#!/usr/bin/env ruby
# Copyright (C) 2013-2015 all contributors <dtas-all@nongnu.org>
# License: GPLv3 or later (https://www.gnu.org/licenses/gpl-3.0.txt)
#
# WARNING: totally unstable API, use dtas-ctl for scripting (but the protocol
# itself is also unstable, but better than this one probably).
require 'dtas/unix_client'
require 'shellwords'

def get_track_ids(c)
  track_ids = c.req("tl tracks")
  # we could get more, but SEQPACKET limits size...
  track_ids = track_ids.split(/ /)
  track_ids.shift
  track_ids
end

def do_edit(c)
  require 'dtas/edit_client'
  require 'yaml'
  require 'tempfile'
  extend DTAS::EditClient
  tmp = Tempfile.new(%w(dtas-tl-edit .txt))
  tmp.binmode
  tmp_path = tmp.path
  orig = []
  orig_idx = {}

  get_track_ids(c).each_slice(128) do |track_ids|
    res = c.req("tl get #{track_ids.join(' ')}")
    res = Shellwords.split(res.sub!(/\A\d+ /, ''))
    while line = res.shift
      line.sub!(/\A(\d+)=/, '') or abort "unexpected line=#{line.inspect}\n"
      track_id = $1.to_i
      orig_idx[track_id] = orig.size
      orig << track_id
      tmp.write("#{Shellwords.escape(line)} =#{track_id}\n")
    end
  end
  tmp.flush

  ed = editor
  # jump to the line of the currently playing track if using vi or vim
  # Patches for other editors welcome: dtas-all@nongnu.org
  if ed =~ /vim?\z/
    cur = YAML.load(c.req('current'))
    if tl = cur['tracklist']
      if pos = tl['pos']
        ed += " +#{pos + 1}"
      end
    end
  end
  # Run the editor and let the user edit!
  system("#{ed} #{Shellwords.escape tmp_path}") or return

  edit = []
  edit_idx = {}
  add = []
  # editor may rename/link a new file into place
  File.open(tmp_path) do |fp|
    while line = fp.gets
      line.chomp!
      if line.sub!(/ =(\d+)\z/, '') # existing tracks
        track_id = $1.to_i
        if edit_idx[track_id] # somebody copy+pasted an existing line
          add << [ File.expand_path(line), edit.last ]
        else # moved line
          edit_idx[track_id] = edit.size
          edit << track_id
        end
      else # entirely new line
        add << [ File.expand_path(line), edit.last ]
      end
    end
  end
  edit.each_with_index do |track_id, i|
    oi = orig_idx[track_id] or warn("unknown track_id=#{track_id}") or next
    next if oi == i # no change, yay!
    prev_track_id = orig[i] or warn("unknown index at #{i}") or next
    c.req("tl swap #{track_id} #{prev_track_id}")
    orig_idx[track_id] = i
    orig_idx[prev_track_id] = oi
    orig[i] = track_id
    orig[oi] = prev_track_id
  end
  orig.each do |track_id|
    edit_idx[track_id] or c.req("tl remove #{track_id}")
  end
  add.each do |path, after_id|
    cmd = %W(tl add #{path})
    cmd << after_id.to_s if after_id
    c.req(cmd)
  end
ensure
  tmp.close! if tmp
end

c = DTAS::UNIXClient.new
case cmd = ARGV[0]
when "cat"
  get_track_ids(c).each do |track_id|
    res = c.req("tl get #{track_id}")
    res.sub!(/\A1 /, '')
    print "#{res}\n"
  end
when "addhead"
  ARGV.shift
  ARGV.reverse.each do |path|
    path = File.expand_path(path)
    res = c.req(%W(tl add #{path}))
    print "#{path} #{res}\n"
  end
when "addtail"
  ARGV.shift
  track_ids = get_track_ids(c)
  last_id = track_ids.pop
  ARGV.each do |path|
    path = File.expand_path(path)
    req = %W(tl add #{path})
    req << last_id.to_s if last_id
    res = c.req(req)
    print "#{path} #{res}\n"
    last_id = res if res =~ /\A\d+\z/
  end
when "reto"
  fixed = ARGV.delete("-F")
  ignorecase = ARGV.delete("-i")
  re = ARGV[1]
  time = ARGV[2]
  re = Regexp.quote(re) if fixed
  re = ignorecase ? %r{#{re}}i : %r{#{re}}
  get_track_ids(c).each do |track_id|
    res = c.req("tl get #{track_id}")
    res.sub!(/\A1 \d+=/, '')
    if re =~ res
      req = %W(tl goto #{track_id})
      req << time if time
      res = c.req(req)
      puts res
      exit(res == "OK")
    end
  end
  warn "#{re.inspect} not found"
  exit 1
when 'edit' then do_edit(c)
else
  # act like dtas-ctl for now...
  puts c.req([ "tl", *ARGV ])
end