class Bundler::Plugin::Index

def command_plugin(command)
  @commands[command]
end

def global_index_file
  Plugin.global_root.join("index")
end

def hook_plugins(event)
  @hooks[event] || []
end

def index_file
  Plugin.root.join("index")
end

def initialize
  @plugin_paths = {}
  @commands = {}
  @sources = {}
  @hooks = {}
  @load_paths = {}
  begin
    load_index(global_index_file, true)
  rescue GenericSystemCallError
    # no need to fail when on a read-only FS, for example
    nil
  end
  load_index(local_index_file) if SharedHelpers.in_bundle?
end

def installed?(name)
  @plugin_paths[name]
end

def installed_plugins
  @plugin_paths.keys
end

def load_index(index_file, global = false)
  SharedHelpers.filesystem_access(index_file, :read) do |index_f|
    valid_file = index_f && index_f.exist? && !index_f.size.zero?
    break unless valid_file
    data = index_f.read
    require_relative "../yaml_serializer"
    index = YAMLSerializer.load(data)
    @commands.merge!(index["commands"])
    @hooks.merge!(index["hooks"])
    @load_paths.merge!(index["load_paths"])
    @plugin_paths.merge!(index["plugin_paths"])
    @sources.merge!(index["sources"]) unless global
  end
end

def load_paths(name)
  @load_paths[name]
end

def local_index_file
  Plugin.local_root.join("index")
end

def plugin_commands(plugin)
  @commands.find_all {|_, n| n == plugin }.map(&:first)
end

def plugin_path(name)
  Pathname.new @plugin_paths[name]
end

def register_plugin(name, path, load_paths, commands, sources, hooks)
  old_commands = @commands.dup
  common = commands & @commands.keys
  raise CommandConflict.new(name, common) unless common.empty?
  commands.each {|c| @commands[c] = name }
  common = sources & @sources.keys
  raise SourceConflict.new(name, common) unless common.empty?
  sources.each {|k| @sources[k] = name }
  hooks.each do |event|
    event_hooks = (@hooks[event] ||= []) << name
    event_hooks.uniq!
  end
  @plugin_paths[name] = path
  @load_paths[name] = load_paths
  save_index
rescue StandardError
  @commands = old_commands
  raise
end

def save_index
  index = {
    "commands" => @commands,
    "hooks" => @hooks,
    "load_paths" => @load_paths,
    "plugin_paths" => @plugin_paths,
    "sources" => @sources,
  }
  require_relative "../yaml_serializer"
  SharedHelpers.filesystem_access(index_file) do |index_f|
    FileUtils.mkdir_p(index_f.dirname)
    File.open(index_f, "w") {|f| f.puts YAMLSerializer.dump(index) }
  end
end

def source?(source)
  @sources.key? source
end

def source_plugin(name)
  @sources[name]
end

def unregister_plugin(name)
  @commands.delete_if {|_, v| v == name }
  @sources.delete_if {|_, v| v == name }
  @hooks.each do |hook, names|
    names.delete(name)
    @hooks.delete(hook) if names.empty?
  end
  @plugin_paths.delete(name)
  @load_paths.delete(name)
  save_index
end