// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
//
// 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 <string.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"

#include "esp_panic.h"
#include "esp_partition.h"

#if CONFIG_ESP32_ENABLE_COREDUMP_TO_FLASH || CONFIG_ESP32_ENABLE_COREDUMP_TO_UART
#include "esp_log.h"
const static char *TAG = "esp_core_dump";

// TODO: allow user to set this in menuconfig or get tasks iteratively
#define COREDUMP_MAX_TASKS_NUM    32

typedef esp_err_t (*esp_core_dump_write_prepare_t)(void *priv, uint32_t *data_len, int verb);
typedef esp_err_t (*esp_core_dump_write_start_t)(void *priv, int verb);
typedef esp_err_t (*esp_core_dump_write_end_t)(void *priv, int verb);
typedef esp_err_t (*esp_core_dump_flash_write_data_t)(void *priv, void * data, uint32_t data_len, int verb);

typedef struct _core_dump_write_config_t
{
    esp_core_dump_write_prepare_t       prepare;
    esp_core_dump_write_start_t         start;
    esp_core_dump_write_end_t           end;
    esp_core_dump_flash_write_data_t    write;
    void *                              priv;

} core_dump_write_config_t;

static void esp_core_dump_write(XtExcFrame *frame, core_dump_write_config_t *write_cfg, int verb)
{
    union
    {
        uint8_t    data8[12];
        uint32_t   data32[3];
    } rom_data;
    //const esp_partition_t *core_part;
    esp_err_t err;
    TaskSnapshot_t tasks[COREDUMP_MAX_TASKS_NUM];
    UBaseType_t tcb_sz, task_num;
    uint32_t data_len = 0, i, len;
    //size_t off;

    task_num = uxTaskGetSnapshotAll(tasks, COREDUMP_MAX_TASKS_NUM, &tcb_sz);
    // take TCB padding into account, actual TCB size will be stored in header
    if (tcb_sz % sizeof(uint32_t))
        len = (tcb_sz / sizeof(uint32_t) + 1) * sizeof(uint32_t);
    else
        len = tcb_sz;
    // header + tasknum*(tcb + stack start/end + tcb addr)
    data_len = 3*sizeof(uint32_t) + task_num*(len + 2*sizeof(uint32_t) + sizeof(uint32_t *));
    for (i = 0; i < task_num; i++) {
        if (tasks[i].pxTCB == xTaskGetCurrentTaskHandle()) {
            // set correct stack top for current task
            tasks[i].pxTopOfStack = (StackType_t *)frame;
            if (verb)
                ets_printf("Current task EXIT/PC/PS/A0/SP %x %x %x %x %x\r\n", frame->exit, frame->pc, frame->ps, frame->a0, frame->a1);
        }
        else {
            if (verb) {
                XtSolFrame *task_frame = (XtSolFrame *)tasks[i].pxTopOfStack;
                if (task_frame->exit == 0) {
                    ets_printf("Task EXIT/PC/PS/A0/SP %x %x %x %x %x\r\n", task_frame->exit, task_frame->pc, task_frame->ps, task_frame->a0, task_frame->a1);
                }
                else {
                    XtExcFrame *task_frame2 = (XtExcFrame *)tasks[i].pxTopOfStack;
                    ets_printf("Task EXIT/PC/PS/A0/SP %x %x %x %x %x\r\n", task_frame2->exit, task_frame2->pc, task_frame2->ps, task_frame2->a0, task_frame2->a1);
                }
            }
        }
#if( portSTACK_GROWTH < 0 )
        len = (uint32_t)tasks[i].pxEndOfStack - (uint32_t)tasks[i].pxTopOfStack;
#else
        len = (uint32_t)tasks[i].pxTopOfStack - (uint32_t)tasks[i].pxEndOfStack;
#endif
        if (verb) {
            ets_printf("Stack len = %lu (%x %x)\r\n", len, tasks[i].pxTopOfStack, tasks[i].pxEndOfStack);
        }
        // take stack padding into account
        if (len % sizeof(uint32_t))
            len = (len / sizeof(uint32_t) + 1) * sizeof(uint32_t);
        data_len += len;
    }

