#!/usr/bin/env ruby

$LOAD_PATH[0, 0] = File.join(File.dirname(__FILE__), '..', 'lib')

require 'linguist'
require 'rugged'
require 'json'
require 'optparse'
require 'pathname'

HELP_TEXT = <<~HELP
Linguist v#{Linguist::VERSION}
Detect language type and determine language breakdown for a given Git repository.

Usage: linguist <path>
       linguist <path> [--rev REV] [--tree-size] [--breakdown] [--json]
       linguist [--rev REV] [--tree-size] [--breakdown] [--json]
HELP

def github_linguist(args)
  breakdown = false
  json_output = false
  tree_size = Linguist::Repository::MAX_TREE_SIZE
  rev = 'HEAD'
  path = Dir.pwd

  parser = OptionParser.new do |opts|
    opts.banner = HELP_TEXT
    opts.version = Linguist::VERSION

    opts.on("-b", "--breakdown", "Analyze entire repository and display detailed usage statistics") { breakdown = true }
    opts.on("-j", "--json", "Output results as JSON") { json_output = true }
    opts.on("-r", "--rev REV", String,
            "Analyze specific git revision",
            "defaults to HEAD, see gitrevisions(1) for alternatives") { |r| rev = r }
    opts.on("-t", "--tree-size=NUMBER", Integer,
            "Maximum number of files scanned to detect languages (default: #{Linguist::Repository::MAX_TREE_SIZE})") { |t| tree_size = t }
    opts.on("-h", "--help", "Display a short usage summary, then exit") do
      puts opts
      exit
    end
  end

  parser.parse!(args)

  if !args.empty?
    if File.directory?(args[0]) || File.file?(args[0])
      path = args[0]
    else
      abort HELP_TEXT
    end
  end

  if File.directory?(path)
    rugged = Rugged::Repository.new(path)
    begin
      target_oid = rugged.rev_parse_oid(rev)
    rescue
      puts "invalid revision '#{rev}' for repo '#{path}'"
      exit 1
    end
    repo = Linguist::Repository.new(rugged, target_oid, tree_size)

    full_results = {}
    repo.languages.each do |language, size|
      percentage = ((size / repo.size.to_f) * 100)
      percentage = sprintf '%.2f' % percentage
      full_results.merge!({"#{language}": { size: size, percentage: percentage } })
    end

    if !json_output
      full_results.sort_by { |_, v| v[:size] }.reverse.each do |language, details|
        puts "%-7s %-10s %s" % ["#{details[:percentage]}%", details[:size], language]
      end
      if breakdown
        puts
        file_breakdown = repo.breakdown_by_file
        file_breakdown.each do |lang, files|
          puts "#{lang}:"
          files.each do |file|
            puts file
          end
          puts
        end
      end
    else
      if !breakdown
        puts JSON.dump(full_results)
      else
        combined_results = full_results.merge({})

        repo.breakdown_by_file.each do |language, files|
          combined_results[language.to_sym].update({"files": files})
        end
        puts JSON.dump(combined_results)
      end
    end
  elsif File.file?(path)

    begin
      # Check if this file is inside a git repository so we have things like
      # `.gitattributes` applied.
      file_full_path = File.realpath(path)
      rugged = Rugged::Repository.discover(file_full_path)
      file_rel_path = file_full_path.sub(rugged.workdir, '')
      oid = -> { rugged.head.target.tree.walk_blobs { |r, b| return b[:oid] if r + b[:name] == file_rel_path } }
      blob = Linguist::LazyBlob.new(rugged, oid.call, file_rel_path)
    rescue Rugged::RepositoryError
      blob = Linguist::FileBlob.new(path, Dir.pwd)
    end

    type = if blob.text?
      'Text'
    elsif blob.image?
      'Image'
    else
      'Binary'
    end

    if json_output
      puts JSON.generate( { path =>  {
                                        :lines => blob.loc,
                                        :sloc => blob.sloc,
                                        :type => type,
                                        :mime_type => blob.mime_type,
                                        :language => blob.language,
                                        :large => blob.large?,
                                        :generated => blob.generated?,
                                        :vendored => blob.vendored?,
                                      }
                          } )
    else
      puts "#{path}: #{blob.loc} lines (#{blob.sloc} sloc)"
      puts "  type:      #{type}"
      puts "  mime type: #{blob.mime_type}"
      puts "  language:  #{blob.language}"

      if blob.large?
        puts "  blob is too large to be shown"
      end

      if blob.generated?
        puts "  appears to be generated source code"
      end

      if blob.vendored?
        puts "  appears to be a vendored file"
      end
    end
  else
    abort HELP_TEXT
  end
end

github_linguist(ARGV)