#include <HardFaultAnalysis.h>
#include <stdio.h>
#include <string.h>

/* ------------------------------------------------------------------------------------------------------------------ */
/*  */

// 定义常见 Cortex-M 芯片的内存映射边界
#define FLASH_START      0x08000000
#define FLASH_END        0x0C000000
#define SRAM_START       0x20000000
#define SRAM_END         0x30000000
#define PERIPH_START     0x40000000
#define PERIPH_END       0x60000000
#define FMC_START        0x60000000
#define FMC_END          0xA0000000

/* ------------------------------------------------------------------------------------------------------------------ */
/*  */

// 深度分析崩溃的物理地址
static void analyze_fault_address(const char* fault_type, uint32_t addr) {
    printf("\n🔍 [%s Address Analysis] ----------------\n", fault_type);
    printf("Target Address: 0x%08X\n", addr);

    // 1. 经典空指针或极其接近0的地址（如结构体成员偏移）
    if (addr < 0x00000400) {
        printf("🚨 诊断结论: 空指针 (NULL Pointer) 解引用！\n");
        if (addr == 0) {
            printf("   -> 代码尝试直接读取或写入 NULL。\n");
        } else {
            printf("   -> 代码操作了 NULL 结构体指针，该地址是成员偏移量 (Offset: %d bytes)。\n", addr);
        }
        return;
    }

    // 2. 检查是否在代码区 (Flash)
    if (addr >= FLASH_START && addr < FLASH_END) {
        printf("🚨 诊断结论: 尝试写入只读的 Flash 区域，或者读取了未初始化的非法 Flash 地址！\n");
        printf("   -> 请检查代码是否在尝试修改常量(const)或直接通过指针对0x08xxxxxx地址写数据。\n");
        return;
    }

    // 3. 检查是否在运行内存区 (SRAM)
    if (addr >= SRAM_START && addr < SRAM_END) {
        printf("🚨 诊断结论: 访问 SRAM 时崩溃。\n");
        printf("   -> 极大可能是 数组越界 或 堆栈溢出 (Stack Overflow) 破坏了相邻的数据边界。\n");
        printf("   -> 请在 .map 文件中查找哪个全局/静态变量的地址最接近 0x%08X。\n", addr);
        return;
    }

    // 4. 检查是否在外设寄存器区 (Peripheral)
    if (addr >= PERIPH_START && addr < PERIPH_END) {
        printf("🚨 诊断结论: 访问外设寄存器时总线报错。\n");
        printf("   -> 原因 1: 该外设的时钟 (RCC) 没有开启，就去读写它的寄存器！(最常见)\n");
        printf("   -> 原因 2: 尝试访问当前芯片型号根本不存在的外设。\n");
        return;
    }

    // 5. 检查是否在外部扩展内存 (FMC/FSMC, 如外部 SDRAM/LCD)
    if (addr >= FMC_START && addr < FMC_END) {
        printf("🚨 诊断结论: 访问外部存储器(FMC/FSMC)报错。\n");
        printf("   -> 请检查外部 SDRAM/NAND/LCD 的初始化代码是否未执行，或者硬件引脚接触不良。\n");
        return;
    }

    // 6. 处于完全未定义的无人区 (野指针)
    printf("🚨 诊断结论: 绝对的野指针 (Wild Pointer) 访问！\n");
    printf("   -> 0x%08X 是一个完全不合法的未映射地址空间。\n", addr);
    printf("   -> 通常是因为指针变量未初始化、指针转义、或者堆栈被破坏导致恢复出的指针变成了垃圾值。\n");
}

static void decode_xpsr(uint32_t xpsr) {
    printf("\n------ [ xPSR Detail Analysis ] ------\n");
    printf("xPSR: 0x%08X\n", xpsr);

    // 检查第 24 位 (1 << 24 = 0x01000000)
    if ((xpsr & (1 << 24)) == 0) {
        printf("🚨 [CRITICAL ERROR] xPSR T-bit (Bit 24) is 0!\n");
        printf("   Cortex-M processors ONLY support Thumb state.\n");
        printf("   Switching to ARM state (T=0) is illegal and caused this crash.\n");
        printf("💡 [SUGGESTION] This usually happens because:\n");
        printf("   1. A function pointer lacked the LSB set to 1 (e.g., calling an even address).\n");
        printf("   2. Destructed stack frame or corrupted LR/PC during pop/return.\n");
    } else {
        printf("   -> T-bit (Bit 24) = 1 (Correct: Processor is in Thumb state).\n");
    }

    // 顺便打印当前处于哪个中断/异常中 (IPSR 位: Bit 0-8)
    uint8_t exception_number = (xpsr & 0x1FF);
    if (exception_number == 0) {
        printf("   -> Mode: Thread Mode (Application code).\n");
    } else {
        printf("   -> Mode: Handler Mode (Interrupt/Exception Handler #%d).\n", exception_number);
    }
}

