/*
 * Copyright (c) 2015 ARM Limited. All rights reserved.
 * SPDX-License-Identifier: Apache-2.0
 * Licensed under the Apache License, Version 2.0 (the License); you may
 * not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an AS IS BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#include "mbed-client/m2mconstants.h"
#include "mbed-client/m2mresource.h"
#include "mbed-client/m2mobservationhandler.h"
#include "include/m2mreporthandler.h"
#include "include/m2mtlvserializer.h"
#include "include/m2mtlvdeserializer.h"
#include "mbed-trace/mbed_trace.h"

#include <stdlib.h>

#define TRACE_GROUP "mClt"

M2MResource::M2MResource(M2MObjectInstance &parent,
                         const String &resource_name,
                         const String &resource_type,
                         M2MResourceInstance::ResourceType type,
                         const uint8_t *value,
                         const uint8_t value_length,
                         char *path,
                         const uint16_t object_instance_id,
                         bool multiple_instance,
                         bool external_blockwise_store)
: M2MResourceInstance(*this, resource_name, resource_type, type, value, value_length,
                      object_instance_id,
                      path, external_blockwise_store),
  _parent(parent),
  _delayed_token(NULL),
  _delayed_token_len(0),
  _has_multiple_instances(multiple_instance),
  _delayed_response(false)
{
    M2MBase::set_base_type(M2MBase::Resource);
    M2MBase::set_operation(M2MBase::GET_ALLOWED);
    M2MBase::set_observable(false);

}

M2MResource::M2MResource(M2MObjectInstance &parent,
                         const lwm2m_parameters_s* s,
                          M2MResourceInstance::ResourceType type,
                         const uint16_t object_instance_id)
: M2MResourceInstance(*this, s, type, object_instance_id),
  _parent(parent),
  _delayed_token(NULL),
  _delayed_token_len(0),
  _has_multiple_instances(false),
  _delayed_response(false)
{
    // tbd: _has_multiple_instances could be in flash, but no real benefit, because of current alignment.
}

M2MResource::M2MResource(M2MObjectInstance &parent,
                         const String &resource_name,
                         const String &resource_type,
                         M2MResourceInstance::ResourceType type,
                         bool observable,
                         char *path,
                         const uint16_t object_instance_id,
                         bool multiple_instance,
                         bool external_blockwise_store)
: M2MResourceInstance(*this, resource_name, resource_type, type,
                      object_instance_id,
                      path,
                      external_blockwise_store),
  _parent(parent),
  _delayed_token(NULL),
  _delayed_token_len(0),
  _has_multiple_instances(multiple_instance),
  _delayed_response(false)
{
    M2MBase::set_base_type(M2MBase::Resource);
    M2MBase::set_operation(M2MBase::GET_PUT_ALLOWED);
    M2MBase::set_observable(observable);
}


M2MResource::~M2MResource()
{
    if(!_resource_instance_list.empty()) {
        M2MResourceInstance* res = NULL;
        M2MResourceInstanceList::const_iterator it;
        it = _resource_instance_list.begin();
        for (; it!=_resource_instance_list.end(); it++ ) {
            //Free allocated memory for resources.
            res = *it;
            delete res;
        }
        _resource_instance_list.clear();
    }
    free(_delayed_token);
}

bool M2MResource::supports_multiple_instances() const
{
    return _has_multiple_instances;
}

void M2MResource::set_delayed_response(bool delayed_response)
{
    _delayed_response = delayed_response;
}

bool M2MResource::send_delayed_post_response()
{
    bool success = false;
    if(_delayed_response) {
        success = true;
        observation_handler()->send_delayed_response(this);
    }
    return success;
}

void M2MResource::get_delayed_token(uint8_t *&token, uint8_t &token_length)
{
    token_length = 0;
    if(token) {
        free(token);
        token = NULL;
    }
    if(_delayed_token && _delayed_token_len > 0) {
        token = alloc_copy(_delayed_token, _delayed_token_len);
        if(token) {
            token_length = _delayed_token_len;
        }
    }
}

bool M2MResource::remove_resource_instance(uint16_t inst_id)
{
    tr_debug("M2MResource::remove_resource(inst_id %d)", inst_id);
    bool success = false;
    if(!_resource_instance_list.empty()) {
        M2MResourceInstance* res = NULL;
        M2MResourceInstanceList::const_iterator it;
        it = _resource_instance_list.begin();
        int pos = 0;
        for ( ; it != _resource_instance_list.end(); it++, pos++ ) {
            if(((*it)->instance_id() == inst_id)) {
                // Resource found and deleted.
                res = *it;
                delete res;
                _resource_instance_list.erase(pos);
                success = true;
                break;
            }
        }
    }
    return success;
}

