🏗 Merge C++ into python codebase (#504)

## Description:

Move esphome-core codebase into esphome (and a bunch of other refactors). See https://github.com/esphome/feature-requests/issues/97

Yes this is a shit ton of work and no there's no way to automate it :( But it will be worth it 👍

Progress:
- Core support (file copy etc): 80%
- Base Abstractions (light, switch): ~50%
- Integrations: ~10%
- Working? Yes, (but only with ported components).

Other refactors:
- Moves all codegen related stuff into a single class: `esphome.codegen` (imported as `cg`)
- Rework coroutine syntax
- Move from `component/platform.py` to `domain/component.py` structure as with HA
- Move all defaults out of C++ and into config validation.
- Remove `make_...` helpers from Application class. Reason: Merge conflicts with every single new integration.
- Pointer Variables are stored globally instead of locally in setup(). Reason: stack size limit.

Future work:
- Rework const.py - Move all `CONF_...` into a conf class (usage `conf.UPDATE_INTERVAL` vs `CONF_UPDATE_INTERVAL`). Reason: Less convoluted import block
- Enable loading from `custom_components` folder.

**Related issue (if applicable):** https://github.com/esphome/feature-requests/issues/97

**Pull request in [esphome-docs](https://github.com/esphome/esphome-docs) with documentation (if applicable):** esphome/esphome-docs#<esphome-docs PR number goes here>

## Checklist:
  - [ ] The code change is tested and works locally.
  - [ ] Tests have been added to verify that the new code works (under `tests/` folder).

If user exposed functionality or configuration variables are added/changed:
  - [ ] Documentation added/updated in [esphomedocs](https://github.com/OttoWinter/esphomedocs).

esphome/components/gpio/__init__.py

@@ -0,0 +1,3 @@
+import esphome.codegen as cg
+
+gpio_ns = cg.esphome_ns.namespace('gpio')

esphome/components/gpio/binary_sensor/__init__.py

@@ -0,0 +1,21 @@
+import esphome.codegen as cg
+import esphome.config_validation as cv
+from esphome import pins
+from esphome.components import binary_sensor
+from esphome.const import CONF_ID, CONF_NAME, CONF_PIN
+from .. import gpio_ns
+
+GPIOBinarySensor = gpio_ns.class_('GPIOBinarySensor', binary_sensor.BinarySensor, cg.Component)
+
+CONFIG_SCHEMA = cv.nameable(binary_sensor.BINARY_SENSOR_SCHEMA.extend({
+    cv.GenerateID(): cv.declare_variable_id(GPIOBinarySensor),
+    cv.Required(CONF_PIN): pins.gpio_input_pin_schema
+}).extend(cv.COMPONENT_SCHEMA))
+
+
+def to_code(config):
+    pin = yield cg.gpio_pin_expression(config[CONF_PIN])
+    rhs = GPIOBinarySensor.new(config[CONF_NAME], pin)
+    gpio = cg.Pvariable(config[CONF_ID], rhs)
+    yield cg.register_component(gpio, config)
+    yield binary_sensor.register_binary_sensor(gpio, config)

esphome/components/gpio/binary_sensor/gpio_binary_sensor.cpp

@@ -0,0 +1,26 @@
+#include "esphome/components/gpio/binary_sensor/gpio_binary_sensor.h"
+#include "esphome/core/log.h"
+
+namespace esphome {
+namespace gpio {
+
+static const char *TAG = "gpio.binary_sensor";
+
+void GPIOBinarySensor::setup() {
+  this->pin_->setup();
+  this->publish_initial_state(this->pin_->digital_read());
+}
+
+void GPIOBinarySensor::dump_config() {
+  LOG_BINARY_SENSOR("", "GPIO Binary Sensor", this);
+  LOG_PIN("  Pin: ", this->pin_);
+}
+
+void GPIOBinarySensor::loop() { this->publish_state(this->pin_->digital_read()); }
+
+float GPIOBinarySensor::get_setup_priority() const { return setup_priority::HARDWARE; }
+GPIOBinarySensor::GPIOBinarySensor(const std::string &name, GPIOPin *pin)
+    : binary_sensor::BinarySensor(name), pin_(pin) {}
+
+}  // namespace gpio
+}  // namespace esphome

esphome/components/gpio/binary_sensor/gpio_binary_sensor.h

@@ -0,0 +1,28 @@
+#pragma once
+
+#include "esphome/core/component.h"
+#include "esphome/components/binary_sensor/binary_sensor.h"
+
+namespace esphome {
+namespace gpio {
+
+class GPIOBinarySensor : public binary_sensor::BinarySensor, public Component {
+ public:
+  explicit GPIOBinarySensor(const std::string &name, GPIOPin *pin);
+
+  // ========== INTERNAL METHODS ==========
+  // (In most use cases you won't need these)
+  /// Setup pin
+  void setup() override;
+  void dump_config() override;
+  /// Hardware priority
+  float get_setup_priority() const override;
+  /// Check sensor
+  void loop() override;
+
+ protected:
+  GPIOPin *pin_;
+};
+
+}  // namespace gpio
+}  // namespace esphome

