#!/usr/bin/env ruby

require 'json'
require 'net/http'
require 'optparse'
require 'plist'
require 'set'
require 'thread'
require 'tmpdir'
require 'uri'
require 'yaml'

ROOT = File.expand_path("../..", __FILE__)
GRAMMARS_PATH = File.join(ROOT, "grammars")
SOURCES_FILE = File.join(ROOT, "grammars.yml")
CSONC = File.join(ROOT, "node_modules", ".bin", "csonc")

$options = {
  :add => false,
  :install => true,
  :output => SOURCES_FILE,
  :remote => true,
}

class SingleFile
  def initialize(path)
    @path = path
  end

  def url
    @path
  end

  def fetch(tmp_dir)
    [@path]
  end
end

class DirectoryPackage
  def self.fetch(dir)
    Dir["#{dir}/**/*"].select do |path|
      case File.extname(path.downcase)
      when '.plist'
        path.split('/')[-2] == 'Syntaxes'
      when '.tmlanguage', '.yaml-tmlanguage'
        true
      when '.cson', '.json'
        path.split('/')[-2] == 'grammars'
      else
        false
      end
    end
  end

  def initialize(directory)
    @directory = directory
  end

  def url
    @directory
  end

  def fetch(tmp_dir)
    self.class.fetch(File.join(ROOT, @directory))
  end
end

class TarballPackage
  def self.fetch(tmp_dir, url)
    `curl --silent --location --max-time 30 --output "#{tmp_dir}/archive" "#{url}"`
    raise "Failed to fetch GH package: #{url} #{$?.to_s}" unless $?.success?

    output = File.join(tmp_dir, 'extracted')
    Dir.mkdir(output)
    `tar -C "#{output}" -xf "#{tmp_dir}/archive"`
    raise "Failed to uncompress tarball: #{tmp_dir}/archive (from #{url}) #{$?.to_s}" unless $?.success?

    DirectoryPackage.fetch(output)
  end

  attr_reader :url

  def initialize(url)
    @url = url
  end

  def fetch(tmp_dir)
    self.class.fetch(tmp_dir, url)
  end
end

class SingleGrammar
  attr_reader :url

  def initialize(url)
    @url = url
  end

  def fetch(tmp_dir)
    filename = File.join(tmp_dir, File.basename(url))
    `curl --silent --location --max-time 10 --output "#{filename}" "#{url}"`
    raise "Failed to fetch grammar: #{url}: #{$?.to_s}" unless $?.success?
    [filename]
  end
end

class SVNPackage
  attr_reader :url

  def initialize(url)
    @url = url
  end

  def fetch(tmp_dir)
    `svn export -q "#{url}/Syntaxes" "#{tmp_dir}/Syntaxes"`
    raise "Failed to export SVN repository: #{url}: #{$?.to_s}" unless $?.success?
    Dir["#{tmp_dir}/Syntaxes/*.{plist,tmLanguage,tmlanguage,YAML-tmLanguage}"]
  end
end

class GitHubPackage
  def self.parse_url(url)
    url, ref = url.split("@", 2)
    path = URI.parse(url).path.split('/')
    [path[1], path[2].chomp('.git'), ref || "master"]
  end

  attr_reader :user
  attr_reader :repo
  attr_reader :ref

  def initialize(url)
    @user, @repo, @ref = self.class.parse_url(url)
  end

  def url
    suffix = "@#{ref}" unless ref == "master"
    "https://github.com/#{user}/#{repo}#{suffix}"
  end

  def fetch(tmp_dir)
    url = "https://github.com/#{user}/#{repo}/archive/#{ref}.tar.gz"
    TarballPackage.fetch(tmp_dir, url)
  end
end

def load_grammar(path)
  case File.extname(path.downcase)
  when '.plist', '.tmlanguage'
    Plist::parse_xml(path)
  when '.yaml-tmlanguage'
    content = File.read(path)
    # Attempt to parse YAML file even if it has a YAML 1.2 header
    if content.lines[0] =~ /^%YAML[ :]1\.2/
      content = content.lines[1..-1].join
    end
    begin
      YAML.load(content)
    rescue Psych::SyntaxError => e
      $stderr.puts "Failed to parse YAML grammar '#{path}'"
    end
  when '.cson'
    cson = `"#{CSONC}" "#{path}"`
    raise "Failed to convert CSON grammar '#{path}': #{$?.to_s}" unless $?.success?
    JSON.parse(cson)
  when '.json'
    JSON.parse(File.read(path))
  else
    raise "Invalid document type #{path}"
  end
end

