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

#include <coreinit/debug.h>
#include <coreinit/thread.h>
#include <coreinit/cache.h>
#include <coreinit/memdefaultheap.h>
#include <whb/sdcard.h>
#include <whb/file.h>
#include <whb/log.h>

#include "elf_abi.h"



int32_t LoadFileToMem(const char *relativefilepath, char **fileOut, uint32_t * sizeOut) {
    char path[256];
    int result = 0;
    char * sdRootPath = "";
    if (!WHBMountSdCard()) {
        WHBLogPrintf("Failed to mount SD Card...");
        result = -1;
        goto exit;
    }

    sdRootPath = WHBGetSdCardMountPath();
    sprintf(path, "%s/%s", sdRootPath,relativefilepath);

    WHBLogPrintf("Loading file %s.",path);

    *fileOut = WHBReadWholeFile(path, sizeOut);
    if (!(*fileOut)) {
        result = -2;
        WHBLogPrintf("WHBReadWholeFile(%s) returned NULL", path);
        goto exit;
    }

exit:
    WHBUnmountSdCard();
    return result;
}
static void InstallMain(void *data_elf);

uint32_t load_loader_elf_from_sd(unsigned char* baseAddress, const char* relativePath) {
    char * elf_data = NULL;
    uint32_t fileSize = 0;
    if(LoadFileToMem(relativePath, &elf_data, &fileSize) != 0) {
        return 0;
    }

    InstallMain(elf_data);

    Elf32_Ehdr* ehdr = ( Elf32_Ehdr*)elf_data;

    uint32_t res = ehdr->e_entry;

    MEMFreeToDefaultHeap((void*)elf_data);

    return res;
}

static unsigned int get_section(unsigned char *data, const char *name, unsigned int * size, unsigned int * addr, int fail_on_not_found) {
    Elf32_Ehdr *ehdr = (Elf32_Ehdr *) data;

    if (   !data
            || !IS_ELF (*ehdr)
            || (ehdr->e_type != ET_EXEC)
            || (ehdr->e_machine != EM_PPC)) {
        OSFatal("Invalid elf file");
    }

    Elf32_Shdr *shdr = (Elf32_Shdr *) (data + ehdr->e_shoff);
    int i;
    for(i = 0; i < ehdr->e_shnum; i++) {
        const char *section_name = ((const char*)data) + shdr[ehdr->e_shstrndx].sh_offset + shdr[i].sh_name;
        if(strcmp(section_name, name) == 0) {
            if(addr)
                *addr = shdr[i].sh_addr;
            if(size)
                *size = shdr[i].sh_size;
            return shdr[i].sh_offset;
        }
    }

    if(fail_on_not_found)
        OSFatal((char*)name);

    return 0;
}

/* ****************************************************************** */
/*                         INSTALL MAIN CODE                          */
/* ****************************************************************** */
static void InstallMain(void *data_elf) {
    // get .text section
    unsigned int main_text_addr = 0;
    unsigned int main_text_len = 0;
    unsigned int section_offset = get_section(data_elf, ".text", &main_text_len, &main_text_addr, 1);
    unsigned char *main_text = data_elf + section_offset;
    /* Copy main .text to memory */
    if(section_offset > 0) {
        WHBLogPrintf("%08X %08X %d", main_text_addr, main_text, main_text_len);
        memcpy((void*)(main_text_addr), (void *)main_text, main_text_len);
        DCFlushRange((void*)main_text_addr, main_text_len);
        ICInvalidateRange((void*)main_text_addr, main_text_len);
    }


    // get the .rodata section
    unsigned int main_rodata_addr = 0;
    unsigned int main_rodata_len = 0;
    section_offset = get_section(data_elf, ".rodata", &main_rodata_len, &main_rodata_addr, 0);
    if(section_offset > 0) {
        unsigned char *main_rodata = data_elf + section_offset;
        /* Copy main rodata to memory */
        memcpy((void*)(main_rodata_addr), (void *)main_rodata, main_rodata_len);
        DCFlushRange((void*)main_rodata_addr, main_rodata_len);
        ICInvalidateRange((void*)main_rodata_addr, main_rodata_len);

    }

    // get the .data section
    unsigned int main_data_addr = 0;
    unsigned int main_data_len = 0;
    section_offset = get_section(data_elf, ".data", &main_data_len, &main_data_addr, 0);
    if(section_offset > 0) {
        unsigned char *main_data = data_elf + section_offset;
        /* Copy main data to memory */
        memcpy((void*)(main_data_addr), (void *)main_data, main_data_len);
        DCFlushRange((void*)main_data_addr, main_data_len);
        ICInvalidateRange((void*)main_data_addr, main_data_len);
    }

    // get the .bss section
    unsigned int main_bss_addr = 0;
    unsigned int main_bss_len = 0;
    section_offset = get_section(data_elf, ".bss", &main_bss_len, &main_bss_addr, 0);
    if(section_offset > 0) {
        unsigned char *main_bss = data_elf + section_offset;
        /* Copy main data to memory */
        memcpy((void*)(main_bss_addr), (void *)main_bss, main_bss_len);
        DCFlushRange((void*)main_bss_addr, main_bss_len);
        ICInvalidateRange((void*)main_bss_addr, main_bss_len);
    }

}