# Copyright (c) 2007 Kelly McCauley <kelly@whoisat@drotner.com>
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.


namespace :migration do
  desc "Prints out the list of migrations"
  task :list => :environment do
    migration_files.each {|f| puts f}
  end

  desc "Prints out the commands needed to renumber the given migration. Usage: FROM=number TO=number"
  task :renumber => :environment do

    if ENV['FROM'].blank?
      raise 'No FROM value given.  Set FROM=number.'
    end
    from_num = ENV['FROM'].to_i

    if ENV['TO'].blank?
      raise 'No TO value given. Set TO=number.'
    end
    to_num = ENV['TO'].to_i

    return if from_num == to_num

    min_num = from_num
    min_num = to_num if to_num < from_num
    min_num -= 1

    if !current_migrations.key?(from_num)
      raise "There is no " << sprintf('%03d', from_num) << " migration"
    end

    # Create the commands
    puts 'Cut and paste the following...'
    puts "----- BEGIN -----\n\n"
    puts "rake db:migrate VERSION=#{sprintf('%03d', min_num)}"
    puts "cd #{File.join('db','migrate')}"
    mv_cmd = 'mv '
    svn_mv_cmd = 'svn mv '

    if !current_migrations.key?(to_num)
      # The target migration number is not taken, so just move it.
      # cmd = ''
      # if current_migrations[from_num][1]
      #   cmd << svn_mv_cmd
      # else
      #   cmd << mv_cmd
      # end
      # cmd << sprintf('%03d', from_num) << '_' << current_migrations[from_num][0] << ' '
      # cmd << sprintf('%03d', to_num) << '_' << current_migrations[from_num][0]
      # puts cmd

      print_cmd(to_num, current_migrations[from_num])


    elsif from_num > to_num
      to_num.upto(from_num - 1) do |i|
        next unless current_migrations.key?(i)
        # cmd = ''
        # if current_migrations[i][1]
        #   cmd << svn_mv_cmd
        # else
        #   cmd << mv_cmd
        # end
        # cmd << sprintf('%03d', i) << '_' << current_migrations[i][0] << ' '
        # cmd << sprintf('%03d', i + 1) << '_' << current_migrations[i][0]
        # puts cmd
        print_cmd(i + 1, current_migrations[i])
      end

      cmd = ''
      # if current_migrations[from_num][1]
      #   cmd << svn_mv_cmd
      # else
      #   cmd << mv_cmd
      # end
      # cmd << sprintf('%03d', from_num) << '_' << current_migrations[from_num][0] << ' '
      # cmd << sprintf('%03d', to_num) << '_' << current_migrations[from_num][0]
      # puts cmd
      print_cmd(to_num, current_migrations[from_num])


    elsif from_num < to_num
      (from_num + 1).upto(to_num) do |i|
        next unless current_migrations.key?(i)
        # cmd = ''
        # if current_migrations[i][1]
        #   cmd << svn_mv_cmd
        # else
        #   cmd << mv_cmd
        # end
        # cmd << sprintf('%03d', i) << '_' << current_migrations[i][0] << ' '
        # cmd << sprintf('%03d', i - 1) << '_' << current_migrations[i][0]
        # puts cmd
        print_cmd(i - 1, current_migrations[i])
      end

      # cmd = ''
      # if current_migrations[from_num][1]
      #   cmd << svn_mv_cmd
      # else
      #   cmd << mv_cmd
      # end
      # cmd << sprintf('%03d', from_num) << '_' << current_migrations[from_num][0] << ' '
      # cmd << sprintf('%03d', to_num) << '_' << current_migrations[from_num][0]
      # puts cmd
      print_cmd(to_num, current_migrations[from_num])

    end
    puts "cd #{File.join('..','..')}"
    puts "rake db:migrate"
    puts "\n----- END -----"


    #puts files.join("\n")
  end

  desc "Prints out the commands needed to close all gaps in the migration numbering."
  task :close_gaps => :environment do

    highest = current_migrations.keys.sort.last

    idx = 1

    # Create the commands
    cmds = []
    first_idx_to_move = nil

    1.upto(highest) {|i|
      if current_migrations.key?(i)
        if idx != current_migrations[i][2]
          first_idx_to_move = idx if first_idx_to_move.nil?
          cmds << fmt_cmd(idx, current_migrations[i])
        end
        idx += 1
      end
    }

    if first_idx_to_move.nil?
      puts "No migration numbering gaps to close"

    else
      migrate_to_version = first_idx_to_move <= 1 ? 0 : first_idx_to_move - 1

      puts 'Cut and paste the following...'
      puts "----- BEGIN -----\n\n"
      puts "rake db:migrate VERSION=#{mn_fmt(migrate_to_version)}"
      puts "cd #{File.join('db','migration')}"

      cmds.each {|c| puts c}

      puts "cd #{File.join('..','..')}"
      puts "rake db:migrate"
      puts "\n----- END -----"
    end


  end

  private

  # Checks to see if subversion is installed
  def has_subversion?
    unless @has_subversion
      @has_subversion = false
      `svn --version` rescue nil
      @has_subversion = true if !$?.nil? && $?.success?
    end

    return @has_subversion
  end

  def migration_dir
    unless @migration_dir
      @migration_dir = File.join(RAILS_ROOT, 'db', 'migrate')
    end

    return @migration_dir
  end

  def using_subversion?
    unless @svn_dir
      @svn_dir = File.join(migration_dir, '.svn')
    end

    return File.exists?(@svn_dir)
  end

  def migration_files
    files = Dir.entries(migration_dir)
    files.delete_if{|x| x !~ /\.rb$/}
    files.sort!

    return files
  end

  def current_migrations
    unless @current_migrations
      @current_migrations = {}
      migration_files.each {|f|
        f = f.to_s
        use_svn_mv = false
        #if has_subversion && using_subversion
        if has_subversion? && using_subversion?
          file_path = File.join(migration_dir, f)
          out = `svn status -v #{file_path}`
          use_svn_mv = true if out !~ /^\?/
        end
        num, name = f.split(/_/, 2)
        num = num.to_i
        # puts "#{num} #{name} #{use_svn_mv}"
        @current_migrations[num] = [name, use_svn_mv, num]
      }

    end

    return @current_migrations

  end

  def mn_fmt(mn)
    sprintf('%03d',mn)
  end

  def print_cmd(to_number, m_data)
    puts fmt_cmd(to_number, m_data)
  end

  def fmt_cmd(to_number, m_data)
    name = m_data[0]
    use_svn_mv = m_data[1]
    from_number = m_data[2]

    cmd = ''
    if use_svn_mv
      cmd << 'svn mv '
    else
      cmd << 'mv '
    end

    cmd << mn_fmt(from_number) << '_' << name << ' ' << mn_fmt(to_number) << '_' << name

    return cmd
  end


end