ota.h

/*
 * AWS IoT Over-the-air Update v3.3.0
 * Copyright (C) 2020 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 * the Software, and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

/**
 * @file ota.h
 * @brief OTA Agent Interface
 */

#ifndef OTA_H
#define OTA_H

/* *INDENT-OFF* */
#ifdef __cplusplus
    extern "C" {
#endif
/* *INDENT-ON* */

/* Standard includes. */
/* For FILE type in OtaFileContext_t.*/
#include <stdio.h>
#include <stdint.h>

/* OTA Library Interface include. */
#include "ota_private.h"
#include "ota_os_interface.h"
#include "ota_mqtt_interface.h"
#include "ota_http_interface.h"
#include "ota_platform_interface.h"

/**
 * @ingroup ota_helpers
 * @brief Evaluates to the length of a constant string defined like 'static const char str[]= "xyz";
 */
#define CONST_STRLEN( s )    ( ( ( uint32_t ) sizeof( s ) ) - 1UL )


#define OTA_FILE_SIG_KEY_STR_MAX_LENGTH    32 /*!< Maximum length of the file signature key. */


/**
 * @ingroup ota_helpers
 * @brief The OTA signature algorithm string is specified by the PAL.
 *
 */

/* MISRA rule 8.6 requires identifier with external linkage to have exact one external definition.
 * However, this variable is defined in OTA platform abstraction layer implementation, which is
 * not in this repository but in C-SDK and amazon-freertos repo, so it's a false positive. */
/* coverity[misra_c_2012_rule_8_6_violation] */
extern const char OTA_JsonFileSignatureKey[ OTA_FILE_SIG_KEY_STR_MAX_LENGTH ];

/*-------------------------- OTA enumerated types --------------------------*/

/**
 * @ingroup ota_enum_types
 * @brief The OTA API return status.
 * OTA agent error codes are in the upper 8 bits of the 32 bit OTA error word, OtaErr_t.
 */
typedef enum OtaErr
{
    OtaErrNone = 0,               /*!< @brief No error occurred during the operation. */
    OtaErrUninitialized,          /*!< @brief The error code has not yet been set by a logic path. */
    OtaErrPanic,                  /*!< @brief Unrecoverable Firmware error. Probably should log error and reboot. */
    OtaErrInvalidArg,             /*!< @brief API called with invalid argument. */
    OtaErrAgentStopped,           /*!< @brief Returned when operations are performed that requires OTA Agent running & its stopped. */
    OtaErrSignalEventFailed,      /*!< @brief Failed to send event to OTA state machine. */
    OtaErrRequestJobFailed,       /*!< @brief Failed to request the job document. */
    OtaErrInitFileTransferFailed, /*!< @brief Failed to update the OTA job status. */
    OtaErrRequestFileBlockFailed, /*!< @brief Failed to request file block. */
    OtaErrCleanupControlFailed,   /*!< @brief Failed to clean up the control plane. */
    OtaErrCleanupDataFailed,      /*!< @brief Failed to clean up the data plane. */
    OtaErrUpdateJobStatusFailed,  /*!< @brief Failed to update the OTA job status. */
    OtaErrJobParserError,         /*!< @brief An error occurred during job document parsing. See reason sub-code. */
    OtaErrInvalidDataProtocol,    /*!< @brief Job does not have a valid protocol for data transfer. */
    OtaErrMomentumAbort,          /*!< @brief Too many OTA stream requests without any response. */
    OtaErrDowngradeNotAllowed,    /*!< @brief Firmware version is older than the previous version. */
    OtaErrSameFirmwareVersion,    /*!< @brief Firmware version is the same as previous. New firmware could have failed to commit. */
    OtaErrImageStateMismatch,     /*!< @brief The OTA job was in Self Test but the platform image state was not. Possible tampering. */
    OtaErrNoActiveJob,            /*!< @brief Attempt to set final image state without an active job. */
    OtaErrUserAbort,              /*!< @brief User aborted the active OTA. */
    OtaErrFailedToEncodeCbor,     /*!< @brief Failed to encode CBOR object for requesting data block from streaming service. */
    OtaErrFailedToDecodeCbor,     /*!< @brief Failed to decode CBOR object from streaming service response. */
    OtaErrActivateFailed,         /*!< @brief Failed to activate the new image. */
    OtaErrFileSizeOverflow        /*!< @brief Firmware file size greater than the max allowed size. */
} OtaErr_t;

