#pragma once

#include "stdint.h"

#define PCI_CONFIG_ADDRESS 0xCF8
#define PCI_CONFIG_DATA    0xCFC

typedef struct pci_device {
    uint8_t  bus;
    uint8_t  slot;
    uint8_t  func;
    uint16_t vendor_id;
    uint16_t device_id;
    uint8_t  class_code;
    uint8_t  subclass;
    uint8_t  prog_if;
    uint8_t  header_type;
} pci_device_t;

typedef struct gpu_info {
    uint16_t vendor_id;
    uint16_t device_id;
    uint8_t  bus;
    uint8_t  slot;
    uint8_t  func;
    uint32_t vram_mb;
    char     vendor_name[32];
    char     model_name[64];
} gpu_info_t;

#ifdef __cplusplus
extern "C" {
#endif

uint32_t pci_read_config_dword(uint8_t bus, uint8_t slot, uint8_t func, uint8_t offset);
void     pci_write_config_dword(uint8_t bus, uint8_t slot, uint8_t func, uint8_t offset, uint32_t val);
uint16_t pci_get_vendor_id(uint8_t bus, uint8_t slot, uint8_t func);
uint16_t pci_get_device_id(uint8_t bus, uint8_t slot, uint8_t func);
uint32_t pci_get_bar_size(uint8_t bus, uint8_t slot, uint8_t func, uint8_t bar_idx);

const char *pci_class_to_string(uint8_t class_code, uint8_t subclass);
const char *pci_vendor_to_string(uint16_t vendor_id);

int pci_detect_gpu(gpu_info_t *out_gpu);

typedef void (*pci_scan_callback_t)(const pci_device_t *dev);
void pci_scan_bus(pci_scan_callback_t callback);

#ifdef __cplusplus
}
#endif