esphome/components/gpio/output/__init__.py

@@ -0,0 +1,21 @@
+import esphome.codegen as cg
+import esphome.config_validation as cv
+from esphome import pins
+from esphome.components import output
+from esphome.const import CONF_ID, CONF_PIN
+from .. import gpio_ns
+
+GPIOBinaryOutput = gpio_ns.class_('GPIOBinaryOutput', output.BinaryOutput,
+                                  cg.Component)
+
+CONFIG_SCHEMA = output.BINARY_OUTPUT_SCHEMA.extend({
+    cv.Required(CONF_ID): cv.declare_variable_id(GPIOBinaryOutput),
+    cv.Required(CONF_PIN): pins.gpio_output_pin_schema,
+}).extend(cv.COMPONENT_SCHEMA)
+
+
+def to_code(config):
+    pin = yield cg.gpio_pin_expression(config[CONF_PIN])
+    gpio = cg.new_Pvariable(config[CONF_ID], pin)
+    yield output.register_output(gpio, config)
+    yield cg.register_component(gpio, config)

esphome/components/gpio/output/gpio_binary_output.cpp

@@ -0,0 +1,16 @@
+#include "gpio_binary_output.h"
+#include "esphome/core/log.h"
+
+namespace esphome {
+namespace gpio {
+
+static const char *TAG = "gpio.output";
+
+void GPIOBinaryOutput::dump_config() {
+  ESP_LOGCONFIG(TAG, "GPIO Binary Output:");
+  LOG_PIN("  Pin: ", this->pin_);
+  LOG_BINARY_OUTPUT(this);
+}
+
+}  // namespace gpio
+}  // namespace esphome

esphome/components/gpio/output/gpio_binary_output.h

@@ -0,0 +1,29 @@
+#pragma once
+
+#include "esphome/core/component.h"
+#include "esphome/core/esphal.h"
+#include "esphome/components/output/binary_output.h"
+
+namespace esphome {
+namespace gpio {
+
+class GPIOBinaryOutput : public output::BinaryOutput, public Component {
+ public:
+  explicit GPIOBinaryOutput(GPIOPin *pin) : pin_(pin) {}
+
+  void setup() override {
+    this->turn_off();
+    this->pin_->setup();
+    this->turn_off();
+  }
+  void dump_config() override;
+  float get_setup_priority() const override { return setup_priority::HARDWARE; }
+
+ protected:
+  void write_state(bool state) override { this->pin_->digital_write(state); }
+
+  GPIOPin *pin_;
+};
+
+}  // namespace gpio
+}  // namespace esphome

esphome/components/gpio/switch/__init__.py

@@ -0,0 +1,41 @@
+import esphome.config_validation as cv
+import esphome.codegen as cg
+from esphome import pins
+from esphome.components import switch
+from esphome.const import CONF_ID, CONF_INTERLOCK, CONF_NAME, CONF_PIN, CONF_RESTORE_MODE
+from .. import gpio_ns
+
+GPIOSwitch = gpio_ns.class_('GPIOSwitch', switch.Switch, cg.Component)
+GPIOSwitchRestoreMode = gpio_ns.enum('GPIOSwitchRestoreMode')
+
+RESTORE_MODES = {
+    'RESTORE_DEFAULT_OFF': GPIOSwitchRestoreMode.GPIO_SWITCH_RESTORE_DEFAULT_OFF,
+    'RESTORE_DEFAULT_ON': GPIOSwitchRestoreMode.GPIO_SWITCH_RESTORE_DEFAULT_ON,
+    'ALWAYS_OFF': GPIOSwitchRestoreMode.GPIO_SWITCH_ALWAYS_OFF,
+    'ALWAYS_ON': GPIOSwitchRestoreMode.GPIO_SWITCH_ALWAYS_ON,
+}
+
+CONFIG_SCHEMA = cv.nameable(switch.SWITCH_SCHEMA.extend({
+    cv.GenerateID(): cv.declare_variable_id(GPIOSwitch),
+    cv.Required(CONF_PIN): pins.gpio_output_pin_schema,
+    cv.Optional(CONF_RESTORE_MODE, default='RESTORE_DEFAULT_OFF'):
+        cv.one_of(*RESTORE_MODES, upper=True, space='_'),
+    cv.Optional(CONF_INTERLOCK): cv.ensure_list(cv.use_variable_id(switch.Switch)),
+}).extend(cv.COMPONENT_SCHEMA))
+
+
+def to_code(config):
+    pin = yield cg.gpio_pin_expression(config[CONF_PIN])
+    rhs = GPIOSwitch.new(config[CONF_NAME], pin)
+    gpio = cg.Pvariable(config[CONF_ID], rhs)
+    yield cg.register_component(gpio, config)
+    yield switch.register_switch(gpio, config)
+
+    cg.add(gpio.set_restore_mode(RESTORE_MODES[config[CONF_RESTORE_MODE]]))
+
+    if CONF_INTERLOCK in config:
+        interlock = []
+        for it in config[CONF_INTERLOCK]:
+            lock = yield cg.get_variable(it)
+            interlock.append(lock)
+        cg.add(gpio.set_interlock(interlock))

