# frozen_string_literal: true

require 'uri'
require 'socket'

require 'puma/const'
require 'puma/util'
require 'puma/minissl/context_builder'

module Puma
  class Binder
    include Puma::Const

    RACK_VERSION = [1,6].freeze

    def initialize(events)
      @events = events
      @listeners = []
      @inherited_fds = {}
      @activated_sockets = {}
      @unix_paths = []

      @proto_env = {
        "rack.version".freeze => RACK_VERSION,
        "rack.errors".freeze => events.stderr,
        "rack.multithread".freeze => true,
        "rack.multiprocess".freeze => false,
        "rack.run_once".freeze => false,
        "SCRIPT_NAME".freeze => ENV['SCRIPT_NAME'] || "",

        # I'd like to set a default CONTENT_TYPE here but some things
        # depend on their not being a default set and inferring
        # it from the content. And so if i set it here, it won't
        # infer properly.

        "QUERY_STRING".freeze => "",
        SERVER_PROTOCOL => HTTP_11,
        SERVER_SOFTWARE => PUMA_SERVER_STRING,
        GATEWAY_INTERFACE => CGI_VER
      }

      @envs = {}
      @ios = []
    end

    attr_reader :ios, :listeners, :unix_paths, :proto_env, :envs, :activated_sockets, :inherited_fds
    attr_writer :ios, :listeners

    def env(sock)
      @envs.fetch(sock, @proto_env)
    end

    def close
      @ios.each { |i| i.close }
    end

    def connected_ports
      ios.map { |io| io.addr[1] }.uniq
    end

    def create_inherited_fds(env_hash)
      env_hash.select {|k,v| k =~ /PUMA_INHERIT_\d+/}.each do |_k, v|
        fd, url = v.split(":", 2)
        @inherited_fds[url] = fd.to_i
      end.keys # pass keys back for removal
    end

    # systemd socket activation.
    # LISTEN_FDS = number of listening sockets. e.g. 2 means accept on 2 sockets w/descriptors 3 and 4.
    # LISTEN_PID = PID of the service process, aka us
    # see https://www.freedesktop.org/software/systemd/man/systemd-socket-activate.html
    def create_activated_fds(env_hash)
      return [] unless env_hash['LISTEN_FDS'] && env_hash['LISTEN_PID'].to_i == $$
      env_hash['LISTEN_FDS'].to_i.times do |index|
        sock = TCPServer.for_fd(socket_activation_fd(index))
        key = begin # Try to parse as a path
          [:unix, Socket.unpack_sockaddr_un(sock.getsockname)]
        rescue ArgumentError # Try to parse as a port/ip
          port, addr = Socket.unpack_sockaddr_in(sock.getsockname)
          addr = "[#{addr}]" if addr =~ /\:/
          [:tcp, addr, port]
        end
        @activated_sockets[key] = sock
        @events.debug "Registered #{key.join ':'} for activation from LISTEN_FDS"
      end
      ["LISTEN_FDS", "LISTEN_PID"] # Signal to remove these keys from ENV
    end

    def parse(binds, logger, log_msg = 'Listening')
      binds.each do |str|
        uri = URI.parse str
        case uri.scheme
        when "tcp"
          if fd = @inherited_fds.delete(str)
            io = inherit_tcp_listener uri.host, uri.port, fd
            logger.log "* Inherited #{str}"
          elsif sock = @activated_sockets.delete([ :tcp, uri.host, uri.port ])
            io = inherit_tcp_listener uri.host, uri.port, sock
            logger.log "* Activated #{str}"
          else
            params = Util.parse_query uri.query

            opt = params.key?('low_latency')
            bak = params.fetch('backlog', 1024).to_i

            io = add_tcp_listener uri.host, uri.port, opt, bak

            @ios.each do |i|
              next unless TCPServer === i
              addr = if i.local_address.ipv6?
                "[#{i.local_address.ip_unpack[0]}]:#{i.local_address.ip_unpack[1]}"
              else
                i.local_address.ip_unpack.join(':')
              end

              logger.log "* #{log_msg} on tcp://#{addr}"
            end
          end

          @listeners << [str, io] if io
        when "unix"
          path = "#{uri.host}#{uri.path}".gsub("%20", " ")

          if fd = @inherited_fds.delete(str)
            io = inherit_unix_listener path, fd
            logger.log "* Inherited #{str}"
          elsif sock = @activated_sockets.delete([ :unix, path ])
            io = inherit_unix_listener path, sock
            logger.log "* Activated #{str}"
          else
            umask = nil
            mode = nil
            backlog = 1024

            if uri.query
              params = Util.parse_query uri.query
              if u = params['umask']
                # Use Integer() to respect the 0 prefix as octal
                umask = Integer(u)
              end

              if u = params['mode']
                mode = Integer('0'+u)
              end

              if u = params['backlog']
                backlog = Integer(u)
              end
            end

            io = add_unix_listener path, umask, mode, backlog
            logger.log "* #{log_msg} on #{str}"
          end

          @listeners << [str, io]
        when "ssl"
          params = Util.parse_query uri.query
          ctx = MiniSSL::ContextBuilder.new(params, @events).context

          if fd = @inherited_fds.delete(str)
            logger.log "* Inherited #{str}"
            io = inherit_ssl_listener fd, ctx
          elsif sock = @activated_sockets.delete([ :tcp, uri.host, uri.port ])
            io = inherit_ssl_listener sock, ctx
            logger.log "* Activated #{str}"
          else
            io = add_ssl_listener uri.host, uri.port, ctx
            logger.log "* Listening on #{str}"
          end

