1use comfy_table::{Attribute, Cell, Color};
 2use std::io::IsTerminal;
 3
 4pub struct Theme {
 5    pub red: &'static str,
 6    pub green: &'static str,
 7    pub yellow: &'static str,
 8    pub blue: &'static str,
 9    pub bold: &'static str,
10    pub reset: &'static str,
11}
12
13const ON: Theme = Theme {
14    red: "\x1b[31m",
15    green: "\x1b[32m",
16    yellow: "\x1b[33m",
17    blue: "\x1b[34m",
18    bold: "\x1b[1m",
19    reset: "\x1b[0m",
20};
21
22const OFF: Theme = Theme {
23    red: "",
24    green: "",
25    yellow: "",
26    blue: "",
27    bold: "",
28    reset: "",
29};
30
31fn use_color(is_tty: bool) -> bool {
32    std::env::var_os("NO_COLOR").is_none() && is_tty
33}
34
35/// Colour theme for stdout.
36pub fn stdout_theme() -> &'static Theme {
37    if use_color(std::io::stdout().is_terminal()) {
38        &ON
39    } else {
40        &OFF
41    }
42}
43
44/// Colour theme for stderr.
45pub fn stderr_theme() -> &'static Theme {
46    if use_color(std::io::stderr().is_terminal()) {
47        &ON
48    } else {
49        &OFF
50    }
51}
52
53/// Whether stdout should use colour.
54pub fn stdout_use_color() -> bool {
55    use_color(std::io::stdout().is_terminal())
56}
57
58/// A table cell with bold text.
59pub fn cell_bold(text: impl ToString, use_color: bool) -> Cell {
60    let cell = Cell::new(text);
61    if use_color {
62        cell.add_attribute(Attribute::Bold)
63    } else {
64        cell
65    }
66}
67
68/// A table cell with a coloured foreground.
69pub fn cell_fg(text: impl ToString, color: Color, use_color: bool) -> Cell {
70    let cell = Cell::new(text);
71    if use_color {
72        cell.fg(color)
73    } else {
74        cell
75    }
76}