/**
  ******************************************************************************
  * @file    gd5f2gq5ue.c
  * @brief   GD5F2GQ5UE SPI NAND Flash 驱动实现
  ******************************************************************************
  */

#include "gd5f2gq5ue.h"
#include <string.h>

extern SPI_HandleTypeDef hspi1;

/* ===================== 内部辅助函数 ===================== */

/**
 * @brief  SPI 发送/接收单字节
 */
static uint8_t gd5f_spi_xfer(uint8_t tx)
{
    uint8_t rx;
    HAL_SPI_TransmitReceive(&hspi1, &tx, &rx, 1, 100);
    return rx;
}

/**
 * @brief  SPI 发送缓冲区
 */
static void gd5f_spi_tx(const uint8_t *buf, size_t len)
{
    HAL_SPI_Transmit(&hspi1, (uint8_t *)buf, len, 100);
}

/**
 * @brief  SPI 接收缓冲区
 */
static void gd5f_spi_rx(uint8_t *buf, size_t len)
{
    HAL_SPI_Receive(&hspi1, buf, len, 100);
}

/**
 * @brief  等待操作完成（OIP 位清零）
 * @param  timeout_ms: 超时时间（毫秒）
 * @retval GD5F_OK 成功, GD5F_BUSY_TIMEOUT 超时
 */
static int gd5f_wait_busy(uint32_t timeout_ms)
{
    uint8_t cmd = GD5F_CMD_GET_FEATURE;
    uint8_t addr = GD5F_REG_STATUS;
    uint8_t status;
    uint32_t tickstart = HAL_GetTick();

    while (1) {
        GD5F_CS_LOW();
        gd5f_spi_tx(&cmd, 1);
        gd5f_spi_tx(&addr, 1);
        gd5f_spi_rx(&status, 1);
        GD5F_CS_HIGH();

        if ((status & GD5F_STATUS_OIP) == 0) {
            return GD5F_OK;
        }

        if ((HAL_GetTick() - tickstart) >= timeout_ms) {
            return GD5F_BUSY_TIMEOUT;
        }
    }
}

/**
 * @brief  写使能
 */
static int gd5f_write_enable(void)
{
    uint8_t cmd = GD5F_CMD_WRITE_ENABLE;
    GD5F_CS_LOW();
    gd5f_spi_tx(&cmd, 1);
    GD5F_CS_HIGH();
    return GD5F_OK;
}

/**
 * @brief  读取状态寄存器
 */
static int gd5f_read_status(uint8_t *status)
{
    uint8_t cmd = GD5F_CMD_GET_FEATURE;
    uint8_t addr = GD5F_REG_STATUS;
    GD5F_CS_LOW();
    gd5f_spi_tx(&cmd, 1);
    gd5f_spi_tx(&addr, 1);
    gd5f_spi_rx(status, 1);
    GD5F_CS_HIGH();
    return GD5F_OK;
}

/**
 * @brief  页读取到缓存（Page Read to Cache）
 * @param  page_addr: 页地址（行地址，包含 block + page）
 */
static int gd5f_page_read(uint32_t page_addr)
{
    uint8_t cmd[4];
    cmd[0] = GD5F_CMD_PAGE_READ;
    cmd[1] = (page_addr >> 16) & 0xFF;
    cmd[2] = (page_addr >> 8) & 0xFF;
    cmd[3] = page_addr & 0xFF;

    GD5F_CS_LOW();
    gd5f_spi_tx(cmd, 4);
    GD5F_CS_HIGH();

    return gd5f_wait_busy(100);
}

/**
 * @brief  从缓存读取数据（Read from Cache）
 * @param  column: 列地址（页内偏移）
 * @param  buf: 数据缓冲区
 * @param  size: 读取字节数
 */
static int gd5f_read_from_cache(uint16_t column, uint8_t *buf, size_t size)
{
    uint8_t cmd[5];
    cmd[0] = GD5F_CMD_READ_FROM_CACHE;
    cmd[1] = (column >> 8) & 0xFF;
    cmd[2] = column & 0xFF;
    cmd[3] = 0x00;  /* dummy byte */

    GD5F_CS_LOW();
    gd5f_spi_tx(cmd, 4);
    gd5f_spi_rx(buf, size);
    GD5F_CS_HIGH();

    return GD5F_OK;
}

/**
 * @brief  页编程（从缓存写入阵列）
 * @param  page_addr: 页地址
 * @param  column: 列地址
 * @param  buf: 数据缓冲区
 * @param  size: 写入字节数
 */
static int gd5f_page_program(uint32_t page_addr, uint16_t column, const uint8_t *buf, size_t size)
{
    int ret;
    uint8_t cmd[4];

    /* 1. 写使能 */
    gd5f_write_enable();

    /* 2. 数据加载到缓存 (Program Load) */
    cmd[0] = GD5F_CMD_PROGRAM_LOAD;
    cmd[1] = (column >> 8) & 0xFF;
    cmd[2] = column & 0xFF;

    GD5F_CS_LOW();
    gd5f_spi_tx(cmd, 3);
    gd5f_spi_tx(buf, size);
    GD5F_CS_HIGH();

    /* 3. 编程执行 (Program Execute) */
    cmd[0] = GD5F_CMD_PROGRAM_EXEC;
    cmd[1] = (page_addr >> 16) & 0xFF;
    cmd[2] = (page_addr >> 8) & 0xFF;
    cmd[3] = page_addr & 0xFF;

    GD5F_CS_LOW();
    gd5f_spi_tx(cmd, 4);
    GD5F_CS_HIGH();

