#!/usr/bin/env ruby
require 'mogilefs'
require 'optparse'
[ STDIN, STDOUT, STDERR].each { |io| io.binmode }

trap('INT') { exit 130 }
trap('PIPE') { exit 0 }

# this is to be compatible with config files used by the Perl tools
def parse_config_file!(path, overwrite = false)
  dest = {}
  File.open(path).each_line do |line|
    line.strip!
    if /^(domain|class)\s*=\s*(\S+)/.match(line)
      dest[$1.to_sym] = $2
    elsif m = /^(?:trackers|hosts)\s*=\s*(.*)/.match(line)
      dest[:hosts] = $1.split(/\s*,\s*/)
    elsif m = /^timeout\s*=\s*(.*)/.match(line)
      dest[:timeout] = m[1].to_f
    else
      STDERR.puts "Ignored configuration line: #{line}" unless /^#/.match(line)
    end
  end
  dest
end

# parse the default config file if one exists
def_file = File.expand_path("~/.mogilefs-client.conf")
def_cfg = File.exist?(def_file) ? parse_config_file!(def_file) : {}

# parse the command-line first, these options take precedence over all else
cli_cfg = {}
config_file = nil
ls_l = false
ls_h = false
test = {}
cat = { :raw => false }

ARGV.options do |x|
  x.banner = "Usage: #{$0} [options] <command> [<arguments>]"
  x.separator ''

  x.on('-c', '--config=/path/to/config',
       'config file to load') { |file| config_file = file }

  x.on('-t', '--trackers=host1[,host2]', '--hosts=host1[,host2]', Array,
       'hostnames/IP addresses of trackers') do |trackers|
    cli_cfg[:hosts] = trackers
  end

  x.on('-e', 'True if key exists') { test[:e] = true }
  x.on('-r', '--raw', 'show raw big_info file information') { cat[:raw] = true }

  x.on('-C', '--class=s', 'class') { |klass| cli_cfg[:class] = klass }
  x.on('-d', '--domain=s', 'domain') { |domain| cli_cfg[:domain] = domain }
  x.on('-l', "long listing format (`ls' command)") { ls_l = true }
  x.on('-h', '--human-readable',
       "print sizes in human-readable format (`ls' command)") { ls_h = true }

  x.separator ''
  x.on('--help', 'Show this help message.') { puts x; exit }
  x.parse!
end

# parse the config file specified at the command-line
file_cfg = config_file ? parse_config_file!(config_file, true) : {}

# read environment variables, too.  This Ruby API favors the term
# "hosts", however upstream MogileFS teminology favors "trackers" instead.
# Favor the term more consistent with what the MogileFS inventors used.
env_cfg = {}
if ENV["MOG_TRACKERS"]
  env_cfg[:hosts] = ENV["MOG_TRACKERS"].split(/\s*,\s*/)
end
if ENV["MOG_HOSTS"] && (env_cfg[:hosts] || []).empty?
  env_cfg[:hosts] = ENV["MOG_HOSTS"].split(/\s*,\s*/)
end
env_cfg[:domain] = ENV["MOG_DOMAIN"] if ENV["MOG_DOMAIN"]
env_cfg[:class] = ENV["MOG_CLASS"] if ENV["MOG_CLASS"]

# merge the configs, favoring them in order specified:
cfg = {}.merge(def_cfg).merge(env_cfg).merge(file_cfg).merge(cli_cfg)

# error-checking
err = []
err << "trackers must be specified" if cfg[:hosts].nil? || cfg[:hosts].empty?
err << "domain must be specified" unless cfg[:domain]
if err.any?
  STDERR.puts "Errors:\n  #{err.join("\n  ")}"
  STDERR.puts ARGV.options
  exit 1
end

unless cmd = ARGV.shift
  STDERR.puts ARGV.options
  exit 1
end

cfg[:timeout] ||= 30 # longer timeout for interactive use
mg = MogileFS::MogileFS.new(cfg)

def store_file_retry(mg, key, storage_class, filepath)
  tries = 0
  begin
    mg.store_file(key, storage_class, filepath)
  rescue MogileFS::UnreadableSocketError,
         MogileFS::Backend::NoDevicesError => err
    if ((tries += 1) < 10)
      STDERR.puts "Retrying on error: #{err}: #{err.message} tries: #{tries}"
      retry
    else
      STDERR.puts "FATAL: #{err}: #{err.message} tries: #{tries}"
    end
    exit 1
  end
end

