import fileio
import os

let eaw_txt = '/tmp/EastAsianWidth.txt'

os.system(f"wget -O '{eaw_txt}' https://www.unicode.org/Public/UCD/latest/ucd/EastAsianWidth.txt")

let lines

with fileio.open(eaw_txt,'r') as f:
    lines = f.readlines()

def classify(cp, gr, ct):
    # U+00AD: Soft hyphen - other things seem to want this to be 1
    if cp == 0xAD: return 1
    # Low control codes
    if cp < 0x20:  return -1
    # Del, higher control codes
    if cp >= 0x7f and cp < 0xa0: return -1
    # Surrogates
    if cp >= 0xd800 and cp <= 0xdfff: return -1

    # Combining characters
    if ct in ['Cf','Me','Mn']: return 0

    # Hangul jamo
    if cp >= 0x1160 and cp <= 0x11FF: return 0

    # Zero-width space
    if cp == 0x200b: return 0

    # Mark neutral, narrow, ambigus, and half-width as 1
    if gr in ['N','Na','A','H']: return 1

    # Mark wide and full-width as 2
    if gr in ['W','F']: return 2

    # Mark everything else as invalid
    return -1

let classes = [None] * 0x110000

for line in lines:
    if !line or line.startswith('#') or ';' not in line:
        continue
    line = line.strip()

    let codepoint, rest = line.split(';',1)
    let group, comment = rest.split('#',1)

    group = group.strip()
    comment = comment.strip()

    let ctype = comment.split(' ')[0]

    # Is this a range?
    if '..' in codepoint:
        let start, end = codepoint.split('..',1)
        start = int(f'0x{start}',0)
        end = int(f'0x{end}',0)
        for i = start; i <= end; i++:
            classes[i] = classify(i, group, ctype)
    else:
        codepoint = int(f'0x{codepoint}',0)
        classes[codepoint] = classify(codepoint, group, ctype)

for i in range(1,0x110000):
    if classes[i] is None: classes[i] = -1

print('''/* Generated by util/gen_wcwidth.krk */
#include <wchar.h>

int wcwidth(wchar_t wc) {
\tif (wc == 0) return 0;''')

let last = None

for i in range(1,0x110000):
    if last is not None and classes[i] != last:
        print(f'\telse if (wc < {hex(i)}) return {last};')

    last = classes[i]

print(f'\telse if (wc < 0x110000) return {last};\n\treturn -1;\n}}')