From 2eaa154128b7f59dced72502c304ffd110aeb2b7 Mon Sep 17 00:00:00 2001
From: Marcin Jaworski <mrjaworski@gmail.com>
Date: Sat, 27 Jan 2018 17:34:09 +0100
Subject: [PATCH] Chuangmi IR: Add ability to send any Pronto Hex encoded IR
 command (#183)

---
 miio/chuangmi_ir.py | 78 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)

diff --git a/miio/chuangmi_ir.py b/miio/chuangmi_ir.py
index ad1efb95d..cac801f52 100644
--- a/miio/chuangmi_ir.py
+++ b/miio/chuangmi_ir.py
@@ -1,3 +1,8 @@
+import base64
+from construct import (
+    Struct, Const, Rebuild, this, len_, Adapter, Computed,
+    Int16ul, Int32ul, Int16ub, Array, BitStruct, BitsInteger,
+)
 from .device import Device, DeviceException
 
 
@@ -34,3 +39,76 @@ def play(self, command: str, frequency: int):
             frequency = 38400
         return self.send("miIO.ir_play",
                          {'freq': frequency, 'code': command})
+
+    def play_pronto(self, pronto: str, repeats: int=0):
+        """Play a Pronto Hex encoded IR command.
+        Supports only raw Pronto format, starting with 0000.
+
+        :param str pronto: Pronto Hex string.
+        :param int repeats: Number of extra signal repeats."""
+        if repeats < 0:
+            raise ChuangmiIrException('Invalid repeats value')
+
+        try:
+            pronto_data = Pronto.parse(bytearray.fromhex(pronto))
+        except Exception as ex:
+            raise ChuangmiIrException from ex
+
+        if len(pronto_data.intro) == 0:
+            repeats += 1
+
+        times = set()
+        for pair in pronto_data.intro + pronto_data.repeat * (1 if repeats else 0):
+            times.add(pair.pulse)
+            times.add(pair.gap)
+
+        times = sorted(times)
+        times_map = {t: idx for idx, t in enumerate(times)}
+        edge_pairs = []
+        for pair in pronto_data.intro + pronto_data.repeat * repeats:
+            edge_pairs.append({
+                'pulse': times_map[pair.pulse],
+                'gap': times_map[pair.gap],
+            })
+
+        signal_code = base64.b64encode(ChuangmiIrSignal.build({
+            'times_index': times + [0] * (16 - len(times)),
+            'edge_pairs': edge_pairs,
+        })).decode()
+
+        return self.play(signal_code, int(round(pronto_data.frequency)))
+
+
+class ProntoPulseAdapter(Adapter):
+    def _decode(self, obj, context):
+        return int(obj * context._.modulation_period)
+
+    def _encode(self, obj, context):
+        raise RuntimeError('Not implemented')
+
+
+ChuangmiIrSignal = Struct(
+    Const(0xa567, Int16ul),
+    'edge_count' / Rebuild(Int16ul, len_(this.edge_pairs) * 2 - 1),
+    'times_index' / Array(16, Int32ul),
+    'edge_pairs' / Array((this.edge_count + 1) / 2, BitStruct(
+        'gap' / BitsInteger(4),
+        'pulse' / BitsInteger(4),
+    ))
+)
+
+ProntoBurstPair = Struct(
+    'pulse' / ProntoPulseAdapter(Int16ub),
+    'gap' / ProntoPulseAdapter(Int16ub),
+)
+
+Pronto = Struct(
+    Const(0, Int16ub),
+    '_ticks' / Int16ub,
+    'modulation_period' / Computed(this._ticks * 0.241246),
+    'frequency' / Computed(1000000 / this.modulation_period),
+    'intro_len' / Int16ub,
+    'repeat_len' / Int16ub,
+    'intro' / Array(this.intro_len, ProntoBurstPair),
+    'repeat' / Array(this.repeat_len, ProntoBurstPair),
+)