#!/usr/bin/env ruby
# frozen_string_literal: true

# To update lib/innodb/mysql_collations.rb, run this with a path to the MySQL source directory
# containing CHARSET_INFO collation definitions, e.g.:

# bundle exec bin/innodb_ruby_generate_mysql_collations ~/git/mysql-server > lib/innodb/mysql_collations.rb

MysqlCharsetInfo = Struct.new(
  :number,
  :primary_number,
  :binary_number,
  :state,
  :csname,
  :m_coll_name,
  :comment,
  :tailoring,
  :coll_param,
  :ctype,
  :to_lower,
  :to_upper,
  :sort_order,
  :uca,
  :tab_to_uni,
  :tab_from_uni,
  :caseinfo,
  :state_maps,
  :ident_map,
  :strxfrm_multiply,
  :caseup_multiply,
  :casedn_multiply,
  :mbminlen,
  :mbmaxlen,
  :mbmaxlenlen,
  :min_sort_char,
  :max_sort_char,
  :pad_char,
  :escape_with_backslash_is_dangerous,
  :levels_for_compare,
  :cset,
  :coll,
  :pad_attribute
)

charset_infos = []

raise "First argument must be the path to a modern MySQL source tree" unless (ARGV.size == 1) && Dir.exist?(ARGV[0])

Dir.glob(File.join(ARGV[0], "strings/ctype-**.cc")).each do |filename|
  content = File.read(filename)
  warn "Parsing #{filename}..."

  # Global individual constants e.g. CHARSET_INFO my_charset_utf8mb4_general_ci = { ... }
  charset_info_strings = content.scan(/^CHARSET_INFO \w+ = ({.*?})/m).flatten

  # Global array of constants e.g. CHARSET_INFO compiled_charsets[] = { { ... }, { ... } };
  content.match(/CHARSET_INFO \w+\[\] = {\s*(?:{.*?}\s*,\s*)+/m)
         &.match(0)
         &.gsub(/CHARSET_INFO \w+\[\] = {/, "")
         &.scan(/{.*?}/m)
         &.each do |s|
    charset_info_strings.push(s)
  end

  charset_info_strings = charset_info_strings.map do |x|
    x.gsub(%r{/\*.*?\*/}, "").gsub(%r{//.*?$}, "").gsub(/\s+/, " ").gsub(/["']/, "")
  end

  charset_infos += charset_info_strings.map do |charset_info_string|
    matches = charset_info_string.match(/{(?<definition>.*?)}/)

    MysqlCharsetInfo.new(*matches[:definition].split(",").map(&:strip).map { |x| x =~ /^[0-9]+$/ ? x.to_i : x })
  end
end

if charset_infos.empty?
  warn "No MySQL collations found... bad path provided?"
  exit 1
end

warn "Found #{charset_infos.size} collations, generating output."

puts "# frozen_string_literal: true"
puts
puts "# Generated at #{Time.now.utc} using innodb_ruby_generate_mysql_collations. Do not edit!"
puts

puts "# rubocop:disable all"
charset_infos.sort_by(&:number).each do |charset_info|
  puts format("Innodb::MysqlCollation.add(id: %d, name: %s, character_set_name: %s, mbminlen: %i, mbmaxlen: %i)",
              charset_info.number,
              charset_info.m_coll_name.inspect,
              charset_info.csname.inspect,
              charset_info.mbminlen,
              charset_info.mbmaxlen)
end