/**
 * @ingroup ota_enum_types
 * @brief OTA Agent states.
 *
 * The current state of the OTA Task (OTA Agent).
 *
 * @note There is currently support only for a single OTA context.
 */
typedef enum OtaState
{
    OtaAgentStateNoTransition = -1,
    OtaAgentStateInit = 0,
    OtaAgentStateReady,
    OtaAgentStateRequestingJob,
    OtaAgentStateWaitingForJob,
    OtaAgentStateCreatingFile,
    OtaAgentStateRequestingFileBlock,
    OtaAgentStateWaitingForFileBlock,
    OtaAgentStateClosingFile,
    OtaAgentStateSuspended,
    OtaAgentStateShuttingDown,
    OtaAgentStateStopped,
    OtaAgentStateAll
} OtaState_t;

/**
 * @ingroup ota_enum_types
 * @brief OTA job document parser error codes.
 */
typedef enum OtaJobParseErr
{
    OtaJobParseErrUnknown = -1,        /* @brief The error code has not yet been set by a logic path. */
    OtaJobParseErrNone = 0,            /* @brief Signifies no error has occurred. */
    OtaJobParseErrNullJob,             /* @brief A null job was reported (no job ID). */
    OtaJobParseErrUpdateCurrentJob,    /* @brief We're already busy with the reported job ID. */
    OtaJobParseErrZeroFileSize,        /* @brief Job document specified a zero sized file. This is not allowed. */
    OtaJobParseErrNonConformingJobDoc, /* @brief The job document failed to fulfill the model requirements. */
    OtaJobParseErrBadModelInitParams,  /* @brief There was an invalid initialization parameter used in the document model. */
    OtaJobParseErrNoContextAvailable,  /* @brief There was not an OTA context available. */
    OtaJobParseErrNoActiveJobs         /* @brief No active jobs are available in the service. */
} OtaJobParseErr_t;

/**
 * @ingroup ota_enum_types
 * @brief OTA Job callback events.
 *
 * After an OTA update image is received and authenticated, the agent calls the user
 * callback (set with the @ref OTA_Init API) with the value OtaJobEventActivate to
 * signal that the device must be rebooted to activate the new image. When the device
 * boots, if the OTA job status is in self test mode, the agent calls the user callback
 * with the value OtaJobEventStartTest, signaling that any additional self tests
 * should be performed.
 *
 * If the OTA receive fails for any reason, the agent calls the user callback with
 * the value OtaJobEventFail instead to allow the user to log the failure and take
 * any action deemed appropriate by the user code.
 *
 * See the OtaImageState_t type for more information.
 */
typedef enum OtaJobEvent
{
    OtaJobEventActivate = 0,       /*!< @brief OTA receive is authenticated and ready to activate. */
    OtaJobEventFail = 1,           /*!< @brief OTA receive failed. Unable to use this update. */
    OtaJobEventStartTest = 2,      /*!< @brief OTA job is now in self test, perform user tests. */
    OtaJobEventProcessed = 3,      /*!< @brief OTA event queued by OTA_SignalEvent is processed. */
    OtaJobEventSelfTestFailed = 4, /*!< @brief OTA self-test failed for current job. */
    OtaJobEventParseCustomJob = 5, /*!< @brief OTA event for parsing custom job document. */
    OtaJobEventReceivedJob = 6,    /*!< @brief OTA event when a new valid AFT-OTA job is received. */
    OtaJobEventUpdateComplete = 7, /*!< @brief OTA event when the update is completed. */
    OtaLastJobEvent = OtaJobEventStartTest
} OtaJobEvent_t;

/**
 * @ingroup ota_enum_types
 * @brief Gives the status of the job operation.
 *
 */
typedef enum
{
    JobStatusInProgress = 0,
    JobStatusFailed,
    JobStatusSucceeded,
    JobStatusRejected,      /* Not possible today using the "get next job" feature. FUTURE! */
    JobStatusFailedWithVal, /* This shows 2 numeric reason codes. */
    NumJobStatusMappings
} OtaJobStatus_t;

