//! Helper function collection to provide ascii encodings for styling outputs.
//! Stylings are implemented such that they can be nested in anyway to support
//! multiple styles (i.e. bold and italic).
//!
//! Stylings however also include highlighting for specific terminal capabilities.
//! For example url highlighting.

// taken from https://github.com/rockorager/libvaxis/blob/main/src/Cell.zig (MIT-License)
// with slight modifications

fg: Color = .default,
bg: Color = .default,
ul: Color = .default,
cursor: bool = false,
ul_style: Underline = .off,
emphasis: []const Emphasis,

pub const Underline = enum {
    off,
    single,
    double,
    curly,
    dotted,
    dashed,
};

pub const Emphasis = enum(u8) {
    reset = 0,
    bold = 1,
    dim,
    italic,
    underline,
    blink,
    invert = 7,
    hidden,
    strikethrough,
};

pub fn eql(this: Style, other: Style) bool {
    return meta.eql(this, other);
}

pub fn value(this: Style, writer: *std.Io.Writer, cp: u21) !void {
    var buffer: [4]u8 = undefined;
    const bytes = try unicode.utf8Encode(cp, &buffer);
    assert(bytes > 0);
    // build ansi sequence for 256 colors ...
    // foreground
    try writer.printAscii("\x1b[", .{});
    try this.fg.write(writer, .fg);
    // background
    try writer.printAsciiChar(';', .{});
    try this.bg.write(writer, .bg);
    // underline
    // FIX assert that if the underline property is set that the ul style and the attribute for underlining is available
    try writer.printAsciiChar(';', .{});
    try this.ul.write(writer, .ul);
    // append styles (aka attributes like bold, italic, strikethrough, etc.)
    for (this.emphasis) |attribute| try writer.print(";{d}", .{@intFromEnum(attribute)});
    try writer.printAsciiChar('m', .{});
    // content
    try writer.printAscii(buffer[0..bytes], .{});
    try writer.printAscii("\x1b[0m", .{});
}

// TODO implement helper functions for terminal capabilities:
// - links / url display (osc 8)
// - show / hide cursor?

const std = @import("std");
const unicode = std.unicode;
const meta = std.meta;
const assert = std.debug.assert;
const Color = @import("color.zig").Color;
const Style = @This();