# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with this
# work for additional information regarding copyright ownership.  The ASF
# licenses this file to you 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.


require 'buildr/core/project'
require 'buildr/core/common'
require 'buildr/core/checks'
require 'buildr/core/environment'


module Buildr

  class Options

    # Runs the build in parallel when true (defaults to false). You can force a parallel build by
    # setting this option directly, or by running the parallel task ahead of the build task.
    #
    # This option only affects recursive tasks. For example:
    #   buildr parallel package
    # will run all package tasks (from the sub-projects) in parallel, but each sub-project's package
    # task runs its child tasks (prepare, compile, resources, etc) in sequence.
    attr_accessor :parallel

  end

  task('parallel') { Buildr.options.parallel = true }


  module Build

    include Extension

    first_time do
      desc 'Build the project'
      Project.local_task('build') { |name| "Building #{name}" }
      desc 'Clean files generated during a build'
      Project.local_task('clean') { |name| "Cleaning #{name}" }

      desc 'The default task is build'
      task 'default'=>'build'
    end

    before_define do |project|
      project.recursive_task 'build'
      project.recursive_task 'clean'
      project.clean do
        rm_rf project.path_to(:target)
        rm_rf project.path_to(:reports)
      end
    end


    # *Deprecated:* Use +path_to(:target)+ instead.
    def target
      Buildr.application.deprecated 'Use path_to(:target) instead'
      layout.expand(:target)
    end

    # *Deprecated:* Use Layout instead.
    def target=(dir)
      Buildr.application.deprecated 'Use Layout instead'
      layout[:target] = _(dir)
    end

    # *Deprecated:* Use +path_to(:reports)+ instead.
    def reports()
      Buildr.application.deprecated 'Use path_to(:reports) instead'
      layout.expand(:reports)
    end

    # *Deprecated:* Use Layout instead.
    def reports=(dir)
      Buildr.application.deprecated 'Use Layout instead'
      layout[:reports] = _(dir)
    end

    # :call-seq:
    #    build(*prereqs) => task
    #    build { |task| .. } => task
    #
    # Returns the project's build task. With arguments or block, also enhances that task.
    def build(*prereqs, &block)
      task('build').enhance prereqs, &block
    end

    # :call-seq:
    #    clean(*prereqs) => task
    #    clean { |task| .. } => task
    #
    # Returns the project's clean task. With arguments or block, also enhances that task.
    def clean(*prereqs, &block)
      task('clean').enhance prereqs, &block
    end

  end


  module Git  #:nodoc:

  module_function

    # :call-seq:
    #   git(*args)
    #
    # Executes a Git command and returns the output. Throws exception if the exit status
    # is not zero. For example:
    #   git 'commit'
    #   git 'remote', 'show', 'origin'
    def git(*args)
      cmd = "git #{args.shift} #{args.map { |arg| arg.inspect }.join(' ')}"
      output = `#{cmd}`
      fail "GIT command \"#{cmd}\" failed with status #{$?.exitstatus}\n#{output}" unless $?.exitstatus == 0
      return output
    end

    # Returns list of uncommited/untracked files as reported by git status.
    def uncommitted_files
      `git status`.scan(/^#\s{7}(\S.*)$/).map { |match| match.first.split.last }
    end

    # Commit the given file with a message.
    # The file has to be known to Git meaning that it has either to have been already committed in the past
    # or freshly added to the index. Otherwise it will fail.
    def commit(file, message)
      git 'commit', '-m', message, file
    end

    # Update the remote refs using local refs
    #
    # By default, the "remote" destination of the push is the the remote repo linked to the current branch.
    # The default remote branch is the current local branch.
    def push(remote_repo = remote, remote_branch = current_branch)
      git 'push', remote, current_branch
    end

    # Return the name of the remote repository whose branch the current local branch tracks,
    # or nil if none.
    def remote(branch = current_branch)
      remote = git('config', '--get', "branch.#{branch}.remote").strip
      remote if git('remote').include?(remote)
    rescue
      nil
    end

    # Return the name of the current branch
    def current_branch
      git('branch')[/^\* (.*)$/, 1]
    end

  end


  module Svn #:nodoc:

  module_function

    # :call-seq:
    #   svn(*args)
    #
    # Executes a SVN command and returns the output. Throws exception if the exit status
    # is not zero. For example:
    #   svn 'commit'
    def svn(*args)
      output = `svn #{args.shift} #{args.map { |arg| arg.inspect }.join(' ')}`
      fail "SVN command failed with status #{$?.exitstatus}" unless $?.exitstatus == 0
      return output
    end

    def tag(tag_name)
      url = tag_url repo_url, tag_name
      remove url, 'Removing old copy' rescue nil
      copy Dir.pwd, url, "Release #{tag_name}"
    end

