local args = { ... }
local dfpwm = require("cc.audio.dfpwm")
local ccpi = require("ccpi")

settings.define("video.speaker.left", {
  description = "Speaker ID for left audio channel",
  default = peripheral.getName(peripheral.find("speaker")),
  type = "string"
})

settings.define("video.speaker.right", {
  description = "Speaker ID for right audio channel",
  default = nil,
  type = "string"
})

settings.define("video.monitor", {
  description = "Monitor to draw frames on",
  default = peripheral.getName(peripheral.find("monitor")),
  type = "string"
})

local monitor = peripheral.wrap(settings.get("video.monitor"))
local speakers = {
  l = peripheral.wrap(settings.get("video.speaker.left")),
  r = nil
}
local r_spk_id = settings.get("video.speaker.right")
if r_spk_id then
  speakers.r = peripheral.wrap(r_spk_id)
end

local delay = 0
local loading_concurrency = 8
local buffer_size = 8192
local wait_until_input = false
local n_frames, video_url, audio_url_l, audio_url_r

while args[1] ~= nil and string.sub(args[1], 1, 1) == "-" do
  local k = table.remove(args, 1):sub(2)
  if k == "m" or k == "monitor" then
    monitor = peripheral.wrap(table.remove(args, 1))
  elseif k == "l" or k == "speaker-left" then
    speakers.l = peripheral.wrap(table.remove(args, 1))
  elseif k == "r" or k == "speaker-right" then
    speakers.r = peripheral.wrap(table.remove(args, 1))
  elseif k == "d" or k == "delay" then
    delay = tonumber(table.remove(args, 1))
  elseif k == "t" or k == "threads" then
    loading_concurrency = tonumber(table.remove(args, 1))
  elseif k == "b" or k == "buffer-size" then
    buffer_size = tonumber(table.remove(args, 1))
  elseif k == "w" or k == "wait" then
    wait_until_input = true
  elseif k == "J" or k == "info-json" then
    local req = assert(http.get(table.remove(args, 1)))
    local info = textutils.unserializeJSON(req.readAll())
    delay = info.frame_time
    n_frames = info.frame_count
    video_url = info.video
    audio_url_l = info.audio.l
    audio_url_r = info.audio.r
    req.close()
  end
end

if not monitor then
  printError("No monitor connected or invalid one specified")
  return
end

if not speakers.l then
  printError("No speaker connected or invalid one specified")
  return
end

if not n_frames and not video_url and not audio_url_l then
  if #args < 3 then
    printError("Usage: video [-w] [-b BUFSZ] [-t THREADS] [-J URL] [-m MONITOR] [-l SPK_L] [-r SPK_R] [-d FRAME_T] <N_FRAMES> <VIDEO_TEMPLATE> <LEFT_CHANNEL> [RIGHT_CHANNEL]")
    return
  else
    n_frames = tonumber(table.remove(args, 1))
    video_url = table.remove(args, 1)
    audio_url_l = table.remove(args, 1)
    audio_url_r = #args > 0 and table.remove(args, 1) or nil
  end
end

print(string.format("Using monitor %s", peripheral.getName(monitor)))
if speakers.r then
  print(string.format("Stereo sound: L=%s R=%s", peripheral.getName(speakers.l), peripheral.getName(speakers.r)))
else
  print("Mono sound: " .. peripheral.getName(speakers.l))
end

if not speakers.r and audio_url_r then
  printError("No right speaker found but right audio channel was specified")
  printError("Right channel will not be played")
elseif speakers.r and not audio_url_r then
  printError("No URL for right channel was specified but right speaker is set")
  printError("Right speaker will remain silent")
end

print("\n\n")
local _, ty = term.getCursorPos()
local tw, _ = term.getSize()

local function draw_bar(y, c1, c2, p, fmt, ...)
    local str = string.format(fmt, ...)
    local w1 = math.ceil(p * tw)
    local w2 = tw - w1

    term.setCursorPos(1, y)
    term.setBackgroundColor(c1)
    term.write(str:sub(1, w1))
    local rem = w1 - #str
    if rem > 0 then
        term.write(string.rep(" ", rem))
    end

    term.setBackgroundColor(c2)
    term.write(str:sub(w1 + 1, w1 + w2))

    rem = math.min(tw - #str, w2)
    if rem > 0 then
        term.write(string.rep(" ", rem))
    end
end

