#!/usr/bin/env ruby

require 'utils'
require 'tins/go'
include Tins::GO
require 'tins/xt/string'
require 'term/ansicolor'

def path_shifter(string, separator: ?/, n: nil)
  n or return string
  n, path = n.to_i, string.split(separator)
  if n < 0
    path = path.slice(n..-1)
  else
    path.slice!(0...n)
  end
  path * separator
end

def underscore(string)
  string = path_shifter(string, n: $opts[?n], separator: '::')
  string = Tins::StringUnderscore.instance_method(:underscore).bind(string).()
  $opts[?s] and string.sub!(/(\.rb)?\z/, '.rb')
  string
end

def parameterize(string, separator)
  underscore(string).gsub(?/, separator) # quick and dirty
end

def camelize(string)
  string = path_shifter(string, n: $opts[?n])
  string = string.gsub(/#{Regexp.quote(File.extname(string))}\Z/, '')
  string.camelize
end

def camelcase?(string)
  string[0, 1] =~ /[A-Z]/
end

def compute_shift(config, string)
  string = underscore(string)
  result = config.classify.shift_path_by_default
  for prefix in config.classify.shift_path_for_prefix
    if string.start_with? prefix
      return prefix.count(?/) + 1
    end
  end
  result
end

def usage
  puts <<~EOT
    Usage: #{File.basename($0)} [OPTS]

    Classifies pathes like foo/bar_baz into Foo::BarBaz if necessary.

    Options are

      -d           declassifies Foo::BarBaz into foo/bar_baz if necessary
      -t           toogle Foo::BarBaz into foo/bar_baz and vice versa
      -n NUMBER    the number of module namespaces to skip from the left
      -b           return right most module namespace
      -s           adds .rb suffix to foo/bar_baz.rb if necessary
      -p SEPARATOR used for declassification
      -h           display this help

  EOT
  exit 0
end

$opts = go 'dtn:bsp:h'

$opts[?h] and usage
string = ARGV.shift or fail "need a class/filepath/filename"
string = Term::ANSIColor.uncolor string

config = Utils::ConfigFile.new
config.configure_from_paths

if $opts[?b]
  $opts[?n] = '-1'
else
  $opts[?n] ||= compute_shift(config, string)
end

print(
  case
  when $opts[?t]
    if camelcase?(string)
      if separator = $opts[?p]
        parameterize string, separator
      else
        underscore string
      end
    else
      camelize string
    end
  when $opts[?d]
    if separator = $opts[?p]
      parameterize string, separator
    else
      underscore string
    end
  else
    camelize string
  end
)