#!/usr/bin/env ruby
 
require 'optparse'
require 'ostruct'
require 'pathname'
require 'fileutils'
require 'digest/sha1'
 
ACTIONS = []
TARGETS = []
 
OPTIONS = OpenStruct.new(
  :force   => false,
  :verbose => false,
  :quiet   => false,
  :noop    => false,
  :color   => false,
  :proto   => Pathname('~/.config/raku/tasks'),
  :target  => Pathname('./tasks')
)
 
target = OPTIONS.target
proto = OPTIONS.proto
 
op = OptionParser.new{|o|
  o.separator(" ")
  o.separator("Target modes:")
  o.on('-P', '--proto', "run commands against #{proto} as target"){ TARGETS << :proto }
  o.on('-T', '--tasks', "run commands against #{target} as target"){ TARGETS << :tasks }
 
  o.separator(" ")
  o.separator("Target commands:")
  o.on('-u', '--update',
       "Update all files in target"){  ACTIONS << :update }
  o.on('-d', '--diff',
       "Diff files between targets"){  ACTIONS << :diff }
  o.on('-l', '--list',
       "List files in target"){        ACTIONS << :list }
  o.on('-i', '--init',
       "Copy the Rakefile to target"){ ACTIONS << :init }
 
  o.on('-p', '--put FILE1,FILE2,...', Array,
       "Put given file(s) into target"){|p| ACTIONS << [:put, *p] }
  o.on('-r', '--remove FILE!,FILE2,...', Array,
       "Remove given files from target"){|r| ACTIONS << [:remove, *r] }
 
  o.separator(" ")
  o.separator("Configuration:")
  o.on('-t', '--target-dir DIR',
       "Location for project tasks, default is #{target}"){|t| OPTIONS.target = t }
  o.on(      '--proto-dir DIR',
       "Location of PROTO, default is #{proto}"){|p| OPTIONS.proto = Pathname(p) }
  o.on('-f', '--force',
       "Don't ask silly questions when overwriting files"){|f| OPTIONS.force = f }
  o.on('-v', '--verbose',
       "Tell me everything"){|v| OPTIONS.verbose = v }
  o.on('-q', '--quiet',
       "Tell me nothing, takes precendence over --verbose"){|q| OPTIONS.quiet = q }
  o.on('-n', '--noop',
       "Don't do anything for real, useful with --verbose"){|n| OPTIONS.noop = n }
  o.on('-c', '--color',
       "Use colors for diff, needs colordiff installed"){|c| OPTIONS.color = c }
 
  o.separator(" ")
  o.separator("About:")
  o.on('-V', '--version', 'Version of Raku'){ puts Raku::VERSION; exit }
  o.on('-h', '--help', 'Display this help'){ puts o; exit }
}
 
class Pathname
  def glob(g)
    self.class.glob(self.join(g))
  end
 
  def digest
    Digest::SHA1.hexdigest(read) if exist?
  end
end
 
class Raku
  VERSION = '2009.03.27'
 
  class ProtoPOV < Raku
    def proto; @options.target.expand_path end
    def target; @options.proto.expand_path end
  end
 
  class TargetPOV < Raku
  end
 
  def initialize(options)
    @options = options
    mkdir_p(proto)
  end
 
  def init
    require 'erb'
 
    target_rakefile = target.join('Rakefile')
    proto_rakefile = proto.join('Rakefile')
 
    cp(proto.join('Rakefile'), target.parent)
 
    File.read(proto_rakefile)
  end
 
  def remove(*files)
  end
 
  def put(*files)
    mkdir_p(target)
    done_something = false
 
    files.each do |file|
      if file.exist?
        done_something = true
        put_file(file)
      else
        proto.glob("*#{file}*.rake").each do |from|
          done_something = true
          put_file(from)
        end
      end
    end
 
    log("No files match your request: %p", files) unless done_something
  end
 
  def put_file(from)
    to = target.join(from.basename)
    log("Put %s into %s", from, to)
    cp(from, to)
  end
 
  def diff
    diffbin = color? ? 'colordiff' : 'diff'
    sh(diffbin, '-u', proto, target)
  end
 
  def list
    proto_files = proto.glob('*.rake')
    target_files = target.glob('*.rake')
 
    hash = Hash.new{|h,k| h[k] = [] }
 
    proto_files.each{|file|  hash[file.digest] << file }
    target_files.each{|file| hash[file.digest] << file }
 
    puts "PROTO = %s | TARGET = %s" % [proto, target]
    puts
    proto_len = proto_files.map{|f| f.basename.to_s.size }.max
    target_len = target_files.map{|f| f.basename.to_s.size }.max
    hash.each do |digest, files|
      args = files.map{|f| f.basename }
      args << '' if args.size == 1
      puts "%40s : %-#{proto_len}s | %-#{target_len}s" % [digest, *args]
    end
  end
 
  def update
    mkdir_p(target)
 
    proto.glob('*.rake').each do |from|
      to = target.join(from.basename)
 
      if from.digest == to.digest
        debug("Won't copy %s, file contents are identical", from.basename)
      else
        cp(from, to)
      end
    end
  end
 
  private
 
  def mkdir_p(dir)
    return if File.directory?(dir)
    debug("Create directory %p", dir)
    FileUtils.mkdir_p(dir)
  end
 
  def cp(from, to)
    if to.exist?
      unless force?
        log("Will not overwrite %s with %s", to.basename, from)
        return
      end
    end
 
    FileUtils.cp(from, to,
                 :noop => noop?,
                 :verbose => verbose?,
                 :preserve => true)
  rescue ArgumentError => ex
    debug(ex.message) unless ex.message =~ /^same file:/
  end
 
  def sh(*cmd)
    debug(cmd.join(' '))
    system(*cmd)
  end
 
  def debug(*args)
    log(*args) if verbose?
  end
 
  def log(format, *args)
    puts(format % args.flatten) unless quiet?
  end
 
  def target;   @options.target.expand_path end
  def proto;    @options.proto.expand_path end
  def color?;   @options.color end
  def force?;   @options.force end
  def noop?;    @options.noop end
  def quiet?;   @options.quiet end
  def verbose?; @options.verbose end
end
 
begin
  op.parse!(ARGV)
rescue OptionParser::MissingArgument => ex
  puts ex
  exit
end
 
if ACTIONS.empty?
  puts op
  exit 1
end
 
if TARGETS.first == :proto
  raku = Raku::ProtoPOV.new(OPTIONS)
else
  raku = Raku::TargetPOV.new(OPTIONS)
end
 
action, *args = ACTIONS.shift
args = (args + ARGV).map{|a| Pathname(a) }
args.delete true
raku.send(action, *args)