dotfiles/.config/wireplumber/scripts/monitors/bluez.lua

-- WirePlumber
--
-- Copyright © 2021 Collabora Ltd.
--    @author George Kiagiadakis <george.kiagiadakis@collabora.com>
--
-- SPDX-License-Identifier: MIT

local config = ... or {}

devices_om = ObjectManager {
  Interest {
    type = "device",
  }
}

nodes_om = ObjectManager {
  Interest {
    type = "node",
    Constraint { "node.name", "#", "*.bluez_*put*"},
    Constraint { "device.id", "+" },
  }
}

-- preprocess rules and create Interest objects
for _, r in ipairs(config.rules or {}) do
  r.interests = {}
  for _, i in ipairs(r.matches) do
    local interest_desc = { type = "properties" }
    for _, c in ipairs(i) do
      c.type = "pw"
      table.insert(interest_desc, Constraint(c))
    end
    local interest = Interest(interest_desc)
    table.insert(r.interests, interest)
  end
  r.matches = nil
end

-- applies properties from config.rules when asked to
function rulesApplyProperties(properties)
  for _, r in ipairs(config.rules or {}) do
    if r.apply_properties then
      for _, interest in ipairs(r.interests) do
        if interest:matches(properties) then
          for k, v in pairs(r.apply_properties) do
            properties[k] = v
          end
        end
      end
    end
  end
end

function setOffloadActive(device, value)
  local pod = Pod.Object {
    "Spa:Pod:Object:Param:Props", "Props", bluetoothOffloadActive = value
  }
  device:set_params("Props", pod)
end

nodes_om:connect("object-added", function(_, node)
  node:connect("state-changed", function(node, old_state, cur_state)
    local interest = Interest {
      type = "device",
      Constraint { "object.id", "=", node.properties["device.id"]}
    }
    for d in devices_om:iterate (interest) do
      if cur_state == "running" then
        setOffloadActive(d, true)
      else
        setOffloadActive(d, false)
      end
    end
  end)
end)

function createOffloadScoNode(parent, id, type, factory, properties)
  local dev_props = parent.properties

  local args = {
    ["audio.channels"] = 1,
    ["audio.position"] = "[MONO]",
  }

  local desc =
      dev_props["device.description"]
      or dev_props["device.name"]
      or dev_props["device.nick"]
      or dev_props["device.alias"]
      or "bluetooth-device"
  -- sanitize description, replace ':' with ' '
  args["node.description"] = desc:gsub("(:)", " ")

  if factory:find("sink") then
    local capture_args = {
      ["device.id"] = parent["bound-id"],
      ["media.class"] = "Audio/Sink",
      ["node.pause-on-idle"] = false,
    }
    for k, v in pairs(properties) do
      capture_args[k] = v
    end

    local name = "bluez_output" .. "." .. (properties["api.bluez5.address"] or dev_props["device.name"]) .. "." .. tostring(id)
    args["node.name"] = name:gsub("([^%w_%-%.])", "_")
    args["capture.props"] = Json.Object(capture_args)
    args["playback.props"] = Json.Object {
      ["node.passive"] = true,
      ["node.pause-on-idle"] = false,
    }
  elseif factory:find("source") then
    local playback_args = {
      ["device.id"] = parent["bound-id"],
      ["media.class"] = "Audio/Source",
      ["node.pause-on-idle"] = false,
    }
    for k, v in pairs(properties) do
      playback_args[k] = v
    end

    local name = "bluez_input" .. "." .. (properties["api.bluez5.address"] or dev_props["device.name"]) .. "." .. tostring(id)
    args["node.name"] = name:gsub("([^%w_%-%.])", "_")
    args["capture.props"] = Json.Object {
      ["node.passive"] = true,
      ["node.pause-on-idle"] = false,
    }
    args["playback.props"] = Json.Object(playback_args)
  else
    Log.warning(parent, "Unsupported factory: " .. factory)
    return
  end

  -- Transform 'args' to a json object here
  local args_json = Json.Object(args)

  -- and get the final JSON as a string from the json object
  local args_string = args_json:get_data()

  local loopback_properties = {}

  local loopback = LocalModule("libpipewire-module-loopback", args_string, loopback_properties)
  parent:store_managed_object(id, loopback)
end

function createNode(parent, id, type, factory, properties)
  local dev_props = parent.properties

  if config.properties["bluez5.hw-offload-sco"] and factory:find("sco") then
    createOffloadScoNode(parent, id, type, factory, properties)
    return
  end

  -- set the device id and spa factory name; REQUIRED, do not change
  properties["device.id"] = parent["bound-id"]
  properties["factory.name"] = factory

  -- set the default pause-on-idle setting
  properties["node.pause-on-idle"] = false