    // prepare write
    if (write_cfg->prepare) {
        err = write_cfg->prepare(write_cfg->priv, &data_len, verb);
        if (err != ESP_OK) {
            ets_printf("ERROR: Failed to prepare core dump (%d)!\r\n", err);
            return;
        }
    }

    if (verb) {
        ets_printf("Core dump len = %lu\r\n", data_len);
    }

    // write start
    if (write_cfg->start) {
        err = write_cfg->start(write_cfg->priv, verb);
        if (err != ESP_OK) {
            ets_printf("ERROR: Failed to start core dump (%d)!\r\n", err);
            return;
        }
    }

    // write header
    rom_data.data32[0] = data_len;
    rom_data.data32[1] = task_num;
    rom_data.data32[2] = tcb_sz;
    err = write_cfg->write(write_cfg->priv, &rom_data, 3*sizeof(uint32_t), verb);
    if (err != ESP_OK) {
        ets_printf("ERROR: Failed to write core dump header (%d)!\r\n", err);
        return;
    }

    // write tasks
    for (i = 0; i < task_num; i++) {
        if (verb) {
            ets_printf("Dump task %x\r\n", tasks[i].pxTCB);
        }
        // save TCB address, stack base and stack top addr
        rom_data.data32[0] = (uint32_t)tasks[i].pxTCB;
        rom_data.data32[1] = (uint32_t)tasks[i].pxTopOfStack;
        rom_data.data32[2] = (uint32_t)tasks[i].pxEndOfStack;
        err = write_cfg->write(write_cfg->priv, &rom_data, 3*sizeof(uint32_t), verb);
        if (err != ESP_OK) {
            ets_printf("ERROR: Failed to write task header (%d)!\r\n", err);
            return;
        }
        // save TCB
        err = write_cfg->write(write_cfg->priv, tasks[i].pxTCB, tcb_sz, verb);
        if (err != ESP_OK) {
            ets_printf("ERROR: Failed to write TCB (%d)!\r\n", err);
            return;
        }
        // save task stack
        err = write_cfg->write(write_cfg->priv,
#if( portSTACK_GROWTH < 0 )
                tasks[i].pxTopOfStack,
                (uint32_t)tasks[i].pxEndOfStack - (uint32_t)tasks[i].pxTopOfStack
#else
                tasks[i].pxEndOfStack,
                (uint32_t)tasks[i].pxTopOfStack - (uint32_t)tasks[i].pxEndOfStack
#endif
                , verb);
        if (err != ESP_OK) {
            ets_printf("ERROR: Failed to write task stack (%d)!\r\n", err);
            return;
        }
    }

    // write end
    if (write_cfg->end) {
        err = write_cfg->end(write_cfg->priv, verb);
        if (err != ESP_OK) {
            ets_printf("ERROR: Failed to end core dump (%d)!\r\n", err);
            return;
        }
    }
}

#if CONFIG_ESP32_ENABLE_COREDUMP_TO_FLASH

// magic numbers to control core dump data consistency
#define COREDUMP_FLASH_MAGIC_START    0xE32C04EDUL
#define COREDUMP_FLASH_MAGIC_END      0xE32C04EDUL

typedef struct _core_dump_write_flash_data_t
{
    uint32_t    off;
} core_dump_write_flash_data_t;

// core dump partition start
static uint32_t s_core_part_start;
// core dump partition size
static uint32_t s_core_part_size;

static uint32_t esp_core_dump_write_flash_padded(size_t off, uint8_t *data, uint32_t data_size)
{
    esp_err_t err;
    uint32_t data_len = 0, k, len;
    union
    {
        uint8_t    data8[4];
        uint32_t   data32;
    } rom_data;

    data_len = (data_size / sizeof(uint32_t)) * sizeof(uint32_t);
    err = spi_flash_write(off, data, data_len);
    if (err != ESP_OK) {
        ets_printf("ERROR: Failed to write data to flash (%d)!\r\n", err);
        return 0;
    }

