#include "../memory/pageframealloc.h"
#include "../boot/multiboot/data.h"
#include "pageframe.h"
#include "../debug/output.h"

#include "../memory/config.h"
#include "../arch/lapic.h"
#include "../arch/apic.h"

uint8_t PageFrameAllocator::bitmap[4294967296 / 4096 / 8];

void mark_unavailable(uintptr_t start, uintptr_t end){
    DBG << "start: " << hex << start << " end: " << end << endl;

    for(uint64_t i = start; i < end; i += 4096){
        uint64_t pg = i/4096;
        PageFrameAllocator::bitmap[pg/8] &= ~(1 << pg%8);
    }
}

void PageFrameAllocator::init(){
    Multiboot::Memory* memory_map_entry = Multiboot::getMemoryMap();

    dout << "kernel start: " << ___KERNEL_START___;
    dout << " kernel end: " << ___KERNEL_END___ << endl;
    while(memory_map_entry != 0){
        void* start =  memory_map_entry->getStartAddress();
        void* end =  memory_map_entry->getEndAddress();
        bool available = memory_map_entry->isAvailable();

        //TODO priotity for conflicting regions
        for(uint64_t i = (uint64_t)start; i < (uint64_t)end; i += 4096){
            uint64_t pg = i/4096;
            if(available)
                bitmap[pg/8] |= 1 << pg%8;
            else
                bitmap[pg/8] &= ~(1 << pg%8);
        }

        memory_map_entry = memory_map_entry->getNext();
    }

    DBG << "kernel image ";
    mark_unavailable((uintptr_t)&___KERNEL_START___, (uintptr_t)&___KERNEL_END___);

    DBG << "ISA adresses ";
    mark_unavailable(0x00F00000, 0x00FFFFFF);

    DBG << "LAPIC ";
    mark_unavailable(0xfee00000, 0xfee003f0);

    DBG << "IO APIC ";
    mark_unavailable(APIC::getIOAPICAddress(), APIC::getIOAPICAddress()+0x10);

    stats();
}

void PageFrameAllocator::stats(){
    Multiboot::Memory* memory_map_entry = Multiboot::getMemoryMap();
    while(memory_map_entry != 0){
        void* start =  memory_map_entry->getStartAddress();
        void* end =  memory_map_entry->getEndAddress();
        bool available = memory_map_entry->isAvailable();
        DBG << "Memory: " << hex << start << " to " << end << " is available: " << available << "." << endl;
        memory_map_entry = memory_map_entry->getNext();
    }

    uint64_t pages_available = 0;
    for(uint64_t i=0; i<sizeof(bitmap)*8;i++)
    {
        if(bitmap[i/8] & (1<<i%8))
            pages_available++;
    }
    for(uint64_t i=0; i < 0x2000000/4096/8; i++){
        if(i%64 == 0){
            DBG << endl << hex << i * 8 * 4096 << " " << flush;
            int x,y;
            dout.getPos(x,y);
            for(uint8_t i=x; i<10; i++){
                DBG<<" ";
            }
        }

        if(bitmap[i] == 0xff)
            DBG << '#';
        else if(bitmap[i] == 0x00)
            DBG << '.';
        else
            DBG << '/';
    }
    DBG << "\npages available: " << dec << pages_available << endl;

}

PageFrame* PageFrameAllocator::alloc(bool kernel){
    (void) kernel;
    return 0;
}

void PageFrameAllocator::free(PageFrame* frame){
    (void) frame;
}

void PageFrameAllocator::free(uintptr_t addr){
    (void) addr;
}