#!/usr/bin/env ruby

require 'method_log'
require 'method_log/version'
require 'optimist'

options = Optimist::options do
  version MethodLog::VERSION
  banner <<-EOS
Build a parallel git repository of method definitions.

Usage:
       build_methods_repo [options] <source-repo-path> <target-repo-path>

source-repo-path: the path to the source repository from which to read
target-repo-path: the path to the target repository to which to write

[options] are:
EOS
  opt :ruby_version, 'Parser Ruby version (e.g. 2.5)', default: 'current'
  opt :excluded_directories, 'Directories in source repository to exclude from analysis', type: :strings, default: []
end

Optimist.die 'No source path specified' if ARGV[0].nil?
source_path = ARGV[0]
Optimist.die 'Source repository does not exist' unless Dir.exist?(source_path)

Optimist.die 'No target path specified' if ARGV[1].nil?
target_path = ARGV[1]
Optimist.die 'Target repository already exists' if Dir.exist?(target_path)

case ruby_version = options[:ruby_version]
when 'current'
  require 'parser/current'
when /^(\d)\.(\d)$/
  begin
    require "parser/ruby#{$1}#{$2}"
    Parser::CurrentRuby = Parser.const_get("Ruby#{$1}#{$2}")
  rescue LoadError
    Optimist.die "Ruby version not supported: #{ruby_version}"
  end
else
  Optimist.die "Ruby version not supported: #{ruby_version}"
end

require 'method_log/repository'
require 'method_log/method_finder'
require 'method_log/source_file'

def unindent(code)
  lines = code.split($/)
  indent = lines.reject { |l| l.strip.length == 0 }.map { |l| l[/^ */].length }.min
  lines.map { |l| l.sub(Regexp.new(' ' * indent), '') }.join($/)
end

new_repository_path = File.expand_path(target_path)
Rugged::Repository.init_at(new_repository_path, :bare)
new_repository = MethodLog::Repository.new(new_repository_path)

repository_path = File.expand_path(source_path)
repository = MethodLog::Repository.new(repository_path)
repository.commits(sorting: Rugged::SORT_TOPO | Rugged::SORT_REVERSE).each do |commit|
  puts commit.to_s
  new_commit = new_repository.build_commit
  commit.source_files.each do |source_file|
    next if options[:excluded_directories].any? { |d| source_file.path.start_with?(d) }
    begin
      method_finder = MethodLog::MethodFinder.new(source_file)
      method_finder.methods.each do |method_signature, method_definition|
        _, namespace, name = method_signature.match(/^(.*)([#.].*)$/).to_a
        path = namespace.split('::').push(name).join(File::SEPARATOR) + '.rb'
        method_source = unindent(method_definition.source) + $/
        method_source_file = MethodLog::SourceFile.new(path: path, source: method_source)
        new_commit.add(method_source_file)
      end
    rescue Parser::SyntaxError => e
      p e
    end
  end
  new_commit.apply(user: commit.author, message: commit.message)
end