M2MResourceInstance* M2MResource::resource_instance(uint16_t inst_id) const
{
    tr_debug("M2MResource::resource(resource_name inst_id %d)", inst_id);
    M2MResourceInstance *res = NULL;
    if(!_resource_instance_list.empty()) {
        M2MResourceInstanceList::const_iterator it;
        it = _resource_instance_list.begin();
        for ( ; it != _resource_instance_list.end(); it++ ) {
            if(((*it)->instance_id() == inst_id)) {
                // Resource found.
                res = *it;
                break;
            }
        }
    }
    return res;
}

const M2MResourceInstanceList& M2MResource::resource_instances() const
{
    return _resource_instance_list;
}

uint16_t M2MResource::resource_instance_count() const
{
    return (uint16_t)_resource_instance_list.size();
}

bool M2MResource::delayed_response() const
{
    return _delayed_response;
}

bool M2MResource::handle_observation_attribute(const char *query)
{
    tr_debug("M2MResource::handle_observation_attribute - is_under_observation(%d)", is_under_observation());
    bool success = false;
    M2MReportHandler *handler = M2MBase::report_handler();
    if (!handler) {
        handler = M2MBase::create_report_handler();
    }

    if (handler) {
        success = handler->parse_notification_attribute(query,
                M2MBase::base_type(), _resource_type);
        if (success) {
            if (is_under_observation()) {
                handler->set_under_observation(true);
            }
        }
        else {
            handler->set_default_values();
        }

        if (success) {
            if(!_resource_instance_list.empty()) {
                M2MResourceInstanceList::const_iterator it;
                it = _resource_instance_list.begin();
                for ( ; it != _resource_instance_list.end(); it++ ) {
                    M2MReportHandler *report_handler = (*it)->report_handler();
                    if(report_handler && is_under_observation()) {
                        report_handler->set_notification_trigger();
                    }
                }
            }
        }
    }
    return success;
}

void M2MResource::add_observation_level(M2MBase::Observation observation_level)
{
    M2MBase::add_observation_level(observation_level);
    if(!_resource_instance_list.empty()) {
        M2MResourceInstanceList::const_iterator inst;
        inst = _resource_instance_list.begin();
        for ( ; inst != _resource_instance_list.end(); inst++ ) {
            (*inst)->add_observation_level(observation_level);
        }
    }
}

void M2MResource::remove_observation_level(M2MBase::Observation observation_level)
{
    M2MBase::remove_observation_level(observation_level);
    if(!_resource_instance_list.empty()) {
        M2MResourceInstanceList::const_iterator inst;
        inst = _resource_instance_list.begin();
        for ( ; inst != _resource_instance_list.end(); inst++ ) {
            (*inst)->remove_observation_level(observation_level);
        }
    }
}

void M2MResource::add_resource_instance(M2MResourceInstance *res)
{
    tr_debug("M2MResource::add_resource_instance()");
    if(res) {
        _resource_instance_list.push_back(res);
    }
}

sn_coap_hdr_s* M2MResource::handle_get_request(nsdl_s *nsdl,
                                               sn_coap_hdr_s *received_coap_header,
                                               M2MObservationHandler *observation_handler)
{
    tr_debug("M2MResource::handle_get_request()");
    sn_coap_msg_code_e msg_code = COAP_MSG_CODE_RESPONSE_CONTENT;
    sn_coap_hdr_s * coap_response = NULL;
    if(_has_multiple_instances) {
        coap_response = sn_nsdl_build_response(nsdl,
                                               received_coap_header,
                                               msg_code);
        if(received_coap_header) {
            // process the GET if we have registered a callback for it
            if ((operation() & SN_GRS_GET_ALLOWED) != 0) {
                if(coap_response) {
                    uint16_t coap_content_type = 0;
                    bool content_type_present = false;
                    if(received_coap_header->content_format != COAP_CT_NONE){
                        content_type_present = true;
                        coap_content_type = received_coap_header->content_format;
                    }

                    if(!content_type_present &&
                       M2MBase::coap_content_type() == COAP_CONTENT_OMA_TLV_TYPE) {
                        coap_content_type = COAP_CONTENT_OMA_TLV_TYPE;
                    }

