#!/usr/bin/env ruby

require 'etc'
require 'optparse'
require 'ostruct'
require 'rubygems'
require 'repo-permissions'
require 'json'
require 'json/add/core'

# We want everything printed on stderr
$stdout = $stderr

# Command line options
options = OpenStruct.new
options.git_repo_root = '/var/git'
options.min_local_uid = 1000
options.config_dir = '/var/git/permissions'
options.admin_email = 'jannis@xfce.org'

# Classifications used in the git repository layout
CLASSIFICATIONS = [ 
  'apps', 
  'archive',
  'art',
  'bindings',
  'libs',
  'panel-plugins', 
  'thunar-plugins', 
  'www',
  'xfce',
]

# Parse command line options
ARGV.options do |opts|
  opts.banner = "Usage: #{$0} [OPTIONS] REFNAME OLD_REV NEW_REV"

  opts.on('-c', '--config-dir=DIR', "Location of the config files (default=#{options.config_dir})") do |dir|
    options.config_dir = dir
  end

  opts.on('-g', '--git-repo-root=DIR', "Location of the git repositories (default=#{options.git_repo_root})") do |dir|
    options.git_repo_root = dir
  end

  opts.on('-u', '--min-local-uid=UID', Integer, "Minimum UID to allow committers from system acconuts (default=#{options.min_local_uid})") do |uid|
    options.min_local_uid = uid
  end
end.parse!

unless ARGV.length == 3 and ENV.has_key?('GIT_DIR') and ENV.has_key?('REPO')
  puts ARGV.options
  exit 1
end

# Fix GIT_DIR sometimes (always?) being set to '.' 
ENV['GIT_DIR'] = Dir.pwd

# Determine username
if ENV.has_key?('HTTP_REMOTE_USER')
  username = ENV['HTTP_REMOTE_USER']
else
  uid = Process::UID.eid
  if uid < options.min_local_uid
    puts "This script cannot be run by UIDs lower than #{options.min_local_uid}"
    puts 'Please ensure that the script is either run as a CGI with'
    puts 'the HTTP_REMOTE_USER environment variable set, or logically'
    puts 'with a regular user account.'
    puts
    puts "Contact #{options.admin_email} for help."
    exit 1
  end

  begin
    pwent = Etc.getpwuid(uid)
    username = pwent.name
  rescue ArgumentError
    puts "Unable to resolve user id #{uid}. Contact #{options.admin_email} for help."
    exit 1
  end
end

# Load users
RepoPermissions::User.load do 
  JSON.load(File.new(File.join(options.config_dir, 'users.json')))
end

# Load groups
RepoPermissions::Group.load do
  JSON.load(File.new(File.join(options.config_dir, 'groups.json')))
end

# Load repositories
RepoPermissions::Repository.load do
  repositories = CLASSIFICATIONS.collect do |base|
    JSON.load(File.new(File.join(options.config_dir, "#{base}.json")))
  end
  repositories.flatten
end

user = RepoPermissions::User.find_by_username(username)
if user.nil?
  puts "Unknown username '#{username}'. Contact #{options.admin_email} for help."
  exit 1
end

repository = RepoPermissions::Repository.find_by_name(ENV['REPO'])
if repository.nil?
  puts "Unknown repository '#{ENV['REPO']}'. Contact #{options.admin_email} for help."
  exit 1
end

# Make update fail if the user has no commit access to this repository
unless repository.allowed?(user)
  puts "Commit access to repository '#{repository.name}' denied for user '#{user.username}'."
  puts "Contact #{options.admin_email} for help."
  exit 1
end

users = RepoPermissions::Group.find_all.collect do |group| 
  group.users 
end.flatten

for repository in RepoPermissions::Repository.find_all do
  users |= repository.groups.collect do 
    |group| group.users
  end.flatten

  users |= repository.users
end

active, inactive = RepoPermissions::User.find_all.partition do |user|
  users.include?(user)
end
 
active_names = active.collect do |u| u.username end
inactive_names = inactive.collect do |u| u.username end
puts active_names
puts
puts inactive_names