esphome/components/gpio/switch/gpio_switch.cpp

@@ -0,0 +1,90 @@
+#include "esphome/components/gpio/switch/gpio_switch.h"
+#include "esphome/core/log.h"
+
+namespace esphome {
+namespace gpio {
+
+static const char *TAG = "switch.gpio";
+
+GPIOSwitch::GPIOSwitch(const std::string &name, GPIOPin *pin) : Switch(name), Component(), pin_(pin) {}
+
+float GPIOSwitch::get_setup_priority() const { return setup_priority::HARDWARE; }
+void GPIOSwitch::setup() {
+  ESP_LOGCONFIG(TAG, "Setting up GPIO Switch '%s'...", this->name_.c_str());
+
+  bool initial_state = false;
+  switch (this->restore_mode_) {
+    case GPIO_SWITCH_RESTORE_DEFAULT_OFF:
+      initial_state = this->get_initial_state().value_or(false);
+      break;
+    case GPIO_SWITCH_RESTORE_DEFAULT_ON:
+      initial_state = this->get_initial_state().value_or(true);
+      break;
+    case GPIO_SWITCH_ALWAYS_OFF:
+      initial_state = false;
+      break;
+    case GPIO_SWITCH_ALWAYS_ON:
+      initial_state = true;
+      break;
+  }
+
+  // write state before setup
+  if (initial_state)
+    this->turn_on();
+  else
+    this->turn_off();
+  this->pin_->setup();
+  // write after setup again for other IOs
+  if (initial_state)
+    this->turn_on();
+  else
+    this->turn_off();
+}
+void GPIOSwitch::dump_config() {
+  LOG_SWITCH("", "GPIO Switch", this);
+  LOG_PIN("  Pin: ", this->pin_);
+  const char *restore_mode = "";
+  switch (this->restore_mode_) {
+    case GPIO_SWITCH_RESTORE_DEFAULT_OFF:
+      restore_mode = "Restore (Defaults to OFF)";
+      break;
+    case GPIO_SWITCH_RESTORE_DEFAULT_ON:
+      restore_mode = "Restore (Defaults to ON)";
+      break;
+    case GPIO_SWITCH_ALWAYS_OFF:
+      restore_mode = "Always OFF";
+      break;
+    case GPIO_SWITCH_ALWAYS_ON:
+      restore_mode = "Always ON";
+      break;
+  }
+  ESP_LOGCONFIG(TAG, "  Restore Mode: %s", restore_mode);
+  if (!this->interlock_.empty()) {
+    ESP_LOGCONFIG(TAG, "  Interlocks:");
+    for (auto *lock : this->interlock_) {
+      if (lock == this)
+        continue;
+      ESP_LOGCONFIG(TAG, "    %s", lock->get_name().c_str());
+    }
+  }
+}
+void GPIOSwitch::write_state(bool state) {
+  if (state != this->inverted_) {
+    // Turning ON, check interlocking
+    for (auto *lock : this->interlock_) {
+      if (lock == this)
+        continue;
+
+      if (lock->state)
+        lock->turn_off();
+    }
+  }
+
+  this->pin_->digital_write(state);
+  this->publish_state(state);
+}
+void GPIOSwitch::set_restore_mode(GPIOSwitchRestoreMode restore_mode) { this->restore_mode_ = restore_mode; }
+void GPIOSwitch::set_interlock(const std::vector<Switch *> &interlock) { this->interlock_ = interlock; }
+
+}  // namespace gpio
+}  // namespace esphome

esphome/components/gpio/switch/gpio_switch.h

@@ -0,0 +1,39 @@
+#pragma once
+
+#include "esphome/core/component.h"
+#include "esphome/components/switch/switch.h"
+
+namespace esphome {
+namespace gpio {
+
+enum GPIOSwitchRestoreMode {
+  GPIO_SWITCH_RESTORE_DEFAULT_OFF,
+  GPIO_SWITCH_RESTORE_DEFAULT_ON,
+  GPIO_SWITCH_ALWAYS_OFF,
+  GPIO_SWITCH_ALWAYS_ON,
+};
+
+class GPIOSwitch : public switch_::Switch, public Component {
+ public:
+  GPIOSwitch(const std::string &name, GPIOPin *pin);
+
+  void set_restore_mode(GPIOSwitchRestoreMode restore_mode);
+
+  // ========== INTERNAL METHODS ==========
+  // (In most use cases you won't need these)
+  float get_setup_priority() const override;
+
+  void setup() override;
+  void dump_config() override;
+  void set_interlock(const std::vector<Switch *> &interlock);
+
+ protected:
+  void write_state(bool state) override;
+
+  GPIOPin *pin_;
+  GPIOSwitchRestoreMode restore_mode_{GPIO_SWITCH_RESTORE_DEFAULT_OFF};
+  std::vector<Switch *> interlock_;
+};
+
+}  // namespace gpio
+}  // namespace esphome