require "thor"
require "thor/group"
require "thor/core_ext/io_binary_read"

require "yaml"
require "digest/md5"
require "pathname"

class Thor::Runner < Thor #:nodoc: # rubocop:disable ClassLength
  map "-T" => :list, "-i" => :install, "-u" => :update, "-v" => :version

  def self.banner(command, all = false, subcommand = false)
    "thor " + command.formatted_usage(self, all, subcommand)
  end

  def self.exit_on_failure?
    true
  end

  # Override Thor#help so it can give information about any class and any method.
  #
  def help(meth = nil)
    if meth && !respond_to?(meth)
      initialize_thorfiles(meth)
      klass, command = Thor::Util.find_class_and_command_by_namespace(meth)
      self.class.handle_no_command_error(command, false) if klass.nil?
      klass.start(["-h", command].compact, :shell => shell)
    else
      super
    end
  end

  # If a command is not found on Thor::Runner, method missing is invoked and
  # Thor::Runner is then responsible for finding the command in all classes.
  #
  def method_missing(meth, *args)
    meth = meth.to_s
    initialize_thorfiles(meth)
    klass, command = Thor::Util.find_class_and_command_by_namespace(meth)
    self.class.handle_no_command_error(command, false) if klass.nil?
    args.unshift(command) if command
    klass.start(args, :shell => shell)
  end

  desc "install NAME", "Install an optionally named Thor file into your system commands"
  method_options :as => :string, :relative => :boolean, :force => :boolean
  def install(name) # rubocop:disable MethodLength
    initialize_thorfiles

    # If a directory name is provided as the argument, look for a 'main.thor'
    # command in said directory.
    begin
      if File.directory?(File.expand_path(name))
        base = File.join(name, "main.thor")
        package = :directory
        contents = open(base, &:read)
      else
        base = name
        package = :file
        contents = open(name, &:read)
      end
    rescue OpenURI::HTTPError
      raise Error, "Error opening URI '#{name}'"
    rescue Errno::ENOENT
      raise Error, "Error opening file '#{name}'"
    end

    say "Your Thorfile contains:"
    say contents

    unless options["force"]
      return false if no?("Do you wish to continue [y/N]?")
    end

    as = options["as"] || begin
      first_line = contents.split("\n")[0]
      (match = first_line.match(/\s*#\s*module:\s*([^\n]*)/)) ? match[1].strip : nil
    end

    unless as
      basename = File.basename(name)
      as = ask("Please specify a name for #{name} in the system repository [#{basename}]:")
      as = basename if as.empty?
    end

    location = if options[:relative] || name =~ %r{^https?://}
      name
    else
      File.expand_path(name)
    end

    thor_yaml[as] = {
      :filename   => Digest::MD5.hexdigest(name + as),
      :location   => location,
      :namespaces => Thor::Util.namespaces_in_content(contents, base)
    }

    save_yaml(thor_yaml)
    say "Storing thor file in your system repository"
    destination = File.join(thor_root, thor_yaml[as][:filename])

    if package == :file
      File.open(destination, "w") { |f| f.puts contents }
    else
      require "fileutils"
      FileUtils.cp_r(name, destination)
    end

    thor_yaml[as][:filename] # Indicate success
  end

  desc "version", "Show Thor version"
  def version
    require "thor/version"
    say "Thor #{Thor::VERSION}"
  end

  desc "uninstall NAME", "Uninstall a named Thor module"
  def uninstall(name)
    raise Error, "Can't find module '#{name}'" unless thor_yaml[name]
    say "Uninstalling #{name}."
    require "fileutils"
    FileUtils.rm_rf(File.join(thor_root, (thor_yaml[name][:filename]).to_s))

    thor_yaml.delete(name)
    save_yaml(thor_yaml)

    puts "Done."
  end

  desc "update NAME", "Update a Thor file from its original location"
  def update(name)
    raise Error, "Can't find module '#{name}'" if !thor_yaml[name] || !thor_yaml[name][:location]

    say "Updating '#{name}' from #{thor_yaml[name][:location]}"

    old_filename = thor_yaml[name][:filename]
    self.options = options.merge("as" => name)

    if File.directory? File.expand_path(name)
      require "fileutils"
      FileUtils.rm_rf(File.join(thor_root, old_filename))

      thor_yaml.delete(old_filename)
      save_yaml(thor_yaml)

      filename = install(name)
    else
      filename = install(thor_yaml[name][:location])
    end

    File.delete(File.join(thor_root, old_filename)) unless filename == old_filename
  end

  desc "installed", "List the installed Thor modules and commands"
  method_options :internal => :boolean
  def installed
    initialize_thorfiles(nil, true)
    display_klasses(true, options["internal"])
  end

  desc "list [SEARCH]", "List the available thor commands (--substring means .*SEARCH)"
  method_options :substring => :boolean, :group => :string, :all => :boolean, :debug => :boolean
  def list(search = "")
    initialize_thorfiles

    search = ".*#{search}" if options["substring"]
    search = /^#{search}.*/i
    group  = options[:group] || "standard"

    klasses = Thor::Base.subclasses.select do |k|
      (options[:all] || k.group == group) && k.namespace =~ search
    end

    display_klasses(false, false, klasses)
  end

private

  def thor_root
    Thor::Util.thor_root
  end

  def thor_yaml
    @thor_yaml ||= begin
      yaml_file = File.join(thor_root, "thor.yml")
      yaml = YAML.load_file(yaml_file) if File.exist?(yaml_file)
      yaml || {}
    end
  end

