// SD Card example esp-idf
// from:
// https://github.com/espressif/esp-idf/blob/master/examples/storage/sd_card/sdspi/main/sd_card_example_main.c
// Only PINS and host.slot changed see BOARD CONFIG section

#include <stdio.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"

#include <esp_log.h>
#define CONFIG_LOG_DEFAULT_LEVEL_VERBOSE 1
#define CONFIG_LOG_MAXIMUM_LEVEL 5
#define TAG "SD"

#include <esp_vfs.h>
#include <esp_vfs_fat.h>
#include <sdmmc_cmd.h>

#define EXAMPLE_MAX_CHAR_SIZE    64
#define MOUNT_POINT "/sdcard"

static esp_err_t s_example_write_file(const char *path, char *data)
{
    ESP_LOGI(TAG, "Opening file %s", path);
    FILE *f = fopen(path, "w");
    if (f == NULL) {
        ESP_LOGE(TAG, "Failed to open file for writing");
        return ESP_FAIL;
    }
    fprintf(f, data);
    fclose(f);
    ESP_LOGI(TAG, "File written");

    return ESP_OK;
}

static esp_err_t s_example_read_file(const char *path)
{
    ESP_LOGI(TAG, "Reading file %s", path);
    FILE *f = fopen(path, "r");
    if (f == NULL) {
        ESP_LOGE(TAG, "Failed to open file for reading");
        return ESP_FAIL;
    }
    char line[EXAMPLE_MAX_CHAR_SIZE];
    fgets(line, sizeof(line), f);
    fclose(f);

    // strip newline
    char *pos = strchr(line, '\n');
    if (pos) {
        *pos = '\0';
    }
    ESP_LOGI(TAG, "Read from file: '%s'", line);

    return ESP_OK;
}

void app_main() {

  
  printf("Hello, Wokwi!!\n");
  esp_log_level_set(TAG, ESP_LOG_INFO); 

  esp_err_t ret;

    // Options for mounting the filesystem.
    // If format_if_mount_failed is set to true, SD card will be partitioned and
    // formatted in case when mounting fails.
    esp_vfs_fat_sdmmc_mount_config_t mount_config = {
        .format_if_mount_failed = true,
        .max_files = 5,
        .allocation_unit_size = 16 * 1024
    };
    sdmmc_card_t *card;
    const char mount_point[] = MOUNT_POINT;
    ESP_LOGI(TAG, "Initializing SD card");

    // Use settings defined above to initialize SD card and mount FAT filesystem.
    // Note: esp_vfs_fat_sdmmc/sdspi_mount is all-in-one convenience functions.
    // Please check its source code and implement error recovery when developing
    // production applications.
    ESP_LOGI(TAG, "Using SPI peripheral");

    // By default, SD card frequency is initialized to SDMMC_FREQ_DEFAULT (20MHz)
    // For setting a specific frequency, use host.max_freq_khz (range 400kHz - 20MHz for SDSPI)
    // Example: for fixed frequency of 10MHz, use host.max_freq_khz = 10000;
    sdmmc_host_t host = SDSPI_HOST_DEFAULT();
    
    // BOARD CONFIG

    ESP_LOGI(TAG, "SDSPI_HOST_DEFAULT host: %d", host.slot);
    host.slot = SPI2_HOST;
    ESP_LOGI(TAG, "SDSPI_HOST : %d", host.slot);

    ESP_LOGI(TAG, "SDSPI_HOST_DEFAULT max_freq_khz: %d", host.max_freq_khz);
    //host.max_freq_khz = 20000; //20Mhz default
    //host.max_freq_khz = 400;

    spi_bus_config_t bus_cfg = {
        .mosi_io_num = 35,
        .miso_io_num = 37,
        .sclk_io_num = 36,
        .quadwp_io_num = -1,
        .quadhd_io_num = -1,
        .max_transfer_sz = 4000,
    };

    // CS pin
    int gpio_cs = 0;

    // END BOARD CONFIG

    ret = spi_bus_initialize(host.slot, &bus_cfg, SDSPI_DEFAULT_DMA);
    if (ret != ESP_OK) {
        ESP_LOGE(TAG, "Failed to initialize bus..");
        return;
    }

    // This initializes the slot without card detect (CD) and write protect (WP) signals.
    // Modify slot_config.gpio_cd and slot_config.gpio_wp if your board has these signals.
    sdspi_device_config_t slot_config = SDSPI_DEVICE_CONFIG_DEFAULT();
    slot_config.gpio_cs = gpio_cs;
    slot_config.host_id = host.slot;

    ESP_LOGI(TAG, "Mounting filesystem");
    ret = esp_vfs_fat_sdspi_mount(mount_point, &host, &slot_config, &mount_config, &card);

    if (ret != ESP_OK) {
        if (ret == ESP_FAIL) {
            ESP_LOGE(TAG, "Failed to mount filesystem. "
                     "If you want the card to be formatted, set the CONFIG_EXAMPLE_FORMAT_IF_MOUNT_FAILED menuconfig option.");
        } else {
            ESP_LOGE(TAG, "Failed to initialize the card (%s). "
                     "Make sure SD card lines have pull-up resistors in place.", esp_err_to_name(ret));
        }
        return;
    }
    ESP_LOGI(TAG, "Filesystem mounted");
    // Card has been initialized, print its properties
    sdmmc_card_print_info(stdout, card);

    // Use POSIX and C standard library functions to work with files.

    // First create a file.
    const char *file_hello = MOUNT_POINT"/hello.txt";
    char data[EXAMPLE_MAX_CHAR_SIZE];
    snprintf(data, EXAMPLE_MAX_CHAR_SIZE, "%s %s!\n", "Hello", card->cid.name);
    ret = s_example_write_file(file_hello, data);
    if (ret != ESP_OK) {
        return;
    }

    const char *file_foo = MOUNT_POINT"/foo.txt";

    // Check if destination file exists before renaming
    struct stat st;
    if (stat(file_foo, &st) == 0) {
        // Delete it if it exists
        unlink(file_foo);
    }

    // Rename original file
    ESP_LOGI(TAG, "Renaming file %s to %s", file_hello, file_foo);
    if (rename(file_hello, file_foo) != 0) {
        ESP_LOGE(TAG, "Rename failed");
        return;
    }

    ret = s_example_read_file(file_foo);
    if (ret != ESP_OK) {
        return;
    }

    // delete file
    ret = unlink(file_foo);
    if (ret != ESP_OK) {
      ESP_LOGE(TAG, "delete failed");
      return;
    }

    ret = s_example_read_file(file_foo);
    if (ret != ESP_OK) {
        ESP_LOGE(TAG, "read failed - file was deleted, as expected");
    }

    ESP_LOGE(TAG, "commands completed entering loop");

  while (true) {
    vTaskDelay(1000 / portTICK_PERIOD_MS);
  }
}