          @listeners << [str, io] if io
        else
          logger.error "Invalid URI: #{str}"
        end
      end

      # If we inherited fds but didn't use them (because of a
      # configuration change), then be sure to close them.
      @inherited_fds.each do |str, fd|
        logger.log "* Closing unused inherited connection: #{str}"

        begin
          IO.for_fd(fd).close
        rescue SystemCallError
        end

        # We have to unlink a unix socket path that's not being used
        uri = URI.parse str
        if uri.scheme == "unix"
          path = "#{uri.host}#{uri.path}"
          File.unlink path
        end
      end

      # Also close any unused activated sockets
      @activated_sockets.each do |key, sock|
        logger.log "* Closing unused activated socket: #{key.join ':'}"
        begin
          sock.close
        rescue SystemCallError
        end
        # We have to unlink a unix socket path that's not being used
        File.unlink key[1] if key[0] == :unix
      end
    end

    # Tell the server to listen on host +host+, port +port+.
    # If +optimize_for_latency+ is true (the default) then clients connecting
    # will be optimized for latency over throughput.
    #
    # +backlog+ indicates how many unaccepted connections the kernel should
    # allow to accumulate before returning connection refused.
    #
    def add_tcp_listener(host, port, optimize_for_latency=true, backlog=1024)
      if host == "localhost"
        loopback_addresses.each do |addr|
          add_tcp_listener addr, port, optimize_for_latency, backlog
        end
        return
      end

      host = host[1..-2] if host and host[0..0] == '['
      tcp_server = TCPServer.new(host, port)
      if optimize_for_latency
        tcp_server.setsockopt(Socket::IPPROTO_TCP, Socket::TCP_NODELAY, 1)
      end
      tcp_server.setsockopt(Socket::SOL_SOCKET,Socket::SO_REUSEADDR, true)
      tcp_server.listen backlog

      @ios << tcp_server
      tcp_server
    end

    def inherit_tcp_listener(host, port, fd)
      if fd.kind_of? TCPServer
        s = fd
      else
        s = TCPServer.for_fd(fd)
      end

      @ios << s
      s
    end

    def add_ssl_listener(host, port, ctx,
                         optimize_for_latency=true, backlog=1024)
      require 'puma/minissl'

      MiniSSL.check

      if host == "localhost"
        loopback_addresses.each do |addr|
          add_ssl_listener addr, port, ctx, optimize_for_latency, backlog
        end
        return
      end

      host = host[1..-2] if host[0..0] == '['
      s = TCPServer.new(host, port)
      if optimize_for_latency
        s.setsockopt(Socket::IPPROTO_TCP, Socket::TCP_NODELAY, 1)
      end
      s.setsockopt(Socket::SOL_SOCKET,Socket::SO_REUSEADDR, true)
      s.listen backlog


      ssl = MiniSSL::Server.new s, ctx
      env = @proto_env.dup
      env[HTTPS_KEY] = HTTPS
      @envs[ssl] = env

      @ios << ssl
      s
    end

    def inherit_ssl_listener(fd, ctx)
      require 'puma/minissl'
      MiniSSL.check

      if fd.kind_of? TCPServer
        s = fd
      else
        s = TCPServer.for_fd(fd)
      end
      ssl = MiniSSL::Server.new(s, ctx)

      env = @proto_env.dup
      env[HTTPS_KEY] = HTTPS
      @envs[ssl] = env

      @ios << ssl

      s
    end

    # Tell the server to listen on +path+ as a UNIX domain socket.
    #
    def add_unix_listener(path, umask=nil, mode=nil, backlog=1024)
      @unix_paths << path unless File.exist? path

      # Let anyone connect by default
      umask ||= 0

      begin
        old_mask = File.umask(umask)

        if File.exist? path
          begin
            old = UNIXSocket.new path
          rescue SystemCallError, IOError
            File.unlink path
          else
            old.close
            raise "There is already a server bound to: #{path}"
          end
        end

        s = UNIXServer.new(path)
        s.listen backlog
        @ios << s
      ensure
        File.umask old_mask
      end

      if mode
        File.chmod mode, path
      end

      env = @proto_env.dup
      env[REMOTE_ADDR] = "127.0.0.1"
      @envs[s] = env

      s
    end

    def inherit_unix_listener(path, fd)
      @unix_paths << path unless File.exist? path

      if fd.kind_of? TCPServer
        s = fd
      else
        s = UNIXServer.for_fd fd
      end
      @ios << s

      env = @proto_env.dup
      env[REMOTE_ADDR] = "127.0.0.1"
      @envs[s] = env

      s
    end

    def close_listeners
      listeners.each do |l, io|
        io.close unless io.closed? # Ruby 2.2 issue
        uri = URI.parse(l)
        next unless uri.scheme == 'unix'
        unix_path = "#{uri.host}#{uri.path}"
        File.unlink unix_path if unix_paths.include? unix_path
      end
    end

    def redirects_for_restart
      redirects = listeners.map { |a| [a[1].to_i, a[1].to_i] }.to_h
      redirects[:close_others] = true
      redirects
    end

    def redirects_for_restart_env
      listeners.each_with_object({}).with_index do |(listen, memo), i|
        memo["PUMA_INHERIT_#{i}"] = "#{listen[1].to_i}:#{listen[0]}"
      end
    end

    private

    def loopback_addresses
      Socket.ip_address_list.select do |addrinfo|
        addrinfo.ipv6_loopback? || addrinfo.ipv4_loopback?
      end.map { |addrinfo| addrinfo.ip_address }.uniq
    end

    def socket_activation_fd(int)
      int + 3 # 3 is the magic number you add to follow the SA protocol
    end
  end
end