scripts: rewrite policy-device-profile and m-default-profile into a set of hooks

... excluding the persistent profile functionality for now (I am not convinced)

modules/module-standard-event-source.c

@@ -132,7 +132,8 @@ get_object_type (gpointer obj, WpProperties **properties)
 static gint
 get_default_event_priority (const gchar *event_type)
 {
-  if (!g_strcmp0 (event_type, "find-target-si-and-link"))
+  if (!g_strcmp0 (event_type, "find-target-si-and-link") ||
+      !g_strcmp0 (event_type, "select-profile"))
     return 500;
   else if (!g_strcmp0 (event_type, "rescan-session"))
     return -500;

src/scripts/device/apply-profile.lua

@@ -0,0 +1,56 @@
+-- WirePlumber
+--
+-- Copyright © 2022 Collabora Ltd.
+--
+-- SPDX-License-Identifier: MIT
+
+cutils = require ("common-utils")
+
+AsyncEventHook {
+  name = "apply-profile@device",
+  after = { "find-stored-profile@device", "find-best-profile@device" },
+  interests = {
+    EventInterest {
+      Constraint { "event.type", "=", "select-profile" },
+    },
+  },
+  steps = {
+    start = {
+      next = "none",
+      execute = function (event, transition)
+        local device = event:get_subject ()
+        local profile = event:get_data ("selected-profile")
+        local dev_name = device.properties ["device.name"]
+
+        if not profile then
+          Log.info (device, "No profile found to set on " .. dev_name)
+          transition:advance ()
+          return
+        end
+
+        for p in device:iterate_params ("Profile") do
+          local active_profile = cutils.parseParam (p, "Profile")
+          if active_profile.index == profile.index then
+            Log.info (device, "Profile " .. profile.name .. " is already set on " .. dev_name)
+            transition:advance ()
+            return
+          end
+        end
+
+        local param = Pod.Object {
+          "Spa:Pod:Object:Param:Profile", "Profile",
+          index = profile.index,
+        }
+        Log.info (device, "Setting profile " .. profile.name .. " on " .. dev_name)
+        device:set_param ("Profile", param)
+
+        -- FIXME: add cancellability
+        -- sync on the pipewire connection to ensure that the param
+        -- has been configured on the remote device object
+        Core.sync (function ()
+          transition:advance ()
+        end)
+      end
+    },
+  }
+}:register()

src/scripts/device/find-best-profile.lua

@@ -0,0 +1,65 @@
+-- WirePlumber
+--
+-- Copyright © 2022 Collabora Ltd.
+--
+-- SPDX-License-Identifier: MIT
+--
+-- Find the best profile for a device based on profile priorities and
+-- availability
+
+cutils = require ("common-utils")
+
+SimpleEventHook {
+  name = "find-best-profile@device",
+  after = "find-stored-profile@device",
+  interests = {
+    EventInterest {
+      Constraint { "event.type", "=", "select-profile" },
+    },
+  },
+  execute = function (event)
+    local selected_profile = event:get_data ("selected-profile")
+    local device = event:get_subject ()
+    local dev_name = device.properties["device.name"]
+    local off_profile = nil
+    local best_profile = nil
+    local unk_profile = nil
+
+    -- skip hook if profile is already selected
+    if selected_profile then
+      return
+    end
+
+    for p in device:iterate_params ("EnumProfile") do
+      profile = cutils.parseParam (p, "EnumProfile")
+      if profile and profile.name ~= "pro-audio" then
+        if profile.name == "off" then
+          off_profile = profile
+        elseif profile.available == "yes" then
+          if best_profile == nil or profile.priority > best_profile.priority then
+            best_profile = profile
+          end
+        elseif profile.available ~= "no" then
+          if unk_profile == nil or profile.priority > unk_profile.priority then
+            unk_profile = profile
+          end
+        end
+      end
+    end
+
+    if best_profile ~= nil then
+      selected_profile = best_profile
+    elseif unk_profile ~= nil then
+      selected_profile = unk_profile
+    elseif off_profile ~= nil then
+      selected_profile = off_profile
+    end
+
+    if selected_profile then
+      Log.info (device, string.format (
+          "Found best profile '%s' (%d) for device '%s'",
+          selected_profile.name, selected_profile.index, dev_name))
+      event:set_data ("selected-profile", selected_profile)
+    end
+  end
+}:register()

