/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */

#ifndef H_IMG_MGMT_
#define H_IMG_MGMT_

#include <inttypes.h>
#include "img_mgmt_config.h"
#include "mgmt/mgmt.h"

struct image_version;

#ifdef __cplusplus
extern "C" {
#endif

#define IMG_MGMT_HASH_STR         48
#define IMG_MGMT_HASH_LEN         32
#define IMG_MGMT_DATA_SHA_LEN     32 /* SHA256 */

/*
 * Image state flags
 */
#define IMG_MGMT_STATE_F_PENDING    0x01
#define IMG_MGMT_STATE_F_CONFIRMED  0x02
#define IMG_MGMT_STATE_F_ACTIVE     0x04
#define IMG_MGMT_STATE_F_PERMANENT  0x08

#define IMG_MGMT_VER_MAX_STR_LEN    25  /* 255.255.65535.4294967295\0 */

/*
 * Swap Types for image management state machine
 */
#define IMG_MGMT_SWAP_TYPE_NONE     0
#define IMG_MGMT_SWAP_TYPE_TEST     1
#define IMG_MGMT_SWAP_TYPE_PERM     2
#define IMG_MGMT_SWAP_TYPE_REVERT   3

/**
 * Command IDs for image management group.
 */
#define IMG_MGMT_ID_STATE           0
#define IMG_MGMT_ID_UPLOAD          1
#define IMG_MGMT_ID_FILE            2
#define IMG_MGMT_ID_CORELIST        3
#define IMG_MGMT_ID_CORELOAD        4
#define IMG_MGMT_ID_ERASE           5

/*
 * IMG_MGMT_ID_UPLOAD statuses.
 */
#define IMG_MGMT_ID_UPLOAD_STATUS_START         0
#define IMG_MGMT_ID_UPLOAD_STATUS_ONGOING       1
#define IMG_MGMT_ID_UPLOAD_STATUS_COMPLETE      2

extern int boot_current_slot;
extern struct img_mgmt_state g_img_mgmt_state;

/** Represents an individual upload request. */
struct img_mgmt_upload_req {
    unsigned long long int off;     /* -1 if unspecified */
    unsigned long long int size;    /* -1 if unspecified */
    size_t data_len;
    size_t data_sha_len;
    uint8_t img_data[IMG_MGMT_UL_CHUNK_SIZE];
    uint8_t data_sha[IMG_MGMT_DATA_SHA_LEN];
    bool upgrade;                   /* Only allow greater version numbers. */
};

/** Global state for upload in progress. */
struct img_mgmt_state {
    /** Flash area being written; -1 if no upload in progress. */
    int area_id;
    /** Flash offset of next chunk. */
    uint32_t off;
    /** Total size of image data. */
    uint32_t size;
    /** Hash of image data; used for resumption of a partial upload. */
    uint8_t data_sha_len;
    uint8_t data_sha[IMG_MGMT_DATA_SHA_LEN];
#if IMG_MGMT_LAZY_ERASE
    int sector_id;
    uint32_t sector_end;
#endif
};

/** Describes what to do during processing of an upload request. */
struct img_mgmt_upload_action {
    /** The total size of the image. */
    unsigned long long size;
    /** The number of image bytes to write to flash. */
    int write_bytes;
    /** The flash area to write to. */
    int area_id;
    /** Whether to process the request; false if offset is wrong. */
    bool proceed;
    /** Whether to erase the destination flash area. */
    bool erase;
};

/**
 * @brief Registers the image management command handler group.
 */ 
void img_mgmt_register_group(void);

/**
 * @brief Read info of an image give the slot number
 *
 * @param image_slot     Image slot to read info from
 * @param image_version  Image version to be filled up
 * @param hash           Ptr to the read image hash
 * @param flags          Ptr to flags filled up from the image
 */
int img_mgmt_read_info(int image_slot, struct image_version *ver,
                       uint8_t *hash, uint32_t *flags);

/**
 * @brief Get the current running image version
 *
 * @param image_version Given image version
 *
 * @return 0 on success, non-zero on failure
 */
int img_mgmt_my_version(struct image_version *ver);

/**
 * @brief Get image version in string from image_version
 *
 * @param image_version Structure filled with image version
 *                      information
 * @param dst           Destination string created from the given
 *                      in image version
 *
 * @return 0 on success, non-zero on failure
 */
int img_mgmt_ver_str(const struct image_version *ver, char *dst);

/**
 * @brief Check if the image slot is in use
 *
 * @param slot Slot to check if its in use
 *
 * @return 0 on success, non-zero on failure
 */
int img_mgmt_slot_in_use(int slot);