    len = data_size % sizeof(uint32_t);
    if (len) {
        // write last bytes with padding, actual TCB len can be retrieved by esptool from core dump header
        rom_data.data32 = 0;
        for (k = 0; k < len; k++)
            rom_data.data8[k] = *(data + data_len + k);
        err = spi_flash_write(off + data_len, &rom_data, sizeof(uint32_t));
        if (err != ESP_OK) {
            ets_printf("ERROR: Failed to finish write data to flash (%d)!\r\n", err);
            return 0;
        }
        data_len += sizeof(uint32_t);
    }

    return data_len;
}

static esp_err_t esp_core_dump_flash_write_prepare(void *priv, uint32_t *data_len, int verb)
{
    esp_err_t err;
    uint32_t sec_num;
    core_dump_write_flash_data_t *wr_data = (core_dump_write_flash_data_t *)priv;

    // add space for 2 magics. TODO: change to CRC
    if ((*data_len + 2*sizeof(uint32_t)) > s_core_part_size) {
        ets_printf("ERROR: Not enough space to save core dump!\r\n");
        return ESP_ERR_NO_MEM;
    }
    *data_len += 2*sizeof(uint32_t);

    wr_data->off = 0;

    sec_num = *data_len / SPI_FLASH_SEC_SIZE;
    if (*data_len % SPI_FLASH_SEC_SIZE)
        sec_num++;
    err = spi_flash_erase_range(s_core_part_start + 0, sec_num * SPI_FLASH_SEC_SIZE);
    if (err != ESP_OK) {
        ets_printf("ERROR: Failed to erase flash (%d)!\r\n", err);
        return err;
    }

    return err;
}

static esp_err_t esp_core_dump_flash_write_word(core_dump_write_flash_data_t *wr_data, uint32_t word)
{
    esp_err_t err = ESP_OK;
    uint32_t  data32 = word;

    err = spi_flash_write(s_core_part_start + wr_data->off, &data32, sizeof(uint32_t));
    if (err != ESP_OK) {
        ets_printf("ERROR: Failed to write to flash (%d)!\r\n", err);
        return err;
    }
    wr_data->off += sizeof(uint32_t);

    return err;
}

static esp_err_t esp_core_dump_flash_write_start(void *priv, int verb)
{
    core_dump_write_flash_data_t *wr_data = (core_dump_write_flash_data_t *)priv;
    // save magic 1
    return esp_core_dump_flash_write_word(wr_data, COREDUMP_FLASH_MAGIC_START);
}

static esp_err_t esp_core_dump_flash_write_end(void *priv, int verb)
{
    core_dump_write_flash_data_t *wr_data = (core_dump_write_flash_data_t *)priv;
    uint32_t i;
    union
    {
        uint8_t    data8[16];
        uint32_t   data32[4];
    } rom_data;

    if (verb) {
        // TEST READ START
        esp_err_t err = spi_flash_read(s_core_part_start + 0, &rom_data, sizeof(rom_data));
        if (err != ESP_OK) {
            ets_printf("ERROR: Failed to read flash (%d)!\r\n", err);
            return err;
        }
        else {
            ets_printf("Data from flash:\r\n");
            for (i = 0; i < sizeof(rom_data)/sizeof(rom_data.data32[0]); i++) {
                ets_printf("%x\r\n", rom_data.data32[i]);
            }
        }
        // TEST READ END
    }

    // save magic 2
    return esp_core_dump_flash_write_word(wr_data, COREDUMP_FLASH_MAGIC_END);
}

static esp_err_t esp_core_dump_flash_write_data(void *priv, void * data, uint32_t data_len, int verb)
{
    esp_err_t err = ESP_OK;
    core_dump_write_flash_data_t *wr_data = (core_dump_write_flash_data_t *)priv;

    uint32_t len = esp_core_dump_write_flash_padded(s_core_part_start + wr_data->off, data, data_len);
    if (len != data_len)
        return ESP_FAIL;

    wr_data->off += len;

    return err;
}

void esp_core_dump_to_flash(XtExcFrame *frame)
{
    core_dump_write_config_t wr_cfg;
    core_dump_write_flash_data_t wr_data;