                    tr_debug("M2MResource::handle_get_request() - Request Content-Type %d", coap_content_type);
                    if (coap_response->content_format == COAP_CT_NONE) {
                        coap_response->content_format = sn_coap_content_format_e(coap_content_type);
                        if (coap_response->content_format != COAP_CT_NONE) {
                            set_coap_content_type(coap_content_type);
                        }
                    }
                    uint8_t *data = NULL;
                    uint32_t data_length = 0;
                    // fill in the CoAP response payload
                    if(COAP_CONTENT_OMA_TLV_TYPE == coap_content_type) {
                        M2MTLVSerializer serializer;
                        data = serializer.serialize(this, data_length);
                    } else {
                        msg_code = COAP_MSG_CODE_RESPONSE_UNSUPPORTED_CONTENT_FORMAT; // Content format not supported
                    }

                    coap_response->payload_len = data_length;
                    coap_response->payload_ptr = data;

                    coap_response->options_list_ptr = sn_nsdl_alloc_options_list(nsdl, coap_response);

                    coap_response->options_list_ptr->max_age = max_age();

                    if(received_coap_header->options_list_ptr) {
                        if(received_coap_header->options_list_ptr->observe != -1) {
                            if (is_observable()) {
                                uint32_t number = 0;
                                uint8_t observe_option = 0;
                                observe_option = received_coap_header->options_list_ptr->observe;
                                if(START_OBSERVATION == observe_option) {
                                    tr_debug("M2MResource::handle_get_request - Starts Observation");
                                    // If the observe length is 0 means register for observation.
                                    if(received_coap_header->options_list_ptr->observe != -1) {
                                        number = received_coap_header->options_list_ptr->observe;
                                    }
                                    if(received_coap_header->token_ptr) {
                                        tr_debug("M2MResource::handle_get_request - Sets Observation Token to resource");
                                        set_observation_token(received_coap_header->token_ptr,
                                                              received_coap_header->token_len);
                                    }

                                    // If the observe value is 0 means register for observation.
                                    if(number == 0) {
                                        tr_debug("M2MResource::handle_get_request - Put Resource under Observation");
                                        M2MResourceInstanceList::const_iterator it;
                                        it = _resource_instance_list.begin();
                                        for (; it!=_resource_instance_list.end(); it++ ) {
                                            tr_debug("M2MResource::handle_get_request - set_resource_observer");
                                            (*it)->set_resource_observer(this);
                                            (*it)->add_observation_level(M2MBase::R_Attribute);
                                        }
                                        set_under_observation(true,observation_handler);
                                        M2MBase::add_observation_level(M2MBase::R_Attribute);
                                        coap_response->options_list_ptr->observe = observation_number();
                                    }
                                } else if (STOP_OBSERVATION == observe_option) {
                                    tr_debug("M2MResource::handle_get_request - Stops Observation");
                                    set_under_observation(false,NULL);
                                    M2MBase::remove_observation_level(M2MBase::R_Attribute);
                                    M2MResourceInstanceList::const_iterator it;
                                    it = _resource_instance_list.begin();
                                    for (; it!=_resource_instance_list.end(); it++ ) {
                                        (*it)->set_resource_observer(NULL);
                                    }
                                }
                                msg_code = COAP_MSG_CODE_RESPONSE_CONTENT;
                            }
                            else {
                                msg_code = COAP_MSG_CODE_RESPONSE_METHOD_NOT_ALLOWED;
                            }
                        }
                    }
                }
            } else {
                tr_error("M2MResource::handle_get_request - Return COAP_MSG_CODE_RESPONSE_METHOD_NOT_ALLOWED");
                // Operation is not allowed.
                msg_code = COAP_MSG_CODE_RESPONSE_METHOD_NOT_ALLOWED;
            }
        }
        if(coap_response) {
            coap_response->msg_code = msg_code;
        }
    } else {
        coap_response = M2MResourceInstance::handle_get_request(nsdl,
                            received_coap_header,
                            observation_handler);
    }
    return coap_response;
}

