#!/usr/bin/ruby

require 'fileutils'

if ARGV.length < 2
  puts "this script can be used to adjust the file names and paths of duplicates."
  puts "the second duplicate will be moved to the prefix replaced path of the first duplicate unless it already exists."
  puts "use case: mirrored files that have become moved or renamed on one side."
  puts "does a dry-run unless the third argumen is the word run"
  puts "usage: sdupes-rename drop_prefix add_prefix"
  puts "usage: sdupes-rename drop_prefix add_prefix run"
  exit
end

drop_prefix = ARGV[0]
add_prefix = ARGV[1]
dry_run = ARGV[2] != "run"
clusters = $stdin.read.split "\n\n"

clusters.each {|cluster|
  paths = cluster.split("\n")
  next unless paths.length > 1
  targets, duplicates = paths.partition {|a| a.start_with? drop_prefix}
  target = targets.first
  target = target.sub /^#{drop_prefix}/, add_prefix
  FileUtils.mkdir_p File.dirname(target) unless dry_run
  unless File.exists? target
    if dry_run
      puts duplicates.first + " -> " + target
    else
      FileUtils.mv duplicates.first, target
    end
  end
}