src/scripts/device/select-profile.lua

@@ -0,0 +1,25 @@
+-- WirePlumber
+--
+-- Copyright © 2022 Collabora Ltd.
+--
+-- SPDX-License-Identifier: MIT
+
+cutils = require ("common-utils")
+
+SimpleEventHook {
+  name = "select-profile@device",
+  interests = {
+    EventInterest {
+      Constraint { "event.type", "=", "device-added" },
+    },
+    EventInterest {
+      Constraint { "event.type", "=", "device-params-changed" },
+      Constraint { "event.subject.param-id", "=", "EnumProfile" },
+    },
+  },
+  execute = function (event)
+    local source = event:get_source ()
+    local device = event:get_subject ()
+    source:call ("push-event", "select-profile", device, nil)
+  end
+}:register()

src/scripts/device/state-profile.lua

@@ -0,0 +1,120 @@
+-- WirePlumber
+--
+-- Copyright © 2022 Collabora Ltd.
+--
+-- SPDX-License-Identifier: MIT
+--
+-- This file contains all the logic related to saving device profiles
+-- to a state file and restoring them later on.
+
+cutils = require ("common-utils")
+
+state = State ("default-profile")
+state_table = state:load ()
+
+SimpleEventHook {
+  name = "find-stored-profile@device",
+  interests = {
+    EventInterest {
+      Constraint { "event.type", "=", "select-profile" },
+    },
+  },
+  execute = function (event)
+    local selected_profile = event:get_data ("selected-profile")
+    local device = event:get_subject ()
+    local dev_name = device.properties["device.name"]
+
+    -- skip hook if profile is already selected
+    if selected_profile then
+      return
+    end
+
+    if not dev_name then
+      Log.critical (device, "invalid device.name")
+      return
+    end
+
+    local profile_name = state_table[dev_name]
+
+    if profile_name then
+      for p in device:iterate_params ("EnumProfile") do
+        local profile = cutils.parseParam (p, "EnumProfile")
+        if profile.name == profile_name then
+          selected_profile = profile
+          break
+        end
+      end
+    end
+
+    if selected_profile then
+      Log.info (device, string.format (
+          "Found stored profile '%s' (%d) for device '%s'",
+          selected_profile.name, selected_profile.index, dev_name))
+      event:set_data ("selected-profile", selected_profile)
+    end
+  end
+}:register()
+
+SimpleEventHook {
+  name = "store-user-selected-profile@device",
+  interests = {
+    EventInterest {
+      Constraint { "event.type", "=", "device-params-changed" },
+      Constraint { "event.subject.param-id", "=", "Profile" },
+    },
+  },
+  execute = function (event)
+    local device = event:get_subject ()
+
+    for p in device:iterate_params ("Profile") do
+      local profile = cutils.parseParam (p, "Profile")
+      if profile.save then
+        -- store only if this was a user-generated action (save == true)
+        updateStoredProfile (device, profile)
+      end
+    end
+  end
+}:register()
+
+function updateStoredProfile (device, profile)
+  local dev_name = device.properties["device.name"]
+  local index = nil
+
+  if not dev_name then
+    Log.critical (device, "invalid device.name")
+    return
+  end
+
+  Log.debug (device, string.format (
+      "update stored profile to '%s' (%d) for device '%s'",
+      profile.name, profile.index, dev_name))
+
+  -- check if the new profile is the same as the current one
+  if state_table[dev_name] == profile.name then
+    Log.debug (device, " ... profile is already stored")
+    return
+  end
+
+  -- find the full profile from EnumProfile, making also sure that the
+  -- user / client application has actually set an existing profile
+  for p in device:iterate_params ("EnumProfile") do
+    local enum_profile = cutils.parseParam (p, "EnumProfile")
+    if enum_profile.name == profile.name then
+      index = enum_profile.index
+    end
+  end
+
+  if not index then
+    Log.info (device, string.format (
+        "profile '%s' (%d) is not valid on device '%s'",
+        profile.name, profile.index, dev_name))
+    return
+  end
+
+  state_table[dev_name] = profile.name
+  cutils.storeAfterTimeout (state, state_table)
+
+  Log.info (device, string.format (
+      "stored profile '%s' (%d) for device '%s'",
+      profile.name, index, dev_name))
+end