/**
 * NRF24L01+ 驱动实现
 */
#include "nrf24l01.h"
#include <string.h>

/* 全局状态 */
uint8_t nrf_connected = 0;
uint8_t nrf_bind_phrase[7] = "LOVE";
uint8_t nrf_channel = 40;
uint8_t nrf_tx_addr[NRF_ADDR_WIDTH] = {0xE7, 0xE7, 0xE7, 0xE7, 0xE7};

/* ---- 低层 SPI 操作 ---- */
static void NRF_SPI_CS(uint8_t level) {
    if (level) NRF_CSN_H(); else NRF_CSN_L();
}

static uint8_t NRF_SPI_Transfer(uint8_t dat) {
    uint8_t rx;
    HAL_SPI_TransmitReceive(&hspi1, &dat, &rx, 1, 10);
    return rx;
}

uint8_t NRF24L01_ReadReg(uint8_t reg) {
    uint8_t val;
    NRF_SPI_CS(0);
    NRF_SPI_Transfer(NRF_CMD_R_REGISTER | reg);
    val = NRF_SPI_Transfer(0xFF);
    NRF_SPI_CS(1);
    return val;
}

void NRF24L01_WriteReg(uint8_t reg, uint8_t value) {
    NRF_SPI_CS(0);
    NRF_SPI_Transfer(NRF_CMD_W_REGISTER | reg);
    NRF_SPI_Transfer(value);
    NRF_SPI_CS(1);
}

void NRF24L01_ReadBuf(uint8_t reg, uint8_t *buf, uint8_t len) {
    NRF_SPI_CS(0);
    NRF_SPI_Transfer(NRF_CMD_R_REGISTER | reg);
    for (uint8_t i = 0; i < len; i++)
        buf[i] = NRF_SPI_Transfer(0xFF);
    NRF_SPI_CS(1);
}

void NRF24L01_WriteBuf(uint8_t reg, const uint8_t *buf, uint8_t len) {
    NRF_SPI_CS(0);
    NRF_SPI_Transfer(NRF_CMD_W_REGISTER | reg);
    for (uint8_t i = 0; i < len; i++)
        NRF_SPI_Transfer(buf[i]);
    NRF_SPI_CS(1);
}

/* ---- 初始化 ---- */
void NRF24L01_Init(void) {
    NRF_CE_L();
    NRF_CSN_H();

    /* 上电延时 */
    HAL_Delay(100);

    /* 配置寄存器 */
    NRF24L01_WriteReg(NRF_CONFIG, 0x0E);  /* EN_CRC, CRC0, PWR_UP, PTX */
    NRF24L01_WriteReg(NRF_EN_AA, 0x01);   /* pipe0 auto ACK */
    NRF24L01_WriteReg(NRF_EN_RXADDR, 0x01); /* pipe0 enable */
    NRF24L01_WriteReg(NRF_SETUP_AW, 0x03); /* 5 bytes address */
    NRF24L01_WriteReg(NRF_SETUP_RETR, 0x1A); /* 500us + 15 retries */
    NRF24L01_WriteReg(NRF_RF_CH, nrf_channel);
    NRF24L01_WriteReg(NRF_RF_SETUP, NRF_RATE_1M | NRF_PA_MAX);
    NRF24L01_WriteReg(NRF_RX_PW_P0, 32);  /* payload = 32 bytes */
    NRF24L01_WriteReg(NRF_FIFO_STATUS, 0x11); /* clear FIFO */

    /* 设置地址 */
    NRF24L01_SetTXAddr(nrf_tx_addr);
    NRF24L01_SetRXAddr(0, nrf_tx_addr);

    /* 清空 FIFO */
    NRF_SPI_CS(0);
    NRF_SPI_Transfer(NRF_CMD_FLUSH_TX);
    NRF_SPI_CS(1);
    NRF_SPI_CS(0);
    NRF_SPI_Transfer(NRF_CMD_FLUSH_RX);
    NRF_SPI_CS(1);

    /* 清除状态 */
    NRF24L01_WriteReg(NRF_STATUS, NRF_STATUS_RX_DR | NRF_STATUS_TX_DS | NRF_STATUS_MAX_RT);

    NRF_CE_L();
}

uint8_t NRF24L01_Check(void) {
    uint8_t buf[5] = {0xA5, 0xA5, 0xA5, 0xA5, 0xA5};
    uint8_t rx[5];
    NRF24L01_WriteBuf(NRF_TX_ADDR, buf, 5);
    NRF24L01_ReadBuf(NRF_TX_ADDR, rx, 5);
    for (uint8_t i = 0; i < 5; i++)
        if (rx[i] != 0xA5) return 0;
    return 1;
}

