# This file is not a standalone script. It is a kind

# of lightweight Mercurial library used by other scripts.

require 'uri'

require 'open3'

require 'shellwords'

# Following hack is to make hglib.rb working wit both jv:scripts and

# Smalltalk/X rakefiles. 

begin

  require 'rakelib/inifile'

rescue

  begin

    require 'inifile'

  rescue LoadError => ex

    $LOGGER.error("Cannot load package 'inifile'")

    $LOGGER.error("Run 'gem install inifile' to install it")

    exit 1

  end

end

if not $LOGGER then

  if STDOUT.tty? then

    require 'logger'

    $LOGGER = Logger.new(STDOUT)

    $LOGGER.level = Logger::INFO

  else 

    require 'syslog/logger'

    $LOGGER = Syslog::Logger.new($0)    

  end

end

module HG

  @@config = nil

  GLOBAL_OPTIONS= [:'cwd', :'repository', :'noninteractive', :'config', :'debug', :'debugger',

       :'encoding',:'encodingmode',:'traceback',:'time', :'profile',:'version', :'help',

       :'hidden' ]

  # Execute `hg` command with given positional arguments and

  # keyword arguments turned into command options. For example, 

  #

  #     HG::hg("heads", "default", cwd: '/tmp/testrepo')

  #

  # will result in executing

  # 

  #     hg --cwd '/tmp/testrepo' heads default

  #

  # In addition if block is passed, then the block is evaluate with

  # `hg` command exit status (as Process::Status) and (optionally)

  # with contents of `hg` command stdout and stderr. 

  # If no block is given, an exception is raised when `hg` command 

  # exit status IS NOT zero.

  def self.hg(command, *args, **options, &block)

    g_opts = []

    c_opts = []

    options.each do | k , v |       

      if v != false                

        o = k.size == 1 ? "-#{k}" : "--#{k}"                

        if GLOBAL_OPTIONS.include? k then                  

          if v.kind_of?(Array)

            v.each do | e |

              g_opts << o << (e == true ? '' : e)  

            end

          else

            g_opts << o << (v == true ? '' : v)

          end

        else

          if v.kind_of?(Array)

            v.each do | e |

              c_opts << o << (e == true ? '' : e)  

            end

          else

            c_opts << o << (v == true ? '' : v)

          end

        end

      end

    end

    c_opts.reject! { | e | e.size == 0 }

    cmd = ['hg'] + g_opts + [command] + c_opts + args      

    $LOGGER.debug("executing: #{cmd.shelljoin}")

    if block_given? then

      stdout, stderr, status = Open3.capture3(*cmd)

      case block.arity

      when 1        

        yield status

      when 2        

        yield status, stdout

      when 3        

        yield status, stdout, stderr

      else

        raise Exception.new("invalid arity of given block")

      end

    else

      if not system(*cmd) then

        raise Exception.new("command failed: #{cmd.join(' ')}")

      end

    end    

  end

  def self.config()

    if @@config == nil

      files = Dir.glob('/etc/mercurial/hgrc.d/*.rc') + 

          [ '/etc/mercurial/hgrc' ,

          hgrc() ]  

      @@config = IniFile.new()

      files.each do | file |

        if File.exist?(file)

          $LOGGER.debug("Loading global config from \"#{file}\"")

          @@config.merge!(IniFile.new(:filename => file))

        end

      end  

    end

    return @@config

  end

  def self.hgrc()

  	return File.expand_path('~/.hgrc')

  end

  class Repository

    attr_accessor :path, :config

    # Clone a repository from given `uri` to given `directory`. 

    # Returns an `HG::Repository` instance representing the repository

    # clone. 

    # If `noupdate` is true, working copy is not updated, i.e., will be

    # empty. Use this when you're going to issue `update(rev)` shortly after.

    #

    def self.clone(uri, directory, noupdate: false)

      if noupdate then

        HG::hg("clone", uri, directory, noupdate: true)

      else

        HG::hg("clone", uri, directory)

      end

      return HG::Repository.new(directory)

    end

    # Like HG::hg, but passes --cwd @path

    def hg(command, *args, **options, &block)

      options[:cwd] = @path

      HG::hg(command, *args, **options, &block)

    end

    def hgrc() 

      return File.join(@path, '.hg', 'hgrc')

    end

    def initialize(directory)

      @path = directory

      config_file = hgrc()

      if File.exist? ( config_file ) 

        $LOGGER.debug("Loading repository config from \"#{config_file}\"")

        @config = HG::config().merge(IniFile.new(:filename => config_file))

      else

        @config = HG::config()

      end

    end

    def log(revset, template = "{node|short}\n")      

      log = []

      hg("log", rev: revset, template: template) do | status, out |     

        if status.success?