/**
 * @ingroup ota_struct_types
 * @brief OTA Job document.
 * @note This is provided as context to the app callback, #OtaAppCallback_t,
 * to provide information of a custom job that cannot be parsed.
 *
 * Structure representing OTA job document.
 */
typedef struct OtaJobDocument
{
    const uint8_t * pJobDocJson; /*!< @brief Job document in JSON format. */
    size_t jobDocLength;         /*!< @brief Job document length in bytes. */
    const uint8_t * pJobId;      /*!< @brief Job ID associated with the job document. */
    size_t jobIdLength;          /*!< @brief Length of job ID in bytes. */
    uint32_t fileTypeId;         /*!< @brief File Type ID from the job document. */
    OtaJobParseErr_t parseErr;   /*!< @brief Job parsing status. */
    OtaJobStatus_t status;       /*!< @brief Job status. */
    int32_t reason;              /*!< @brief Job status reason. */
    int32_t subReason;           /*!< @brief Job status subreason. */
} OtaJobDocument_t;

/*------------------------- OTA callbacks --------------------------*/

/**
 * @ingroup ota_callback_types
 * @brief OTA update complete callback function typedef.
 *
 * The user must register a callback function when initializing the OTA Agent. This
 * callback is used to notify the main application when the OTA update job is complete.
 * Typically, it is used to reset the device after a successful update by calling
 * @ref OTA_ActivateNewImage and may also be used to kick off user specified self tests
 * during the Self Test phase.
 *
 * The callback function is called with one of the following arguments:
 *
 *      OtaJobEventActivate      OTA update is authenticated and ready to activate.
 *      OtaJobEventFail          OTA update failed. Unable to use this update.
 *      OtaJobEventStartTest     OTA job is now ready for optional user self tests.
 *
 * When OtaJobEventActivate is received, the job status details have been updated with
 * the state as ready for Self Test. After reboot, the new firmware will (normally) be
 * notified that it is in the Self Test phase via the callback and the application may
 * then optionally run its own tests before committing the new image.
 *
 * If the callback function is called with a result of OtaJobEventFail, the OTA update
 * job has failed in some way and should be rejected.
 *
 * @param[in] eEvent An OTA update event from the OtaJobEvent_t enum.
 *
 * @param[in] pData Optional data related to the event.
 */
typedef void (* OtaAppCallback_t)( OtaJobEvent_t eEvent,
                                   const void * pData );

/*--------------------------- OTA structs ----------------------------*/


/**
 * @ingroup ota_struct_types
 * @brief OTA Interface for referencing different components.
 *
 * Information about the different interfaces used to initialize
 * the OTA agent with references to components.
 */
typedef struct OtaInterface
{
    OtaOSInterface_t os;     /*!< @brief OS interface to store event, timers and memory operations. */
    OtaMqttInterface_t mqtt; /*!< @brief MQTT interface that references the publish subscribe methods and callbacks. */
    OtaHttpInterface_t http; /*!< @brief HTTP interface to request data. */
    OtaPalInterface_t pal;   /*!< @brief OTA PAL callback structure. */
} OtaInterfaces_t;

/**
 * @ingroup ota_struct_types
 * @brief OTA Application Buffer size information.
 *
 * File key signature information to verify the authenticity of the incoming file
 */
typedef struct OtaAppBuffer
{
    uint8_t * pUpdateFilePath;   /*!< @brief Path to store the files. */
    uint16_t updateFilePathsize; /*!< @brief Maximum size of the file path. */
    uint8_t * pCertFilePath;     /*!< @brief Path to certificate file. */
    uint16_t certFilePathSize;   /*!< @brief Maximum size of the certificate file path. */
    uint8_t * pStreamName;       /*!< @brief Name of stream to download the files. */
    uint16_t streamNameSize;     /*!< @brief Maximum size of the stream name. */
    uint8_t * pDecodeMemory;     /*!< @brief Place to store the decoded files. */
    uint32_t decodeMemorySize;   /*!< @brief Maximum size of the decoded files buffer. */
    uint8_t * pFileBitmap;       /*!< @brief Bitmap of the parameters received. */
    uint16_t fileBitmapSize;     /*!< @brief Maximum size of the bitmap. */
    uint8_t * pUrl;              /*!< @brief Presigned url to download files from S3. */
    uint16_t urlSize;            /*!< @brief Maximum size of the URL. */
    uint8_t * pAuthScheme;       /*!< @brief Authentication scheme used to validate download. */
    uint16_t authSchemeSize;     /*!< @brief Maximum size of the auth scheme. */
} OtaAppBuffer_t;

