examples/daemon/ledflasher/ledflasher.cc

// Copyright 2015 The Weave Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "examples/daemon/common/daemon.h"

#include <weave/device.h>

#include <base/bind.h>
#include <base/memory/weak_ptr.h>

#include <bitset>

namespace {
// Supported LED count on this device
const size_t kLedCount = 3;

const char kTraits[] = R"({
  "_ledflasher": {
    "commands": {
      "set": {
        "minimalRole": "user",
        "parameters": {
          "led": {
            "type": "integer",
            "minimum": 1,
            "maximum": 3
          },
          "on": { "type": "boolean" }
        }
      },
      "toggle": {
        "minimalRole": "user",
        "parameters": {
          "led": {
            "type": "integer",
            "minimum": 1,
            "maximum": 3
          }
        }
      }
    },
    "state": {
      "leds": {
        "type": "array",
        "items": { "type": "boolean" }
      }
    }
  }
})";

const char kComponent[] = "ledflasher";

}  // namespace

// LedFlasherHandler is a complete command handler example that shows
// how to handle commands that modify device state.
class LedFlasherHandler {
 public:
  LedFlasherHandler() {}
  void Register(weave::Device* device) {
    device_ = device;

    device->AddTraitDefinitionsFromJson(kTraits);
    CHECK(device->AddComponent(kComponent, {"_ledflasher"}, nullptr));
    UpdateLedState();

    device->AddCommandHandler(
        kComponent, "_ledflasher.toggle",
        base::Bind(&LedFlasherHandler::OnFlasherToggleCommand,
                   weak_ptr_factory_.GetWeakPtr()));
    device->AddCommandHandler(
        kComponent, "_ledflasher.set",
        base::Bind(&LedFlasherHandler::OnFlasherSetCommand,
                   weak_ptr_factory_.GetWeakPtr()));
  }

 private:
  void OnFlasherSetCommand(const std::weak_ptr<weave::Command>& command) {
    auto cmd = command.lock();
    if (!cmd)
      return;
    LOG(INFO) << "received command: " << cmd->GetName();
    int32_t led_index = 0;
    const auto& params = cmd->GetParameters();
    bool cmd_value = false;
    if (params.GetInteger("led", &led_index) &&
        params.GetBoolean("on", &cmd_value)) {
      // Display this command in terminal
      LOG(INFO) << cmd->GetName() << " led: " << led_index
                << ", on: " << (cmd_value ? "true" : "false");

      led_index--;
      int new_state = cmd_value ? 1 : 0;
      int cur_state = led_status_[led_index];
      led_status_[led_index] = new_state;

      if (cmd_value != cur_state) {
        UpdateLedState();
      }
      cmd->Complete({}, nullptr);
      return;
    }
    weave::ErrorPtr error;
    weave::Error::AddTo(&error, FROM_HERE, "invalid_parameter_value",
                        "Invalid parameters");
    cmd->Abort(error.get(), nullptr);
  }

  void OnFlasherToggleCommand(const std::weak_ptr<weave::Command>& command) {
    auto cmd = command.lock();
    if (!cmd)
      return;
    LOG(INFO) << "received command: " << cmd->GetName();
    const auto& params = cmd->GetParameters();
    int32_t led_index = 0;
    if (params.GetInteger("led", &led_index)) {
      LOG(INFO) << cmd->GetName() << " led: " << led_index;
      led_index--;
      led_status_[led_index] = ~led_status_[led_index];

      UpdateLedState();
      cmd->Complete({}, nullptr);
      return;
    }
    weave::ErrorPtr error;
    weave::Error::AddTo(&error, FROM_HERE, "invalid_parameter_value",
                        "Invalid parameters");
    cmd->Abort(error.get(), nullptr);
  }

  void UpdateLedState() {
    base::ListValue list;
    for (uint32_t i = 0; i < led_status_.size(); i++)
      list.AppendBoolean(led_status_[i] ? true : false);

    device_->SetStateProperty(kComponent, "_ledflasher.leds", list, nullptr);
  }

  weave::Device* device_{nullptr};

  // Simulate LED status on this device so client app could explore
  // Each bit represents one device, indexing from LSB
  std::bitset<kLedCount> led_status_{0};
  base::WeakPtrFactory<LedFlasherHandler> weak_ptr_factory_{this};
};

int main(int argc, char** argv) {
  Daemon::Options opts;
  if (!opts.Parse(argc, argv)) {
    Daemon::Options::ShowUsage(argv[0]);
    return 1;
  }
  Daemon daemon{opts};
  LedFlasherHandler handler;
  handler.Register(daemon.GetDevice());
  daemon.Run();
  return 0;
}