// epd7in5_v3.h

#ifndef epd7in5_v3_H
#define epd7in5_v3_H

#include <stdint.h>
#include "driver/spi_master.h"
#include "esp_err.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"

#ifdef __cplusplus
extern "C" {
#endif

#define EPD_WIDTH   800
#define EPD_HEIGHT  480

// Default pin assignments (override in your own board header or before init)
#ifndef EPD_RST_PIN
#define EPD_RST_PIN    8
#endif
#ifndef EPD_DC_PIN
#define EPD_DC_PIN     9
#endif
#ifndef EPD_CS_PIN
#define EPD_CS_PIN     10
#endif
#ifndef EPD_BUSY_PIN
#define EPD_BUSY_PIN   7
#endif

typedef enum {
    CMD_PANEL_SETTING                     = 0x00,
    CMD_POWER_SETTING                     = 0x01,
    CMD_POWER_OFF                         = 0x02,
    CMD_POWER_OFF_SEQUENCE_SETTING        = 0x03,
    CMD_POWER_ON                          = 0x04,
    CMD_POWER_ON_MEASURE                  = 0x05,
    CMD_BOOSTER_SOFT_START                = 0x06,
    CMD_DISPLAY_START_TRANSMISSION_1      = 0x10,
    CMD_DISPLAY_REFRESH                   = 0x12,
    CMD_DISPLAY_START_TRANSMISSION_2      = 0x13,
    CMD_DUAL_SPI                          = 0x15,
    CMD_VCOM_AND_DATA_INTERVAL_SETTING    = 0x50,
    CMD_TCON_SETTING                      = 0x60,
    CMD_RESOLUTION_SETTING                = 0x61,
    CMD_PARTIAL_WINDOW                    = 0x90,
    CMD_PARTIAL_IN                        = 0x91,
    CMD_PARTIAL_OUT                       = 0x92,
    CMD_CASCADE_SETTING                   = 0xE0,
    CMD_FORCE_TEMPERATURE                 = 0xE5,
} epd_cmd_t;

typedef struct {
    spi_device_handle_t spi;
    spi_host_device_t spi_host;
    int8_t pin_rst;
    int8_t pin_dc;
    int8_t pin_cs;
    int8_t pin_busy;
    uint16_t width;
    uint16_t height;
} epd7in5_v3_t;

/**
 * @brief  Initialize the SPI bus, GPIOs and EPD hardware.
 * @param  epd      Pointer to an epd7in5_v3_t struct (must be allocated by caller).
 * @param  host     SPI host to use (e.g. VSPI_HOST).
 * @return ESP_OK on success, or an error code.
 */
esp_err_t epd7in5_v3_create(epd7in5_v3_t *epd, spi_host_device_t host);

/**
 * @brief  Initialize the EPD panel with default settings.
 * @param  epd      Pointer to an epd7in5_v3_t struct (must be allocated by caller).
 * @return ESP_OK on success, or an error code.
 */
esp_err_t epd7in5_v3_init(epd7in5_v3_t *epd);

/**
 * @brief  Send a blocking command byte.
 */
esp_err_t epd7in5_v3_send_command(epd7in5_v3_t *epd, uint8_t cmd);

/**
 * @brief  Send a blocking data byte.
 */
esp_err_t epd7in5_v3_send_data(epd7in5_v3_t *epd, uint8_t data);

/**
 * @brief  Send a block of data.
 */
esp_err_t epd7in5_v3_send_data_block(epd7in5_v3_t *epd, const uint8_t *data, size_t len);

/**
 * @brief  Wait until BUSY line goes high (not busy).
 */
void epd7in5_v3_busy_wait(epd7in5_v3_t *epd);

/**
 * @brief  Full-screen update of a black/white image (size = width*height/8).
 */
esp_err_t epd7in5_v3_display(epd7in5_v3_t *epd, const uint8_t *image);

/**
 * @brief  Clear the display (white).
 */
esp_err_t epd7in5_v3_clear(epd7in5_v3_t *epd);

/**
 * @brief  Put the panel into deep sleep.
 */
esp_err_t epd7in5_v3_sleep(epd7in5_v3_t *epd);

#ifdef __cplusplus
}
#endif

#endif  // epd7in5_v3_H