          puts out

          log = out.split("\n")

        end

      end

      return log

    end

    # Return changeset IDs of all head revisions. 

    # If `branch` is given, return only heads in given

    # branch.

    def heads(branch = nil) 

      if branch then

        return log("head() and branch('#{branch}')")

      else

        return log("head()")

      end

    end

    # Return a hash "bookmark => revision" of all 

    # bookmarks. 

    def bookmarks(branch = nil)

      revset  = "bookmark()"

      revset += " and branch('#{branch}')" if branch

      bookmarks = {}

      self.log(revset, "{bookmarks}|{node|short}\n").each do | line |

        bookmark, changesetid = line.split("|")

        bookmarks[bookmark] = changesetid

      end

      return bookmarks

    end

    def pull(remote = 'default', user: nil, pass: nil)

      authconf = []

      if pass != nil then

        if user == nil then

          raise Exception.new("Password given but not username! Use user: named param to specify username.")

        end

        # If user/password is provided, make sure we don't have

        # username in remote URI. Otherwise Mercurial won't use 

        # password from config!

        uri = URI.parse(remote)

        uri.user = nil

        remote = uri.to_s        

        authconf << "auth.bb.prefix=#{remote}"

        authconf << "auth.bb.username=#{user}"        

        authconf << "auth.bb.password=#{pass}"        

      end

      hg("pull", remote, config: authconf) do | status |

        if not status.success? then

          raise Exception.new("Failed to pull from #{remote}")

        end

      end

    end

    def push(remote = 'default', user: nil, pass: nil)

      authconf = []

      if pass != nil then

        if user == nil then

          raise Exception.new("Password given but not username! Use user: named param to specify username.")

        end

        # If user/password is provided, make sure we don't have

        # username in remote URI. Otherwise Mercurial won't use 

        # password from config!

        uri = URI.parse(remote)

        uri.user = nil

        remote = uri.to_s                

        authconf << "bb.prefix = #{remote}"

        authconf << "bb.username = #{user}"        

        authconf << "bb.password = #{pass}"        

      end

      hg("pull", remote, config: authconf) do | status |

        if status.exitstatus != 0 and status.exitstatus != 1 then

          raise Exception.new("Failed to pull from #{remote}")

        end

      end      

    end

    # Create a shared clone in given directory, Return a new

    # HG::Repository object on the shared clone

    def share(dst, rev = nil)

      if File.exist? dst then

        raise Exception.new("Destination file exists: #{dst}")

      end

      if rev == nil then

        rev = log('.')[0]

      end

      if not has_revision?(rev) 

        raise Exception.new("Revision #{rev} does not exist")

      end

      mkdir_p File.dirname(dst);

      HG::hg("share", path, dst, config: 'extensions.share=', noupdate: true, bookmarks: false)

      share = Repository.new(dst)

      share.update(rev);

      return share

    end

    # Updates the repository's working copy to given 

    # revision if given. If not, update to most-recent

    # head, as plain

    #

    #   hg update

    #

    # would do. 

    def update(rev = nil)

      if rev 

        if not has_revision? rev then

          raise Exception.new("Revision #{rev} does not exist")

        end

        hg("update", rev: rev)

      else

        hg("update")

      end

    end

    # Merge given revision. Return true, if the merge was

    # successful, false otherwise

    def merge(rev)

      if not has_revision? rev then

        raise Exception.new("Revision #{rev} does not exist")

      end

      hg("merge", rev) do | status |

        return status.success?

      end

    end

    def commit(message)

      user = ''

      if not @config['ui'].has_key? 'username' then

        user = @config['ui']['username']

      end

      hg("commit", message: message, user: user)

    end

    def has_revision?(rev)

    	revs = log(rev)

    	return revs.size > 0      

    end

    # Lookup a repository in given `directory`. If found,

    # return it as instance of HG::Repository. If not,

    # `nil` is returned.

    def self.lookup(directory)

      return nil if not File.exist?(directory)

      repo_dir = directory

      while repo_dir != nil

        if HG::repository? repo_dir

          return Repository.new(repo_dir)

        end

        repo_dir_parent = File.dirname(repo_dir)

        if repo_dir_parent == repo_dir

          repo_dir = nil

        else 

          repo_dir = repo_dir_parent

        end

      end

    end    

    # Initializes and empty Mercurial repository in given `directory`

    def self.init(directory)

      FileUtils.mkdir_p File.dirname(directory)

      HG::hg("init", directory)

      return Repository.new(directory)

    end

  end # class Repository 

  # Return `true` if given `directory` is a root of mercurial

  # repository, `false` otherwise.

  def self.repository?(directory)

    return File.directory? File.join(directory, '.hg')

  end

  # Enumerate all repositories in given `directory`

  def self.forest(directory, &block)      

    if repository? directory  

      yield Repository.new(directory)

    end

    Dir.foreach(directory) do |x|

      path = File.join(directory, x)

      if File.directory? path       

        if x == "." or x == ".." or x == ".svn" or x == '.git'

          next    

        elsif File.directory?(path)

          forest(path, &block)

        end

      end

    end  

  end

end # module HG