From b17d044bb58292000fe72694ff3a011a47add7a4 Mon Sep 17 00:00:00 2001
From: Rahix <h.w.seiler@gmx.de>
Date: Mon, 10 Apr 2017 16:52:41 +0200
Subject: [PATCH] Initial

---
 _bc_backend.lua |  75 +++++++++++++++++++++++++++++++++++
 bc.lua          | 101 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 176 insertions(+)
 create mode 100644 _bc_backend.lua
 create mode 100644 bc.lua

diff --git a/_bc_backend.lua b/_bc_backend.lua
new file mode 100644
index 000000000000..95db0efdbbf3
--- /dev/null
+++ b/_bc_backend.lua
@@ -0,0 +1,75 @@
+_bc_backend = { local_addr = "address_light", power = 12, iscb = false, cbid = 0, cbn = "" }
+
+function _bc_backend:init(cb_handler)
+  local o = {}
+  setmetatable(o, self)
+  self.__index = self
+  o.cb_handler = cb_handler
+  return o
+end
+
+function _bc_backend:fetch_list(master_id)
+  return {
+    nouns = {
+      ["power"] = "address_power",
+      ["light"] = "address_light",
+    },
+    verbs = {
+      ["inc_pwr"] = "address_power",
+      ["toggle_light"] = "address_light",
+    }
+  }
+end
+
+function _bc_backend:request_noun(addr, n)
+  if addr == "address_power" and n == "power" then
+    return self.power
+  end
+  return nil
+end
+
+function _bc_backend:call_verb(addr, v, param)
+  if addr == "address_power" and v == "inc_pwr" then
+    self.power = param
+    if self.iscb then
+      self.cb_handler("listen", 101010)
+    end
+  end
+end
+
+function _bc_backend:register_callback(addr, n, query, qparam)
+  self.iscb = true
+  return 101010
+end
+
+function _bc_backend:cancel_callback(addr, n, id)
+  self.iscb = false
+end
+
+function _bc_backend:call_listener(addr, n, id, value)
+  if id == self.cbid and addr == "foobar" and n == self.cbn then
+    self.cb(value)
+  end
+end
+
+-- Debug handlers
+function _bc_backend:debug_request_noun(n)
+  -- Ask cb for noun value
+  return self.cb_handler("noun", n)
+end
+
+function _bc_backend:debug_call_verb(v, arg)
+  self.cb_handler("verb", v, arg)
+end
+
+function _bc_backend:debug_register_cb(n, query, qparam, cb)
+  self.cbid = self.cb_handler("reg_nl", n, {query = query, qparam = qparam, addr = "foobar"})
+  self.cbn = n
+  self.cb = cb
+end
+
+function _bc_backend:debug_cancel_cb()
+  self.cb_handler("unreg_nl", self.cbn, self.cbid)
+end
+
+return _bc_backend
diff --git a/bc.lua b/bc.lua
new file mode 100644
index 000000000000..4cc0f4df14c1
--- /dev/null
+++ b/bc.lua
@@ -0,0 +1,101 @@
+bc = {}
+
+_bc_backend = require("_bc_backend")
+
+function bc:init(master_id)
+  local o = {}
+  setmetatable(o, self)
+  self.__index = self
+  -- Init backend and cb handler
+  o._listen_callbacks = {}
+  o._verb_handlers = {}
+  o._listeners = {}
+  local function cb_handler(cb_type, param, arg)
+    if cb_type == "listen" then
+      if type(o._listen_callbacks[param]) == "function" then
+        o._listen_callbacks[param]()
+      end
+    elseif cb_type == "verb" then
+      o._verb_handlers[param](arg)
+    elseif cb_type == "noun" then
+      return o._mynouns[param]
+    elseif cb_type == "reg_nl" then
+      -- Create array if there is not one already
+      o._listeners[param] = o._listeners[param] or {}
+      -- Insert parameters
+      table.insert(o._listeners[param], arg)
+      return #o._listeners[param]
+    elseif cb_type == "unreg_nl" then
+      o._listeners[param][arg] = true;
+    else
+      error("Wrong cb type")
+    end
+  end
+  o._backend = _bc_backend:init(cb_handler)
+  -- Fetch list of nouns and verbs from master
+  local list = o._backend:fetch_list(master_id)
+  o._nouns = list.nouns
+  o._verbs = list.verbs
+  -- Initialize own nouns
+  o._mynouns = {}
+  for noun, addr in pairs(o._nouns) do
+    if addr == o._backend.local_addr then
+      o._mynouns[noun] = 0
+    end
+  end
+  list = nil
+  return o
+end
+
+function bc:get_noun(n)
+  if self._nouns[n] == self._backend.local_addr then
+    return self._mynouns[n]
+  else
+    return self._backend:request_noun(self._nouns[n], n)
+  end
+end
+
+function bc:set_noun(n, val)
+  if self._nouns[n] == self._backend.local_addr then
+    -- Call listeners
+    if type(self._listeners[n]) == "table" then
+      for i, listener in ipairs(self._listeners[n]) do
+        -- Check condition
+        if type(listener) == "table" and
+           ( (listener.query == "onchange" and self._mynouns[n] ~= val)
+          or (listener.query == "onrising" and self._mynouns[n] < val)
+          or (listener.query == "onfalling" and self._mynouns[n] > val)
+          or (listener.query == "onabove" and val > listener.qparam)
+          or (listener.query == "onbelow" and val < listener.qparam)
+          or (listener.query == "onvalue" and val == listener.qparam)
+          ) then
+            self._backend:call_listener(listener.addr, n, i, val)
+        end
+      end
+    end
+    -- Set value
+    self._mynouns[n] = val
+    return true
+  end
+  return false
+end
+
+function bc:on_verb(v, handler)
+  self._verb_handlers[v] = handler
+end
+
+function bc:call_verb(v, param)
+  self._backend:call_verb(self._verbs[v], v, param)
+end
+
+function bc:listen_noun(n, query, qparam, cb)
+  local id = self._backend:register_callback(self._nouns[n], n, query, qparam)
+  self._listen_callbacks[id] = cb
+  return id
+end
+
+function bc:listen_cancel(n, id)
+  self._backend:cancel_callback(n, id)
+end
+
+return bc