  # Save the yaml file. If none exists in thor root, creates one.
  #
  def save_yaml(yaml)
    yaml_file = File.join(thor_root, "thor.yml")

    unless File.exist?(yaml_file)
      require "fileutils"
      FileUtils.mkdir_p(thor_root)
      yaml_file = File.join(thor_root, "thor.yml")
      FileUtils.touch(yaml_file)
    end

    File.open(yaml_file, "w") { |f| f.puts yaml.to_yaml }
  end

  # Load the Thorfiles. If relevant_to is supplied, looks for specific files
  # in the thor_root instead of loading them all.
  #
  # By default, it also traverses the current path until find Thor files, as
  # described in thorfiles. This look up can be skipped by supplying
  # skip_lookup true.
  #
  def initialize_thorfiles(relevant_to = nil, skip_lookup = false)
    thorfiles(relevant_to, skip_lookup).each do |f|
      Thor::Util.load_thorfile(f, nil, options[:debug]) unless Thor::Base.subclass_files.keys.include?(File.expand_path(f))
    end
  end

  # Finds Thorfiles by traversing from your current directory down to the root
  # directory of your system. If at any time we find a Thor file, we stop.
  #
  # We also ensure that system-wide Thorfiles are loaded first, so local
  # Thorfiles can override them.
  #
  # ==== Example
  #
  # If we start at /Users/wycats/dev/thor ...
  #
  # 1. /Users/wycats/dev/thor
  # 2. /Users/wycats/dev
  # 3. /Users/wycats <-- we find a Thorfile here, so we stop
  #
  # Suppose we start at c:\Documents and Settings\james\dev\thor ...
  #
  # 1. c:\Documents and Settings\james\dev\thor
  # 2. c:\Documents and Settings\james\dev
  # 3. c:\Documents and Settings\james
  # 4. c:\Documents and Settings
  # 5. c:\ <-- no Thorfiles found!
  #
  def thorfiles(relevant_to = nil, skip_lookup = false)
    thorfiles = []

    unless skip_lookup
      Pathname.pwd.ascend do |path|
        thorfiles = Thor::Util.globs_for(path).map { |g| Dir[g] }.flatten
        break unless thorfiles.empty?
      end
    end

    files  = (relevant_to ? thorfiles_relevant_to(relevant_to) : Thor::Util.thor_root_glob)
    files += thorfiles
    files -= ["#{thor_root}/thor.yml"]

    files.map! do |file|
      File.directory?(file) ? File.join(file, "main.thor") : file
    end
  end

  # Load Thorfiles relevant to the given method. If you provide "foo:bar" it
  # will load all thor files in the thor.yaml that has "foo" e "foo:bar"
  # namespaces registered.
  #
  def thorfiles_relevant_to(meth)
    lookup = [meth, meth.split(":")[0...-1].join(":")]

    files = thor_yaml.select do |_, v|
      v[:namespaces] && !(v[:namespaces] & lookup).empty?
    end

    files.map { |_, v| File.join(thor_root, (v[:filename]).to_s) }
  end

  # Display information about the given klasses. If with_module is given,
  # it shows a table with information extracted from the yaml file.
  #
  def display_klasses(with_modules = false, show_internal = false, klasses = Thor::Base.subclasses)
    klasses -= [Thor, Thor::Runner, Thor::Group] unless show_internal

    raise Error, "No Thor commands available" if klasses.empty?
    show_modules if with_modules && !thor_yaml.empty?

    list = Hash.new { |h, k| h[k] = [] }
    groups = klasses.select { |k| k.ancestors.include?(Thor::Group) }

    # Get classes which inherit from Thor
    (klasses - groups).each { |k| list[k.namespace.split(":").first] += k.printable_commands(false) }

    # Get classes which inherit from Thor::Base
    groups.map! { |k| k.printable_commands(false).first }
    list["root"] = groups

    # Order namespaces with default coming first
    list = list.sort { |a, b| a[0].sub(/^default/, "") <=> b[0].sub(/^default/, "") }
    list.each { |n, commands| display_commands(n, commands) unless commands.empty? }
  end

  def display_commands(namespace, list) #:nodoc:
    list.sort! { |a, b| a[0] <=> b[0] }

    say shell.set_color(namespace, :blue, true)
    say "-" * namespace.size

    print_table(list, :truncate => true)
    say
  end
  alias_method :display_tasks, :display_commands

  def show_modules #:nodoc:
    info = []
    labels = %w(Modules Namespaces)

    info << labels
    info << ["-" * labels[0].size, "-" * labels[1].size]

    thor_yaml.each do |name, hash|
      info << [name, hash[:namespaces].join(", ")]
    end

    print_table info
    say ""
  end
end
