path: root/src/cli.rs

use std::collections::{HashMap, HashSet};
#[cfg(test)]
use std::ffi::OsString;
use std::path::PathBuf;

use lazy_static::lazy_static;
use structopt::clap::AppSettings::{ColorAlways, ColoredHelp, DeriveDisplayOrder};
use structopt::{clap, StructOpt};
use syntect::highlighting::Theme as SyntaxTheme;
use syntect::parsing::SyntaxSet;

use crate::bat_utils::assets::HighlightingAssets;
use crate::bat_utils::output::PagingMode;
use crate::git_config::{GitConfig, GitConfigEntry};
use crate::options;

#[derive(StructOpt, Clone, Default)]
#[structopt(
    name = "delta",
    about = "A viewer for git and diff output",
    setting(ColorAlways),
    setting(ColoredHelp),
    setting(DeriveDisplayOrder),
    after_help = "\
GIT CONFIG
----------

By default, delta takes settings from a section named \"delta\" in git config files, if one is
present. The git config file to use for delta options will usually be ~/.gitconfig, but delta
follows the rules given in https://git-scm.com/docs/git-config#FILES. Most delta options can be
given in a git config file, using the usual option names but without the initial '--'. An example
is

[delta]
    line-numbers = true
    zero-style = dim syntax

FEATURES
--------
A feature is a named collection of delta options in git config. An example is:

[delta \"my-delta-feature\"]
    syntax-theme = Dracula
    plus-style = bold syntax \"#002800\"

To activate those options, you would use:

delta --features my-delta-feature

A feature name may not contain whitespace. You can activate multiple features:

[delta]
    features = my-highlight-styles-colors-feature my-line-number-styles-feature

If more than one feature sets the same option, the last one wins.

STYLES
------

All options that have a name like --*-style work the same way. It is very similar to how
colors/styles are specified in a gitconfig file:
https://git-scm.com/docs/git-config#Documentation/git-config.txt-color

Here is an example:

--minus-style 'red bold ul \"#ffeeee\"'

That means: For removed lines, set the foreground (text) color to 'red', make it bold and
            underlined, and set the background color to '#ffeeee'.

See the COLORS section below for how to specify a color. In addition to real colors, there are 4
special color names: 'auto', 'normal', 'raw', and 'syntax'.

Here is an example of using special color names together with a single attribute:

--minus-style 'syntax bold auto'

That means: For removed lines, syntax-highlight the text, and make it bold, and do whatever delta
            normally does for the background.

The available attributes are: 'blink', 'bold', 'dim', 'hidden', 'italic', 'reverse', 'strike',
and 'ul' (or 'underline').

The attribute 'omit' is supported by commit-style, file-style, and hunk-header-style, meaning to
remove the element entirely from the output.

A complete description of the style string syntax follows:

- If the input that delta is receiving already has colors, and you want delta to output those
  colors unchanged, then use the special style string 'raw'. Otherwise, delta will strip any colors
  from its input.

- A style string consists of 0, 1, or 2 colors, together with an arbitrary number of style
  attributes, all separated by spaces.

- The first color is the foreground (text) color. The second color is the background color.
  Attributes can go in any position.

- This means that in order to specify a background color you must also specify a foreground (text)
  color.

- If you want delta to choose one of the colors automatically, then use the special color 'auto'.
  This can be used for both foreground and background.

- If you want the foreground/background color to be your terminal's foreground/background color,
  then use the special color 'normal'.

- If you want the foreground text to be syntax-highlighted according to its language, then use the
  special foreground color 'syntax'. This can only be used for the foreground (text).

- The minimal style specification is the empty string ''. This means: do not apply any colors or
  styling to the element in question.

COLORS
------

There are three ways to specify a color (this section applies to foreground and background colors
within a style string):

1. RGB hex code

   An example of using an RGB hex code is:
   --file-style=\"#0e7c0e\"

2. ANSI color name

   There are 8 ANSI color names:
   black, red, green, yellow, blue, magenta, cyan, white.

