#include "../include/disk.h"
#include "../include/utils.h"
#include "../include/stdio.h"

// Define the IDE registers
#define IDE_CMD 0x1F7
#define IDE_DATA 0x1F0
#define IDE_SEC_COUNT 0x1F2
#define IDE_SEC_NUM 0x1F3
#define IDE_CYL_LOW 0x1F4
#define IDE_CYL_HIGH 0x1F5
#define IDE_HEAD 0x1F6
#define IDE_STATUS 0x1F7
#define IDE_COMMAND 0x1F7

#define STATUS_ERR 0x01
#define STATUS_BUSY 0x80
#define STATUS_DRQ 0x08

// Define the IDE commands
#define IDE_CMD_IDENTIFY 0xEC


void ide_send_command(unsigned char command) {
    __asm__ __volatile__("outb %0, %1" : : "a" (command), "d" (IDE_COMMAND));
}

unsigned short ide_read_data() {
    unsigned short data;
    //__asm__ __volatile__("inw %1, %0" : "=a" (data) : "d" (IDE_DATA));
    __asm__ __volatile__("inw %w1, %0" : "=a" (data) : "Nd" (IDE_DATA));
    return data;
}

unsigned char ide_read_status() {
    unsigned char status;
    __asm__ __volatile__("inb %1, %0" : "=a" (status) : "d" (IDE_STATUS));
    return status;
}

uint16_t inw(uint16_t port) {
    uint16_t value;
    __asm__ __volatile__("inw %w1, %w0" : "=a" (value) : "Nd" (port));
    return value;
}

//https://wiki.osdev.org/ATA_PIO_Mode#IDENTIFY_command
void get_disk_info(disk_info *info) {
    outportb(0x1F6, 0xA0);//select master drive, 0xA0 - master, 0xB0 - slave

    //set sectorcount, LBAlo, LBAmid, LBAhi IO ports to 0
    outportb(0x1F2, 0x0);
    outportb(0x1F3, 0x0);
    outportb(0x1F4, 0x0);
    outportb(0x1F5, 0x0);

    // Send the identify command
    ide_send_command(IDE_CMD_IDENTIFY);//0xEC

    uint8_t status = inportb(0x1F7);
    printf("status is %X\n", status);

    if(!status)
    {
        printf("!status\n");
	return;
    }
    while((inportb(0x1F7) & STATUS_BUSY) != 0);

    while(1){
	status = inportb(0x1F7);
    	if(status & STATUS_ERR)
    	{
        	printf("ERROR! drive has err set. returning...\n");
        	return;
    	}
        if(status & STATUS_DRQ)
		break;
    }

    printf("disk is online\n");

    uint8_t lbaMID, lbaHI;
    lbaMID = inportb(0x1F4);
    lbaHI = inportb(0x1F5);

    if(lbaMID != 0 || lbaHI != 0)
    {
        printf("ERROR! lbaMID: %X, lbaHI: %X\n", lbaMID, lbaHI);
        printf("The drive is not ATA\n");
        return;
    }

    // Read the data
    unsigned short data[256];
    for (int i = 0; i < 256; i++) {
        data[i] = ide_read_data();
    }

    // Extract the disk information
    info->cylinders = (data[1] >> 8) | (data[2] << 8); // Cylinder count
    info->heads = data[6]; // Heads per cylinder
    info->sectors = data[3]; // Sectors per track
}

// Function to check if a disk is present
int ide_check_disk_present() {
    // Send the identify command
    ide_send_command(IDE_CMD_IDENTIFY);

    // Wait for 1 second
    for (int i = 0; i < 1000000; i++);

    // Check the status register
    unsigned char status;
    __asm__ __volatile__("inb %1, %0" : "=a" (status) : "d" (IDE_STATUS));

    // If the device is not busy and there's no error, it's likely a disk is present
    if ((status & 0x80) == 0 && (status & 0x01) == 0) {
        return 1; // Disk present
    }

    // If the device is busy, it might be a disk, so let's try again
    if (status & 0x80) {
        // Wait for the device to become ready
        while ((ide_read_status() & 0x80)!= 0);

        // Check the status register again
        __asm__ __volatile__("inb %1, %0" : "=a" (status) : "d" (IDE_STATUS));

        // If the device is not busy and there's no error, it's likely a disk is present
        if ((status & 0x80) == 0 && (status & 0x01) == 0) {
            return 1; // Disk present
        }
    }

    return 0; // No disk present
}