/*******************************************************************************
 * @file    w25q32.c
 * @brief   W25Q32RV External SPI Flash Driver (HW SPI via spi2_bus)
 ******************************************************************************/

#include "w25q32.h"
#include "../../debug_print.h"
#include "../../spi2_bus.h"
#include "nrf_gpio.h"
#include "nrf_delay.h"
#include <string.h>

/*==============================================================================
 * COMMANDS
 *============================================================================*/

#define CMD_JEDEC_ID      0x9F
#define CMD_READ          0x03
#define CMD_WREN          0x06
#define CMD_PP            0x02
#define CMD_SECTOR_ERASE  0x20
#define CMD_CHIP_ERASE    0xC7
#define CMD_RDSR          0x05

#define SR_BUSY           0x01

/*==============================================================================
 * CS CONTROL (manual GPIO - P0.24)
 *============================================================================*/

static inline void cs_low(void)  { nrf_gpio_pin_clear(W25Q_CS_PIN); }
static inline void cs_high(void) { nrf_gpio_pin_set(W25Q_CS_PIN);   }

/*==============================================================================
 * SPI BUS HELPERS
 *============================================================================*/

static void ensure_spi_ready(void)
{
    if (!spi2_bus_is_initialized()) {
        spi2_bus_init();
    }
}

/*==============================================================================
 * POWER CONTROL - P0.01 + P0.11 both HIGH = W25Q32 power ON
 *============================================================================*/

void w25q32_power_on(void)
{
    nrf_gpio_cfg_output(W25Q_PWR_PIN1);
    nrf_gpio_cfg_output(W25Q_PWR_PIN2);
    nrf_gpio_pin_set(W25Q_PWR_PIN1);   /* P0.01 HIGH */
    nrf_gpio_pin_set(W25Q_PWR_PIN2);   /* P0.11 HIGH */
    nrf_delay_ms(10);  /* Wait for power stabilization */
    DBG_PRINTF("[W25Q] Power ON (P0.%d=H, P0.%d=H)\r\n", W25Q_PWR_PIN1, W25Q_PWR_PIN2);
}

void w25q32_power_off(void)
{
    nrf_gpio_pin_clear(W25Q_PWR_PIN1);
    nrf_gpio_pin_clear(W25Q_PWR_PIN2);
    DBG_PRINTF("[W25Q] Power OFF\r\n");
}

/*==============================================================================
 * PRIVATE HELPERS
 *============================================================================*/

static uint8_t read_status(void)
{
    uint8_t tx[2] = { CMD_RDSR, 0xFF };
    uint8_t rx[2] = { 0 };
    ret_code_t err;

    cs_low();
    err = spi2_bus_transfer(tx, 2, rx, 2);
    cs_high();

    if (err != NRF_SUCCESS) {
        DBG_PRINTF("[W25Q] read_status ERR=%d\r\n", err);
    }
    return rx[1];
}

static void wait_ready(void)
{
    while (read_status() & SR_BUSY) {
        nrf_delay_ms(1);
    }
}

static void write_enable(void)
{
    uint8_t cmd = CMD_WREN;
    cs_low();
    spi2_bus_transfer(&cmd, 1, NULL, 0);
    cs_high();
}

/*==============================================================================
 * PUBLIC FUNCTIONS
 *============================================================================*/

bool w25q32_init(void)
{
    DBG_PRINTF("[W25Q] init (HW SPI)\r\n");

    w25q32_power_on();

    /* CS pin setup */
    nrf_gpio_cfg_output(W25Q_CS_PIN);
    nrf_gpio_pin_set(W25Q_CS_PIN);

    ensure_spi_ready();
    nrf_delay_ms(5);

    return w25q32_check_jedec();
}

bool w25q32_check_jedec(void)
{
    uint8_t tx[4] = { CMD_JEDEC_ID, 0xFF, 0xFF, 0xFF };
    uint8_t rx[4] = { 0 };

    ensure_spi_ready();

    cs_low();
    spi2_bus_transfer(tx, 4, rx, 4);
    cs_high();

    /* rx[0] = dummy (during CMD), rx[1]=mfr, rx[2]=type, rx[3]=cap */
    DBG_PRINTF("[W25Q] JEDEC = %02X %02X %02X\r\n", rx[1], rx[2], rx[3]);

    /* Winbond = 0xEF, W25Q32 = 0x40 0x16 */
    return (rx[1] == 0xEF);
}

void w25q32_read(uint32_t addr, uint8_t *buf, uint32_t len)
{
    uint8_t cmd[4];

    DBG_PRINTF("[W25Q] read addr=0x%06X len=%u\r\n", addr, len);
    ensure_spi_ready();

    cmd[0] = CMD_READ;
    cmd[1] = (uint8_t)(addr >> 16);
    cmd[2] = (uint8_t)(addr >> 8);
    cmd[3] = (uint8_t)(addr);

    cs_low();
    /* Send command + address */
    spi2_bus_transfer(cmd, 4, NULL, 0);
    /* Read data - send dummy bytes, receive into buf */
    while (len > 0) {
        uint8_t chunk = (len > 255) ? 255 : (uint8_t)len;
        uint8_t dummy[255];
        memset(dummy, 0xFF, chunk);
        spi2_bus_transfer(dummy, chunk, buf, chunk);
        buf += chunk;
        len -= chunk;
    }
    cs_high();
}

void w25q32_write(uint32_t addr, const uint8_t *buf, uint32_t len)
{
    uint8_t cmd[255];

    DBG_PRINTF("[W25Q] write addr=0x%06X len=%u\r\n", addr, len);
    ensure_spi_ready();

    while (len) {
        uint32_t page = 256 - (addr & 0xFF);
        if (page > len) page = len;
        if (page > 251) page = 251;  /* 4 (cmd+addr) + 251 = 255 max */

        write_enable();

        /* Build command: PP + 3-byte address + data */
        cmd[0] = CMD_PP;
        cmd[1] = (uint8_t)(addr >> 16);
        cmd[2] = (uint8_t)(addr >> 8);
        cmd[3] = (uint8_t)(addr);
        memcpy(&cmd[4], buf, page);

        cs_low();
        spi2_bus_transfer(cmd, (uint8_t)(4 + page), NULL, 0);
        cs_high();

        wait_ready();
        DBG_PRINTF("[W25Q] page done %u bytes\r\n", page);

        addr += page;
        buf  += page;
        len  -= page;
    }
    DBG_PRINTF("[W25Q] write OK\r\n");
}

void w25q32_sector_erase(uint32_t addr)
{
    uint8_t cmd[4];

    ensure_spi_ready();

    addr &= ~0xFFF;  /* Align to 4KB sector */

    write_enable();

    cmd[0] = CMD_SECTOR_ERASE;
    cmd[1] = (uint8_t)(addr >> 16);
    cmd[2] = (uint8_t)(addr >> 8);
    cmd[3] = (uint8_t)(addr);

    cs_low();
    spi2_bus_transfer(cmd, 4, NULL, 0);
    cs_high();

    wait_ready();
}

void w25q32_chip_erase(void)
{
    uint8_t cmd;

    ensure_spi_ready();

    DBG_PRINTF("[W25Q] Chip erase...\r\n");

    write_enable();

    cmd = CMD_CHIP_ERASE;
    cs_low();
    spi2_bus_transfer(&cmd, 1, NULL, 0);
    cs_high();

    wait_ready();

    DBG_PRINTF("[W25Q] Erase done\r\n");
}