# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at https://mozilla.org/MPL/2.0/.

# frozen_string_literal: true

require 'pathname'

namespace :hhvm do
  def filter_set_hhvm_third_party_source_args(tokens)
    args = tokens[0]
    allowed_arguments = tokens[1..].each_slice(2)
      .filter do |key, _value|
        !key.end_with?('_URL') && !key.end_with?('_HASH')
      end

    allowed_arguments
      .flatten
      .prepend("  #{args}")
      .join("\n  ")
  end

  def split_set_hhvm_third_party_source_args(section_content)
    section_content
      .split("\n")
      .map do |line|
        hash_index = line.index '#'
        line = line[...hash_index] unless hash_index.nil?

        line.strip
      end
  end

  def rewrite_set_hhvm_third_party_source_args(contents)
    set_hhvm_start = contents.index 'SET_HHVM_THIRD_PARTY_SOURCE_ARGS('
    return nil if set_hhvm_start.nil?

    section_contents = contents[set_hhvm_start + 'SET_HHVM_THIRD_PARTY_SOURCE_ARGS('.length..]
    set_hhvm_end = section_contents.index ')'

    lines = split_set_hhvm_third_party_source_args section_contents[...set_hhvm_end]
    new_cmake_section = filter_set_hhvm_third_party_source_args lines.reject(&:blank?).join(' ').split

    contents[...set_hhvm_start] +
      "SET_HHVM_THIRD_PARTY_SOURCE_ARGS(\n#{new_cmake_section}\n)\n" +
      section_contents[set_hhvm_end..]
  end

  desc 'Generates diffs with removed download URLs'
  task :bundled_dependencies, [:version] do |_, arguments|
    run_on_source arguments[:version] do |third_party|
      c_make_lists = third_party + 'CMakeLists.txt'
      next unless c_make_lists.exist?

      contents = c_make_lists.read
      rewritten_cmake = rewrite_set_hhvm_third_party_source_args contents
      next if rewritten_cmake.nil?

      puts Open3.capture2('diff', '-Nur', c_make_lists.to_path, '-', stdin_data: rewritten_cmake).first
    end
  end

  desc 'Generated SlackBuild code to prepare bundled dependencies'
  task :bundled_code, [:version] do |_, arguments|
    run_on_source arguments[:version] do |third_party|
      c_make_lists = third_party + 'CMakeLists.txt'
      next unless c_make_lists.exist?

      contents = c_make_lists.read
      set_hhvm_start = contents.index 'SET_HHVM_THIRD_PARTY_SOURCE_ARGS('
      next if set_hhvm_start.nil?

      set_hhvm_end = contents.index ')', set_hhvm_start
      set_hhvm_start += 'SET_HHVM_THIRD_PARTY_SOURCE_ARGS('.length
      set_hhvm_end -= 1
      contents = contents[set_hhvm_start..set_hhvm_end].split[1..].map(&:strip)

      src = Pathname.new('third-party') +
        third_party.basename +
        "bundled_#{third_party.basename}-prefix" + 'src'
      bundled = src + "bundled_#{third_party.basename}"
      archive_name = contents[1][contents[1].rindex('/') + 1..-2]

      puts "mkdir -p #{bundled}"
      puts "install -m 0644 -D $CWD/#{archive_name} #{src + archive_name}"
      puts "tar -zxvf $CWD/#{archive_name} -C #{bundled}"
      puts
    end
  end
end

private

def run_on_source(version, &block)
  package = Package.new 'development/hhvm',
    version: version,
    homepage: 'https://hhvm.com/',
    requires: %w[tbb glog libdwarf libmemcached dobule-conversion]
  repository = SlackBuilder.clone 'https://github.com/facebook/hhvm.git', package, 'HHVM-'

  (repository + 'third-party').each_child do |third_party|
    block.call third_party
  end
end