#
# Author:: Adam Jacob (<adam@opscode.com>)
# Copyright:: Copyright (c) 2008 Opscode, Inc.
# License:: Apache License, Version 2.0
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

require 'chef/config'
require 'chef/log'
require 'chef/mixin/params_validate'

# Actually, this file depends on nearly every provider in chef, but actually
# requiring them causes circular requires resulting in uninitialized constant
# errors.
require 'chef/provider'
require 'chef/provider/log'
require 'chef/provider/user'
require 'chef/provider/group'
require 'chef/provider/mount'
require 'chef/provider/service'
require 'chef/provider/package'


class Chef
  class Platform

    class << self
      attr_writer :platforms

      def platforms
        @platforms ||= {
          :mac_os_x => {
            :default => {
              :package => Chef::Provider::Package::Macports,
              :user => Chef::Provider::User::Dscl,
              :group => Chef::Provider::Group::Dscl
            }
          },
          :freebsd => {
            :default => {
              :group   => Chef::Provider::Group::Pw,
              :package => Chef::Provider::Package::Freebsd,
              :service => Chef::Provider::Service::Freebsd,
              :user    => Chef::Provider::User::Pw,
              :cron    => Chef::Provider::Cron
            }
          },
          :ubuntu   => {
            :default => {
              :package => Chef::Provider::Package::Apt,
              :service => Chef::Provider::Service::Debian,
              :cron => Chef::Provider::Cron,
              :mdadm => Chef::Provider::Mdadm
            }
          },
          :debian => {
            :default => {
              :package => Chef::Provider::Package::Apt,
              :service => Chef::Provider::Service::Debian,
              :cron => Chef::Provider::Cron,
              :mdadm => Chef::Provider::Mdadm
            }
          },
          :centos   => {
            :default => {
              :service => Chef::Provider::Service::Redhat,
              :cron => Chef::Provider::Cron,
              :package => Chef::Provider::Package::Yum,
              :mdadm => Chef::Provider::Mdadm
            }
          },
          :scientific => {
            :default => {
              :service => Chef::Provider::Service::Redhat,
              :cron => Chef::Provider::Cron,
              :package => Chef::Provider::Package::Yum,
              :mdadm => Chef::Provider::Mdadm
            }
          },
          :fedora   => {
            :default => {
              :service => Chef::Provider::Service::Redhat,
              :cron => Chef::Provider::Cron,
              :package => Chef::Provider::Package::Yum,
              :mdadm => Chef::Provider::Mdadm
            }
          },
          :suse     => {
            :default => {
              :service => Chef::Provider::Service::Redhat,
              :cron => Chef::Provider::Cron,
              :package => Chef::Provider::Package::Zypper
            }
          },
          :redhat   => {
            :default => {
              :service => Chef::Provider::Service::Redhat,
              :cron => Chef::Provider::Cron,
              :package => Chef::Provider::Package::Yum,
              :mdadm => Chef::Provider::Mdadm
            }
          },
          :gentoo   => {
            :default => {
              :package => Chef::Provider::Package::Portage,
              :service => Chef::Provider::Service::Gentoo,
              :cron => Chef::Provider::Cron,
              :mdadm => Chef::Provider::Mdadm
            }
          },
          :arch   => {
            :default => {
              :package => Chef::Provider::Package::Pacman,
              :service => Chef::Provider::Service::Arch,
              :cron => Chef::Provider::Cron,
              :mdadm => Chef::Provider::Mdadm
            }
          },
          :mswin => {
            :default => {
              :env =>  Chef::Provider::Env::Windows,
              :service => Chef::Provider::Service::Windows,
              :user => Chef::Provider::User::Windows,
              :group => Chef::Provider::Group::Windows
            }
          },
          :mingw32 => {
            :default => {
              :env =>  Chef::Provider::Env::Windows,
              :service => Chef::Provider::Service::Windows,
              :user => Chef::Provider::User::Windows,
              :group => Chef::Provider::Group::Windows
            }
          },
          :windows => {
            :default => {
              :env =>  Chef::Provider::Env::Windows,
              :service => Chef::Provider::Service::Windows,
              :user => Chef::Provider::User::Windows,
              :group => Chef::Provider::Group::Windows
            }
          },
          :solaris  => {},
          :solaris2 => {
            :default => {
              :service => Chef::Provider::Service::Solaris
            }
          },
          :default  => {
            :file => Chef::Provider::File,
            :directory => Chef::Provider::Directory,
            :link => Chef::Provider::Link,
            :template => Chef::Provider::Template,
            :remote_directory => Chef::Provider::RemoteDirectory,
            :execute => Chef::Provider::Execute,
            :mount => Chef::Provider::Mount::Mount,
            :script => Chef::Provider::Script,
            :service => Chef::Provider::Service::Init,
            :perl => Chef::Provider::Script,
            :python => Chef::Provider::Script,
            :ruby => Chef::Provider::Script,
            :bash => Chef::Provider::Script,
            :csh => Chef::Provider::Script,
            :user => Chef::Provider::User::Useradd,
            :group => Chef::Provider::Group::Gpasswd,
            :http_request => Chef::Provider::HttpRequest,
            :route => Chef::Provider::Route,
            :ifconfig => Chef::Provider::Ifconfig,
            :ruby_block => Chef::Provider::RubyBlock,
            :erl_call => Chef::Provider::ErlCall,
            :log => Chef::Provider::Log::ChefLog
          }
        }
      end

