require "mkmf"

require 'net/http'

LIBDIR     = RbConfig::CONFIG['libdir']
INCLUDEDIR = RbConfig::CONFIG['includedir']

HEADER_DIRS = [INCLUDEDIR]

LIB_DIRS = [LIBDIR, File.expand_path(File.join(File.dirname(__FILE__), "lib"))]

COMMIT = "df45c48"

# TODO: this is not very accurate, but it works for now
OS = RUBY_PLATFORM.include?("darwin") ? "mac" : "linux"
ARCH = RUBY_PLATFORM.include?("arm64") ? "arm64" : "amd64"

PREFIX = "/static-libs/#{COMMIT}/#{OS}-#{ARCH}"

ROOT = File.expand_path("..", __FILE__)

def run(str)
  system(str) || fail("command failed: #{str}")
end

if ENV["PYROSCOPE_RUBY_LOCAL"]
  puts "PYROSCOPE_RUBY_LOCAL yes"
  # TODO: make configurable
  pyroscope_path = "#{ENV["HOME"]}/pyroscope"
  run("rm -rf #{File.join(ROOT, "build")}")
  run("cd #{pyroscope_path} && make build-rust-dependencies-docker")
  run("cp #{pyroscope_path}/out/libpyroscope.rbspy.a #{File.join(ROOT, "lib/libpyroscope.rbspy.a")}")
  run("cp #{pyroscope_path}/out/librustdeps.a #{File.join(ROOT, "lib/librustdeps.a")}")
else
  Net::HTTP.start("dl.pyroscope.io", 443, :use_ssl => true) do |http|
    ["libpyroscope.rbspy.a", "librustdeps.a"].each do |name|
      url = PREFIX+"/#{name}.gz"
      req = Net::HTTP::Get.new(url)
      http.request(req) do |resp|
        raise "HTTP error: #{resp.code}" unless resp.code == "200"

        r, w = IO.pipe

        t = Thread.new do
          zreader = Zlib::GzipReader.new(r)
          File.open(File.join(ROOT, "lib/#{name}"), "wb") do |f|
            loop do
              begin
                chunk = zreader.readpartial(32768)
                break if chunk.nil?
              rescue EOFError
                break
              end
              f.write(chunk)
            end
          end
        end

        resp.read_body do |chunk|
          w.write(chunk)
        end

        t.join
      end
    end
  end
end

# this is now done upstream
# system "strip --strip-debug #{File.join(ROOT, "lib/libpyroscope.rbspy.combo.a")}"

dir_config('pyroscope', HEADER_DIRS, LIB_DIRS)

libs = ['-lpyroscope.rbspy', '-lrustdeps']
libs.each do |lib|
  $LOCAL_LIBS << "#{lib} "
end

create_makefile('pyroscope_c')