    # Status check reveals modified files, but also SVN externals which we can safely ignore.
    def uncommitted_files
      svn('status', '--ignore-externals').split("\n").reject { |line| line =~ /^X\s/ }
    end

    def commit(file, message)
      svn 'commit', '-m', message, file
    end
    
    # :call-seq:
    #   tag_url(svn_url, version) => tag_url
    #
    # Returns the SVN url for the tag.
    # Can tag from the trunk or from branches.
    # Can handle the two standard repository layouts.
    #   - http://my.repo/foo/trunk => http://my.repo/foo/tags/1.0.0
    #   - http://my.repo/trunk/foo => http://my.repo/tags/foo/1.0.0
    def tag_url(svn_url, tag)
      trunk_or_branches = Regexp.union(%r{^(.*)/trunk(.*)$}, %r{^(.*)/branches(.*)/([^/]*)$})
      match = trunk_or_branches.match(svn_url)
      prefix = match[1] || match[3]
      suffix = match[2] || match[4]
      prefix + '/tags' + suffix + '/' + tag
    end

    # Return the current SVN URL
    def repo_url
      svn('info', '--xml')[/<url>(.*?)<\/url>/, 1].strip
    end
    
    def copy(dir, url, message)
      svn 'copy', dir, url, '-m', message
    end
    
    def remove(url, message)
      svn 'remove', url, '-m', message
    end

  end
  

  class Release #:nodoc:

    THIS_VERSION_PATTERN  = /(THIS_VERSION|VERSION_NUMBER)\s*=\s*(["'])(.*)\2/

    class << self
      
      # :call-seq:
      #     add(MyReleaseClass)
      #
      # Add a Release implementation to the list of available Release classes.
      def add(release)
        @list ||= []
        @list |= [release]
      end
      alias :<< :add

      # The list of supported Release implementations
      def list
        @list ||= []
      end

    end
 
    # Use this to specify a different tag name for tagging the release in source control.
    # You can set the tag name or a proc that will be called with the version number,
    # for example:
    #   Release.tag_name = lambda { |ver| "foo-#{ver}" }
    attr_accessor :tag_name

    # Use this to specify a different commit message to commit the buildfile with the next version in source control.
    # You can set the commit message or a proc that will be called with the next version number,
    # for example:
    #   Release.commit_message = lambda { |ver| "Changed version number to #{ver}" }
    attr_accessor :commit_message

    # :call-seq:
    #   make()
    #
    # Make a release.
    def make
      check
      with_release_candidate_version do |release_candidate_buildfile|
        args = '-S', 'buildr', "_#{Buildr::VERSION}_", '--buildfile', release_candidate_buildfile
        args << '--environment' << Buildr.environment unless Buildr.environment.to_s.empty?
        args << 'clean' << 'upload' << 'DEBUG=no'
        ruby *args 
      end
      tag_release resolve_tag
      update_version_to_next
    end
    
    # :call-seq:
    #   extract_version() => this_versin
    #
    # Extract the current version number from the buildfile.
    # Raise an error if not found.
    def extract_version
      buildfile = File.read(Buildr.application.buildfile.to_s)
      buildfile.scan(THIS_VERSION_PATTERN)[0][2]
    rescue
      fail 'Looking for THIS_VERSION = "..." in your Buildfile, none found'
    end
    
  protected
    
    # :call-seq:
    #   with_release_candidate_version() { |filename| ... }
    #
    # Yields to block with release candidate buildfile, before committing to use it.
    #
    # We need a Buildfile with upgraded version numbers to run the build, but we don't want the
    # Buildfile modified unless the build succeeds. So this method updates the version number in
    # a separate (Buildfile.next) file, yields to the block with that filename, and if successful
    # copies the new file over the existing one.
    #
    # The release version is the current version without '-SNAPSHOT'.  So:
    #   THIS_VERSION = 1.1.0-SNAPSHOT
    # becomes:
    #   THIS_VERSION = 1.1.0
    # for the release buildfile.
    def with_release_candidate_version
      release_candidate_buildfile = Buildr.application.buildfile.to_s + '.next'
      release_candidate_buildfile_contents = change_version { |version| version[-1] = version[-1].to_i }
      File.open(release_candidate_buildfile, 'w') { |file| file.write release_candidate_buildfile_contents }
      begin
        yield release_candidate_buildfile
        mv release_candidate_buildfile, Buildr.application.buildfile.to_s
      ensure
        rm release_candidate_buildfile rescue nil
      end
    end

