const std = @import("std");
const fmt = std.fmt;

pub const RGB = struct {
    r: u8,
    g: u8,
    b: u8,

    pub fn init(comptime string: []const u8) !RGB {
        std.debug.assert(string.len == 6 or string.len == 7);
        comptime var index: usize = 0;
        if (string[0] == '#') index += 1;
        return .{
            .r = try fmt.parseInt(u8, string[index .. index + 2], 16),
            .g = try fmt.parseInt(u8, string[index + 2 .. index + 4], 16),
            .b = try fmt.parseInt(u8, string[index + 4 .. index + 6], 16),
        };
    }
};

// pub const Default256 = [_]RGB{
//     RGB{ .r = 0, .g = 0, .b = 0 },
//     RGB{ .r = 204, .g = 4, .b = 3 },
//     RGB{ .r = 25, .g = 203, .b = 0 },
//     RGB{ .r = 206, .g = 203, .b = 0 },
//     RGB{ .r = 13, .g = 115, .b = 204 },
//     RGB{ .r = 203, .g = 30, .b = 209 },
//     RGB{ .r = 13, .g = 205, .b = 205 },
//     RGB{ .r = 221, .g = 221, .b = 221 },
// };

test "RGB init from string" {
    const red = try RGB.init("#ff0000");
    try std.testing.expectEqual(0xff, red.r);
    try std.testing.expectEqual(0x00, red.g);
    try std.testing.expectEqual(0x00, red.b);

    const green = try RGB.init("00ff00");
    try std.testing.expectEqual(0x00, green.r);
    try std.testing.expectEqual(0xff, green.g);
    try std.testing.expectEqual(0x00, green.b);

    const blue = try RGB.init("#0000ff");
    try std.testing.expectEqual(0x00, blue.r);
    try std.testing.expectEqual(0x00, blue.g);
    try std.testing.expectEqual(0xff, blue.b);

    try std.testing.expectError(fmt.ParseIntError.InvalidCharacter, RGB.init("xyzxyz"));
}