   In addition, all of them have a bright form:
   brightblack, brightred, brightgreen, brightyellow, brightblue, brightmagenta, brightcyan, brightwhite.

   An example of using an ANSI color name is:
   --file-style=\"green\"

   Unlike RGB hex codes, ANSI color names are just names: you can choose the exact color that each
   name corresponds to in the settings of your terminal application (the application you use to
   enter commands at a shell prompt). This means that if you use ANSI color names, and you change
   the color theme used by your terminal, then delta's colors will respond automatically, without
   needing to change the delta command line.

   \"purple\" is accepted as a synonym for \"magenta\". Color names and codes are case-insensitive.

3. ANSI color number

   An example of using an ANSI color number is:
   --file-style=28

   There are 256 ANSI color numbers: 0-255. The first 16 are the same as the colors described in
   the \"ANSI color name\" section above. See https://en.wikipedia.org/wiki/ANSI_escape_code#8-bit.
   Specifying colors like this is useful if your terminal only supports 256 colors (i.e. doesn\'t
   support 24-bit color).


LINE NUMBERS
------------

To display line numbers, use --line-numbers.

Line numbers are displayed in two columns. Here's what it looks like by default:

 1  ⋮ 1  │ unchanged line
 2  ⋮    │ removed line
    ⋮ 2  │ added line

In that output, the line numbers for the old (minus) version of the file appear in the left column,
and the line numbers for the new (plus) version of the file appear in the right column. In an
unchanged (zero) line, both columns contain a line number.

The following options allow the line number display to be customized:

--line-numbers-left-format:  Change the contents of the left column
--line-numbers-right-format: Change the contents of the right column
--line-numbers-left-style:   Change the style applied to the left column
--line-numbers-right-style:  Change the style applied to the right column
--line-numbers-minus-style:  Change the style applied to line numbers in minus lines
--line-numbers-zero-style:   Change the style applied to line numbers in unchanged lines
--line-numbers-plus-style:   Change the style applied to line numbers in plus lines

Options --line-numbers-left-format and --line-numbers-right-format allow you to change the contents
of the line number columns. Their values are arbitrary format strings, which are allowed to contain
the placeholders {nm} for the line number associated with the old version of the file and {np} for
the line number associated with the new version of the file. The placeholders support a subset of
the string formatting syntax documented here: https://doc.rust-lang.org/std/fmt/#formatting-parameters.
Specifically, you can use the alignment and width syntax.

For example, the default value of --line-numbers-left-format is '{nm:^4}⋮'. This means that the
left column should display the minus line number (nm), center-aligned, padded with spaces to a
width of 4 characters, followed by a unicode dividing-line character (⋮).

Similarly, the default value of --line-numbers-right-format is '{np:^4}│'. This means that the
right column should display the plus line number (np), center-aligned, padded with spaces to a
width of 4 characters, followed by a unicode dividing-line character (│).

Use '<' for left-align, '^' for center-align, and '>' for right-align.


If something isn't working correctly, or you have a feature request, please open an issue at
https://github.com/dandavison/delta/issues.
"
)]
pub struct Opt {
    /// Use default colors appropriate for a light terminal background. For more control, see the
    /// style options and --syntax-theme.
    #[structopt(long = "light")]
    pub light: bool,

    /// Use default colors appropriate for a dark terminal background. For more control, see the
    /// style options and --syntax-theme.
    #[structopt(long = "dark")]
    pub dark: bool,

    /// Display line numbers next to the diff. See LINE NUMBERS section.
    #[structopt(short = "n", long = "line-numbers")]
    pub line_numbers: bool,

    /// Display a side-by-side diff view instead of the traditional view.
    #[structopt(short = "s", long = "side-by-side")]
    pub side_by_side: bool,

    #[structopt(long = "diff-highlight")]
    /// Emulate diff-highlight (https://github.com/git/git/tree/master/contrib/diff-highlight)
    pub diff_highlight: bool,

