module strconv

import strings

pub fn format_str_sb(s string, p BF_param, mut sb strings.Builder) {
    if p.len0 <= 0 {
        sb.write_string(s)
        return
    }

    dif := p.len0 - utf8_str_visible_length(s)

    if dif <= 0 {
        sb.write_string(s)
        return
    }

    if p.align == .right {
        for i1 := 0; i1 < dif; i1++ {
            sb.write_u8(p.pad_ch)
        }
    }

    sb.write_string(s)

    if p.align == .left {
        for i1 := 0; i1 < dif; i1++ {
            sb.write_u8(p.pad_ch)
        }
    }
}

// digit pairs in reverse order
const digit_pairs = '00102030405060708090011121314151617181910212223242526272829203132333435363738393041424344454647484940515253545556575859506162636465666768696071727374757677787970818283848586878889809192939495969798999'

// format_dec_sb format a u64
@[direct_array_access]
pub fn format_dec_sb(d u64, p BF_param, mut res strings.Builder) {
    mut n_char := dec_digits(d)
    sign_len := if !p.positive || p.sign_flag { 1 } else { 0 }
    number_len := sign_len + n_char
    dif := p.len0 - number_len
    mut sign_written := false

    if p.align == .right {
        if p.pad_ch == `0` {
            if p.positive {
                if p.sign_flag {
                    res.write_u8(`+`)
                    sign_written = true
                }
            } else {
                res.write_u8(`-`)
                sign_written = true
            }
        }
        // write the pad chars
        for i1 := 0; i1 < dif; i1++ {
            res.write_u8(p.pad_ch)
        }
    }

    if !sign_written {
        // no pad char, write the sign before the number
        if p.positive {
            if p.sign_flag {
                res.write_u8(`+`)
            }
        } else {
            res.write_u8(`-`)
        }
    }

    // Legacy version
    // max u64 18446744073709551615 => 20 byte
    mut buf := [32]u8{}
    mut i := 20
    mut d1 := d
    for i >= (21 - n_char) {
        buf[i] = u8(d1 % 10) + `0`

        d1 = d1 / 10
        i--
    }

    for _ in 0 .. n_char {
        i++
        res.write_u8(buf[i])
    }
    i++

    //===========================================

    if p.align == .left {
        for i1 := 0; i1 < dif; i1++ {
            res.write_u8(p.pad_ch)
        }
    }
    return
}