const std = @import("std");

const Allocator = std.mem.Allocator;
const ArrayList = std.ArrayList;
const CaseData = @import("CaseData");
const GenCatData = @import("GenCatData");
const Utf8View = std.unicode.Utf8View;

pub fn escapeXml(writer: anytype, text: []const u8) !void {
    for (text) |ch| {
        try switch (ch) {
            '<' => writer.writeAll("&lt;"),
            '>' => writer.writeAll("&gt;"),
            '&' => writer.writeAll("&amp;"),
            '"' => writer.writeAll("&quot;"),
            else => writer.writeByte(ch),
        };
    }
}

var gcd_global: ?GenCatData = null;

pub fn getGCD() !GenCatData {
    if (gcd_global) |gcd| {
        return gcd;
    }
    gcd_global = try GenCatData.init(std.heap.page_allocator);
    return gcd_global.?;
}

var cd_global: ?CaseData = null;

pub fn getCD() !CaseData {
    if (cd_global) |cd| {
        return cd;
    }
    cd_global = try CaseData.init(std.heap.page_allocator);
    return cd_global.?;
}

pub inline fn isNull(value: anytype) bool {
    return switch (@typeInfo(@TypeOf(value))) {
        .Null => true,
        .Optional => value == null,
        else => false,
    };
}

pub fn isTgWhitespaceStr(str: []const u8) !bool {
    const view = try Utf8View.init(str);
    const gcd = try getGCD();

    var it = view.iterator();
    while (it.nextCodepoint()) |cp| {
        if (!isTgWhitespace(gcd, cp)) {
            return false;
        }
    }

    return true;
}

inline fn isTgWhitespace(gcd: GenCatData, cp: u21) bool {
    return gcd.isSeparator(cp) or gcd.isControl(cp) or cp == 0x2800 // BRAILLE PATTERN BLANK, telegram treats messages with just this as invalid messages
    ;
}