    #[structopt(long = "diff-so-fancy")]
    /// Emulate diff-so-fancy (https://github.com/so-fancy/diff-so-fancy)
    pub diff_so_fancy: bool,

    #[structopt(long = "navigate")]
    /// Activate diff navigation: use n to jump forwards and N to jump backwards. To change the
    /// file labels used see --file-modified-label, --file-removed-label, --file-added-label,
    /// --file-renamed-label.
    pub navigate: bool,

    #[structopt(long = "hyperlinks")]
    /// Render commit hashes, file names, and line numbers as hyperlinks, according to the
    /// hyperlink spec for terminal emulators:
    /// https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda. By default, file names
    /// and line numbers link to the local file using a file URL, whereas commit hashes link to the
    /// commit in GitHub, if the remote repository is hosted by GitHub. See
    /// --hyperlinks-file-link-format for full control over the file URLs emitted. Hyperlinks are
    /// supported by several common terminal emulators. To make them work, you must pass the -r (as
    /// opposed to -R) flag to less, e.g. via `export DELTA_PAGER=less -rX`. If you use tmux, then
    /// you will also need a patched fork of tmux (see https://github.com/dandavison/tmux).
    pub hyperlinks: bool,

    #[structopt(long = "keep-plus-minus-markers")]
    /// Prefix added/removed lines with a +/- character, exactly as git does. By default, delta
    /// does not emit any prefix, so code can be copied directly from delta's output.
    pub keep_plus_minus_markers: bool,

    /// Display the active values for all Delta options. Style options are displayed with
    /// foreground and background colors. This can be used to experiment with colors by combining
    /// this option with other options such as --minus-style, --zero-style, --plus-style, --light,
    /// --dark, etc.
    #[structopt(long = "show-config")]
    pub show_config: bool,

    /// List supported languages and associated file extensions.
    #[structopt(long = "list-languages")]
    pub list_languages: bool,

    /// List available syntax-highlighting color themes.
    #[structopt(long = "list-syntax-themes")]
    pub list_syntax_themes: bool,

    /// Show all available syntax-highlighting themes, each with an example of highlighted diff output.
    /// If diff output is supplied on standard input then this will be used for the demo. For
    /// example: `git show --color=always | delta --show-syntax-themes`.
    #[structopt(long = "show-syntax-themes")]
    pub show_syntax_themes: bool,

    #[structopt(long = "no-gitconfig")]
    /// Do not take any settings from git config. See GIT CONFIG section.
    pub no_gitconfig: bool,

    #[structopt(long = "raw")]
    /// Do not alter the input in any way. This is mainly intended for testing delta.
    pub raw: bool,

    #[structopt(long = "color-only")]
    /// Do not alter the input structurally in any way, but color and highlight hunk lines
    /// according to your delta configuration. This is mainly intended for other tools that use
    /// delta.
    pub color_only: bool,

    ////////////////////////////////////////////////////////////////////////////////////////////
    #[structopt(long = "features", default_value = "", env = "DELTA_FEATURES")]
    /// Name of delta features to use (space-separated). A feature is a named collection of delta
    /// options in ~/.gitconfig. See FEATURES section.
    pub features: String,

    #[structopt(long = "syntax-theme", env = "BAT_THEME")]
    /// The code syntax-highlighting theme to use. Use --show-syntax-themes to demo available
    /// themes. If the syntax-highlighting theme is not set using this option, it will be taken
    /// from the BAT_THEME environment variable, if that contains a valid theme name.
    /// --syntax-theme=none disables all syntax highlighting.
    pub syntax_theme: Option<String>,

    #[structopt(long = "minus-style", default_value = "normal auto")]
    /// Style (foreground, background, attributes) for removed lines. See STYLES section.
    pub minus_style: String,

    #[structopt(long = "zero-style", default_value = "syntax normal")]
    /// Style (foreground, background, attributes) for unchanged li