#include <stdio.h>
#include <string.h>
#include <stdint.h>
#include <stdlib.h>
#include <sys/ksys.h>
#define SIGNATURE_SIZE 8

typedef struct {
    char signature[SIGNATURE_SIZE];
    uint32_t version;
    uint32_t start_address;
    uint32_t file_size;
    uint32_t memory_required;
    uint32_t esp_value;
    uint32_t param_address;
    uint32_t file_path_address;
    uint32_t tls_data_address;    // This field is only for MENUET02 signature
} menuet_header_t;

void show_menuet_xx(const char *fpath) {
    ksys_ufile_t file = _ksys_load_file(fpath);
    if (file.data == NULL) {
        printf("Error: Unable to open file.");
        return;
    }
    menuet_header_t header;
    if (file.size < sizeof(menuet_header_t)) {
        printf("Error: Unable to read header information.");
        return;
    } else {
        memcpy(&header, file.data, sizeof(menuet_header_t));
    }

    if (strncmp(header.signature, "MENUET01", SIGNATURE_SIZE) != 0 && strncmp(header.signature, "MENUET02", SIGNATURE_SIZE) != 0) {
        printf("Error: Invalid signature.\n");
        return;
    }
    printf("Signature:         %.*s\n", SIGNATURE_SIZE, header.signature);
    printf("Version:           0x%x\n", header.version);
    printf("Start Address:     0x%x\n", header.start_address);
    printf("File Size:         %u bytes\n", header.file_size);
    printf("Memory Required:   %u bytes\n", header.memory_required);
    printf("ESP Value:         0x%x\n", header.esp_value);
    printf("Parameter Address: 0x%x\n", header.param_address);
    printf("File Path Address: 0x%x\n", header.file_path_address);
    if (strncmp(header.signature, "MENUET02", SIGNATURE_SIZE) == 0) {
        printf("TLS Data Address:  0x%x\n", header.tls_data_address);
    }
}

void show_library(const char *fpath) {
    ksys_dll_t *table = _ksys_dlopen(fpath);
    if (table == NULL) {
        printf("Failed to load library.");
        return;
    }
    printf("Export table:\n\nFunction                   Address\n-------------------------------------\n");
    size_t i = 0;
    for (;;) {
        char *func_name = (table + i)->func_name;
        void *func_ptr = (table + i)->func_ptr;
        if (func_name == NULL) {
            if (i == 0) {
                printf("No functions in export table.");
            }
            return;
        } else {
            printf("%s", func_name);
            int x = strlen(func_name);
            while (x < 25) {
                putc(' ');
                x++;
            }
            putc(' ');
            printf(" 0x%x\n", func_ptr);
        }
        i++;
    }
}


int main(int argc, char *argv[]) {
    if (argc < 2) {
        printf("Usage:\nkexview <kex_file> - view info about kex program\nkexview -l <obj_file> - view info about obj library");
        return;
    }
    
    if (strcmp(argv[1], "-l") == 0) {
        if (argc < 3) {
            printf("Error: library expected after -l");
            return;
        }
        show_library(argv[2]);
    } else {
        show_menuet_xx(argv[1]);  
    }

    return 0;
}