require "git_fusion_strings/version"

module GitFusionStrings
  # These constants are used as the default configuration for the
  # encode and decode methods.

  # GitFusion-specific character encodings to use in Perforce
  # This enables select characters to be used as repo names
  GF_CHARACTER_MAPPING = {
      '/' => '_0xS_',
      ':' => '_0xC_',
  }
  GF_DEFAULT_ILLEGAL_CHARS = GF_CHARACTER_MAPPING.keys
  # Characters that are permitted in usernames in Perforce
  # but render URI impossible to decode
  URI_RESERVED_CHARACTERS = ['/', '\\', ':', '?', '=', '%', ':', '#']

  # Encodes a string for Git Fusion use
  def self.encode(str, illegal_characters: GF_DEFAULT_ILLEGAL_CHARS)
    str.chars.map do |ch|
      if illegal_characters.include?(ch)
        GF_CHARACTER_MAPPING[ch]
      else
        ch
      end
    end.join('')
  end

  # Decodes a string coming from GitFusion encoding
  def self.decode(str, illegal_characters: GF_DEFAULT_ILLEGAL_CHARS)
    escape_map = Hash[illegal_characters.map{ |c| [c, GF_CHARACTER_MAPPING[c]] }]
    escape_map.each do |ch, escaped|
      str = str.gsub(escaped, ch)
    end
    str
  end
end