#include "bga.h"

#include "assert.h"
#include "console.h"
#include "const.h"
#include "global.h"
#include "keyboard.h"
#include "memman.h"
#include "pci.h"
#include "proc.h"
#include "protect.h"
#include "proto.h"
#include "stdio.h"
#include "string.h"
#include "tty.h"
#include "type.h"
#include "x86.h"

#define VBE_DISPI_IOPORT_INDEX 0x01CE
#define VBE_DISPI_IOPORT_DATA 0x01CF

#define VBE_DISPI_INDEX_ID 0x0
#define VBE_DISPI_INDEX_XRES 0x1
#define VBE_DISPI_INDEX_YRES 0x2
#define VBE_DISPI_INDEX_BPP 0x3
#define VBE_DISPI_INDEX_ENABLE 0x4
#define VBE_DISPI_INDEX_BANK 0x5
#define VBE_DISPI_INDEX_VIRT_WIDTH 0x6
#define VBE_DISPI_INDEX_VIRT_HEIGHT 0x7
#define VBE_DISPI_INDEX_X_OFFSET 0x8
#define VBE_DISPI_INDEX_Y_OFFSET 0x9

#define VBE_DISPI_DISABLED 0x00
#define VBE_DISPI_ENABLED 0x01
#define VBE_DISPI_LFB_ENABLED 0x40

static uint16_t bga_screen_width, bga_screen_height;
static uint32_t bga_screen_line_size, bga_screen_buffer_size;
static uint32_t bga_buf_paddr;

static inline void _bga_write_reg(uint16_t cmd, uint16_t data) {
    outw(VBE_DISPI_IOPORT_INDEX, cmd);
    outw(VBE_DISPI_IOPORT_DATA, data);
}

static inline uint16_t _bga_read_reg(uint16_t cmd) {
    outw(VBE_DISPI_IOPORT_INDEX, cmd);
    return inw(VBE_DISPI_IOPORT_DATA);
}

static void _bga_set_resolution(uint16_t width, uint16_t height) {
    _bga_write_reg(VBE_DISPI_INDEX_ENABLE, VBE_DISPI_DISABLED);
    _bga_write_reg(VBE_DISPI_INDEX_XRES, width);
    _bga_write_reg(VBE_DISPI_INDEX_YRES, height);
    _bga_write_reg(VBE_DISPI_INDEX_VIRT_WIDTH, width);
    _bga_write_reg(VBE_DISPI_INDEX_VIRT_HEIGHT, (uint16_t)height * 2);
    _bga_write_reg(VBE_DISPI_INDEX_BPP, 32);
    _bga_write_reg(VBE_DISPI_INDEX_X_OFFSET, 0);
    _bga_write_reg(VBE_DISPI_INDEX_Y_OFFSET, 0);
    _bga_write_reg(VBE_DISPI_INDEX_ENABLE,
                   VBE_DISPI_ENABLED | VBE_DISPI_LFB_ENABLED);
    _bga_write_reg(VBE_DISPI_INDEX_BANK, 0);

    bga_screen_line_size = (uint32_t)width * 4;
}

static void bga_set_resolution(uint32_t width, uint32_t height) {
    _bga_set_resolution(width, height);
    bga_screen_width = width;
    bga_screen_height = height;
    bga_screen_buffer_size = bga_screen_line_size * height * 2;
}

int bga_ioctl(uintptr_t cmd, uintptr_t arg) {
    uint32_t y_offset = 0;
    switch (cmd) {
        case BGA_GET_HEIGHT:
            return bga_screen_height;
        case BGA_GET_WIDTH:
            return bga_screen_width;
        case BGA_GET_SCALE:
            return 1;
        case BGA_GET_BUFFER:
            if (arg == 0)
                return bga_buf_paddr;
            else
                return bga_buf_paddr + bga_screen_buffer_size / 2;
        case BGA_SWAP_BUFFERS:
            y_offset = bga_screen_height * (arg & 1);
            _bga_write_reg(VBE_DISPI_INDEX_Y_OFFSET, (uint16_t)y_offset);
            return 0;
        case BGA_DISABLE:
            _bga_write_reg(VBE_DISPI_INDEX_ENABLE, VBE_DISPI_DISABLED);
            return 0;
        case BGA_SET_WIDTH:
            bga_screen_width = arg;
            return 0;
        case BGA_SET_HEIGHT:
            bga_screen_height = arg;
            return 0;
        case BGA_SET_UPDATE:
            bga_set_resolution(bga_screen_width, bga_screen_height);
            return 0;
        default:
            return -1;
    }
}

int init_bga(pci_dev_t *dev) {
    if (dev->type != DEVICE_DISPLAY) {
        return -1;
    }

    bga_buf_paddr = pci_read_bar(dev, 0) & 0xfffffff0;
    bga_set_resolution(1024, 768);
    kprintf("bga buf paddr=%p; buf size= %d KB\n", bga_buf_paddr,
            bga_screen_buffer_size / 1024);
    kprintf("bga mapped in kernel cr3=%p\n", read_cr3());
    // for (int k = 0; k < bga_screen_buffer_size; k += 4096) {
    //     klin_mapping_phy(bga_buf_paddr + k, bga_buf_paddr + k,
    //                      PG_P | PG_USU | PG_RWW, PG_P | PG_USU | PG_RWW);
    // }
    // uint32_t *test = (uint32_t *)bga_buf_paddr;
    // uint32_t *test2 = (uint32_t *)(bga_buf_paddr + bga_screen_buffer_size / 2);
    // for (int i = 0; i <= 1024 * 20; ++i) test[i] = 0x00ff12;
    // for (int i = 1024 * 20; i <= 1024 * 40; ++i) test2[i] = 0x0000ff;
    // while (1) {
    //     bga_ioctl(BGA_SWAP_BUFFERS, 1);
    //     for (volatile int i = 0; i < 0x03ffffff; ++i)
    //         ;
    //     bga_ioctl(BGA_SWAP_BUFFERS, 0);
    //     for (volatile int i = 0; i < 0x03ffffff; ++i)
    //         ;
    // }
    return 0;
}