#include <string.h>
#include <grub/text_fb_info.h>
#include <ipc/vfs.h>
#include <elf.h>
#include <mailboxes.h>
#include <memory.h>
#include <tasking.h>
#include <stdlib.h>
#include <stdio.h>
#include <initrd.h>
#include <dbg.h>
#include <vfs.h>

typedef struct {
  char filename[100];
  char mode[8];
  char uid[8];
  char gid[8];
  char size[12];
  char mtime[12];
  char chksum[8];
  char typeflag[1];
} tar_header;

uint32_t getsize(const char *in) {
    uint32_t size=0;
    uint32_t j;
    uint32_t count=1;
    for (j=11;j>0;j--,count*=8) {
        size+=((in[j-1]-'0')*count);
    }
    return size;
}

uint32_t find_loc(char* name,char* initrd) {
  uint32_t pos=0;
  tar_header tar_hdr;
  for (int i=0;;i++) {
    char* tar_hdr_ptr=(char*)&tar_hdr;
    for (size_t i=0;i<sizeof(tar_hdr);i++) {
      tar_hdr_ptr[i]=initrd[pos+i];
    }
    if (tar_hdr.filename[0]=='\0') break;
    uint32_t size=getsize(tar_hdr.size);
    pos+=512;
    if (strcmp(tar_hdr.filename,name)==0) {
      return pos;
      break;
    }
    pos+=size;
    if (pos%512!=0) {
      pos+=512-(pos%512);
    }
  }
  return 0;
}

char load_task(uint32_t datapos,char* initrd) {
  int pos=0;
  elf_header header;
  pos=datapos;
  char* hdr_ptr=(char*)&header;
  for (size_t i=0;i<sizeof(elf_header);i++) {
    hdr_ptr[i]=initrd[pos];
    pos++;
  }
  if (header.magic!=ELF_MAGIC) {
    return 0;
  } else {
    void* cr3=new_address_space();
    for (int i=0;i<header.pheader_ent_nm;i++) {
      elf_pheader pheader;
      pos=(header.prog_hdr)+(header.pheader_ent_sz*i)+datapos;
      char* phdr_ptr=(char*)&pheader;
      for (size_t i=0;i<sizeof(elf_pheader);i++) {
        phdr_ptr[i]=initrd[pos];
        pos++;
      }
      char* ptr=alloc_memory(((pheader.memsz)/4096)+1);
      memset(ptr,0,pheader.memsz);
      if (pheader.filesz>0) {
        pos=pheader.offset+datapos;
        for (size_t i=0;i<pheader.filesz;i++) {
          ptr[i]=initrd[pos];
          pos++;
        }
      }
      copy_data(cr3,ptr,pheader.memsz,(void*)pheader.vaddr);
    }
    createTaskCr3((void*)header.entry,cr3);
  }
  return 1;
}

int main() {
  long size=initrd_sz();
  char* initrd=malloc(size);
  initrd_get(initrd);
  uint32_t datapos=find_loc("vfs",initrd);
  load_task(datapos,initrd);
  yield(); // Bochs fails here
  datapos=find_loc("devfs",initrd);
  load_task(datapos,initrd);
  yieldToPID(3);
  datapos=find_loc("vga_drv",initrd);
  load_task(datapos,initrd);
  free(initrd);
  yieldToPID(4);
  mount("","devfs","/dev/");
  FILE* file;
  do {
    file=fopen("/dev/vga","w");
  } while(file==NULL);
  do {
    file=fopen("/dev/vga","w");
  } while(file==NULL);
  fputs("FPUTS String\n",file);
  printf("Printf %d\n",size);
}