ResponderSettings.h

/*
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 *
 * ResponderSettings.h
 * Copyright (C) 2013 Simon Newton
 */

#ifndef INCLUDE_OLA_RDM_RESPONDERSETTINGS_H_
#define INCLUDE_OLA_RDM_RESPONDERSETTINGS_H_

#include <ola/rdm/RDMCommand.h>
#include <ola/rdm/ResponderHelper.h>
#include <stdint.h>
#include <string>
#include <vector>

namespace ola {
namespace rdm {

class SettingInterface {
 public:
    virtual ~SettingInterface() {}

    virtual std::string Description() const = 0;

    virtual unsigned int DescriptionResponseSize() const = 0;

    virtual unsigned int GenerateDescriptionResponse(uint8_t index,
                                                     uint8_t *data) const = 0;
};

class BasicSetting : SettingInterface {
 public:
    typedef const char* ArgType;

    explicit BasicSetting(const ArgType description);

    std::string Description() const { return m_description; }

    unsigned int DescriptionResponseSize() const {
      return sizeof(description_s);
    }

    unsigned int GenerateDescriptionResponse(uint8_t index,
                                             uint8_t *data) const;

 private:
    struct description_s {
      uint8_t setting;
      char description[MAX_RDM_STRING_LENGTH];
    } __attribute__((packed));

    std::string m_description;
};


class FrequencyModulationSetting : SettingInterface {
 public:
    struct FrequencyModulationArg {
      uint32_t frequency;  
      const char *description;  
    };

    typedef FrequencyModulationArg ArgType;

    explicit FrequencyModulationSetting(const ArgType &arg);

    std::string Description() const { return m_description; }

    uint32_t Frequency() const { return m_frequency; }

    unsigned int DescriptionResponseSize() const {
      return sizeof(description_s);
    }

    unsigned int GenerateDescriptionResponse(uint8_t index,
                                             uint8_t *data) const;

 private:
    struct description_s {
      uint8_t setting;
      uint32_t frequency;
      char description[MAX_RDM_STRING_LENGTH];
    } __attribute__((packed));

    uint32_t m_frequency;
    std::string m_description;
};


template <class SettingType>
class SettingCollection {
 public:
    SettingCollection(const typename SettingType::ArgType args[],
                      unsigned int arg_count,
                      bool zero_offset = false)
        : m_zero_offset(zero_offset) {
      for (unsigned int i = 0; i < arg_count; i++) {
        m_settings.push_back(SettingType(args[i]));
      }
    }

    uint8_t Count() const { return m_settings.size(); }

    const SettingType *Lookup(uint8_t index) const {
      if (index > m_settings.size()) {
        return NULL;
      }
      return &m_settings[index];
    }

    unsigned int Offset() const {
      return m_zero_offset ? 0 : 1;
    }

 protected:
    SettingCollection() {}

 private:
    std::vector<SettingType> m_settings;
    const bool m_zero_offset;
};


template <class SettingType>
class SettingManager {
 public:
    explicit SettingManager(const SettingCollection<SettingType> *settings)
        : m_settings(settings),
          m_current_setting(settings->Offset()) {
    }

    virtual ~SettingManager() {}

    const RDMResponse *Get(const RDMRequest *request) const;
    const RDMResponse *Set(const RDMRequest *request);
    const RDMResponse *GetDescription(const RDMRequest *request) const;

    uint8_t Count() const {
      return m_settings->Count();
    }

    uint8_t CurrentSetting() const {
      return m_current_setting + m_settings->Offset();
    }

    bool ChangeSetting(uint8_t state);

 private:
    const SettingCollection<SettingType> *m_settings;
    uint8_t m_current_setting; 
};

typedef SettingCollection<BasicSetting> BasicSettingCollection;
typedef SettingManager<BasicSetting> BasicSettingManager;

template <class SettingType>
const RDMResponse *SettingManager<SettingType>::Get(
    const RDMRequest *request) const {
  uint16_t data = ((m_current_setting + m_settings->Offset()) << 8 |
      m_settings->Count());
  if (m_settings->Offset() == 0) {
    // don't count the 0-state
    data--;
  }
  return ResponderHelper::GetUInt16Value(request, data);
}

template <class SettingType>
const RDMResponse *SettingManager<SettingType>::Set(
    const RDMRequest *request) {
  uint8_t arg;
  if (!ResponderHelper::ExtractUInt8(request, &arg)) {
    return NackWithReason(request, NR_FORMAT_ERROR);
  }

  unsigned int offset = m_settings->Offset();
  if (arg < offset || arg >= m_settings->Count() + offset) {
    return NackWithReason(request, NR_DATA_OUT_OF_RANGE);
  } else {
    m_current_setting = arg - offset;
    return ResponderHelper::EmptySetResponse(request);
  }
}

template <class SettingType>
const RDMResponse *SettingManager<SettingType>::GetDescription(
    const RDMRequest *request) const {
  uint8_t arg;
  if (!ResponderHelper::ExtractUInt8(request, &arg)) {
    return NackWithReason(request, NR_FORMAT_ERROR);
  }

  unsigned int offset = m_settings->Offset();
  // never reply for the first setting - see LOCK_STATE
  if (arg == 0 || arg >= m_settings->Count() + offset) {
    return NackWithReason(request, NR_DATA_OUT_OF_RANGE);
  } else {
    const SettingType *setting = m_settings->Lookup(arg - offset);
    uint8_t output[setting->DescriptionResponseSize()]; // NOLINT
    unsigned int size = setting->GenerateDescriptionResponse(arg, output);
    return GetResponseFromData(request, output, size, RDM_ACK);
  }
}

template <class SettingType>
bool SettingManager<SettingType>::ChangeSetting(uint8_t new_setting) {
  uint8_t offset = m_settings->Offset();

  if (new_setting < offset || new_setting  >= m_settings->Count() + offset)
    return false;

  m_current_setting = new_setting - offset;
  return true;
}
}  // namespace rdm
}  // namespace ola
#endif  // INCLUDE_OLA_RDM_RESPONDERSETTINGS_H_