      include Chef::Mixin::ParamsValidate

      def find(name, version)
        provider_map = platforms[:default].clone

        name_sym = name
        if name.kind_of?(String)
          name.downcase!
          name.gsub!(/\s/, "_")
          name_sym = name.to_sym
        end

        if platforms.has_key?(name_sym)
          if platforms[name_sym].has_key?(version)
            Chef::Log.debug("Platform #{name.to_s} version #{version} found")
            if platforms[name_sym].has_key?(:default)
              provider_map.merge!(platforms[name_sym][:default])
            end
            provider_map.merge!(platforms[name_sym][version])
          elsif platforms[name_sym].has_key?(:default)
            provider_map.merge!(platforms[name_sym][:default])
          end
        else
          Chef::Log.debug("Platform #{name} not found, using all defaults. (Unsupported platform?)")
        end
        provider_map
      end

      def find_platform_and_version(node)
        platform = nil
        version = nil

        if node[:platform]
          platform = node[:platform]
        elsif node.attribute?("os")
          platform = node[:os]
        end

        raise ArgumentError, "Cannot find a platform for #{node}" unless platform

        if node[:platform_version]
          version = node[:platform_version]
        elsif node[:os_version]
          version = node[:os_version]
        elsif node[:os_release]
          version = node[:os_release]
        end

        raise ArgumentError, "Cannot find a version for #{node}" unless version

        return platform, version
      end

      def provider_for_resource(resource)
        node = resource.run_context && resource.run_context.node
        raise ArgumentError, "Cannot find the provider for a resource with no run context set" unless node
        find_provider_for_node(node, resource).new(resource, resource.run_context)
      end

      def provider_for_node(node, resource_type)
        raise NotImplementedError, "#{self.class.name} no longer supports #provider_for_node"
        find_provider_for_node(node, resource_type).new(node, resource_type)
      end

      def find_provider_for_node(node, resource_type)
        platform, version = find_platform_and_version(node)
        provider = find_provider(platform, version, resource_type)
      end

      def set(args)
        validate(
          args,
          {
            :platform => {
              :kind_of => Symbol,
              :required => false,
            },
            :version => {
              :kind_of => String,
              :required => false,
            },
            :resource => {
              :kind_of => Symbol,
            },
            :provider => {
              :kind_of => [ String, Symbol, Class ],
            }
          }
        )
        if args.has_key?(:platform)
          if args.has_key?(:version)
            if platforms.has_key?(args[:platform])
              if platforms[args[:platform]].has_key?(args[:version])
                platforms[args[:platform]][args[:version]][args[:resource].to_sym] = args[:provider]
              else
                platforms[args[:platform]][args[:version]] = {
                  args[:resource].to_sym => args[:provider]
                }
              end
            else
              platforms[args[:platform]] = {
                args[:version] => {
                  args[:resource].to_sym => args[:provider]
                }
              }
            end
          else
            if platforms.has_key?(args[:platform])
              if platforms[args[:platform]].has_key?(:default)
                platforms[args[:platform]][:default][args[:resource].to_sym] = args[:provider]
              else
                platforms[args[:platform]] = { :default => { args[:resource].to_sym => args[:provider] } }
              end
            else
              platforms[args[:platform]] = {
                :default => {
                  args[:resource].to_sym => args[:provider]
                }
              }
            end
          end
        else
          if platforms.has_key?(:default)
            platforms[:default][args[:resource].to_sym] = args[:provider]
          else
            platforms[:default] = {
              args[:resource].to_sym => args[:provider]
            }
          end
        end
      end

      def find_provider(platform, version, resource_type)
        pmap = Chef::Platform.find(platform, version)
        provider_klass = explicit_provider(platform, version, resource_type) ||
                         platform_provider(platform, version, resource_type) ||
                         resource_matching_provider(platform, version, resource_type)

        raise ArgumentError, "Cannot find a provider for #{resource_type} on #{platform} version #{version}" if provider_klass.nil?

        provider_klass
      end

      private

        def explicit_provider(platform, version, resource_type)
          resource_type.kind_of?(Chef::Resource) ? resource_type.provider : nil
        end

        def platform_provider(platform, version, resource_type)
          pmap = Chef::Platform.find(platform, version)
          rtkey = resource_type.kind_of?(Chef::Resource) ? resource_type.resource_name.to_sym : resource_type
          pmap.has_key?(rtkey) ? pmap[rtkey] : nil
        end

        def resource_matching_provider(platform, version, resource_type)
          if resource_type.kind_of?(Chef::Resource)
            begin
              Chef::Provider.const_get(resource_type.class.to_s.split('::').last)
            rescue NameError
              nil
            end
          else
            nil
          end
        end

    end

  end
end