class PackageConfig

def all_required_packages
  collect_requires do |package|
    package.requires_private + package.requires
  end
end

def cflags
  path_flags, other_flags = collect_cflags
  (other_flags + path_flags).join(" ")
end

def cflags_only_I
  collect_cflags[0].join(" ")
end

def cflags_only_other
  collect_cflags[1].join(" ")
end

def clear_configure_args_cache
  @native_pkg_config = nil
  @native_pkg_config_prefix = nil
  @default_path = nil
  @custom_override_variables = nil
end

def collect_cflags
  target_packages = sort_packages([self, *all_required_packages])
  cflags_set = []
  target_packages.each do |package|
    cflags_set << package.declaration("Cflags")
  end
  all_cflags = normalize_cflags(Shellwords.split(cflags_set.join(" ")))
  path_flags, other_flags = all_cflags.partition {|flag| /\A-I/ =~ flag}
  path_flags = normalize_path_flags(path_flags, "-I")
  path_flags = path_flags.reject do |flag|
    flag == "-I/usr/include"
  end
  path_flags = path_flags.uniq
  if @msvc_syntax
    path_flags = path_flags.collect do |flag|
      flag.gsub(/\A-I/, "/I")
    end
  end
  [path_flags, other_flags]
end

def collect_libs
  target_packages = sort_packages(required_packages + [self])
  libs_set = []
  target_packages.each do |package|
    libs_set << package.declaration("Libs")
  end
  all_flags = split_lib_flags(libs_set.join(" "))
  path_flags, other_flags = all_flags.partition {|flag| /\A-L/ =~ flag}
  path_flags = normalize_path_flags(path_flags, "-L")
  path_flags = path_flags.reject do |flag|
    /\A-L\/usr\/lib(?:64|x32)?\z/ =~ flag
  end
  path_flags = path_flags.uniq
  if @msvc_syntax
    path_flags = path_flags.collect do |flag|
      flag.gsub(/\A-L/, "/libpath:")
    end
    other_flags = other_flags.collect do |flag|
      if /\A-l/ =~ flag
        "#{$POSTMATCH}.lib"
      else
        flag
      end
    end
  end
  [path_flags, other_flags]
end

def collect_requires(processed_packages={}, &block)
  packages = []
  targets = yield(self)
  targets.each do |name|
    next if processed_packages.key?(name)
    package = self.class.new(name, @options)
    processed_packages[name] = package
    packages << package
    packages.concat(package.collect_requires(processed_packages, &block))
  end
  packages_without_self = packages.reject do |package|
    package.name == @name
  end
  packages_without_self.uniq do |package|
    package.name
  end
end

def compute_default_path
  default_paths = nil
  if native_pkg_config
    pc_path = run_command(native_pkg_config.to_s,
                          "--variable=pc_path",
                          "pkg-config")
    if pc_path
      default_paths = pc_path.strip.split(SEPARATOR)
      default_paths = nil if default_paths.empty?
    end
  end
  if default_paths.nil?
    arch_depended_path = Dir.glob("/usr/lib/*/pkgconfig")
    default_paths = []
    pkg_config_prefix = native_pkg_config_prefix
    if pkg_config_prefix
      pkg_config_arch_depended_paths =
        Dir.glob((pkg_config_prefix + "lib/*/pkgconfig").to_s)
      default_paths.concat(pkg_config_arch_depended_paths)
      default_paths << (pkg_config_prefix + "lib64/pkgconfig").to_s
      default_paths << (pkg_config_prefix + "libx32/pkgconfig").to_s
      default_paths << (pkg_config_prefix + "lib/pkgconfig").to_s
      default_paths << (pkg_config_prefix + "libdata/pkgconfig").to_s
      default_paths << (pkg_config_prefix + "share/pkgconfig").to_s
    end
    conda_prefix = ENV["CONDA_PREFIX"]
    if conda_prefix
      default_paths << File.join(conda_prefix, "lib", "pkgconfig")
    end
    default_paths << "/usr/local/lib64/pkgconfig"
    default_paths << "/usr/local/libx32/pkgconfig"
    default_paths << "/usr/local/lib/pkgconfig"
    default_paths << "/usr/local/libdata/pkgconfig"
    default_paths << "/usr/local/share/pkgconfig"
    default_paths << "/opt/local/lib/pkgconfig"
    default_paths.concat(arch_depended_path)
    default_paths << "/usr/lib64/pkgconfig"
    default_paths << "/usr/libx32/pkgconfig"
    default_paths << "/usr/lib/pkgconfig"
    default_paths << "/usr/libdata/pkgconfig"
    default_paths << "/usr/X11R6/lib/pkgconfig"
    default_paths << "/usr/X11R6/share/pkgconfig"
    default_paths << "/usr/X11/lib/pkgconfig"
    default_paths << "/opt/X11/lib/pkgconfig"
    default_paths << "/usr/share/pkgconfig"
  end
  if Object.const_defined?(:RubyInstaller)
    mingw_bin_path = RubyInstaller::Runtime.msys2_installation.mingw_bin_path
    mingw_pkgconfig_path = Pathname.new(mingw_bin_path) + "../lib/pkgconfig"
    default_paths.unshift(mingw_pkgconfig_path.cleanpath.to_s)
  end
  libdir = ENV["PKG_CONFIG_LIBDIR"]
  default_paths.unshift(libdir) if libdir
  paths = []
  if /-darwin\d[\d\.]*\z/ =~ RUBY_PLATFORM and
    /\A(\d+\.\d+)/ =~ run_command("sw_vers", "-productVersion")
    mac_os_version = $1
    homebrew_repository_candidates = []
    if pkg_config_prefix
      brew_path = pkg_config_prefix + "bin" + "brew"
      if brew_path.exist?
        homebrew_repository = run_command(brew_path.to_s, "--repository")
        if homebrew_repository
          homebrew_repository_candidates <<
            Pathname.new(homebrew_repository.strip)
        end
      else
        homebrew_repository_candidates << pkg_config_prefix + "Homebrew"
        homebrew_repository_candidates << pkg_config_prefix
      end
    end
    brew = search_executable_from_path("brew")
    if brew
      homebrew_repository = run_command("brew", "--repository")
      if homebrew_repository
      homebrew_repository_candidates <<
        Pathname(homebrew_repository.to_s)
      end
    end
    homebrew_repository_candidates.uniq.each do |candidate|
      pkgconfig_base_path = candidate + "Library/Homebrew/os/mac/pkgconfig"
      path = pkgconfig_base_path + mac_os_version
      unless path.exist?
        path = pkgconfig_base_path + mac_os_version.gsub(/\.\d+\z/, "")
      end
      paths << path.to_s if path.exist?
    end
  end
  paths.concat(default_paths)
  paths.join(SEPARATOR)
end