def human_size(size)
  suff = ''
  %w(K M G).each do |s|
    size /= 1024.0
    if size <= 1024
      suff = s
      break
    end
  end
  sprintf("%.1f%s", size, suff)
end

begin
  case cmd
  when 'cp'
    filename = ARGV.shift or raise ArgumentError, '<filename> <key>'
    key = ARGV.shift or raise ArgumentError, '<filename> <key>'
    ARGV.shift and raise ArgumentError, '<filename> <key>'
    store_file_retry(mg, key, cfg[:class], filename)
  when 'cat'
    ARGV.empty? and raise ArgumentError, '<key1> [<key2> ...]'
    ARGV.each do |key|
      if (!cat[:raw] && key =~ /^_big_info:/)
        mg.bigfile_write(key, STDOUT, {:verify => true})
      else
        mg.get_file_data(key, STDOUT)
      end
    end
  when 'ls'
    prefixes = ARGV.empty? ? [ nil ] : ARGV
    if ls_l
      each_key = lambda do |key, size, devcount|
        size = ls_h && size > 1024 ? human_size(size) : size.to_s
        size = (' ' * (12 - size.length)) << size # right justify
        puts [ sprintf("% 2d", devcount), size, key ].pack("A4 A16 A*")
      end
    else
      each_key = lambda { |key| puts key }
    end
    prefixes.each { |prefix| mg.each_key(prefix, &each_key) }
  when 'rm'
    ARGV.empty? and raise ArgumentError, '<key1> [<key2>]'
    ARGV.each { |key| mg.delete(key) }
  when 'mv'
    from = ARGV.shift or raise ArgumentError, '<from> <to>'
    to = ARGV.shift or raise ArgumentError, '<from> <to>'
    ARGV.shift and raise ArgumentError, '<from> <to>'
    mg.rename(from, to)
  when 'stat' # this outputs a RFC822-like format
    ARGV.empty? and raise ArgumentError, '<key1> [<key2>]'
    ARGV.each_with_index do |key, i|
      if size = mg.size(key)
        puts "Key: #{key}"
        puts "Size: #{size}"
        mg.get_paths(key).each_with_index do |path,i|
          puts "URL-#{i}: #{path}"
        end
        puts ""
      else
        STDERR.puts "No such key: #{key}"
      end
    end
  when 'tee'
    require 'tempfile'
    key = ARGV.shift or raise ArgumentError, '<key>'
    ARGV.shift and raise ArgumentError, '<key>'
    cfg[:class] or raise ArgumentError, 'E: --class must be specified'
    buf = ''
    tmp = Tempfile.new('mog-tee') # TODO: explore Transfer-Encoding:chunked :)

    # if stdout is pointing to /dev/null, don't bother installing the filter.
    STDOUT.sync = true
    tee_obj = tmp
    if File.stat('/dev/null') != STDOUT.stat
      tee_obj = lambda do |buf|
        rv = nil
        [ STDOUT, tmp ].each { |io| rv = io.write(buf) }
        rv
      end
      def tee_obj.write(buf)
        self[buf]
      end
    end
    begin
      MogileFS::X.copy_stream(STDIN, tee_obj)
      store_file_retry(mg, key, cfg[:class], tmp.path)
    ensure
      tmp.close!
    end
  when 'test'
    truth, ok = true, nil
    raise ArgumentError, "-e must be specified" unless (test.size == 1)

    truth, key = case ARGV.size
    when 1
      [ true, ARGV[0] ]
    when 2
      if ARGV[0] != "!"
        raise ArgumentError, "#{ARGV[0]}: binary operator expected"
      end
      [ false, ARGV[1] ]
    else
      raise ArgumentError, "Too many arguments"
    end

    paths = mg.get_paths(key)
    if test[:e]
      ok = !!(paths && paths.size > 0)
    else
      raise ArgumentError, "Unknown flag: -#{test.keys.first}"
    end

    truth or ok = ! ok
    exit ok ? 0 : 1
  else
    raise ArgumentError, "Unknown command: #{cmd}"
  end
rescue ArgumentError => err
  STDERR.puts "Usage: #{$0} #{cmd} #{err.message}"
  exit 1
end
exit 0