sn_coap_hdr_s* M2MResource::handle_put_request(nsdl_s *nsdl,
                                               sn_coap_hdr_s *received_coap_header,
                                               M2MObservationHandler *observation_handler,
                                               bool &execute_value_updated)
{
    tr_debug("M2MResource::handle_put_request()");
    sn_coap_msg_code_e msg_code = COAP_MSG_CODE_RESPONSE_CHANGED; // 2.04
    sn_coap_hdr_s * coap_response = NULL;
    if(_has_multiple_instances) {
        coap_response = sn_nsdl_build_response(nsdl,
                                               received_coap_header,
                                               msg_code);
        // process the PUT if we have registered a callback for it
        if(received_coap_header) {
            uint16_t coap_content_type = 0;
            bool content_type_present = false;
            if(received_coap_header->content_format != COAP_CT_NONE && coap_response) {
                content_type_present = true;
                coap_content_type = received_coap_header->content_format;
            }
            if(received_coap_header->options_list_ptr &&
               received_coap_header->options_list_ptr->uri_query_ptr) {
                char *query = (char*)alloc_string_copy(received_coap_header->options_list_ptr->uri_query_ptr,
                                                        received_coap_header->options_list_ptr->uri_query_len);
                if (query){
                    msg_code = COAP_MSG_CODE_RESPONSE_CHANGED;
                    tr_debug("M2MResource::handle_put_request() - Query %s", query);
                    // if anything was updated, re-initialize the stored notification attributes
                    if (!handle_observation_attribute(query)){
                        tr_debug("M2MResource::handle_put_request() - Invalid query");
                        msg_code = COAP_MSG_CODE_RESPONSE_BAD_REQUEST; // 4.00
                    }
                    free(query);
                }
            } else if ((operation() & SN_GRS_PUT_ALLOWED) != 0) {
                if(!content_type_present &&
                   M2MBase::coap_content_type() == COAP_CONTENT_OMA_TLV_TYPE) {
                    coap_content_type = COAP_CONTENT_OMA_TLV_TYPE;
                }

                tr_debug("M2MResource::handle_put_request() - Request Content-Type %d", coap_content_type);

                if(COAP_CONTENT_OMA_TLV_TYPE == coap_content_type) {
                    M2MTLVDeserializer deserializer;
                    M2MTLVDeserializer::Error error = M2MTLVDeserializer::None;
                    error = deserializer.deserialize_resource_instances(received_coap_header->payload_ptr,
                                                                         received_coap_header->payload_len,
                                                                         *this,
                                                                         M2MTLVDeserializer::Put);
                    switch(error) {
                        case M2MTLVDeserializer::None:
                            if(observation_handler) {
                                String value = "";
                                if (received_coap_header->uri_path_ptr != NULL &&
                                    received_coap_header->uri_path_len > 0) {

                                    value.append_raw((char*)received_coap_header->uri_path_ptr,received_coap_header->uri_path_len);
                                }
                                execute_value_updated = true;
                            }
                            msg_code = COAP_MSG_CODE_RESPONSE_CHANGED;
                            break;
                        case M2MTLVDeserializer::NotFound:
                            msg_code = COAP_MSG_CODE_RESPONSE_NOT_FOUND;
                            break;
                        case M2MTLVDeserializer::NotAllowed:
                            msg_code = COAP_MSG_CODE_RESPONSE_METHOD_NOT_ALLOWED;
                            break;
                        case M2MTLVDeserializer::NotValid:
                            msg_code = COAP_MSG_CODE_RESPONSE_BAD_REQUEST;
                            break;
                    }
                } else {
                    msg_code =COAP_MSG_CODE_RESPONSE_UNSUPPORTED_CONTENT_FORMAT;
                } // if(COAP_CONTENT_OMA_TLV_TYPE == coap_content_type)
            } else {
                // Operation is not allowed.
                tr_error("M2MResource::handle_put_request() - COAP_MSG_CODE_RESPONSE_METHOD_NOT_ALLOWED");
                msg_code = COAP_MSG_CODE_RESPONSE_METHOD_NOT_ALLOWED;
            }
        } else {
            msg_code = COAP_MSG_CODE_RESPONSE_METHOD_NOT_ALLOWED;
        }
        if(coap_response) {
            coap_response->msg_code = msg_code;
        }
    } else {
        coap_response = M2MResourceInstance::handle_put_request(nsdl,
                            received_coap_header,
                            observation_handler,
                            execute_value_updated);
    }
    return coap_response;
}