def compute_native_pkg_config_prefix
  pkg_config = native_pkg_config
  return nil unless pkg_config.absolute?
  return nil unless pkg_config.exist?
  pkg_config_prefix = pkg_config.parent.parent
  if File::ALT_SEPARATOR
    normalized_pkg_config_prefix =
      pkg_config_prefix.to_s.split(File::ALT_SEPARATOR).join(File::SEPARATOR)
    Pathname(normalized_pkg_config_prefix)
  else
    pkg_config_prefix
  end
end

def custom_override_variables
  @custom_override_variables ||= with_config("override-variables", "")
end

def declaration(name)
  parse_pc if @declarations.nil?
  expand_value(@declarations[name])
end

def default_path
  @default_path ||= compute_default_path
end

def description
  declaration("Description")
end

def exist?
  not pc_path.nil?
end

def expand_value(value)
  return nil if value.nil?
  value.gsub(/\$\{(#{IDENTIFIER_RE})\}/) do
    variable($1)
  end
end

def guess_native_pkg_config
  exeext = RbConfig::CONFIG["EXEEXT"]
  default_pkg_config = ENV["PKG_CONFIG"] || "pkg-config#{exeext}"
  pkg_config = with_config("pkg-config", default_pkg_config)
  pkg_config = Pathname.new(pkg_config)
  unless pkg_config.absolute?
    found_pkg_config = search_executable_from_path(pkg_config)
    pkg_config = found_pkg_config if found_pkg_config
  end
  unless pkg_config.absolute?
    found_pkg_config = search_pkg_config_by_dln_find_exe(pkg_config)
    pkg_config = found_pkg_config if found_pkg_config
  end
  pkg_config
end

def initialize(name, options={})
  if Pathname(name).absolute?
    @pc_path = name
    @path_position = 0
    @name = File.basename(@pc_path, ".*")
  else
    @pc_path = nil
    @path_position = nil
    @name = name
  end
  @options = options
  path = @options[:path] || ENV["PKG_CONFIG_PATH"]
  @paths = [path, self.class.default_path].compact.join(SEPARATOR).split(SEPARATOR)
  @paths.unshift(*(@options[:paths] || []))
  @paths = normalize_paths(@paths)
  @msvc_syntax = @options[:msvc_syntax]
  @variables = @declarations = nil
  override_variables = self.class.custom_override_variables
  @override_variables = parse_override_variables(override_variables)
  default_override_variables = @options[:override_variables] || {}
  @override_variables = default_override_variables.merge(@override_variables)
end

def libs
  path_flags, other_flags = collect_libs
  (path_flags + other_flags).join(" ")
end

def libs_only_L
  collect_libs[0].find_all do |arg|
    if @msvc_syntax
      /\A\/libpath:/ =~ arg
    else
      /\A-L/ =~ arg
    end
  end.join(" ")
end

def libs_only_l
  collect_libs[1].find_all do |arg|
    if @msvc_syntax
      /\.lib\z/ =~ arg
    else
      /\A-l/ =~ arg
    end
  end.join(" ")
end