/**
 * @brief Check if the DFU status is pending
 *
 * @return 1 if there's pending DFU otherwise 0.
 */
int img_mgmt_state_any_pending(void);

/**
 * @brief Collects information about the specified image slot
 *
 * @param query_slot Slot to read state flags from
 *
 * @return return the state flags
 */
uint8_t img_mgmt_state_flags(int query_slot);

/**
 * @brief Sets the pending flag for the specified image slot.  That is, the system
 * will swap to the specified image on the next reboot.  If the permanent
 * argument is specified, the system doesn't require a confirm after the swap
 * occurs.
 *
 * @param slot       Image slot to set pending
 * @param permanent  If set no confirm is required after image swap
 *
 * @return 0 on success, non-zero on failure
 */
int img_mgmt_state_set_pending(int slot, int permanent);

/**
 * Confirms the current image state.  Prevents a fallback from occurring on the
 * next reboot if the active image is currently being tested.
 *
 * @return 0 on success, non -zero on failure
 */
int img_mgmt_state_confirm(void);

/** @brief Generic callback function for events */
typedef void (*img_mgmt_dfu_cb)(void);

/** Callback function pointers */
typedef struct {
    img_mgmt_dfu_cb dfu_started_cb;
    img_mgmt_dfu_cb dfu_stopped_cb;
    img_mgmt_dfu_cb dfu_pending_cb;
    img_mgmt_dfu_cb dfu_confirmed_cb;
} img_mgmt_dfu_callbacks_t;

/** @typedef img_mgmt_upload_fn
 * @brief Application callback that is executed when an image upload request is
 * received.
 *
 * The callback's return code determines whether the upload request is accepted
 * or rejected.  If the callback returns 0, processing of the upload request
 * proceeds.  If the callback returns nonzero, the request is rejected with a
 * response containing an `rc` value equal to the return code.
 *
 * @param offset                The offset specified by the incoming request.
 * @param size                  The total size of the image being uploaded.
 * @param arg                   Optional argument specified when the callback
 *                                  was configured.
 *
 * @return                      0 if the upload request should be accepted;
 *                              nonzero to reject the request with the
 *                                  specified status.
 */
typedef int img_mgmt_upload_fn(uint32_t offset, uint32_t size, void *arg);

/**
 * @brief Configures a callback that gets called whenever a valid image upload
 * request is received.
 *
 * The callback's return code determines whether the upload request is accepted
 * or rejected.  If the callback returns 0, processing of the upload request
 * proceeds.  If the callback returns nonzero, the request is rejected with a
 * response containing an `rc` value equal to the return code.
 *
 * @param cb                    The callback to execute on rx of an upload
 *                                  request.
 * @param arg                   Optional argument that gets passed to the
 *                                  callback.
 */
void img_mgmt_set_upload_cb(img_mgmt_upload_fn *cb, void *arg);
void img_mgmt_register_callbacks(const img_mgmt_dfu_callbacks_t *cb_struct);
void img_mgmt_dfu_stopped(void);
void img_mgmt_dfu_started(void);
void img_mgmt_dfu_pending(void);
void img_mgmt_dfu_confirmed(void);

#if IMG_MGMT_VERBOSE_ERR
int img_mgmt_error_rsp(struct mgmt_ctxt *ctxt, int rc, const char *rsn);
extern const char *img_mgmt_err_str_app_reject;
extern const char *img_mgmt_err_str_hdr_malformed;
extern const char *img_mgmt_err_str_magic_mismatch;
extern const char *img_mgmt_err_str_no_slot;
extern const char *img_mgmt_err_str_flash_open_failed;
extern const char *img_mgmt_err_str_flash_erase_failed;
extern const char *img_mgmt_err_str_flash_write_failed;
extern const char *img_mgmt_err_str_downgrade;
extern const char *img_mgmt_err_str_image_bad_flash_addr;
#else
#define img_mgmt_error_rsp(ctxt, rc, rsn)             (rc)
#define img_mgmt_err_str_app_reject                   NULL
#define img_mgmt_err_str_hdr_malformed                NULL
#define img_mgmt_err_str_magic_mismatch               NULL
#define img_mgmt_err_str_no_slot                      NULL
#define img_mgmt_err_str_flash_open_failed            NULL
#define img_mgmt_err_str_flash_erase_failed           NULL
#define img_mgmt_err_str_flash_write_failed           NULL
#define img_mgmt_err_str_downgrade                    NULL
#define img_mgmt_err_str_image_bad_flash_addr         NULL
#endif

#ifdef __cplusplus
}
#endif

#endif /* H_IMG_MGMT_ */