// Copyright june 2026

const std = @import("std");
const unicode = std.unicode;
const mem = std.mem;
const c = std.c;

const wc = @import("wchar");

pub fn width(s: []const u8) !usize {
    var w: usize = 0;
    var i: usize = 0;

    while (i < s.len) {
        const len = try unicode.utf8ByteSequenceLength(s[i]);
        const dec = try unicode.utf8Decode(s[i .. i + len]);

        const cw = wc.wcwidth(@intCast(dec));
        if (cw > 0) w += @intCast(cw);

        i += len;
    }

    return w;
}

test "strwidth" {
    try std.testing.expectEqual(16, width(
        \\      へ  ♡  ╱|、
    ));
    try std.testing.expectEqual(17, width(
        \\   ૮ -  ՛)  (` - 7
    ));
    try std.testing.expectEqual(18, width(
        \\    / ⁻ ៸|   |、⁻〵
    ));
    try std.testing.expectEqual(22, width(
        \\ 乀(ˍ, ل ل   じしˍ,)ノ
    ));
}