/**
 * @ingroup ota_private_struct_types
 * @brief  The OTA agent is a singleton today. The structure keeps it nice and organized.
 */

typedef struct OtaAgentContext
{
    OtaState_t state;                                      /*!< State of the OTA agent. */
    uint8_t pThingName[ otaconfigMAX_THINGNAME_LEN + 1U ]; /*!< Thing name + zero terminator. */
    OtaFileContext_t fileContext;                          /*!< Static array of OTA file structures. */
    uint32_t fileIndex;                                    /*!< Index of current file in the array. */
    uint32_t serverFileID;                                 /*!< Variable to store current file ID passed down */
    uint8_t pActiveJobName[ OTA_JOB_ID_MAX_SIZE ];         /*!< The currently active job name. We only allow one at a time. */
    uint8_t * pClientTokenFromJob;                         /*!< The clientToken field from the latest update job. */
    uint32_t timestampFromJob;                             /*!< Timestamp received from the latest job document. */
    OtaImageState_t imageState;                            /*!< The current application image state. */
    uint32_t numOfBlocksToReceive;                         /*!< Number of data blocks to receive per data request. */
    OtaAgentStatistics_t statistics;                       /*!< The OTA agent statistics block. */
    uint32_t requestMomentum;                              /*!< The number of requests sent before a response was received. */
    const OtaInterfaces_t * pOtaInterface;                 /*!< Collection of all interfaces used by the agent. */
    OtaAppCallback_t OtaAppCallback;                       /*!< OTA App callback. */
    uint8_t unsubscribeOnShutdown;                         /*!< Flag to indicate if unsubscribe from job topics should be done at shutdown. */
} OtaAgentContext_t;