// 解析 CFSR 寄存器 (Cortex-M3/M4/M7/M33 适用)
static void decode_cfsr(uint32_t cfsr, uint32_t bfar, uint32_t mmfar) {
    uint8_t mmfsr = (cfsr & 0x000000FF);
    uint8_t bfsr  = ((cfsr & 0x0000FF00) >> 8);
    uint16_t ufsr = ((cfsr & 0xFFFF0000) >> 16);

    printf("\n------ [ CFSR Detail Analysis ] ------\n");

    if (ufsr) {
        printf("[UsageFault] Detected (0x%04X):\n", ufsr);
        if (ufsr & (1 << 9))  printf("  -> DIVBYZERO: Try to divide by zero.\n");
        if (ufsr & (1 << 8))  printf("  -> UNALIGNED: Unaligned memory access alignment fault.\n");
        if (ufsr & (1 << 3))  printf("  -> NOCP: Access to an unenabled coprocessor (e.g. FPU).\n");
        if (ufsr & (1 << 2))  printf("  -> INVPC: Invalid PC load caused by EXC_RETURN.\n");
        if (ufsr & (1 << 1))  printf("  -> INVSTATE: Invalid execution state (Thumb bit issue).\n");
        if (ufsr & (1 << 0))  printf("  -> UNDEFINSTR: Executed an undefined instruction.\n");
    }

    if (bfsr) {
        printf("[BusFault] Detected (0x%02X):\n", bfsr);
        if (bfsr & (1 << 7)) {
            printf("  -> BFARVALID: Address in BFAR is valid.\n");
            analyze_fault_address("BusFault (BFAR)", bfar);
        } else {
            printf("  -> Note: BFAR address is NOT valid (Imprecise fault).\n");
        }
        if (bfsr & (1 << 1))  printf("  -> PRECISERR: Precise data bus error.\n");
        if (bfsr & (1 << 0))  printf("  -> IBUSERR: Instruction bus error.\n");
    }

    if (mmfsr) {
        printf("[MemManage Fault] Detected (0x%02X):\n", mmfsr);
        if (mmfsr & (1 << 7)) {
            printf("  -> MMFARVALID: Address in MMFAR is valid.\n");
            analyze_fault_address("MemManage (MMFAR)", mmfar);
        }
        if (mmfsr & (1 << 1)) printf("  -> DACCVIOL: Data access violation.\n");
    }
}

/* ------------------------------------------------------------------------------------------------------------------ */
/*  */

void HardFaultAnalysis(HardFaultDump_t *dump) {
    printf("==================================================\n");
    printf("        Cortex-M Offline HardFault Decoder        \n");
    printf("==================================================\n");

    printf("\n------ [ Core Registers Snapshot ] ------\n");
    printf("PC   : 0x%08X (崩溃发生在此指令附近)\n", dump->pc);
    printf("LR   : 0x%08X (父级函数返回地址)\n", dump->lr);
    printf("SP   : 0x%08X    R0   : 0x%08X\n", dump->sp, dump->r0);
    printf("R1   : 0x%08X    R2   : 0x%08X\n", dump->r1, dump->r2);
    printf("R3   : 0x%08X    R12  : 0x%08X\n", dump->r3, dump->r12);

    decode_xpsr(dump->xpsr);

    printf("\n------ [ HFSR High Level Summary ] ------\n");
    printf("HFSR : 0x%08X\n", dump->hfsr);
    if (dump->hfsr & (1 << 30)) {
        printf("  -> FORCED: 强制硬件故障。由于其他特定异常升级导致，详情见下方 CFSR。\n");
    }

    decode_cfsr(dump->cfsr, dump->bfar, dump->mmfar);
    printf("==================================================\n");
}

int HardFaultAnalysis_Load(const char* filename, HardFaultDump_t* dump ) {
    FILE *file = fopen(filename, "r");
    if (!file) {
        printf("Error: Cannot open file %s\n", filename);
        return 0;
    }

    char line[256];
    while (fgets(line, sizeof(line), file)) {
        // 忽略注释和空行
        if (line[0] == '#' || line[0] == '/' || line[0] == '\n' || line[0] == '\r') {
            continue;
        }

        char key[32];
        uint32_t val;
        // 解析 "key = 0xValue" 格式
        if (sscanf(line, "%s = %i", key, &val) == 2) {
            if (strcasecmp(key, "r0") == 0) dump->r0 = val;
            else if (strcasecmp(key, "r1") == 0) dump->r1 = val;
            else if (strcasecmp(key, "r2") == 0) dump->r2 = val;
            else if (strcasecmp(key, "r3") == 0) dump->r3 = val;
            else if (strcasecmp(key, "r12") == 0) dump->r12 = val;
            else if (strcasecmp(key, "sp") == 0) dump->sp = val;
            else if (strcasecmp(key, "lr") == 0) dump->lr = val;
            else if (strcasecmp(key, "pc") == 0) dump->pc = val;
            else if (strcasecmp(key, "xpsr") == 0) dump->xpsr = val;
            else if (strcasecmp(key, "hfsr") == 0) dump->hfsr = val;
            else if (strcasecmp(key, "cfsr") == 0) dump->cfsr = val;
            else if (strcasecmp(key, "bfar") == 0) dump->bfar = val;
            else if (strcasecmp(key, "mmfar") == 0) dump->mmfar = val;
        }
    }

    fclose(file);
    return 1;
}