#!/usr/bin/env ruby -wU

# The purpose of this script is to provide a list of files:
#
# - in left but not in right
# - in right but not in left
# - in left and same as in right
# - in left but different from right
require 'optparse'
DEFAULT_PATTERN = ["spec/**/*.*", "app/**/*.*", "lib/**/*.*"]
config = { left: './', dir: false, right: './hyrax-webapp', summary: false, patterns_to_check: DEFAULT_PATTERN }

command_name = File.basename(__FILE__)

consider_replacing_pattern = true
nlp = new_line_padding = " " * 37
optparse = OptionParser.new do |options|
  # This banner is the first line of left help documentation.
  options.set_banner "Usage: #{command_name} [options]\n\n" \
                     "#{command_name} - A command line tool for listing directory differences.\n\n"

  options.on('-r PATH', '--right', String, "The file path that contains the \"on the right\"\n#{nlp}directory.\n#{nlp}Default: #{config[:right]}") do |right|
    config[:right] = right
  end

  options.on('-l PATH', '--left', String, "The file path that contains the \"on the left\"\n#{nlp}directory.\n#{nlp}Default: #{config[:left]}") do |left|
    config[:left] = left
  end

  options.on('-s', '--summary', "Only render a summary.\n#{nlp}Default: #{config[:summary].inspect}") do |summary|
    config[:summary] = summary
  end

  options.on('-d', '--dir-summaries', "Render the directory summaries.\n#{nlp}Default: #{config[:dir].inspect}") do |dir|
    config[:dir] =dir
  end

  options.on('-p STRING', '--pattern', String, %(The pattern(s) to check for variance\n#{nlp}Default:\n#{nlp}  #{config[:patterns_to_check].join("\n#{nlp}  ")})) do |pattern|
    if consider_replacing_pattern
      config[:patterns_to_check] = []
      consider_replacing_pattern = false
    end

    config[:patterns_to_check] << pattern
  end

  options.on_tail('-h', '--help', "You're looking at it!") do
    warn options
    exit 1
  end
end

begin
  optparse.parse!
  mandatory = %i[left right]
  missing = mandatory.select { |param| config[param].nil? }
  raise OptionParser::MissingArgument, missing.join(', ') unless missing.empty?
rescue OptionParser::InvalidOption, OptionParser::MissingArgument
  warn "\e[0m\e[1m\e[31m#{$!}\e[0m\n"
  warn optparse
  exit
end

require 'debug'; binding.break

require 'fileutils'

in_left_but_not_in_right = []
in_right_but_not_in_left = []
duplicates = []
different = []

left = config.fetch(:left)
right = config.fetch(:right)
dir_glob_patterns_to_check = config.fetch(:patterns_to_check)
summary = config.fetch(:summary)

dir_glob_patterns_to_check.each do |pattern|
  Dir.glob(File.join(left, pattern)).each do |left_path|
    path = left_path.sub(File.join(left, '/'), '')
    right_path = File.join(right, path)
    if File.exist?(right_path)
      results = `diff #{left_path} #{right_path}`.strip
      if results.empty?
        duplicates << path
      else
        different << path
      end
    else
      in_left_but_not_in_right << path
    end
  end
  Dir.glob(File.join(right, pattern)).each do |right_path|
    path = right_path.sub(File.join(right, '/'), '')
    left_path = File.join(left, path)
    next if File.exist?(left_path)

    in_right_but_not_in_left << path
  end
end

GitData = Struct.new(:url, :sha, :status, :branch, keyword_init: true)
def git_data_for(source)
  GitData.new(
    url: `cd #{source}; git remote get-url origin`.strip,
    sha: `cd #{source}; git log --pretty=format:'%H' -1`.strip,
    status: `cd #{source}; git status --porcelain`.strip.size.zero? ? "clean" : "dirty",
    branch: `cd #{source}; git branch --show-current`.strip
  )
end

left_data = git_data_for(left)
right_data = git_data_for(right)

puts "#"*72
puts "# #{command_name} run context:"
puts "#"*72
puts "#"
puts "# Working Directory: #{FileUtils.pwd}"
puts "#"
puts "# Left: #{left}"
puts "#   URL: #{left_data.url}"
puts "#   BRANCH: #{left_data.branch}"
puts "#   SHA: #{left_data.sha}"
puts "#   STATUS: #{left_data.status}"
puts "#"
puts "# Right: #{right}"
puts "#   URL: #{right_data.url}"
puts "#   BRANCH: #{right_data.branch}"
puts "#   SHA: #{right_data.sha}"
puts "#   STATUS: #{right_data.status}"
puts "#"
puts "# Patterns to Check:"
config.fetch(:patterns_to_check).each do |pattern|
  puts "#  * #{pattern}"
end
puts "#"

puts "# = Duplicates: #{duplicates.size}"
puts "# < In left but not right: #{in_left_but_not_in_right.size}"
if config.fetch(:dir)
  puts "# < Breakdown:"
  in_left_but_not_in_right.group_by { |path| path.split("/")[0..1].flatten.join("/") }.each do |path, elements|
    puts "# <   #{path}: #{elements.size}"
  end
  puts "#"
end
puts "# > In right but not left: #{in_right_but_not_in_left.size}"
if config.fetch(:dir)
  puts "# > Breakdown:"
  in_right_but_not_in_left.group_by { |path| path.split("/")[0..1].flatten.join("/") }.each do |path, elements|
    puts "# >   #{path}: #{elements.size}"
  end
  puts "#"
end
puts "# Δ Different between left and right: #{different.size}"
if config.fetch(:dir)
  puts "# Δ Breakdown:"
  different.group_by { |path| path.split("/")[0..1].flatten.join("/") }.each do |path, elements|
    puts "# Δ   #{path}: #{elements.size}"
  end
end
puts ""
unless summary
  puts "################################################################"
  puts "# Files in \"left\" that are exact duplicates of \"right\" files"
  puts "# They are prefixed with a `='"
  puts "################################################################"
  duplicates.each do |path|
    puts "= #{path}"
    if ENV['RM_DUPS']
      File.unlink(path)
    end
  end

  puts ""

  puts "#################################################"
  puts "# Files that are in \"left\" but not in \"right\""
  puts "# They are prefixed with a `<'"
  puts "#################################################"
  in_left_but_not_in_right.each do |path|
    puts "< #{path}"
  end

  puts ""

  puts "#################################################"
  puts "# Files that are in \"right\" but not in \"left\""
  puts "# They are prefixed with a `>'"
  puts "#################################################"
  in_right_but_not_in_left.each do |path|
    puts "> #{path}"
  end

  puts ""
  puts "####################################################"
  puts "# Files that are different in \"left\" and \"right\""
  puts "# They are prefixed with a `Δ'"
  puts "####################################################"
  different.each do |path|
    puts "Δ #{path}"
  end
end