class Gem::FakeFetcher

def api_endpoint(uri)
  @api_endpoints[uri] || uri
end

def cache_update_path uri, path = nil, update = true
  if data = fetch_path(uri)
    open(path, 'wb') { |io| io.write data } if path and update
    data
  else
    Gem.read_binary(path) if path
  end
end

def download spec, source_uri, install_dir = Gem.dir
  name = File.basename spec.cache_file
  path = if Dir.pwd == install_dir then # see fetch_command
           install_dir
         else
           File.join install_dir, "cache"
         end
  path = File.join path, name
  if source_uri =~ /^http/ then
    File.open(path, "wb") do |f|
      f.write fetch_path(File.join(source_uri, "gems", name))
    end
  else
    FileUtils.cp source_uri, path
  end
  path
end

def download_to_cache dependency
  found, _ = Gem::SpecFetcher.fetcher.spec_for_dependency dependency
  return if found.empty?
  spec, source = found.first
  download spec, source.uri.to_s
end

def fetch_path path, mtime = nil, head = false
  data = find_data(path)
  if data.respond_to?(:call) then
    data.call
  else
    if path.to_s =~ /gz$/ and not data.nil? and not data.empty? then
      data = Gem.gunzip data
    end
    data
  end
end

def fetch_size(path)
  path = path.to_s
  @paths << path
  raise ArgumentError, 'need full URI' unless path =~ %r'^http://'
  unless @data.key? path then
    raise Gem::RemoteFetcher::FetchError.new("no data for #{path}", path)
  end
  data = @data[path]
  data.respond_to?(:call) ? data.call : data.length
end

def find_data(path)
  return File.read path.path if URI === path and 'file' == path.scheme
  if URI === path and "URI::#{path.scheme.upcase}" != path.class.name then
    raise ArgumentError,
      "mismatch for scheme #{path.scheme} and class #{path.class}"
  end
  path = path.to_s
  @paths << path
  raise ArgumentError, 'need full URI' unless path =~ %r'^https?://'
  unless @data.key? path then
    raise Gem::RemoteFetcher::FetchError.new("no data for #{path}", path)
  end
  @data[path]
end

def initialize
  @data = {}
  @paths = []
  @api_endpoints = {}
end

def open_uri_or_path(path)
  data = find_data(path)
  body, code, msg = data
  response = Net::HTTPResponse.send(:response_class, code.to_s).new("1.0", code.to_s, msg)
  response.instance_variable_set(:@body, body)
  response.instance_variable_set(:@read, true)
  response
end

def pretty_print q # :nodoc:
  q.group 2, '[FakeFetcher', ']' do
    q.breakable
    q.text 'URIs:'
    q.breakable
    q.pp @data.keys
    unless @api_endpoints.empty? then
      q.breakable
      q.text 'API endpoints:'
      q.breakable
      q.pp @api_endpoints.keys
    end
  end
end

def request(uri, request_class, last_modified = nil)
  data = find_data(uri)
  body, code, msg = data
  @last_request = request_class.new uri.request_uri
  yield @last_request if block_given?
  response = Net::HTTPResponse.send(:response_class, code.to_s).new("1.0", code.to_s, msg)
  response.instance_variable_set(:@body, body)
  response.instance_variable_set(:@read, true)
  response
end