    /* init non-OS flash access critical section */
    spi_flash_guard_set(&g_flash_guard_no_os_ops);

    wr_cfg.prepare = esp_core_dump_flash_write_prepare;
    wr_cfg.start = esp_core_dump_flash_write_start;
    wr_cfg.end = esp_core_dump_flash_write_end;
    wr_cfg.write = esp_core_dump_flash_write_data;
    wr_cfg.priv = &wr_data;

    ets_printf("Save core dump to flash...\r\n");
    esp_core_dump_write(frame, &wr_cfg, 0);
    ets_printf("Core dump has been saved to flash.\r\n");
}
#endif

#if CONFIG_ESP32_ENABLE_COREDUMP_TO_UART
static void esp_core_dump_b64_encode(const uint8_t *src, uint32_t src_len, uint8_t *dst) {
    static const char *b64 =
        "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
    int i, j, a, b, c;

    for (i = j = 0; i < src_len; i += 3) {
        a = src[i];
        b = i + 1 >= src_len ? 0 : src[i + 1];
        c = i + 2 >= src_len ? 0 : src[i + 2];

        dst[j++] = b64[a >> 2];
        dst[j++] = b64[((a & 3) << 4) | (b >> 4)];
        if (i + 1 < src_len) {
            dst[j++] = b64[(b & 0x0F) << 2 | (c >> 6)];
        }
        if (i + 2 < src_len) {
            dst[j++] = b64[c & 0x3F];
        }
    }
    while (j % 4 != 0) {
        dst[j++] = '=';
    }
    dst[j++] = '\0';
}

static esp_err_t esp_core_dump_uart_write_start(void *priv, int verb)
{
    esp_err_t err = ESP_OK;
    ets_printf("================= CORE DUMP START =================\r\n");
    return err;
}

static esp_err_t esp_core_dump_uart_write_end(void *priv, int verb)
{
    esp_err_t err = ESP_OK;
    ets_printf("================= CORE DUMP END =================\r\n");
    return err;
}

static esp_err_t esp_core_dump_uart_write_data(void *priv, void * data, uint32_t data_len, int verb)
{
    esp_err_t err = ESP_OK;
    char buf[64 + 4], *addr = data;
    char *end = addr + data_len;


    while (addr < end) {
        size_t len = end - addr;
        if (len > 48) len = 48;
        /* Copy to stack to avoid alignment restrictions. */
        char *tmp = buf + (sizeof(buf) - len);
        memcpy(tmp, addr, len);
        esp_core_dump_b64_encode((const uint8_t *)tmp, len, (uint8_t *)buf);
        addr += len;
        ets_printf("%s\r\n", buf);
    }

    return err;
}

void esp_core_dump_to_uart(XtExcFrame *frame)
{
    core_dump_write_config_t wr_cfg;

    wr_cfg.prepare = NULL;
    wr_cfg.start = esp_core_dump_uart_write_start;
    wr_cfg.end = esp_core_dump_uart_write_end;
    wr_cfg.write = esp_core_dump_uart_write_data;
    wr_cfg.priv = NULL;

    ets_printf("Print core dump to uart...\r\n");
    esp_core_dump_write(frame, &wr_cfg, 0);
    ets_printf("Core dump has been written to uart.\r\n");
}
#endif

void esp_core_dump_init()
{
#if CONFIG_ESP32_ENABLE_COREDUMP_TO_FLASH
    const esp_partition_t *core_part;

    ESP_LOGI(TAG, "Init core dump to flash");
    core_part = esp_partition_find_first(ESP_PARTITION_TYPE_DATA, ESP_PARTITION_SUBTYPE_DATA_COREDUMP, NULL);
    if (!core_part) {
        ESP_LOGE(TAG, "No core dump partition found!");
        return;
    }
    ESP_LOGI(TAG, "Found partition '%s' @ %x %d bytes", core_part->label, core_part->address, core_part->size);
    s_core_part_start = core_part->address;
    s_core_part_size = core_part->size;
#endif
#if CONFIG_ESP32_ENABLE_COREDUMP_TO_UART
    ESP_LOGI(TAG, "Init core dump to UART");
#endif
}

#endif