#!/usr/bin/env ruby
# Copyright (C) 2013-2016 all contributors <dtas-all@nongnu.org>
# License: GPL-3.0+ <https://www.gnu.org/licenses/gpl-3.0.txt>
# frozen_string_literal: true
#
# Note: no idea what I'm doing, especially w.r.t. curses
require 'dtas'
require 'dtas/unix_client'
require 'dtas/rg_state'
require 'dtas/sigevent'
require 'dtas/process'
require 'dtas/format'
include DTAS::Process
require 'yaml'
begin
  require 'curses'
rescue LoadError
  abort "please install the 'curses' RubyGem to use #$0"
end

tsec = false
se = DTAS::Sigevent.new
trap(:WINCH) { se.signal }
w = DTAS::UNIXClient.new
w.req_ok('watch')
c = DTAS::UNIXClient.new
cur = YAML.load(c.req('current'))
readable = [ se, w, $stdin ]

# current rg mode
rg_mode = DTAS::RGState::RG_MODE.keys.unshift("off")
if (rg = cur["rg"]) && (rg = rg["mode"])
  rg_mode_i = rg_mode.index(cur["rg"]["mode"])
else
  rg_mode_i = 0
end

def update_tfmt(prec, tsec)
  if tsec
    prec == 0 ? '%_8s' : "%_8s.%#{prec}N"
  else
    prec == 0 ? '%H:%M:%S' : "%H:%M:%S.%#{prec}N"
  end
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], tsec)
events = []
interval = 1.0 / 10 ** prec_nr

pause = nil

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

def fmt_to_s(f)
  r = [ f['rate'], f['channels'], f['type'], f['bits'] ]
  r.compact!
  r.join(',')
end

def rg_string(rg, current)
  rv = "rg mode=#{rg['mode']||'off'}".dup
  defaults = DTAS::RGState::RG_DEFAULT
  # don't show things that are too rare
  %w(preamp fallback_gain).each do |param|
    val = rg[param] || defaults[param]
    rv << " #{param}=#{val}"
  end
  env = current && current["env"] and rv << " / RGFX='#{env['RGFX']}'"
  rv
end

def may_fail(res, events)
  events << res if res != "OK"
end

pre_mute_vol = 1.0
enc_locale = Encoding.find("locale")
$stdout.set_encoding(enc_locale)
enc_opts = { undef: :replace, invalid: :replace, replace: '?' }
begin
  Curses.init_screen
  Curses.nonl
  Curses.cbreak
  Curses.noecho
  screen = Curses.stdscr
  screen.scrollok(true)
  screen.keypad(true)
  loop do
    lineno = -1
    pfmt = cur['format']
    elapsed = samples = 0
    fmt = total = ''
    paused = false
    if current = cur['current']
      infile = current['infile'] || current['command']
      elapsed = DTAS.now - current['spawn_at']
      if (nr = cur['current_initial']) && (current_format = current['format'])
        rate = current_format['rate'].to_f
        elapsed += nr / rate
        samples = current['samples']
        fmt = "(#{fmt_to_s(current_format)} > #{fmt_to_s(pfmt)})"
      else
        fmt = fmt_to_s(pfmt)
        fmt = "(#{fmt} > #{fmt})"
      end
    elsif cur['paused'] && infile = cur['current_paused']
      fmt = "[paused] (#{fmt_to_s(pfmt)})"
      paused = true
      infile = infile['command'] if Hash === infile
      if Array === infile
        infile, elapsed = infile
        elapsed = elapsed.to_i
        samples = rate = 0
        if (bypass = cur['bypass']) && bypass.include?('rate')
          rate = pfmt['rate'].to_f
        else
          rate = qx(%W(soxi -r #{infile}), err: DTAS.null).to_i rescue 0
        end
        elapsed /= rate.to_f if rate != 0
      end
    end

    if infile
      # FS encoding != locale encoding, but we need to display an FS path
      # name to whatever locale the terminal is encoded to, so force it
      # and risk mojibake...
      infile.encode(enc_locale, enc_opts)
      Curses.setpos(lineno += 1, 0)
      Curses.clrtoeol
      Curses.addstr(infile)
      total = " [#{Time.at(samples / rate).utc.strftime(tfmt)}]" if samples != 0
      Curses.setpos(lineno += 1, 0)
      Curses.clrtoeol
      if rate != 0
        Curses.addstr("#{Time.at(elapsed).utc.strftime(tfmt)}#{total} #{fmt}")
      else
        Curses.addstr("#{elapsed} samples #{total} #{fmt}")
      end
    else
      Curses.setpos(lineno += 1, 0)
      Curses.clrtoeol
      Curses.addstr('idle')
      Curses.setpos(lineno += 1, 0)
      Curses.clrtoeol
    end

    rg = cur['rg'] || {}
    rgs = rg_string(rg, current)
    Curses.setpos(lineno += 1, 0)
    Curses.clrtoeol
    Curses.addstr(rgs)

    Curses.setpos(lineno += 1, 0)
    Curses.clrtoeol
    cur_vol = rg['volume'] || 1.0
    extra = [ "volume=#{cur_vol}" ]
    tl = cur['tracklist'] || {}
    %w(repeat shuffle consume).each { |x| extra << "#{x}=#{tl[x] || 'false'}" }
    trim = cur['trim'] || 'off'
    extra << "trim=#{trim}"
    Curses.addstr(extra.join(' '))
    pre_mute_vol = cur_vol if cur_vol != 0

    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 se
        se.readable_iter {} # noop, just consume the event
        Curses.clear
      when w
        event = w.res_wait
        case event
        when "pause"
          if current
            pause = current['infile'] || current['command']
          end
        when %r{\Afile }
          pause = nil
        end
        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 "q" then exit(0)
        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 '9' then c.req_ok('rg volume-=0.01')
        when '0' then c.req_ok('rg volume+=0.01')
        when '=' then c.req_ok('rg volume=1')
        when '7' then c.req_ok('rg preamp-=1')
        when '8' then c.req_ok('rg preamp+=1')
        when 'm' then c.req_ok("rg volume=#{cur_vol == 0 ? pre_mute_vol : 0}")
        when "F" then c.req_ok("rg fallback_gain+=1")
        when "f" then c.req_ok("rg fallback_gain-=1")
        when ">" then c.req_ok("tl next")
        when "<" then c.req_ok("tl prev")
        when "!" then may_fail(c.req("cue prev"), events)
        when "@" then may_fail(c.req("cue next"), events)
        when "o" then tfmt = update_tfmt(prec_step[prec_nr], tsec = !tsec)
        when " "
          c.req("play_pause")
        when "r" # cycle through replaygain modes
          rg_mode_i >= 1 and c.req_ok("rg mode=#{rg_mode[rg_mode_i -= 1]}")
        when "R"
          rg_mode_i < (rg_mode.size - 1) and
            c.req_ok("rg mode=#{rg_mode[rg_mode_i += 1]}")
        when "p" # lower precision of time display
          if prec_nr >= 1
            prec_nr -= 1
            tfmt = update_tfmt(prec_step[prec_nr], tsec)
            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], tsec)
            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