/* ---- 配置 ---- */
void NRF24L01_SetChannel(uint8_t ch) {
    if (ch > NRF_MAX_CHANNEL) ch = NRF_MAX_CHANNEL;
    nrf_channel = ch;
    NRF24L01_WriteReg(NRF_RF_CH, ch);
}

void NRF24L01_SetRate(uint8_t rate) {
    uint8_t rf = NRF24L01_ReadReg(NRF_RF_SETUP);
    rf &= ~0x28;
    rf |= (rate & 0x28);
    NRF24L01_WriteReg(NRF_RF_SETUP, rf);
}

void NRF24L01_SetPower(uint8_t power) {
    uint8_t rf = NRF24L01_ReadReg(NRF_RF_SETUP);
    rf &= ~0x06;
    rf |= (power & 0x06);
    NRF24L01_WriteReg(NRF_RF_SETUP, rf);
}

void NRF24L01_SetTXAddr(const uint8_t *addr) {
    memcpy(nrf_tx_addr, addr, NRF_ADDR_WIDTH);
    NRF24L01_WriteBuf(NRF_TX_ADDR, addr, NRF_ADDR_WIDTH);
}

void NRF24L01_SetRXAddr(uint8_t pipe, const uint8_t *addr) {
    if (pipe > 5) return;
    if (pipe < 2) {
        NRF24L01_WriteBuf(NRF_RX_ADDR_P0 + pipe, addr, NRF_ADDR_WIDTH);
    } else {
        NRF24L01_WriteReg(NRF_RX_ADDR_P0 + pipe, addr[0]);
    }
}

/* ---- 模式切换 ---- */
void NRF24L01_TXMode(void) {
    NRF_CE_L();
    uint8_t cfg = NRF24L01_ReadReg(NRF_CONFIG);
    cfg &= ~0x01; /* PRIM_RX = 0 -> TX */
    NRF24L01_WriteReg(NRF_CONFIG, cfg);
    NRF_CE_H();
}

void NRF24L01_RXMode(void) {
    NRF_CE_L();
    uint8_t cfg = NRF24L01_ReadReg(NRF_CONFIG);
    cfg |= 0x01; /* PRIM_RX = 1 -> RX */
    NRF24L01_WriteReg(NRF_CONFIG, cfg);
    NRF_CE_H();
}

/* ---- 发送/接收 ---- */
uint8_t NRF24L01_TxPacket(const uint8_t *data, uint8_t len) {
    uint8_t status;

    NRF_CE_L();

    /* 清 TX FIFO */
    NRF_SPI_CS(0);
    NRF_SPI_Transfer(NRF_CMD_FLUSH_TX);
    NRF_SPI_CS(1);

    /* 写 payload */
    NRF_SPI_CS(0);
    NRF_SPI_Transfer(NRF_CMD_W_TX_PAYLOAD);
    for (uint8_t i = 0; i < len && i < 32; i++)
        NRF_SPI_Transfer(data[i]);
    NRF_SPI_CS(1);

    /* 发射 */
    NRF_CE_H();
    HAL_Delay(1);
    NRF_CE_L();

    /* 等待完成 */
    uint32_t timeout = 10000;
    while (timeout--) {
        status = NRF24L01_ReadReg(NRF_STATUS);
        if (status & (NRF_STATUS_TX_DS | NRF_STATUS_MAX_RT)) break;
    }

    /* 清除状态 */
    NRF24L01_WriteReg(NRF_STATUS, NRF_STATUS_TX_DS | NRF_STATUS_MAX_RT);

    if (status & NRF_STATUS_TX_DS) {
        nrf_connected = 1;
        return 1; /* 发送成功 */
    }
    nrf_connected = 0;
    return 0; /* 发送失败 */
}

uint8_t NRF24L01_RxPacket(uint8_t *data) {
    uint8_t status = NRF24L01_ReadReg(NRF_STATUS);
    if (!(status & NRF_STATUS_RX_DR)) return 0;

    /* 读 payload */
    NRF_SPI_CS(0);
    NRF_SPI_Transfer(NRF_CMD_R_RX_PAYLOAD);
    for (uint8_t i = 0; i < 32; i++)
        data[i] = NRF_SPI_Transfer(0xFF);
    NRF_SPI_CS(1);

    /* 清除 RX_DR */
    NRF24L01_WriteReg(NRF_STATUS, NRF_STATUS_RX_DR);

    return 1;
}

uint8_t NRF24L01_IsDataReady(void) {
    uint8_t status = NRF24L01_ReadReg(NRF_STATUS);
    return (status & NRF_STATUS_RX_DR) ? 1 : 0;
}

/* ---- 对频 ---- */
void NRF24L01_BindMode(void) {
    /* 进入接收模式，监听对频请求 */
    NRF_CE_L();
    NRF24L01_WriteReg(NRF_CONFIG, 0x0F); /* PRX, PWR_UP, CRC */
    NRF24L01_WriteReg(NRF_EN_RXADDR, 0x01);
    NRF24L01_WriteReg(NRF_RX_PW_P0, 32);
    NRF24L01_WriteBuf(NRF_RX_ADDR_P0, nrf_tx_addr, NRF_ADDR_WIDTH);
    NRF24L01_WriteReg(NRF_STATUS, 0x70);
    NRF_CE_H();
}

uint8_t NRF24L01_BindScan(uint8_t *found_addr) {
    /* 扫描所有通道寻找对频设备 */
    for (uint8_t ch = 0; ch <= NRF_MAX_CHANNEL; ch++) {
        NRF24L01_SetChannel(ch);
        HAL_Delay(2);
        if (NRF24L01_RxPacket(found_addr)) {
            /* 验证对频短语 */
            if (memcmp(found_addr, nrf_bind_phrase, strlen((char*)nrf_bind_phrase)) == 0) {
                /* 对频成功，记录地址 */
                memcpy(nrf_tx_addr, found_addr + 6, NRF_ADDR_WIDTH);
                nrf_connected = 1;
                return 1;
            }
        }
    }
    return 0;
}