/*------------------------- OTA Public API --------------------------*/

/**
 * @brief OTA Agent initialization function.
 *
 * Initialize the OTA engine by starting the OTA Agent ("OTA Task") in the system. This function must
 * be called with the connection client context before calling @ref OTA_CheckForUpdate. Only one
 * OTA Agent may exist.
 *
 * @param[in] pOtaBuffer Buffers used by the agent to store different params.
 * @param[in] pOtaInterfaces A pointer to the OS context.
 * @param[in] pThingName A pointer to a C string holding the Thing name.
 * @param[in] OtaAppCallback Static callback function for when an OTA job is complete. This function will have
 * input of the state of the OTA image after download and during self-test.
 * @return OtaErr_t The state of the OTA Agent upon return from the OtaState_t enum.
 * If the agent was successfully initialized and ready to operate, the state will be
 * OtaAgentStateReady. Otherwise, it will be one of the other OtaState_t enum values.
 *
 * <b>Example</b>
 * @code{c}
 * // Application callback when the OTA agent has completed the job
 * // or is in self test mode. For example see [demos](https://github.com/aws/aws-iot-device-sdk-embedded-C/tree/main/demos/ota)
 * void otaAppCallback( OtaJobEvent_t event,
 *                      const void * pData );
 *
 * // Optional: User buffer to pass down to the OTA Agent. These
 * // buffers are assumed to be initialized previously, example:
 * // uint8_t updateFilePath[ OTA_MAX_FILE_PATH_SIZE ];
 * OtaAppBuffer_t otaBuffer =
 * {
 *     .pUpdateFilePath    = updateFilePath,
 *     .updateFilePathsize = OTA_MAX_FILE_PATH_SIZE,
 *     .pCertFilePath      = certFilePath,
 *     .certFilePathSize   = OTA_MAX_FILE_PATH_SIZE,
 *     .pDecodeMemory      = decodeMem,
 *     .decodeMemorySize   = otaconfigFILE_BLOCK_SIZE,
 *     .pFileBitmap        = bitmap,
 *     .fileBitmapSize     = OTA_MAX_BLOCK_BITMAP_SIZE,
 *     .pUrl               = updateUrl,
 *     .urlSize            = OTA_MAX_URL_SIZE,
 *     .pAuthScheme        = authScheme,
 *     .authSchemeSize     = OTA_MAX_AUTH_SCHEME_SIZE
 * };
 *
 * // OTA interface context required for library interface functions
 * // The functions set by these interfaces are assumed to be defined
 * // For more information see [demos](https://github.com/aws/aws-iot-device-sdk-embedded-C/tree/main/demos/ota)
 * OtaInterfaces_t pOtaInterfaces =
 * {
 *     // Initialize OTA library OS Interface.
 *     .os.event.init = Posix_OtaInitEvent;
 *     .os.event.send = Posix_OtaSendEvent;
 *     ...
 *     // Initialize the OTA library MQTT Interface.
 *     .mqtt.subscribe = mqttSubscribe;
 *     .mqtt.publish = mqttPublish;
 *     .mqtt.unsubscribe = mqttUnsubscribe;
 *     // Initialize the OTA library HTTP Interface.
 *     .http.init = httpInit;
 *     .http.request = httpRequest;
 *     .http.deinit = httpDeinit;
 *     // Initialize the OTA library PAL Interface.
 *     .pal.getPlatformImageState = otaPal_GetPlatformImageState;
 *     .pal.setPlatformImageState = otaPal_SetPlatformImageState;
 * }
 *
 * // OTA library error status.
 * OtaErr_t otaErr = OtaErrNone;
 *
 * // Unique client identifier
 * char * pClientIdentifier = "uniqueClientID";
 *
 * otaErr = OTA_Init( &otaBuffer,
 *                    &otaInterfaces,
 *                    ( const uint8_t * ) pClientIdentifier,
 *                    otaAppCallback ) ) != OtaErrNone )
 *          if( otaErr == OtaErrNone )
 * {
 *     // Do something with the OTA agent.
 * }
 * @endcode
 */
/* @[declare_ota_init] */
OtaErr_t OTA_Init( OtaAppBuffer_t * pOtaBuffer,
                   const OtaInterfaces_t * pOtaInterfaces,
                   const uint8_t * pThingName,
                   OtaAppCallback_t OtaAppCallback );
/* @[declare_ota_init] */

/**
 * @brief Signal to the OTA Agent to shut down.
 *
 * Signals the OTA agent task to shut down. The OTA agent will unsubscribe from all MQTT job
 * notification topics, stop in progress OTA jobs, if any, and clear all resources.
 *
 * @param[in] ticksToWait The number of ticks to wait for the OTA Agent to complete the shutdown process.
 * If this is set to zero, the function will return immediately without waiting. The actual state is
 * returned to the caller. The agent does not sleep for this while but used for busy looping.
 *
 * @param[in] unsubscribeFlag Flag to indicate if unsubscribe operations should be performed from the job topics when
 * shutdown is called. If the flag is 0 then unsubscribe operations are not called for job topics If application
 * requires it to be unsubscribed from the job topics then flag must be set to 1 when calling OTA_Shutdown.
 *
 * @return One of the OTA agent states from the OtaState_t enum.
 * A normal shutdown will return OtaAgentStateNotReady. Otherwise, refer to the OtaState_t enum for details.
 *
 * <b>Example</b>
 * @code{c}
 * // ticksToWait used for busy looping until shutdown. Actual delay may depend on the agent priority,
 * // and platform.
 * uint32_t ticksToWait = 100;
 *
 * // If it is required that the unsubscribe operations are not
 * //performed while shutting down set this to 0.
 * uint8_t unsubscribe = 1;
 *
 * OTA_Shutdown(ticksToWait, unsubscribe);
 * ...
 *
 * if( OTA_GetState() != OtaAgentStateStopped )
 * {
 *     // Optional: Disconnect MQTT and HTTP connections
 *     // required by the OTA agent and other tasks.
 * }
 * @endcode
 */
/* @[declare_ota_shutdown] */
OtaState_t OTA_Shutdown( uint32_t ticksToWait,
                         uint8_t unsubscribeFlag );
/* @[declare_ota_shutdown] */