    /* 4. 等待完成 */
    ret = gd5f_wait_busy(1000);
    if (ret != GD5F_OK) return ret;

    /* 5. 检查编程结果 */
    uint8_t status;
    gd5f_read_status(&status);
    if (status & GD5F_STATUS_P_FAIL) {
        /* 清除 P_FAIL：写使能 + 读状态 */
        gd5f_write_enable();
        return GD5F_PROGRAM_FAIL;
    }

    return GD5F_OK;
}

/**
 * @brief  块擦除
 * @param  block_addr: 块地址 (0 ~ 2047)
 */
static int gd5f_block_erase(uint32_t block_addr)
{
    int ret;
    uint8_t cmd[4];

    /* 1. 写使能 */
    gd5f_write_enable();

    /* 2. 块擦除命令 */
    cmd[0] = GD5F_CMD_BLOCK_ERASE;
    cmd[1] = (block_addr >> 8) & 0xFF;
    cmd[2] = block_addr & 0xFF;
    cmd[3] = 0x00;

    GD5F_CS_LOW();
    gd5f_spi_tx(cmd, 4);
    GD5F_CS_HIGH();

    /* 3. 等待完成（擦除较慢） */
    ret = gd5f_wait_busy(5000);
    if (ret != GD5F_OK) return ret;

    /* 4. 检查擦除结果 */
    uint8_t status;
    gd5f_read_status(&status);
    if (status & GD5F_STATUS_E_FAIL) {
        gd5f_write_enable();
        return GD5F_ERASE_FAIL;
    }

    return GD5F_OK;
}

/* ===================== 公共接口实现 ===================== */

int gd5f2gq5ue_init(void)
{
    int ret;
    uint8_t mid, did;

    /* 确保控制引脚处于非激活状态 */
    GD5F_CS_HIGH();
    GD5F_WP_HIGH();
    GD5F_HOLD_HIGH();

    /* 小延时等待上电稳定 */
    HAL_Delay(10);

    /* 复位芯片 */
    ret = gd5f2gq5ue_reset();
    if (ret != GD5F_OK) return ret;

    HAL_Delay(5);

    /* 读取 ID 验证通信 */
    ret = gd5f2gq5ue_read_id(&mid, &did);
    if (ret != GD5F_OK) return ret;

    if (mid != GD5F_MANUFACTURER_ID || did != GD5F_DEVICE_ID) {
        return GD5F_ID_MISMATCH;
    }

    return GD5F_OK;
}

int gd5f2gq5ue_read_id(uint8_t *mid, uint8_t *did)
{
    uint8_t cmd = GD5F_CMD_READ_ID;
    uint8_t id_buf[3];

    GD5F_CS_LOW();
    gd5f_spi_tx(&cmd, 1);
    gd5f_spi_rx(id_buf, 3);   /* dummy + MID + DID */
    GD5F_CS_HIGH();

    *mid = id_buf[1];         /* id_buf[0] = dummy */
    *did = id_buf[2];

    return GD5F_OK;
}

int gd5f2gq5ue_read(long offset, uint8_t *buf, size_t size)
{
    int ret;

    while (size > 0) {
        /* 计算页地址和列偏移 */
        uint32_t page_addr = offset / GD5F_PAGE_SIZE;
        uint16_t column = offset % GD5F_PAGE_SIZE;

        /* 本次读取字节数（不超过当前页剩余空间） */
        size_t bytes = GD5F_PAGE_SIZE - column;
        if (bytes > size) bytes = size;

        /* Page Read to Cache */
        ret = gd5f_page_read(page_addr);
        if (ret != GD5F_OK) return ret;

        /* Read from Cache */
        ret = gd5f_read_from_cache(column, buf, bytes);
        if (ret != GD5F_OK) return ret;

        offset += bytes;
        buf += bytes;
        size -= bytes;
    }

    return GD5F_OK;
}

int gd5f2gq5ue_write(long offset, const uint8_t *buf, size_t size)
{
    int ret;

    while (size > 0) {
        /* 计算页地址和列偏移 */
        uint32_t page_addr = offset / GD5F_PAGE_SIZE;
        uint16_t column = offset % GD5F_PAGE_SIZE;

        /* 本次写入字节数（不超过当前页剩余空间） */
        size_t bytes = GD5F_PAGE_SIZE - column;
        if (bytes > size) bytes = size;

        /* 页编程 */
        ret = gd5f_page_program(page_addr, column, buf, bytes);
        if (ret != GD5F_OK) return ret;

        offset += bytes;
        buf += bytes;
        size -= bytes;
    }

    return GD5F_OK;
}

int gd5f2gq5ue_erase(long offset, size_t size)
{
    int ret;

    /* 擦除起始地址必须块对齐 */
    if (offset % GD5F_BLOCK_SIZE != 0) {
        return GD5F_ERROR;
    }

    /* 擦除大小必须为块大小的整数倍 */
    if (size % GD5F_BLOCK_SIZE != 0) {
        return GD5F_ERROR;
    }

    /* 逐块擦除 */
    while (size > 0) {
        uint32_t block_addr = offset / GD5F_BLOCK_SIZE;

        ret = gd5f_block_erase(block_addr);
        if (ret != GD5F_OK) return ret;

        offset += GD5F_BLOCK_SIZE;
        size -= GD5F_BLOCK_SIZE;
    }

    return GD5F_OK;
}

int gd5f2gq5ue_reset(void)
{
    uint8_t cmd = GD5F_CMD_RESET;

    GD5F_CS_LOW();
    gd5f_spi_tx(&cmd, 1);
    GD5F_CS_HIGH();

    HAL_Delay(5);

    return GD5F_OK;
}