#!/usr/bin/env ruby

# A hacky script that allows you to search with ag
# <https://github.com/ggreer/the_silver_searcher> and edit the results in
# $EDITOR. The changes are propagated to all listed files, if any.
#
# Usage: wag [pattern]
#
# TODO Also rename files whose names have been changed

if ARGV.empty?
  puts "You didn't enter in anything!"
  exit 1
end

require 'tempfile'
require 'shellwords'

t = Tempfile.new('.ag-results')
out = system("ag #{ARGV.join(' ')} --nogroup --nocolor > #{t.path}")
if [false, nil].include? out
  puts "No matches" if out === false

  t.unlink
  exit 1
end

old_lines = File.open(t.path).readlines
system("#{ENV['EDITOR']} #{t.path}")
lines = File.open(t.path).readlines
t.unlink

if old_lines.length != lines.length
  puts "There was a line-number mismatch. Abort! Abort! Abort!"
  exit 2
end

i = nil
lines.each_with_index do |line, i|
  next if line.empty? || line.eql?(old_lines[i])

  l = line.split(":", 3)
  unless l.length == 3
    puts "Line #{i} is malformed as was skipped"
    next
  end

  filename = Shellwords.escape(l[0])
  lineno = Shellwords.escape(l[1])
  content = l[2].gsub("'", "\\'")

  if system("sed -i .bak '#{lineno}c\\
#{content}' #{filename}")
    puts "Replaced line #{lineno} in #{filename}"
  else
    puts "Failed to replace line #{lineno} in #{filename}"
  end

  system("rm -f #{filename}.bak") if File.exists?("#{filename}.bak")
end

if i === nil
  puts "Didn't do nuthin'"
else
  puts "Done!"
end