#!/usr/bin/env ruby
# -*- encoding: binary -*-
# Copyright (C) 2013, Eric Wong <normalperson@yhbt.net>
# License: GPLv3 or later (https://www.gnu.org/licenses/gpl-3.0.txt)
#
# Note: no idea what I'm doing, especially w.r.t. curses
require 'dtas/unix_client'
require 'curses'
require 'yaml'

w = DTAS::UNIXClient.new
w.req_ok('watch')
c = DTAS::UNIXClient.new
cur = YAML.load(c.req('current'))
readable = [ w, $stdin ]

def update_tfmt(prec)
  prec == 0 ? '%H:%M:%S' : "%H:%M:%S.%#{prec}N"
end
trap(:INT) { exit(0) }
trap(:TERM) { exit(0) }

# time precision
prec_nr = 1
prec_step = (0..9).to_a
prec_max = prec_step.size - 1
tfmt = update_tfmt(prec_step[prec_nr])
events = []
interval = 1.0 / 10 ** prec_nr

def show_events(lineno, screen, events)
  Curses.setpos(lineno += 1, 0)
  Curses.clrtoeol
  Curses.addstr('Events:')
  maxy = screen.maxy - 1
  maxx = screen.maxx
  events.reverse_each do |e|
    Curses.setpos(lineno += 1, 0)
    Curses.clrtoeol
    extra = e.size/maxx
    break if (lineno + extra) >= maxy

    # deal with long lines
    if extra
      rewind = lineno
      extra.times do
        Curses.setpos(lineno += 1, 0)
        Curses.clrtoeol
      end
      Curses.setpos(rewind, 0)
      Curses.addstr(e)
      Curses.setpos(lineno, 0)
    else
      Curses.addstr(e)
    end
  end

  # discard events we can't show
  nr_events = events.size
  if nr_events > maxy
    events = events[(nr_events - maxy)..-1]
    until lineno >= screen.maxy
      Curses.setpos(lineno += 1, 0)
      Curses.clrtoeol
    end
  else
    Curses.setpos(maxy + 1, 0)
    Curses.clrtoeol
  end
end

begin
  Curses.init_screen
  Curses.nonl
  Curses.cbreak
  Curses.noecho
  screen = Curses.stdscr
  screen.scrollok(true)
  screen.keypad(true)
  loop do
    lineno = -1
    if current = cur['current']
      Curses.setpos(lineno += 1, 0)
      Curses.clrtoeol
      Curses.addstr(current['infile'])

      elapsed = Time.now.to_f - current['spawn_at']
      if (nr = cur['current_initial']) && (current_format = current['format'])
        rate = current_format['rate'].to_f
        elapsed += nr / rate
        total = " [#{Time.at(current['samples'] / rate).strftime(tfmt)}]"
      else
        total = ""
      end

      Curses.setpos(lineno += 1, 0)
      Curses.clrtoeol
      Curses.addstr("#{Time.at(elapsed).strftime(tfmt)}#{total}")
    else
      Curses.setpos(lineno += 1, 0)
      Curses.clrtoeol
      Curses.addstr(cur['paused'] ? 'paused' : 'idle')
      Curses.setpos(lineno += 1, 0)
      Curses.clrtoeol
    end

    show_events(lineno, screen, events)

    Curses.refresh # draw and wait
    r = IO.select(readable, nil, nil, current ? interval : nil) or next
    r[0].each do |io|
      case io
      when w
        event = w.res_wait
        events << "#{Time.now.strftime(tfmt)} #{event}"
        # something happened, refresh current
        # we could be more intelligent here, maybe, but too much work.
        cur = YAML.load(c.req('current'))
      when $stdin
        # keybindings taken from mplayer / vi
        case key = Curses.getch
        when "j" then c.req_ok("seek +5")
        when "k" then c.req_ok("seek -5")
        when Curses::KEY_DOWN then c.req_ok("seek -60")
        when Curses::KEY_UP then c.req_ok("seek +60")
        when Curses::KEY_LEFT then c.req_ok("seek -10")
        when Curses::KEY_RIGHT then c.req_ok("seek +10")
        when Curses::KEY_BACKSPACE then c.req_ok("seek 0")
        # yes, some of us have long audio files
        when Curses::KEY_PPAGE then c.req_ok("seek +600")
        when Curses::KEY_NPAGE then c.req_ok("seek -600")
        when " "
          c.req("play_pause")
        when "p" # lower precision of time display
          if prec_nr >= 1
            prec_nr -= 1
            tfmt = update_tfmt(prec_step[prec_nr])
            interval = 1.0 / 10 ** prec_nr
          end
        when "P" # increase precision of time display
          if prec_nr < prec_max
            prec_nr += 1
            tfmt = update_tfmt(prec_step[prec_nr])
            interval = 1.0 / 10 ** prec_nr
          end
        when 27 # TODO readline/edit mode?
        else
          Curses.setpos(screen.maxy - 1, 0)
          Curses.clrtoeol
          Curses.addstr("unknown key=#{key.inspect}")
        end
      end
    end
  end
rescue EOFError
  Curses.close_screen
  abort "dtas-player exited"
ensure
  Curses.close_screen
end