            Dir.glob("#{runtime_dir}/*").each { |src|
              FileUtils.cp_r(src, tmp_dir)
            }
          end

          # Copy funko
          if funko.path.empty?
            puts "Internal error: empty funko path for #{funko.name}"
            next
          end
          Dir.glob("#{funko.path}/*").each { |src|
            FileUtils.cp_r(src, tmp_dir)
          }

          puts "Building function... #{funko.name} in #{tmp_dir}"

          docker_api = Docr::API.new(Docr::Client.new)
          docker_api.images.build(
            context: tmp_dir.to_s,
            tags: ["#{funko.name}:latest"]) { }
        end
      end
    end

    class Up
      @arguments : Array(String) = [] of String
      @options : Commander::Options

      def initialize(options, arguments)
        @options = options
        @arguments = arguments
      end

      def run
        funkos = Funko.from_paths(@arguments)
        funkos.each do |funko|
          container_name = "faaso-#{funko.name}"
          docker_api = Docr::API.new(Docr::Client.new)
          # Pull image from registry
          # docker_api.images.create(image: tag)

          # Get image history, sorted newer image first
          begin
            images = docker_api.images.history(
              name: funko.name
            ).sort { |a, b| b.@created <=> a.@created }.map(&.@id)
          rescue ex : Docr::Errors::DockerAPIError
            puts "Error: no images available for #{funko.name}:latest"
            puts ex
            next
          end

          latest_image = images[0]

          # Filter by name so only faaso-thisfunko are affected from now on
          # sorted newer image first
          containers = docker_api.containers.list(
            all: true,
            filters: {"name" => [container_name]}
          ).sort { |a, b| (images.index(b.@image_id) || 9999) <=> (images.index(a.@image_id) || 9999) }

          # If it's already up, do nothing
          if containers.any? { |container|
               is_running = container.@state == "running"
               is_old = container.@image_id != latest_image
               p! container.@image_id
               puts "Warning: running outdated version" if is_running && is_old
               is_running
             }
            puts "#{funko.name} is already up"
            next
          end

          # If it is paused, unpause it
          paused = containers.select { |container|
            container.@state == "paused"
          }
          if paused.size > 0
            puts "Resuming existing paused container"
            docker_api.containers.unpause(paused[0].@id)
            next
          end

          # If it is exited, start it
          existing = containers.select { |container|
            container.@state == "exited"
          }

          puts "Starting function #{funko.name}"
          if existing.size > 0
            puts "Restarting existing exited container"
            docker_api.containers.start(existing[0].@id)
            next
          end

          # Deploy from scratch
          Faaso.setup_network # We need it
          puts "Creating new container"
          conf = Docr::Types::CreateContainerConfig.new(
            image: "#{funko.name}:latest",
            hostname: funko.name,
            # Port in the container side
            exposed_ports: {"#{funko.port}/tcp" => {} of String => String},
            host_config: Docr::Types::HostConfig.new(
              network_mode: "faaso-net",
              port_bindings: {"#{funko.port}/tcp" => [Docr::Types::PortBinding.new(
                host_port: "",        # Host port, empty means random
                host_ip: "127.0.0.1", # Host IP
              )]}
            )
          )

          response = docker_api.containers.create(name: container_name, config: conf)
          response.@warnings.each { |msg| puts "Warning: #{msg}" }
          docker_api.containers.start(response.@id)
          containers = docker_api.containers.list(
            all: true,
            filters: {"name" => [container_name]}
          )

          (1..5).each { |_|
            break if containers[0].state == "running"
            sleep 0.1.seconds
          }
          if containers[0].state != "running"
            puts "Container for #{funko.name} is not running yet"
            next
          end
          puts "Container for #{funko.name} is running"
        end
        # TODO: Run test for healthcheck
        # TODO: Return function URL for testing
      end
    end

    class Down
      @arguments : Array(String) = [] of String
      @options : Commander::Options

      def initialize(options, arguments)
        @options = options
        @arguments = arguments
      end

      def run
        @arguments.each do |arg|
          puts "Stopping function... #{arg}"
          # TODO: check if function is running
          # TODO: stop function container
          # TODO: delete function container
          # TODO: remove route from reverse proxy
        end
      end
    end

    class Deploy
      @arguments : Array(String) = [] of String
      @options : Commander::Options

      def initialize(options, arguments)
        @options = options
        @arguments = arguments
      end

      def run
        @arguments.each do |arg|
          puts "Stopping function... #{arg}"
          # TODO: Everything
        end
      end
    end
  end
end