//
// Created by rick on 06-02-21.
//

#include "kprintf.h"
#include "libc.h"
#include <libc/string.h>
#include <libc/va_list.h>
#include <kprint.h>
#include <libk.h>
#include <types.h>

/*
 * Integer to string
 */
void print_int(u32 value, u32 width, char *buf, u32 *ptr, u8 base) {
    // u32 in binary is 32 digits, so never longer than 33 digits
    char msg[33];
    itoa(value, msg, base);
    u32 digits = strlen(msg);
    if (digits < width) {
        for (u32 i = 0; i < (width - digits); ++i) {
            buf[*ptr] = '0';
            *ptr += 1;
        }
    }
    for (u32 i = 0; i < digits; ++i) {
        buf[*ptr] = msg[i];
        *ptr += 1;
    }
}

u32 vasprintf(char *buf, const char *fmt, va_list args) {
    u32 ptr = 0;
    for (int i = 0; i < strlen(fmt); ++i) {
        if (fmt[i] != '%') {
            buf[ptr++] = fmt[i];
            continue;
        }
        ++i;
        u32 arg_width = 0;
        while (fmt[i] >= '0' && fmt[i] <= '9') {
            arg_width *= 10;
            arg_width += fmt[i] - '0';
            ++i;
        }
        switch (fmt[i]) {
            case 's': { // string
                char *s_fmt = (char *) va_arg(args, char*);
                while (*s_fmt) {
                    buf[ptr++] = *s_fmt++;
                }
                break;
            }
            case 'c':
                buf[ptr++] = (char) va_arg(args, int);
                break;
            case 'x':
                print_int((u32) va_arg(args, u32), arg_width, buf, &ptr, 16);
                break;
            case 'd':
                print_int((u32) va_arg(args, u32), arg_width, buf, &ptr, 10);
                break;
            case '%':
                buf[ptr++] = '%';
                break;
            default:
                printf("FMT '%c' is not supported\n", fmt[i]);
                k_panic();
                break;
        }
    }
    buf[ptr] = 0;
    return ptr;
}

int printf(const char *fmt, ...) {
    int result;
    char buf[1024] = {-1};
    va_list args;
    va_start(args, fmt);
    result = vasprintf(buf, fmt, args);
    va_end(args);
    kprint(buf);
    return result;
}

int sprintf(char *target, const char *fmt, ...) {
    int result;
    va_list args;
    va_start(args, fmt);
    result = vasprintf(target, fmt, args);
    va_end(args);
    return result;
}