#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>

struct MiniRV32IMAState;
void ecall_handler(struct MiniRV32IMAState *state);
#define ECALL_HANDLER(state) ecall_handler(state)
#define MINIRV32WARN( x... ) printf( x );
#define MINIRV32_DECORATE  static
#define MINI_RV32_RAM_SIZE (32 * 1024 * 1024)
#define MINIRV32_IMPLEMENTATION

#define MINIRV32_RAM_IMAGE_OFFSET  0x0
#include "mini-rv32ima.h"

#define SYSCALL(num) (1025 + num)
void ecall_handler(struct MiniRV32IMAState *state) {
    uint32_t a0 = REG(10);
    uint32_t a1 = REG(11);
    switch (state->regs[17]) // x17 | a7
    {
    case 1:
        // PrintInt
        printf("%d", a0);
        break;
    case 4:
        // PrintString
        printf("%s", a0);
        break;
    case 10:
        fprintf(stderr, "\nexit: %d\n", a0);
        exit(a0);
    case 11:
        // PrintChar
        printf("%c", a0);
        break;
    case 93:
        fprintf(stderr, "\nmain return code: %d\n", a0);
        exit(a0);
    case SYSCALL(0):
        // getchar();
        REGSET(10, getchar());
    case SYSCALL(1):
        // putchar
        putchar(a0);
        break;
    case SYSCALL(4):
        // input int
        scanf("%d", &a0);
        REGSET(10, a0);
        break;
    case SYSCALL(5):
        // input string
        scanf("%s", a0);
        REGSET(10, a0);
        break;
    default:
        MINIRV32WARN("Unhandled ECALL: %d\n", state->regs[17]);
        exit(1);
        break;
    }
}

int main(int argc, char *argv[]) {
    // gcc -DDEFAULT_FILE='\"flat.bin\"' .\ripes-vm.c -o rv32-vm.exe
    struct MiniRV32IMAState state;
    uint8_t *image = (uint8_t *)malloc(MINI_RV32_RAM_SIZE);

    // 初始化状态
    memset(&state, 0, sizeof(state));
    state.pc = 0; // 程序计数器从0开始
    state.mstatus = 0x80000000; // 设置机器模式
    state.mtvec = 0x1000;
    state.mie = 0x7; // 启用所有中断

    // 初始化内存
    memset(image, 0, MINI_RV32_RAM_SIZE);

    #ifndef DEFAULT_FILE
    #define DEFAULT_FILE "../ccompiler/backend/test_rv.bin"
    #endif
    const char* filename = DEFAULT_FILE;
    // 加载 flatbin 文件
    if (argc == 2) {
        filename = argv[1];
    }
    
    FILE *file = fopen(filename, "rb");
    if (!file) {
        fprintf(stderr, "Usage: %s <flatbin_file>\n", argv[0]);
        printf("Failed to open file %s\n", filename);
        return 1;
    }

    fseek(file, 0, SEEK_END);
    long flen = ftell(file);
    fseek(file, 0, SEEK_SET);

    if (flen > MINI_RV32_RAM_SIZE) {
        fprintf(stderr, "Flatbin file is too large\n");
        fclose(file);
        return 1;
    }

    fread(image, flen, 1, file);
    fclose(file);

    // 运行模拟器
    while (1) {
        int32_t ret = MiniRV32IMAStep(&state, image, MINIRV32_RAM_IMAGE_OFFSET, 0, 1);
        if (ret != 0) {
            printf("Exception or interrupt occurred at PC: %d\n", state.pc);
            return ret;
        }
    }

    free(image);
    return 0;
}

// static void DumpState( struct MiniRV32IMAState * core, uint8_t * ram_image )
// {
// 	uint32_t pc = core->pc;
// 	uint32_t pc_offset = pc - MINIRV32_RAM_IMAGE_OFFSET;
// 	uint32_t ir = 0;

// 	printf( "PC: %08x ", pc );
// 	if( pc_offset >= 0 && pc_offset < ram_amt - 3 )
// 	{
// 		ir = *((uint32_t*)(&((uint8_t*)ram_image)[pc_offset]));
// 		printf( "[0x%08x] ", ir ); 
// 	}
// 	else
// 		printf( "[xxxxxxxxxx] " ); 
// 	uint32_t * regs = core->regs;
// 	printf( "Z:%08x ra:%08x sp:%08x gp:%08x tp:%08x t0:%08x t1:%08x t2:%08x s0:%08x s1:%08x a0:%08x a1:%08x a2:%08x a3:%08x a4:%08x a5:%08x ",
// 		regs[0], regs[1], regs[2], regs[3], regs[4], regs[5], regs[6], regs[7],
// 		regs[8], regs[9], regs[10], regs[11], regs[12], regs[13], regs[14], regs[15] );
// 	printf( "a6:%08x a7:%08x s2:%08x s3:%08x s4:%08x s5:%08x s6:%08x s7:%08x s8:%08x s9:%08x s10:%08x s11:%08x t3:%08x t4:%08x t5:%08x t6:%08x\n",
// 		regs[16], regs[17], regs[18], regs[19], regs[20], regs[21], regs[22], regs[23],
// 		regs[24], regs[25], regs[26], regs[27], regs[28], regs[29], regs[30], regs[31] );
// }