    # :call-seq:
    #   change_version() { |this_version| ... } => buildfile
    #
    # Change version number in the current Buildfile, but without writing a new file (yet).
    # Returns the contents of the Buildfile with the modified version number.
    #
    # This method yields to the block with the current (this) version number as an array and expects
    # the block to update it.
    def change_version
      this_version = extract_version
      new_version = this_version.split('.')
      yield(new_version)
      new_version = new_version.join('.')
      buildfile = File.read(Buildr.application.buildfile.to_s)
      buildfile.gsub(THIS_VERSION_PATTERN) { |ver| ver.sub(/(["']).*\1/, %Q{"#{new_version}"}) }
    end

    # Return the name of the tag to tag the release with.
    def resolve_tag
      version = extract_version
      tag = tag_name || version
      tag = tag.call(version) if Proc === tag
      tag
    end

    # Move the version to next and save the updated buildfile
    def update_buildfile
      buildfile = change_version { |version| version[-1] = (version[-1].to_i + 1).to_s + '-SNAPSHOT' }
      File.open(Buildr.application.buildfile.to_s, 'w') { |file| file.write buildfile }
    end

    # Return the message to use to cimmit the buildfile with the next version
    def message
      version = extract_version
      msg = commit_message || "Changed version number to #{version}"
      msg = msg.call(version) if Proc === msg
      msg
    end

    def update_version_to_next
      update_buildfile
    end
  end


  class GitRelease < Release
    class << self
      def applies_to?(directory = '.')
        File.exist? File.join(directory, '.git/config')
      end
    end

    # Fails if one of theses 2 conditions are not met:
    #    1. the repository is clean: no content staged or unstaged
    #    2. some remote repositories are defined but the current branch does not track any
    def check
      uncommitted = Git.uncommitted_files
      fail "Uncommitted files violate the First Principle Of Release!\n#{uncommitted.join("\n")}" unless uncommitted.empty?
      fail "You are releasing from a local branch that does not track a remote!" unless Git.remote
    end

    # Add a tag reference in .git/refs/tags and push it to the remote if any.
    # If a tag with the same name already exists it will get deleted (in both local and remote repositories).
    def tag_release(tag)
      info "Committing buildfile with version number #{extract_version}"
      Git.commit File.basename(Buildr.application.buildfile.to_s), message
      Git.push if Git.remote
      info "Tagging release #{tag}"
      Git.git 'tag', '-d', tag rescue nil
      Git.git 'push', Git.remote, ":refs/tags/#{tag}" rescue nil if Git.remote
      Git.git 'tag', '-a', tag, '-m', "[buildr] Cutting release #{tag}"
      Git.git 'push', Git.remote, 'tag', tag if Git.remote
    end

    def update_version_to_next
      super
      info "Current version is now #{extract_version}"
      Git.commit File.basename(Buildr.application.buildfile.to_s), message
      Git.push if Git.remote
    end
  end
  

  class SvnRelease < Release
    class << self
      def applies_to?(directory = '.')
        File.exist? File.join(directory, '.svn')
      end
    end
    
    def check
      fail "Uncommitted files violate the First Principle Of Release!\n"+Svn.uncommitted_files.join("\n") unless Svn.uncommitted_files.empty?
      fail "SVN URL must contain 'trunk' or 'branches/...'" unless Svn.repo_url =~ /(trunk)|(branches.*)$/
    end

    def tag_release(tag)
      info "Tagging release #{tag}"
      Svn.tag tag
    end

    def update_version_to_next
      super
      info "Current version is now #{extract_version}"
      Svn.commit Buildr.application.buildfile.to_s, message
    end
  end
  
  Release.add SvnRelease
  Release.add GitRelease

  desc 'Make a release'
  task 'release' do |task|
    klass = Release.list.detect { |impl| impl.applies_to? }
    fail 'Unable to detect the Version Control System.' unless klass
    klass.new.make
  end

end


class Buildr::Project
  include Buildr::Build
end