def load_grammars(tmp_dir, source, all_scopes)
  is_url = source.start_with?("http:", "https:")
  return [] if is_url && !$options[:remote]

  p = if !is_url
        if File.directory?(source)
          DirectoryPackage.new(source)
        else
          SingleFile.new(source)
        end
      elsif source.end_with?('.tmLanguage', '.plist', '.YAML-tmLanguage')
        SingleGrammar.new(source)
      elsif source.start_with?('https://github.com')
        GitHubPackage.new(source)
      elsif source.start_with?('http://svn.textmate.org')
        SVNPackage.new(source)
      elsif source.end_with?('.tar.gz')
        TarballPackage.new(source)
      else
        nil
      end

  raise "Unsupported source: #{source}" unless p

  p.fetch(tmp_dir).map do |path|
    grammar = load_grammar(path)
    scope = grammar['scopeName'] || grammar['scope']

    if all_scopes.key?(scope)
      unless all_scopes[scope] == p.url
        $stderr.puts "WARN: Duplicated scope #{scope}\n" +
          "  Current package: #{p.url}\n" +
          "  Previous package: #{all_scopes[scope]}"
      end
      next
    end
    all_scopes[scope] = p.url
    grammar
  end.compact
end

def install_grammars(grammars, path)
  installed = []

  grammars.each do |grammar|
    scope = grammar['scopeName'] || grammar['scope']
    File.write(File.join(GRAMMARS_PATH, "#{scope}.json"), JSON.pretty_generate(grammar))
    installed << scope
  end

  $stderr.puts("OK #{path} (#{installed.join(', ')})")
end

def run_thread(queue, all_scopes)
  Dir.mktmpdir do |tmpdir|
    loop do
      source, index = begin
        queue.pop(true)
      rescue ThreadError
        # The queue is empty.
        break
      end

      dir = "#{tmpdir}/#{index}"
      Dir.mkdir(dir)

      grammars = load_grammars(dir, source, all_scopes)
      install_grammars(grammars, source) if $options[:install]
    end
  end
end

def generate_yaml(all_scopes, base)
  yaml = all_scopes.each_with_object(base) do |(key,value),out|
    out[value] ||= []
    out[value] << key
  end

  yaml = Hash[yaml.sort]
  yaml.each { |k, v| v.sort! }
  yaml
end

def main(sources)
  begin
    Dir.mkdir(GRAMMARS_PATH)
  rescue Errno::EEXIST
  end

  `npm install`

  all_scopes = {}

  if source = $options[:add]
    Dir.mktmpdir do |tmpdir|
      grammars = load_grammars(tmpdir, source, all_scopes)
      install_grammars(grammars, source) if $options[:install]
    end
    generate_yaml(all_scopes, sources)
  else
    queue = Queue.new

    sources.each do |url, scopes|
      queue.push([url, queue.length])
    end

    threads = 8.times.map do
      Thread.new { run_thread(queue, all_scopes) }
    end
    threads.each(&:join)
    generate_yaml(all_scopes, {})
  end
end

OptionParser.new do |opts|
  opts.banner = "Usage: #{$0} [options]"

  opts.on("--add GRAMMAR", "Add a new grammar. GRAMMAR may be a file path or URL.") do |a|
    $options[:add] = a
  end

  opts.on("--[no-]install", "Install grammars into grammars/ directory.") do |i|
    $options[:install] = i
  end

  opts.on("--output FILE", "Write output to FILE. Use - for stdout.") do |o|
    $options[:output] = o == "-" ? $stdout : o
  end

  opts.on("--[no-]remote", "Download remote grammars.") do |r|
    $options[:remote] = r
  end
end.parse!

sources = File.open(SOURCES_FILE) do |file|
  YAML.load(file)
end

yaml = main(sources)

if $options[:output].is_a?(IO)
  $options[:output].write(YAML.dump(yaml))
else
  File.write($options[:output], YAML.dump(yaml))
end