#include "os/tty.hpp"

#include <cstdio>
#include <cstdlib>
#include "boot.hpp"

extern "C" int gKernelEnd;

namespace
{
void initHeapFromEfiMemoryMap(const EfiMemoryMap& memoryMap) noexcept
{
#if 0
    const uint64_t minAddr = reinterpret_cast<uint64_t>(&gKernelEnd);
    for (uint32_t addr = firstEntryAddr; addr < firstEntryAddr + bufferLength;)
    {
        multiboot_memory_map_t entry = *reinterpret_cast<multiboot_memory_map_t*>(addr);

        if(entry.type == MULTIBOOT_MEMORY_AVAILABLE)
        {
            std::printf("Start Addr: %X | Length: %b\n",
                        static_cast<unsigned>(entry.addr), static_cast<size_t>(entry.len));

            // anything before the kernel we ignore
            if (entry.addr < minAddr)
            {
                // if the entire entry is before the kernel, continue
                if (entry.addr + entry.len <= minAddr)
                {
                    addr += sizeof(entry.size) + entry.size;
                    continue;
                }
                // otherwise shrink it and use the rest
                entry.len -= (minAddr - entry.addr);
                entry.addr = minAddr;
            }
            __ba_registerAllocatableMemory(reinterpret_cast<void*>(entry.addr), entry.len);
        }
        addr += sizeof(entry.size) + entry.size;
    }
#endif
}

using initfunc_t = void *();
extern "C" initfunc_t* start_ctors;
extern "C" initfunc_t* end_ctors;

void initGlobals()
{
    for (initfunc_t** initFunc = &start_ctors; initFunc != &end_ctors; ++initFunc)
    {
        // TODO: this confuses me
        if (*initFunc == reinterpret_cast<initfunc_t*>(0xffffffffffffffff)) {
            break;
        }
        (*initFunc)();
    }
}
}

extern "C"
{
EfiMemoryMap* gMemoryMap;

void _init();
void _fini();
void main();

void kernel_main()
{
    initGlobals();

	/* Initialize terminal interface */
	tty::initialize();

    std::printf("Kernel End: %p\n", &gKernelEnd);

    /* Initialize the heap */
    // assert(gMultibootHeader->flags & MULTIBOOT_INFO_MEM_MAP);
    // initHeapFromMultibootHeader(gMultibootHeader->mmap_addr, gMultibootHeader->mmap_length);
    initHeapFromEfiMemoryMap(*gMemoryMap);

    main();

    _fini();
}
} // extern "C"