#include "pci.h"
#include <cpu/ports.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>

pci_dev_common_info** pci_devs;
static size_t max_devs;
size_t pci_num_devs;

static uint32_t read_config(int bus,int device,int func,int offset) {
  uint32_t address;
  uint32_t lbus=(uint32_t)bus;
  uint32_t ldev=(uint32_t)device;
  uint32_t lfunc=(uint32_t)func;
  address=(uint32_t)((lbus << 16)|(ldev << 11)|(lfunc<<8)|(offset&0xfc)|((uint32_t)0x80000000));
  port_long_out(PCI_CONFIG_ADDRESS,address);
  uint32_t data=port_long_in(PCI_CONFIG_DATA);
  return data;
}

static void write_config(int bus,int device,int func,int offset,uint32_t data) {
  uint32_t address;
  uint32_t lbus=(uint32_t)bus;
  uint32_t ldev=(uint32_t)device;
  uint32_t lfunc=(uint32_t)func;
  address=(uint32_t)((lbus << 16)|(ldev << 11)|(lfunc<<8)|(offset&0xfc)|((uint32_t)0x80000000));
  port_long_out(PCI_CONFIG_ADDRESS,address);
  port_long_out(PCI_CONFIG_DATA,data);
}

pci_dev_common_info* pci_get_dev_info(int bus,int device,int func) {
  uint32_t* info=malloc(sizeof(uint32_t)*5);
  info[0]=read_config(bus,device,func,0);
  info[1]=read_config(bus,device,func,4);
  info[2]=read_config(bus,device,func,8);
  info[3]=read_config(bus,device,func,0xC);
  pci_dev_common_info* pci_info=(pci_dev_common_info*)info;
  return pci_info;
}

void pci_set_dev_info(int bus,int device,int func, pci_dev_common_info* inf) {
  uint32_t* info=(uint32_t*)inf;
  write_config(bus,device,func,0,info[0]);
  write_config(bus,device,func,4,info[1]);
  write_config(bus,device,func,8,info[2]);
  write_config(bus,device,func,0xC,info[3]);
}

static void checkFunction(int bus,int device,int func, pci_dev_common_info* info);

static void checkDevice(int bus, int device) {
  pci_dev_common_info* info=pci_get_dev_info(bus,device,0);
  if(info->vend_id==0xFFFF||info->class_code==0xFF) {
    return;
  }
  checkFunction(bus, device, 0, info);
  if((info->header_type&0x80)!=0) {
    for(int function=1;function<8;function++) {
      pci_dev_common_info* info=pci_get_dev_info(bus,device,function);
      if(info->vend_id!=0xFFFF&&info->class_code!=0xFF) {
        checkFunction(bus,device,function,info);
      }
    }
  }
}

static void printBAR(uint32_t bar,int num) {
  if (bar!=0) {
    if (bar&0x1) {
      printf("[INFO] IO BAR%d:%x\n",num,bar&0xFFFFFFFC);
    } else {
      printf("[INFO] MEM BAR%d:%x\n",num,bar&0xFFFFFFF0);
    }
  }
}

static void checkFunction(int bus,int device,int func,pci_dev_common_info* info) {
  if (pci_num_devs==max_devs) {
    max_devs+=32;
    pci_devs=malloc(sizeof(pci_dev_common_info)*max_devs);
  }
  pci_devs[pci_num_devs]=info;
  if ((info->header_type&0x7f)==0) {
    pci_dev_type0* dev=realloc(info,sizeof(pci_dev_type0));
    uint32_t* dev_word_array=(uint32_t*)dev;
    for (int i=0;i<16;i++) {
      dev_word_array[i]=read_config(bus,device,func,i*4);
    }
    pci_devs[pci_num_devs]=(pci_dev_common_info*)dev;
  }
  pci_num_devs++;
}

void pci_init() {
  pci_devs=malloc(sizeof(pci_dev_common_info)*32);
  max_devs=32;
  pci_num_devs=0;
  for(uint16_t bus=0;bus<1; bus++) {
    for(uint8_t device=0;device<32; device++) {
        checkDevice(bus, device);
    }
  }
  for (int i=0;i<pci_num_devs;i++) {
    pci_dev_common_info* info=pci_devs[i];
    printf("[INFO] Found PCI device. Class code:%x, Subclass:%x Prog IF:%x\n",info->class_code,info->subclass,info->prog_if);
    printf("[INFO] Vendor ID:%x, Device ID:%x\n",info->vend_id,info->dev_id);
    if ((info->header_type&0x7f)==0) {
      pci_dev_type0* dev=(pci_dev_type0*)info;
      printBAR(dev->bar0,0);
      printBAR(dev->bar1,1);
      printBAR(dev->bar2,2);
      printBAR(dev->bar3,3);
      printBAR(dev->bar4,4);
      printBAR(dev->bar5,5);
    }
  }
}