class Bundler::LockfileGenerator

def self.generate(definition)
  new(definition).generate!
end

def add_bundled_with
  add_section("BUNDLED WITH", Bundler::VERSION)
end

def add_dependencies
  out << "\nDEPENDENCIES\n"
  handled = []
  definition.dependencies.sort_by(&:to_s).each do |dep|
    next if handled.include?(dep.name)
    out << dep.to_lock << "\n"
    handled << dep.name
  end
end

def add_locked_ruby_version
  return unless locked_ruby_version = definition.locked_ruby_version
  add_section("RUBY VERSION", locked_ruby_version.to_s)
end

def add_platforms
  add_section("PLATFORMS", definition.platforms)
end

def add_section(name, value)
  out << "\n#{name}\n"
  case value
  when Array
    value.map(&:to_s).sort.each do |val|
      out << "  #{val}\n"
    end
  when Hash
    value.to_a.sort_by {|k, _| k.to_s }.each do |key, val|
      out << "  #{key}: #{val}\n"
    end
  when String
    out << "   #{value}\n"
  else
    raise ArgumentError, "#{value.inspect} can't be serialized in a lockfile"
  end
end

def add_sources
  definition.send(:sources).lock_sources.each_with_index do |source, idx|
    out << "\n" unless idx.zero?
    # Add the source header
    out << source.to_lock
    # Find all specs for this source
    specs = definition.resolve.select {|s| source.can_lock?(s) }
    add_specs(specs)
  end
end

def add_specs(specs)
  # This needs to be sorted by full name so that
  # gems with the same name, but different platform
  # are ordered consistently
  specs.sort_by(&:full_name).each do |spec|
    next if spec.name == "bundler"
    out << spec.to_lock
  end
end

def generate!
  add_sources
  add_platforms
  add_dependencies
  add_locked_ruby_version
  add_bundled_with
  out
end

def initialize(definition)
  @definition = definition
  @out = String.new
end