class Habakiri

# File lib/habakiri.rb, line 5
def initialize(template, prefix = '{{', suffix = '}}')
  @prefix = prefix.to_s
  @suffix = suffix.to_s
  @template = template.to_s
  @keywords = keywords
end

# File lib/habakiri.rb, line 57
def exec(template, text)
  new(template).exec(text)
end

# File lib/habakiri.rb, line 12
def exec(text)
  diffs = Diff::LCS.sdiff(@template, text.to_s)

  @keywords.each.with_object({}){|(key, key_begin, key_end), object|
    index_begin = diffs.index{|d| d.old_position == key_begin }
    index_end = diffs.index{|d| d.old_position == key_end }
    list = diffs[index_begin...index_end]

    # 改行後の追加要素も対応する文字列とみなす
    i = index_end
    if i
      loop do
        diff = diffs[i]
        if diff && (diff.action == '+' || (diff.action == '=' && /\R/.match?(diff.old_element)))
          list.push(diff)
          i += 1
        else
          break
        end
      end
    end

    value = list.map(&:new_element).join.strip
    case object[key]
    when nil
      object[key] = value
    when String
      object[key] = [object[key], value]
    when Array
      object[key] << value
    end
  }
end

# File lib/habakiri.rb, line 48
def keywords
  @template.to_enum(:scan, /#{@prefix}.+?#{@suffix}/).map{
    m = Regexp.last_match
    key = m[0].delete_prefix(@prefix).delete_suffix(@suffix).strip
    [key, m.begin(0), m.end(0)]
  }
end