# redMine - project management software
# Copyright (C) 2006-2007  Jean-Philippe Lang
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
# 
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
# 
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

require 'redmine/scm/adapters/mercurial_adapter'

class Repository::Mercurial < Repository
  # sort changesets by revision number
  has_many :changesets, :order => "#{Changeset.table_name}.id DESC", :foreign_key => 'repository_id'

  attr_protected :root_url
  validates_presence_of :url

  FETCH_AT_ONCE = 100  # number of changesets to fetch at once

  ATTRIBUTE_KEY_NAMES = {
      "url"          => "Root directory",
    }
  def self.human_attribute_name(attribute_key_name)
    ATTRIBUTE_KEY_NAMES[attribute_key_name] || super
  end

  def self.scm_adapter_class
    Redmine::Scm::Adapters::MercurialAdapter
  end

  def self.scm_name
    'Mercurial'
  end

  def repo_log_encoding
    'UTF-8'
  end

  # Returns the readable identifier for the given mercurial changeset
  def self.format_changeset_identifier(changeset)
    "#{changeset.revision}:#{changeset.scmid}"
  end

  # Returns the identifier for the given Mercurial changeset
  def self.changeset_identifier(changeset)
    changeset.scmid
  end

  def branches
    nil
  end

  def tags
    nil
  end

  def diff_format_revisions(cs, cs_to, sep=':')
    super(cs, cs_to, ' ')
  end

  # Finds and returns a revision with a number or the beginning of a hash
  def find_changeset_by_name(name)
    return nil if name.nil? || name.empty?
    if /[^\d]/ =~ name or name.to_s.size > 8
      e = changesets.find(:first, :conditions => ['scmid = ?', name.to_s])
    else
      e = changesets.find(:first, :conditions => ['revision = ?', name.to_s])
    end
    return e if e
    changesets.find(:first, :conditions => ['scmid LIKE ?', "#{name}%"])  # last ditch
  end

  # Returns the latest changesets for +path+; sorted by revision number
  # Default behavior is to search in cached changesets
  #
  # Because :order => 'id DESC' is defined at 'has_many',
  # there is no need to set 'order'.
  # But, MySQL test fails.
  # Sqlite3 and PostgreSQL pass.
  # Is this MySQL bug?
  def latest_changesets(path, rev, limit=10)
    if path.blank?
      changesets.find(:all, :include => :user, :limit => limit, :order => 'id DESC')
    else
      changesets.find(:all, :select => "DISTINCT #{Changeset.table_name}.*",
                      :joins => :changes,
                      :conditions => ["#{Change.table_name}.path = ? OR #{Change.table_name}.path LIKE ? ESCAPE ?",
                                      path.with_leading_slash,
                                      "#{path.with_leading_slash.gsub(/[%_\\]/) { |s| "\\#{s}" }}/%", '\\'],
                      :include => :user, :limit => limit, 
                      :order => "#{Changeset.table_name}.id DESC" )
    end
  end

  def fetch_changesets
    scm_rev = scm.info.lastrev.revision.to_i
    db_rev = latest_changeset ? latest_changeset.revision.to_i : -1
    return unless db_rev < scm_rev  # already up-to-date

    logger.debug "Fetching changesets for repository #{url}" if logger
    (db_rev + 1).step(scm_rev, FETCH_AT_ONCE) do |i|
      transaction do
        scm.each_revision('', i, [i + FETCH_AT_ONCE - 1, scm_rev].min) do |re|
          cs = Changeset.create(:repository => self,
                                :revision => re.revision,
                                :scmid => re.scmid,
                                :committer => re.author,
                                :committed_on => re.time,
                                :comments => re.message)
          re.paths.each { |e| cs.create_change(e) }
        end
      end
    end
    self
  end
end