local function decode_s8(data)
    local buffer = {}
    for i = 1, #data do
        local v = string.byte(data, i)
        if bit32.band(v, 0x80) then
            v = bit32.bxor(v, 0x7F) - 128
        end
        buffer[i] = v
    end
    return buffer
end

local frames = {}
local audio_frames = { l = {}, r = {} }

local subthreads = {}
local dl_channels = {
  l = assert(http.get(audio_url_l, nil, true)),
  r = audio_url_r and assert(http.get(audio_url_r, nil, true)) or nil,
}

local n_audio_samples = math.ceil(dl_channels.l.seek("end") / buffer_size)
dl_channels.l.seek("set", 0)

table.insert(subthreads, function()
  local chunk
  repeat
    chunk = dl_channels.l.read(buffer_size)
    table.insert(audio_frames.l, chunk or {})
    if (#audio_frames.l % 8) == 0 then os.sleep(0) end
  until not chunk or  #chunk == 0
end)

if dl_channels.r then
  table.insert(subthreads, function()
    local chunk
    repeat
      chunk = dl_channels.r.read(buffer_size)
      table.insert(audio_frames.r, chunk or {})
      if (#audio_frames.r % 8) == 0 then os.sleep(0) end
    until not chunk or  #chunk == 0
  end)
end

for i = 1, loading_concurrency do
  table.insert(subthreads, function()
    for ndx = i, n_frames, loading_concurrency do
      local req = assert(http.get(string.format(video_url, ndx), nil, true))
      local img = assert(ccpi.parse(req))
      frames[ndx] = img
      req.close()
    end
  end)
end

table.insert(subthreads, function()
  while #frames ~= n_frames or #audio_frames.l < n_audio_samples do
    draw_bar(ty - 3, colors.blue, colors.gray, #frames / n_frames, "Loading video [%5d / %5d]", #frames, n_frames)
    draw_bar(ty - 2, colors.red, colors.gray, #audio_frames.l / n_audio_samples, "Loading audio [%5d / %5d]", #audio_frames.l, n_audio_samples)
    os.sleep(0.25)
  end
  print()
end)

local playback_done = false

table.insert(subthreads, function()
  local tmr = os.startTimer(0.25)
  while true do
    local ev = { os.pullEvent() }
    if ev[1] == "key" and ev[2] == keys.enter then
      break
    end
    term.setCursorPos(1, ty - 1)
    term.setBackgroundColor(colors.gray)
    term.clearLine()
    term.write(string.format("Waiting for frames... (V:%d, A:%d)", #frames, #audio_frames.l))
    if #frames > 60 and #audio_frames.l >= n_audio_samples and not wait_until_input then
      break
    end
  end
  os.queueEvent("playback_ready")
end)

table.insert(subthreads, function()
  local is_dfpwm = ({ audio_url_l:find("%.dfpwm") })[2] == #audio_url_l
  local decode = use_dfpwm and dfpwm.make_decoder() or decode_s8

  os.pullEvent("playback_ready")

  for i = 1, n_audio_samples do
    local buffer = decode(audio_frames.l[i])
    while not speakers.l.playAudio(buffer) do
      os.pullEvent("speaker_audio_empty")
    end
  end

  playback_done = true
end)

table.insert(subthreads, function()
  if not audio_url_r then return end
  local is_dfpwm = ({ audio_url_r:find("%.dfpwm") })[2] == #audio_url_r
  local decode = use_dfpwm and dfpwm.make_decoder() or decode_s8

  os.pullEvent("playback_ready")

  for i = 1, n_audio_samples do
    local buffer = decode(audio_frames.r[i])
    while not speakers.r.playAudio(buffer) do
      os.pullEvent("speaker_audio_empty")
    end
  end
  playback_done = true
end)

table.insert(subthreads, function()
  os.pullEvent("playback_ready")

  local start_t = os.clock()
  while not playback_done do
    local frame = math.floor((os.clock() - start_t) / math.max(0.05, delay))
    term.setCursorPos(1, ty - 1)
    term.setBackgroundColor(frame >= #frames and colors.red or colors.gray)
    term.clearLine()
    term.write(string.format("Playing frame: %d/%d", frame + 1, #frames))
    if frames[frame] then
      ccpi.draw(frames[frame + 1], 1, 1, monitor)
    end
    os.sleep(delay)
  end
end)

parallel.waitForAll(table.unpack(subthreads))