  -- set the node description
  local desc =
      dev_props["device.description"]
      or dev_props["device.name"]
      or dev_props["device.nick"]
      or dev_props["device.alias"]
      or "bluetooth-device"
  -- sanitize description, replace ':' with ' '
  properties["node.description"] = desc:gsub("(:)", " ")

  -- set the node name
  local name =
      ((factory:find("sink") and "bluez_output") or
       (factory:find("source") and "bluez_input" or factory)) .. "." ..
      (properties["api.bluez5.address"] or dev_props["device.name"]) .. "." ..
      tostring(id)
  -- sanitize name
  properties["node.name"] = name:gsub("([^%w_%-%.])", "_")

  -- set priority
  if not properties["priority.driver"] then
    local priority = factory:find("source") and 2010 or 1010
    properties["priority.driver"] = priority
    properties["priority.session"] = priority
  end

  -- autoconnect if it's a stream
  if properties["api.bluez5.profile"] == "headset-audio-gateway" or
     properties["api.bluez5.profile"] == "bap-sink" or
     factory:find("a2dp.source") or factory:find("media.source") then
    properties["node.autoconnect"] = true
  end

  -- apply properties from config.rules
  rulesApplyProperties(properties)

  -- create the node; bluez requires "local" nodes, i.e. ones that run in
  -- the same process as the spa device, for several reasons
  local node = LocalNode("adapter", properties)
  node:activate(Feature.Proxy.BOUND)
  parent:store_managed_object(id, node)
end

function createDevice(parent, id, type, factory, properties)
  local device = parent:get_managed_object(id)
  if not device then
    -- ensure a proper device name
    local name =
        (properties["device.name"] or
         properties["api.bluez5.address"] or
         properties["device.description"] or
         tostring(id)):gsub("([^%w_%-%.])", "_")

    if not name:find("^bluez_card%.", 1) then
      name = "bluez_card." .. name
    end
    properties["device.name"] = name

    -- set the icon name
    if not properties["device.icon-name"] then
      local icon = nil
      local icon_map = {
        -- form factor -> icon
        ["microphone"] = "audio-input-microphone",
        ["webcam"] = "camera-web",
        ["handset"] = "phone",
        ["portable"] = "multimedia-player",
        ["tv"] = "video-display",
        ["headset"] = "audio-headset",
        ["headphone"] = "audio-headphones",
        ["speaker"] = "audio-speakers",
        ["hands-free"] = "audio-handsfree",
      }
      local f = properties["device.form-factor"]
      local b = properties["device.bus"]

      icon = icon_map[f] or "audio-card"
      properties["device.icon-name"] = icon .. (b and ("-" .. b) or "")
    end

    -- initial profile is to be set by policy-device-profile.lua, not spa-bluez5
    properties["bluez5.profile"] = "off"

    -- apply properties from config.rules
    rulesApplyProperties(properties)

    -- create the device
    device = SpaDevice(factory, properties)
    if device then
      device:connect("create-object", createNode)
      parent:store_managed_object(id, device)
    else
      Log.warning ("Failed to create '" .. factory .. "' device")
      return
    end
  end

  Log.info(parent, string.format("%d, %s (%s): %s",
        id, properties["device.description"],
        properties["api.bluez5.address"], properties["api.bluez5.connection"]))

  -- activate the device after the bluez profiles are connected
  if properties["api.bluez5.connection"] == "connected" then
    device:activate(Feature.SpaDevice.ENABLED | Feature.Proxy.BOUND)
  else
    device:deactivate(Features.ALL)
  end
end

function createMonitor()
  local monitor_props = config.properties or {}
  monitor_props["api.bluez5.connection-info"] = true

  local monitor = SpaDevice("api.bluez5.enum.dbus", monitor_props)
  if monitor then
    monitor:connect("create-object", createDevice)
  else
    Log.message("PipeWire's BlueZ SPA missing or broken. Bluetooth not supported.")
    return nil
  end
  monitor:activate(Feature.SpaDevice.ENABLED)

  return monitor
end

logind_plugin = Plugin.find("logind")
if logind_plugin then
  -- if logind support is enabled, activate
  -- the monitor only when the seat is active
  function startStopMonitor(seat_state)
    Log.info(logind_plugin, "Seat state changed: " .. seat_state)

    if seat_state == "active" then
      monitor = createMonitor()
    elseif monitor then
      monitor:deactivate(Feature.SpaDevice.ENABLED)
      monitor = nil
    end
  end

  logind_plugin:connect("state-changed", function(p, s) startStopMonitor(s) end)
  startStopMonitor(logind_plugin:call("get-state"))
else
  monitor = createMonitor()
end

nodes_om:activate()
devices_om:activate()