sn_coap_hdr_s* M2MResource::handle_post_request(nsdl_s *nsdl,
                                                sn_coap_hdr_s *received_coap_header,
                                                M2MObservationHandler */*observation_handler*/,
                                                bool &/*execute_value_updated*/,
                                                sn_nsdl_addr_s *address)
{
    tr_debug("M2MResource::handle_post_request()");
    sn_coap_msg_code_e msg_code = COAP_MSG_CODE_RESPONSE_CHANGED; // 2.04
    sn_coap_hdr_s * coap_response = sn_nsdl_build_response(nsdl,
                                                           received_coap_header,
                                                           msg_code);
    // process the POST if we have registered a callback for it
    if(received_coap_header) {
        if ((operation() & SN_GRS_POST_ALLOWED) != 0) {
            M2MResource::M2MExecuteParameter *exec_params = new M2MResource::M2MExecuteParameter();
            if (exec_params) {
                exec_params->_object_name = object_name();
                exec_params->_resource_name = name();
                exec_params->_object_instance_id = object_instance_id();
            }
            uint16_t coap_content_type = 0;
            if(received_coap_header->payload_ptr) {
                if(received_coap_header->content_format != COAP_CT_NONE) {
                    coap_content_type = received_coap_header->content_format;
                }
                if(coap_content_type == 0) {
                    if (exec_params){
                        exec_params->_value = alloc_string_copy(received_coap_header->payload_ptr,
                                                                received_coap_header->payload_len);
                        if (exec_params->_value) {
                            exec_params->_value_length = received_coap_header->payload_len;
                        }
                    }
                } else {
                    msg_code = COAP_MSG_CODE_RESPONSE_UNSUPPORTED_CONTENT_FORMAT;
                }
            }
            if(COAP_MSG_CODE_RESPONSE_CHANGED == msg_code) {
                tr_debug("M2MResource::handle_post_request - Execute resource function");
                if(_delayed_response) {
                    msg_code = COAP_MSG_CODE_EMPTY;
                    coap_response->msg_type = COAP_MSG_TYPE_ACKNOWLEDGEMENT;
                    coap_response->msg_code = msg_code;
                    coap_response->msg_id = received_coap_header->msg_id;
                    if(received_coap_header->token_len) {
                        free(_delayed_token);
                        _delayed_token = NULL;
                        _delayed_token_len = 0;
                        _delayed_token = alloc_copy(received_coap_header->token_ptr, received_coap_header->token_len);
                        if(_delayed_token) {
                            _delayed_token_len = received_coap_header->token_len;
                        }
                        sn_nsdl_send_coap_message(nsdl, address, coap_response);
                    }
                } else {
                    uint32_t length = 0;
                    get_value(coap_response->payload_ptr, length);
                    coap_response->payload_len = length;
                }
                execute(exec_params);
            }
            delete exec_params;
        } else { // if ((object->operation() & SN_GRS_POST_ALLOWED) != 0)
            tr_error("M2MResource::handle_post_request - COAP_MSG_CODE_RESPONSE_METHOD_NOT_ALLOWED");
            msg_code = COAP_MSG_CODE_RESPONSE_METHOD_NOT_ALLOWED; // 4.05
        }
    } else { //if(object && received_coap_header)
        tr_error("M2MResource::handle_post_request - COAP_MSG_CODE_RESPONSE_METHOD_NOT_ALLOWED");
        msg_code = COAP_MSG_CODE_RESPONSE_METHOD_NOT_ALLOWED; // 4.01
    }
    if(coap_response) {
        coap_response->msg_code = msg_code;
    }
    return coap_response;
}

void M2MResource::notification_update()
{
    tr_debug("M2MResource::notification_update()");
    M2MReportHandler *report_handler = M2MBase::report_handler();
    if(report_handler && is_observable()) {
        report_handler->set_notification_trigger();
    }
}

M2MObjectInstance& M2MResource::get_parent_object_instance() const
{
    return _parent;
}

const char* M2MResource::object_name() const
{
    const M2MObjectInstance& parent_object_instance = _parent;
    const M2MObject& parent_object = parent_object_instance.get_parent_object();

    return parent_object.name();
}


M2MResource::M2MExecuteParameter::M2MExecuteParameter()
{
    _value = NULL;
    _value_length = 0;
    _object_name = "";
    _resource_name = "";
    _object_instance_id = 0;
}

M2MResource::M2MExecuteParameter::~M2MExecuteParameter()
{
    free(_value);
}

uint8_t *M2MResource::M2MExecuteParameter::get_argument_value() const
{
    return _value;
}

uint16_t M2MResource::M2MExecuteParameter::get_argument_value_length() const
{
    return _value_length;
}

const String& M2MResource::M2MExecuteParameter::get_argument_object_name() const
{
    return _object_name;
}

const String& M2MResource::M2MExecuteParameter::get_argument_resource_name() const
{
    return _resource_name;
}

uint16_t M2MResource::M2MExecuteParameter::get_argument_object_instance_id() const
{
    return _object_instance_id;
}