/**
 * @brief Get the current state of the OTA agent.
 *
 * @return The current state of the OTA agent.
 *
 * <b>Example</b>
 * Check if OTA agent is in suspended state.
 * @code{c}
 * // OTA Agent state
 * OtaState_t state = OTA_GetState();
 *
 * while( state != OtaAgentStateSuspended )
 * {
 *     // Do something while the agent is back to
 *     // the desired state.
 *     state = OTA_GetState();
 * }
 * @endcode
 */
/* @[declare_ota_getstate] */
OtaState_t OTA_GetState( void );
/* @[declare_ota_getstate] */

/**
 * @brief Activate the newest MCU image received via OTA.
 *
 * This function should reset the MCU and cause a reboot of the system to execute the newly updated
 * firmware. It should be called by the user code sometime after the OtaJobEventActivate event
 * is passed to the users application via the OTA Job Complete Callback mechanism. Refer to the
 * @ref OTA_Init function for more information about configuring the callback.
 *
 * @return OtaErrNone if successful, otherwise an error code prefixed with 'OtaErr' from the
 * list above.
 *
 * <b>Example</b>
 * @code{c}
 * static void otaAppCallback( OtaJobEvent_t event,
 *                             const void * pData )
 * {
 *     OtaErr_t otaErr = OtaErrNone;
 *     if( event == OtaJobEventActivate )
 *     {
 *         // Activate the new firmware image.
 *         // This calls the platform specific code required to
 *         // activate the received OTA update firmware.
 *         otaErr = OTA_ActivateNewImage();
 *         if( otaErr == OtaErrActivateFailed )
 *         {
 *              // Handle Image activation failure by requesting manual response, sending
 *              // error logs or retrying activation.
 *         }
 *     }
 *
 *     // Handle other events
 * }
 * @endcode
 */
/* @[declare_ota_activatenewimage] */
OtaErr_t OTA_ActivateNewImage( void );
/* @[declare_ota_activatenewimage] */

/**
 * @brief Set the state of the current MCU image.
 *
 * The states are OtaImageStateTesting, OtaImageStateAccepted, OtaImageStateAborted or
 * OtaImageStateRejected; see OtaImageState_t documentation. This will update the status of the
 * current image and publish to the active job status topic.
 *
 * @param[in] state The state to set of the OTA image.
 *
 * @return OtaErrNone if successful, otherwise an error code prefixed with 'OtaErr' from the
 * list above.
 *
 * <b>Example</b>
 * Set image state to reflect new image is accepted in application callback.
 *
 * @code{c}
 * static void otaAppCallback( OtaJobEvent_t event,
 *                             const void * pData )
 * {
 *     OtaErr_t otaErr = OtaErrNone;
 *
 *     if( event == OtaJobEventStartTest )
 *     {
 *         err = OTA_SetImageState( OtaImageStateAccepted );
 *         if( err != OtaErrNone )
 *         {
 *             // Handle failure or retry setting the image state.
 *         }
 *     }
 *
 *     // Handle other events
 * }
 * @endcode
 */
/* @[declare_ota_setimagestate] */
OtaErr_t OTA_SetImageState( OtaImageState_t state );
/* @[declare_ota_setimagestate] */

/**
 * @brief Get the state of the currently running MCU image.
 *
 * The states are OtaImageStateTesting, OtaImageStateAccepted, OtaImageStateAborted or
 * OtaImageStateRejected; see OtaImageState_t documentation.
 *
 * @return The state of the current context's OTA image.
 */
/* @[declare_ota_getimagestate] */
OtaImageState_t OTA_GetImageState( void );
/* @[declare_ota_getimagestate] */

/**
 * @brief Request for the next available OTA job from the job service.
 *
 * @return OtaErrNone if successful, otherwise an error code prefixed with 'OtaErr' from the
 * list above.
 */
/* @[declare_ota_checkforupdate] */
OtaErr_t OTA_CheckForUpdate( void );
/* @[declare_ota_checkforupdate] */

