#
# Author:: Seth Chisamore (<schisamo@chef.io>)
# Author:: Christopher Maier (<cm@chef.io>)
# Copyright:: Copyright (c) 2013 Opscode, Inc.
# License:: Apache License, Version 2.0
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

module Mixlib
  class Versioning
    class Format
      # Handles version strings based on {http://semver.org/ SemVer 2.0.0-rc.1}.
      #
      # SUPPORTED FORMATS
      # -----------------
      # ```text
      # MAJOR.MINOR.PATCH
      # MAJOR.MINOR.PATCH-PRERELEASE
      # MAJOR.MINOR.PATCH-PRERELEASE+BUILD
      # ```
      #
      # EXAMPLES
      # --------
      # ```text
      # 11.0.0
      # 11.0.0-alpha.1
      # 11.0.0-alpha1+20121218164140
      # 11.0.0-alpha1+20121218164140.git.207.694b062
      # ```
      #
      # @author Seth Chisamore (<schisamo@chef.io>)
      # @author Christopher Maier (<cm@chef.io>)
      class SemVer < Format
        SEMVER_REGEX = /^(0|[1-9]\d*)\.(0|[1-9]\d*)\.(0|[1-9]\d*)(?:-((?:0|[1-9]\d*|\d*[a-zA-Z-][a-zA-Z0-9-]*)(?:\.(?:0|[1-9]\d*|\d*[a-zA-Z-][a-zA-Z0-9-]*))*))?(?:\+([0-9A-Za-z-]+(?:\.[0-9A-Za-z-]+)*))?$/

        # @see Format#parse
        def parse(version_string)
          match = version_string.match(SEMVER_REGEX) rescue nil

          unless match
            fail Mixlib::Versioning::ParseError, "'#{version_string}' is not a valid #{self.class} version string!"
          end

          @major, @minor, @patch, @prerelease, @build = match[1..5]
          @major, @minor, @patch = [@major, @minor, @patch].map(&:to_i)

          @prerelease = nil if @prerelease.nil? || @prerelease.empty?
          @build = nil if @build.nil? || @build.empty?
        end
      end # class SemVer
    end # class Format
  end # module Versioning
end # module Mixlib
