#ifndef __W25Q64_H
#define __W25Q64_H

#include <stdint.h>
#include "main.h"

#ifdef __cplusplus
extern "C" {
#endif

/* -------------------------------------------------
 * W25Q64 外部 SPI Flash 驱动接口
 * 硬件连接（软件 SPI，任意 GPIO）:
 *   CS  -> PB4
 *   CLK -> PB3
 *   DO  -> PB5   (Flash 数据输出 / MCU 输入)
 *   DI  -> PA15  (Flash 数据输入 / MCU 输出)
 * ------------------------------------------------- */

#define W25Q64_FLASH_SIZE        (8ul * 1024 * 1024)  /* 8MB */
#define W25Q64_SECTOR_SIZE       4096u
#define W25Q64_BLOCK_SIZE        65536u
#define W25Q64_PAGE_SIZE         256u

#define W25Q64_JEDEC_ID          0xEF4017u   /* W25Q64JV */

/* 命令字 */
#define W25Q64_CMD_WRITE_ENABLE  0x06u
#define W25Q64_CMD_WRITE_DISABLE 0x04u
#define W25Q64_CMD_READ_STATUS1  0x05u
#define W25Q64_CMD_READ_DATA     0x03u
#define W25Q64_CMD_PAGE_PROGRAM  0x02u
#define W25Q64_CMD_SECTOR_ERASE  0x20u
#define W25Q64_CMD_BLOCK_ERASE   0xD8u
#define W25Q64_CMD_CHIP_ERASE    0xC7u
#define W25Q64_CMD_READ_ID       0x9Fu

/* 外部 Flash 分区布局（每个区 256KB，足够放下 224KB 的 APP） */
#define W25Q64_SLOT_SIZE         0x40000u    /* 256KB */
#define W25Q64_SLOT_BACKUP_ADDR  0x000000u   /* 槽 A：旧版本 / 回退镜像 */
#define W25Q64_SLOT_NEW_ADDR     0x040000u   /* 槽 B：新下载的固件 */

/* 信息区：两个独立的 4KB 扇区，双副本冗余，必须避开固件槽 B 的 0x040000~0x07FFFF */
#define W25Q64_INFO_SECTOR_A     0x080000u
#define W25Q64_INFO_SECTOR_B     0x081000u
#define W25Q64_INFO_MAGIC        0x5741544Fu /* 'WATO' */

/* OTA 状态 */
#define W25Q64_STATE_IDLE        0u
#define W25Q64_STATE_DOWNLOADED  1u
#define W25Q64_STATE_COPYING     2u
#define W25Q64_STATE_INSTALLED   3u
#define W25Q64_STATE_ROLLBACK    4u

#define W25Q64_MAX_TRIALS        3u

#pragma pack(push, 1)
typedef struct {
    uint32_t magic;            /* 0x5741544F */
    uint32_t sequence;         /* 写入序号，越大越新 */
    uint16_t new_version;      /* 新版本号 */
    uint32_t new_size;         /* 新固件大小 */
    uint16_t new_crc16;        /* 新固件 MODBUS CRC16 */
    uint8_t  new_valid;        /* 槽 B 固件是否有效 */
    uint8_t  update_state;     /* 当前 OTA 状态 */
    uint16_t boot_trial_count; /* 已尝试启动次数 */
    uint8_t  app_confirmed;    /* APP 运行稳定后置 1 */
    uint8_t  reserved1;
    uint16_t backup_version;   /* 备份固件版本号 */
    uint32_t backup_size;      /* 备份固件大小 */
    uint16_t backup_crc16;     /* 备份固件 CRC16 */
    uint8_t  backup_valid;     /* 槽 A 备份是否有效 */
    uint8_t  reserved2;
    uint16_t checksum;         /* 前面所有字节累加和 */
} W25Q64_OtaInfo;
#pragma pack(pop)

/* 基础 SPI Flash 操作 */
uint8_t  W25Q64_Init(void);
void     W25Q64_ReadID(uint8_t *id3);
uint8_t  W25Q64_ReadStatus(void);
void     W25Q64_WaitBusy(void);
void     W25Q64_WriteEnable(void);
void     W25Q64_SectorErase(uint32_t addr);
void     W25Q64_BlockErase(uint32_t addr);
void     W25Q64_ChipErase(void);
void     W25Q64_PageProgram(uint32_t addr, const uint8_t *data, uint16_t len);
void     W25Q64_Read(uint32_t addr, uint8_t *buf, uint32_t len);

void     W25Q64_EraseRegion(uint32_t addr, uint32_t size);
int      W25Q64_WriteBuffer(uint32_t addr, const uint8_t *data, uint32_t len);
int      W25Q64_Verify(uint32_t addr, const uint8_t *data, uint32_t len);

/* OTA 专用信息区操作 */
int      W25Q64_OTA_ReadInfo(W25Q64_OtaInfo *info);
int      W25Q64_OTA_WriteInfo(const W25Q64_OtaInfo *info);
int      W25Q64_OTA_SetNewInfo(uint16_t version, uint32_t size, uint16_t crc16);
int      W25Q64_OTA_SetBackupInfo(uint32_t size, uint16_t crc16);
int      W25Q64_OTA_ClearNew(void);
int      W25Q64_OTA_SetState(uint8_t state);
int      W25Q64_OTA_IncTrial(void);
int      W25Q64_OTA_SetConfirmed(void);
int      W25Q64_OTA_ClearConfirmed(void);

uint16_t W25Q64_CRC16(const uint8_t *data, uint32_t len);

#ifdef __cplusplus
}
#endif

#endif /* __W25Q64_H */