/**
 * @brief Suspend OTA agent operations .
 *
 * @return OtaErrNone if successful, otherwise an error code prefixed with 'OtaErr' from the
 * list above.
 *
 * <b>Example</b>
 * Suspend the OTA agent when a network error occurs.
 * @code{c}
 * void handleNetworkErrors()
 * {
 *     OtaErr_t otaErr = OtaErrNone;
 *     int16_t suspendTimeout = 5000U;
 *
 *     // Handle disconnects and other network reset operations
 *
 *     // Suspend OTA operations.
 *     otaErr = OTA_Suspend();
 *
 *     if( otaErr != OtaErrNone )
 *     {
 *         // Suspend may fail due to Event queue failure,
 *         // or if the agent has shut down, handle the failure by
 *         // sending logs or retrying OTA_Suspend().
 *     }
 *     else
 *     {
 *         while( ( ( OTA_GetState() != OtaAgentStateSuspended )
 *                 && ( suspendTimeout > 0 ) )
 *         {
 *             // Wait for OTA Library state to suspend
 *             portSleep( 1000U );
 *             suspendTimeout -= 1000U;
 *         }
 *         if( OTA_GetState() != OtaAgentStateSuspended )
 *         {
 *             // Handle Suspend failure or Retry OTA_Suspend().
 *         }
 *     }
 * }
 * @endcode
 */
/* @[declare_ota_suspend] */
OtaErr_t OTA_Suspend( void );
/* @[declare_ota_suspend] */

/**
 * @brief Resume OTA agent operations .
 *
 * @return OtaErrNone if successful, otherwise an error code prefixed with 'OtaErr' from the
 * list above.
 *
 * <b>Example</b>
 * Resume the OTA agent after the network errors are resolved.
 * @code{c}
 * bool handleReconnect()
 * {
 *     // OTA event message used for sending event to OTA Agent.
 *     OtaEventMsg_t eventMsg = { 0 };
 *     OtaErr_t otaErr = OtaErrUninitialized;
 *     bool returnStatus = establishConnection();
 *
 *     if( returnStatus == EXIT_SUCCESS )
 *     {
 *         // Check if OTA process was suspended and resume if required.
 *         if( OTA_GetState() == OtaAgentStateSuspended )
 *         {
 *             // Resume OTA operations.
 *             otaErr = OTA_Resume();
 *         }
 *         else
 *         {
 *             // Send start event to OTA Agent.
 *             eventMsg.eventId = OtaAgentEventStart;
 *             OTA_SignalEvent( &eventMsg );
 *         }
 *
 *         if( otaErr != OtaErrNone )
 *             returnStatus = false;
 *     }
 *
 *     return returnStatus;
 * }
 * @endcode
 */
/* @[declare_ota_resume] */
OtaErr_t OTA_Resume( void );
/* @[declare_ota_resume] */

/**
 * @brief OTA agent event processing loop.
 *
 * This is the main event loop to handle events for OTA update and needs to be called by
 * the application task. This loop will continue to handle and execute events received for
 * OTA Update until this tasks is terminated by the application.
 *
 * @param[in] pUnused Can be used to pass down functionality to the agent task, Unused for now.
 * This can be a function pointer that executes as the first routine when the
 * event loop starts.
 *
 * For a Posix based reference of creating a thread with this task,
 * please see the [demos in AWS IoT Embedded C SDK repository](https://github.com/aws/aws-iot-device-sdk-embedded-C/tree/main/demos/ota).
 */
/* @[declare_ota_eventprocessingtask] */
void OTA_EventProcessingTask( void * pUnused );
/* @[declare_ota_eventprocessingtask] */


