module Redcar
  GROOVY_YAML=<<-YAML
  - regex:    "class\\s+(\\w+)"
    capture:  1
    type:     id
    kind:     class
  - regex:    "interface\\s+(\\w+)"
    capture:  1
    type:     id
    kind:     interface
  - regex:    "^\\s*((public|private|protected|)\\s+|)(static\\s+|)(([\\.\\w]+|)[A-Z]\\w*(<\\w+>|)|void|int|boolean|byte|short|long|char|float|def)\\s+(\\w+\\s*\\((.*)\\))"
    capture:  7
    type:     id
    kind:     method
  - regex:    "(def|static)\\s+(\\w+)\\s*=\\s*\\{"
    capture:  2
    type:     id
    kind:     closure
  - regex:    "enum\\s+(\\w+)"
    capture:  1
    type:     id
    kind:     attribute
  - regex:    "^\\s*(public|private|protected)\\s+(static\\s+|)([A-Z]\\w+|int|boolean|byte|short|long|char|float|def)\s+(\\w+)\\s*(=|\\n)"
    capture:  4
    type:     id
    kind:     assignment
  YAML

  JAVA_YAML=<<-YAML
  - regex:    "class\\s+(\\w+)"
    capture:  1
    type:     id
    kind:     class
  - regex:    "interface\\s+(\\w+)"
    capture:  1
    type:     id
    kind:     interface
  - regex:    "^\\s*((public|private|protected|)\\s+|)(static\\s+|)(([\\.\\w]+|)[A-Z]\\w*(<\\w+>|)|void|int|boolean|byte|short|long|char|float)\\s+(\\w+\\s*\\((.*)\\))"
    capture:  7
    type:     id
    kind:     method
  - regex:    "enum\\s+(\\w*)"
    capture:  1
    type:     id
    kind:     attribute
  - regex:    "^\\s*(public|private|protected)\\s+(static\\s+|)([A-Z]\\w+|int|boolean|byte|short|long|char|float|def)\s+(\\w+)\\s*(=|;)"
    capture:  4
    type:     id
    kind:     assignment
  YAML

  RUBY_YAML=<<-YAML
  - regex:    "^[^#]*(class|module)\\s+(?:\\w*::)*(\\w+)(?:$|\\s|<)"
    capture:  2
    type:     id
    kind:     class
  - regex:    "^[^#]*def (self\\.)?(\\w+[?!=]?)(\\(.*\\))?(\\s|\\;)+"
    capture:  2
    type:     id
    kind:     method
  - regex:    "^[^#]*attr(_reader|_accessor|_writer)(.*)$"
    capture:  2
    type:     id-list
    kind:     attribute
  - regex:    "^[^#]*alias\\s+:(\\w+)"
    capture:  1
    type:     id
    kind:     alias
  - regex:    "^[^#]*alias_method\\s+:(\\w+[?!]?)"
    capture:  1
    type:     id
    kind:     alias
  - regex:    "^\\s*([A-Z]\\w*)\\s*="
    capture:  1
    type:     id
    kind:     assignment
  YAML

  PHP_YAML=<<-YAML
  - regex:    "class\\s+(\\w+)"
    capture:  1
    type:     id
    kind:     class
  - regex:    "interface\\s+(\\w+)"
    capture:  1
    type:     id
    kind:     interface
  - regex:    "function\\s+(\\w+)\s*\\("
    capture:  1
    type:     id
    kind:     method
  YAML

  JS_YAML=<<-YAML
  - regex:    "function\\s+([A-Z]\\w*)\\(.*\\)"
    capture:  1
    type:     id
    kind:     class
  - regex:    "function\\s+([a-z]\\w*)\\(.*\\)"
    capture:  1
    type:     id
    kind:     method
  YAML

  class Declarations
    class Parser
      DEFINITIONS = {
        /\.rb$/     => YAML.load(RUBY_YAML),
        /\.java$/   => YAML.load(JAVA_YAML),
        /\.groovy$/ => YAML.load(GROOVY_YAML),
        /\.php$/    => YAML.load(PHP_YAML),
        /\.js$/     => YAML.load(JS_YAML)
      }

      attr_reader :tags

      def initialize
        @tags = []
      end

      def parse(files)
        files.each do |path|
          @tags += match_in_file(path)
        end
      end

      def decls_for_file(path)
        DEFINITIONS.each do |fn_re, decls|
          if path =~ fn_re
            return decls
          end
        end
        nil
      end

      def match_kind(path, match)
        if decls = decls_for_file(path)
          decls.each do |decl|
            if match.match(Regexp.new(decl["regex"]))
              return decl["kind"]
            end
          end
        end
      end

      private

      def match_in_file(path)
        tags = []
        begin
          process_file(path) do |line, decl|
            if md = line.match(Regexp.new(decl["regex"]))
              capture = md[decl["capture"]]
              case decl["type"]
              when "id"
                tags << [capture, path, md[0]]
              when "id-list"
                tags += capture.scan(/\w+/).map {|id| [id, path, md[0]] }
              end
            end
          end
          tags
        rescue
          []
        end
      end

      def process_file(path, &block)
        if decls = decls_for_file(path)
          decls.each do |decl|
            file(path).each_line do |line|
              block.call(line, decl)
            end
          end
        end
      end

      def file(path)
        ::File.read(path)
      end

    end
  end
end