#!/usr/bin/ruby -w
# Hookin -- minimalist Ruby package manager

# Copyright (C) 2008 Christian Neukirchen <purl.org/net/chneukirchen>
#
# Hookin is freely distributable under the terms of an MIT-style license.
# See COPYING or http://www.opensource.org/licenses/mit-license.php.

USAGE = <<EOF
Usage: hookin add PKG DIRS...
       hookin remove PKG...
       hookin refresh [--all] PKG...
       hookin check [--all] PKG...
       hookin installed
       hookin contents PKG
EOF

# One of the few rare places these lines are okay.
$:.unshift File.join(File.dirname((File.readlink(__FILE__) rescue __FILE__)),
                     "..", "lib")

# If you ever put that line into your ordinary code, you haven't
# understood hookin.
require 'hookin'

# This triggers a load of the Hookin DB.
require 'rbconfig'


def dlext
  Config::CONFIG["DLEXT"]
end

def save_db
  File.open("#{$HOOKIN_FILE}.new", "w") { |db|
    Marshal.dump($HOOKIN_DB, db)
  }
  File.rename "#{$HOOKIN_FILE}.new", $HOOKIN_FILE
end

def remove_package(package)
  $HOOKIN_DB.delete_if { |l, (d, p, e)| p == package }
end

def add_package(package, dirs)
  remove_package package

  to_be_resolved = []

  dirs.each { |prefix|
    prefix = File.expand_path(prefix)
    presize = prefix.size + 1

    Dir.glob(prefix + "/**/*.{rb,#{dlext}}") { |file|
      ext = File.extname(file)
      lib = file[presize..-1].gsub(/\.(rb|#{dlext})\z/o, '')

      next  if lib == "extconf"   # We never want to install these.

      if record = $HOOKIN_DB[lib] 
        if $HOOKIN_DB[lib][1] == package
          # .rb and .$DLEXT exist in the current project
          to_be_resolved << [lib, *record]
          to_be_resolved << [lib, prefix, package, ext]
        else
          abort "#{file} clashes with package #{record[1]} on #{record[0]}"
        end
      end

      if ext == ".#{dlext}"
        # .so is allowed as a generic .$DLEXT.
        $HOOKIN_DB[lib] = $HOOKIN_DB[lib + ".so"] =
          [prefix, package, ext]
      else
        $HOOKIN_DB[lib] = [prefix, package, ext]
      end
    }
  }

  to_be_resolved.each { |l, d, p, e|
    $HOOKIN_DB[l + e] = [d, p, e]
    $HOOKIN_DB[l] =     [d, p, e]  if l == ".rb"   # .rb wins over .so
  }
end

def all_packages
  $HOOKIN_DB.map { |l, (d, p, e)| p }.uniq
end

def all_files(package)
  $HOOKIN_DB.map { |l, (d, p, e)| 
    if p == package
      if l =~ /\.(so|#{dlext})\z/o
        "#{d}/#{l.gsub(/so\z/, dlext)}"
      elsif l =~ /\.rb\z/
        "#{d}/#{l}"
      else
        "#{d}/#{l}#{e}"
      end
    end
  }.compact.uniq
end

def all_prefixes(package)
  $HOOKIN_DB.map { |l, (d, p, e)| d  if p == package }.compact.uniq
end


case ARGV.shift
when "add"
  add_package(ARGV[0], ARGV[1..-1])
  save_db

when "remove"
  ARGV.each { |p| remove_package p }
  save_db

when "refresh"
  ARGV.replace all_packages  if ARGV == ["--all"]
  abort USAGE  if ARGV.empty?

  ARGV.each { |package| add_package package, all_prefixes(package) }
  save_db

when "check"
  ARGV.replace all_packages  if ARGV == ["--all"] || ARGV.empty?

  ARGV.each { |package|
    indexed = all_files(package)
    actual = all_prefixes(package).map { |prefix|
      Dir.glob(prefix + "/**/*.{rb,#{dlext}}")
    }.flatten.uniq.reject { |file|
      file =~ /\/extconf.rb\z/
    }

    (indexed - actual).each { |f| puts "#{package}: #{f} was REMOVED" }
    (actual - indexed).each { |f| puts "#{package}: #{f} was ADDED" }
  }

when "installed"
  puts all_packages.sort

when "contents"
  contents = all_files(ARGV[0]).sort
  abort "unknown package: #{ARGV[0]}"  if contents.empty?
  puts contents

when "help", "--help"
  puts USAGE

when "--version"
  puts "0.1"

else
  abort USAGE

end