/**
 * @brief Signal event to the OTA Agent task.
 *
 * This function adds the event to the back of event queue and used
 * by internal OTA modules to signal agent task.
 *
 * @param[in] pEventMsg Event to be added to the queue
 * @return true If operation is successful, false If the event can not be added
 *
 * <b>Example</b>
 * Signal OTA agent that a new file block has been received over the http connection.
 * @code{c}
 * OtaHttpStatus_t handleDataFromHTTPService( const HTTPResponse_t * pResponse )
 * {
 *     // Assume otaEventBufferGet is a user defined, thread-safe function
 *     // that gets an available buffer from the pool of OTA buffers.
 *     OtaEventData_t * pData = otaEventBufferGet();
 *     OtaHttpStatus_t returnValue = OtaHttpRequestFailed;
 *     bool result = false;
 *
 *     // Validate pResponse for correct data.
 *
 *     if( pData != NULL )
 *     {
 *         memcpy( pData->data, pResponse->pBody, pResponse->bodyLen );
 *         pData->dataLength = pResponse->bodyLen;
 *
 *         // Send job document received event.
 *         eventMsg.eventId = OtaAgentEventReceivedFileBlock;
 *         eventMsg.pEventData = pData;
 *         result = OTA_SignalEvent( &eventMsg );
 *
 *         if( result )
 *         {
 *             returnValue = OtaHttpSuccess;
 *         }
 *     }
 *     return returnValue;
 * }
 * @endcode
 */
/* @[declare_ota_signalevent] */
bool OTA_SignalEvent( const OtaEventMsg_t * const pEventMsg );
/* @[declare_ota_signalevent] */

/*---------------------------------------------------------------------------*/
/*							Statistics API									 */
/*---------------------------------------------------------------------------*/

/**
 * @brief Get the statistics of OTA message packets.
 *
 * Packet statistics are:
 * <ul>
 *  <li> Received: The number of OTA packets that have been received
 *  but not necessarily queued for processing by the OTA agent.
 *  <li> Queued: The number of OTA packets that have been queued for
 *  processing. This implies there was a free message queue entry so
 *  it can be passed to the agent for processing.
 *  <li> Processed: The number of OTA packets that have actually been
 *  processed.
 *  <li> Dropped: The number of OTA packets that have been dropped
 *  because of either no queue or at shutdown cleanup.
 *</ul>
 * @note Calling @ref OTA_Init will reset this statistic.
 *
 * @return OtaErrNone if the statistics can be received successfully.
 *
 * <b>Example</b>
 * @code{c}
 * // OTA library packet statistics per job.
 * OtaAgentStatistics_t otaStatistics = { 0 };
 * OtaErr_t otaErr = OtaErrNone;
 *
 * // Get the current statistics from the agent.
 * otaErr = OTA_GetStatistics( &otaStatistics );
 *
 * if( otaErr != OtaErrNone )
 * {
 *     printf( " Received: %u   Queued: %u   Processed: %u   Dropped: %u",
 *             otaStatistics.otaPacketsReceived,
 *             otaStatistics.otaPacketsQueued,
 *             otaStatistics.otaPacketsProcessed,
 *             otaStatistics.otaPacketsDropped );
 * }
 * @endcode
 */
/* @[declare_ota_getstatistics] */
OtaErr_t OTA_GetStatistics( OtaAgentStatistics_t * pStatistics );
/* @[declare_ota_getstatistics] */

/**
 * @brief Error code to string conversion for OTA errors.
 *
 * @param[in] err The error to convert to a string.
 *
 * @return The string representation of the error.
 */
/* @[declare_ota_err_strerror] */
const char * OTA_Err_strerror( OtaErr_t err );
/* @[declare_ota_err_strerror] */

/**
 * @brief Error code to string conversion for OTA Job Parsing errors.
 *
 * @param[in] err The error to convert to a string.
 *
 * @return The string representation of the error.
 */
/* @[declare_ota_jobparse_strerror] */
const char * OTA_JobParse_strerror( OtaJobParseErr_t err );
/* @[declare_ota_jobparse_strerror] */

/**
 * @brief Status code to string conversion for OTA PAL status.
 *
 * @param[in] status The status to convert to a string.
 *
 * @return The string representation of the status.
 */
/* @[declare_ota_palstatus_strerror] */
const char * OTA_PalStatus_strerror( OtaPalMainStatus_t status );
/* @[declare_ota_palstatus_strerror] */

/**
 * @brief Status code to string conversion for OTA OS status.
 *
 * @param[in] status The status to convert to a string.
 *
 * @return The string representation of the status.
 */
/* @[declare_ota_osstatus_strerror] */
const char * OTA_OsStatus_strerror( OtaOsStatus_t status );
/* @[declare_ota_osstatus_strerror] */

/* *INDENT-OFF* */
#ifdef __cplusplus
    }
#endif
/* *INDENT-ON* */

#endif /* ifndef OTA_H */