def native_pkg_config
  @native_pkg_config ||= guess_native_pkg_config
end

def native_pkg_config_prefix
  @native_pkg_config_prefix ||= compute_native_pkg_config_prefix
end

def normalize_cflags(cflags)
  normalized_cflags = []
  enumerator = cflags.to_enum
  begin
    loop do
      cflag = enumerator.next
      normalized_cflags << cflag
      case cflag
      when "-I"
        normalized_cflags << enumerator.next
      end
    end
  rescue StopIteration
  end
  normalized_cflags
end

def normalize_path_flags(path_flags, flag_option)
  return path_flags unless /-mingw(?:32|-ucrt)\z/ === RUBY_PLATFORM
  pkg_config_prefix = self.class.native_pkg_config_prefix
  return path_flags unless pkg_config_prefix
  mingw_dir = pkg_config_prefix.basename.to_s
  path_flags.collect do |path_flag|
    path = path_flag.sub(/\A#{Regexp.escape(flag_option)}/, "")
    path = path.sub(/\A\/#{Regexp.escape(mingw_dir)}/i) do
      pkg_config_prefix.to_s
    end
    "#{flag_option}#{path}"
  end
end

def normalize_paths(paths)
  paths.reject do |path|
    path.empty? or !File.exist?(path)
  end
end

def parse_override_variables(override_variables)
  variables = {}
  override_variables.split(",").each do |variable|
    name, value = variable.split("=", 2)
    variables[name] = value
  end
  variables
end

def parse_pc
  raise NotFoundError, ".pc doesn't exist: <#{@name}>" unless exist?
  @variables = {}
  @declarations = {}
  File.open(pc_path) do |input|
    input.each_line do |line|
      line = line.gsub(/#.*/, "").strip
      next if line.empty?
      case line
      when /^(#{IDENTIFIER_RE})\s*=\s*/
        @variables[$1] = $POSTMATCH.strip
      when /^(#{IDENTIFIER_RE})\s*:\s*/
        @declarations[$1] = $POSTMATCH.strip
      end
    end
  end
end

def parse_requires(requires)
  return [] if requires.nil?
  requires_without_version = requires.gsub(/[<>]?=\s*[\d.a-zA-Z_-]+\s*/, "")
  requires_without_version.split(/[,\s]+/)
end

def path_position
  @path_position
end

def pc_path
  if @pc_path
    return @pc_path if File.exist?(@pc_path)
  else
    @paths.each_with_index do |path, i|
      _pc_path = File.join(path, "#{@name}.pc")
      if File.exist?(_pc_path)
        @path_position = i + 1
        return _pc_path
      end
    end
  end
  nil
end

def required_packages
  collect_requires do |package|
    package.requires
  end
end

def requires
  parse_requires(declaration("Requires"))
end

def requires_private
  parse_requires(declaration("Requires.private"))
end

def run_command(*command_line)
  IO.pipe do |input, output|
    begin
      pid = spawn(*command_line,
                  out: output,
                  err: File::NULL)
      output.close
      _, status = Process.waitpid2(pid)
      return nil unless status.success?
      input.read
    rescue SystemCallError
      nil
    end
  end
end

def search_executable_from_path(name)
  (ENV["PATH"] || "").split(SEPARATOR).each do |path|
    try_name = Pathname(path) + name
    return try_name if try_name.executable?
  end
  nil
end

def search_pkg_config_by_dln_find_exe(pkg_config)
  begin
    require "dl/import"
  rescue LoadError
    return nil
  end
  dln = Module.new
  dln.module_eval do
    if DL.const_defined?(:Importer)
      extend DL::Importer
    else
      extend DL::Importable
    end
    begin
      dlload RbConfig::CONFIG["LIBRUBY"]
    rescue RuntimeError
      return nil if $!.message == "unknown error"
      return nil if /: image not found\z/ =~ $!.message
      raise
    rescue DL::DLError
      return nil
    end
    begin
      extern "const char *dln_find_exe(const char *, const char *)"
    rescue DL::DLError
      return nil
    end
  end
  path = dln.dln_find_exe(pkg_config.to_s, nil)
  if path.nil? or path.size.zero?
    nil
  else
    Pathname(path.to_s)
  end
end

def sort_packages(packages)
  packages.sort_by.with_index do |package, i|
    [package.path_position, i]
  end
end

def split_lib_flags(libs_command_line)
  all_flags = {}
  flags = []
  in_option = false
  libs_command_line.gsub(/-([Ll]) /, "\\1").split.each do |arg|
    if in_option
      flags << arg
      in_option = false
    else
      case arg
      when /-[lL]/
        next if all_flags.key?(arg)
        all_flags[arg] = true
        flags << arg
        in_option = true
      else
        flags << arg
      end
    end
  end
  flags
end

def variable(name)
  parse_pc if @variables.nil?
  expand_value(@override_variables[name] || @variables[name])
end

def version
  declaration("Version")
end

def with_config(config, default=nil)
  if defined?(super)
    super
  else
    default
  end
end