path: root/src/assets.rs

use std::ffi::OsStr;
use std::fs;
use std::path::Path;

use once_cell::unsync::OnceCell;

use syntect::highlighting::Theme;
use syntect::parsing::{SyntaxReference, SyntaxSet};

use path_abs::PathAbs;

use crate::error::*;
use crate::input::{InputReader, OpenedInput};
use crate::syntax_mapping::ignored_suffixes::IgnoredSuffixes;
use crate::syntax_mapping::MappingTarget;
use crate::{bat_warning, SyntaxMapping};

use lazy_theme_set::LazyThemeSet;

use serialized_syntax_set::*;

#[cfg(feature = "build-assets")]
pub use crate::assets::build_assets::*;

pub(crate) mod assets_metadata;
#[cfg(feature = "build-assets")]
mod build_assets;
mod lazy_theme_set;
mod serialized_syntax_set;

#[derive(Debug)]
pub struct HighlightingAssets {
    syntax_set_cell: OnceCell<SyntaxSet>,
    serialized_syntax_set: SerializedSyntaxSet,

    theme_set: LazyThemeSet,
    fallback_theme: Option<&'static str>,
}

#[derive(Debug)]
pub struct SyntaxReferenceInSet<'a> {
    pub syntax: &'a SyntaxReference,
    pub syntax_set: &'a SyntaxSet,
}

/// Lazy-loaded syntaxes are already compressed, and we don't want to compress
/// already compressed data.
pub(crate) const COMPRESS_SYNTAXES: bool = false;

/// We don't want to compress our [LazyThemeSet] since the lazy-loaded themes
/// within it are already compressed, and compressing another time just makes
/// performance suffer
pub(crate) const COMPRESS_THEMES: bool = false;

/// Compress for size of ~40 kB instead of ~200 kB without much difference in
/// performance due to lazy-loading
pub(crate) const COMPRESS_LAZY_THEMES: bool = true;

/// Compress for size of ~10 kB instead of ~120 kB
pub(crate) const COMPRESS_ACKNOWLEDGEMENTS: bool = true;

impl HighlightingAssets {
    fn new(serialized_syntax_set: SerializedSyntaxSet, theme_set: LazyThemeSet) -> Self {
        HighlightingAssets {
            syntax_set_cell: OnceCell::new(),
            serialized_syntax_set,
            theme_set,
            fallback_theme: None,
        }
    }

    /// The default theme.
    ///
    /// ### Windows and Linux
    ///
    /// Windows and most Linux distributions has a dark terminal theme by
    /// default. On these platforms, this function always returns a theme that
    /// looks good on a dark background.
    ///
    /// ### macOS
    ///
    /// On macOS the default terminal background is light, but it is common that
    /// Dark Mode is active, which makes the terminal background dark. On this
    /// platform, the default theme depends on
    /// ```bash
    /// defaults read -globalDomain AppleInterfaceStyle
    /// ```
    /// To avoid the overhead of the check on macOS, simply specify a theme
    /// explicitly via `--theme`, `BAT_THEME`, or `~/.config/bat`.
    ///
    /// See <https://github.com/sharkdp/bat/issues/1746> and
    /// <https://github.com/sharkdp/bat/issues/1928> for more context.
    pub fn default_theme() -> &'static str {
        #[cfg(not(target_os = "macos"))]
        {
            Self::default_dark_theme()
        }
        #[cfg(target_os = "macos")]
        {
            if macos_dark_mode_active() {
                Self::default_dark_theme()
            } else {
                Self::default_light_theme()
            }
        }
    }

    /**
     * The default theme that looks good on a dark background.
     */
    fn default_dark_theme() -> &'static str {
        "Monokai Extended"
    }

    /**
     * The default theme that looks good on a light background.
     */
    #[cfg(target_os = "macos")]
    fn default_light_theme() -> &'static str {
        "Monokai Extended Light"
    }

    pub fn from_cache(cache_path: &Path) -> Result<Self> {
        Ok(HighlightingAssets::new(
            SerializedSyntaxSet::FromFile(cache_path.join("syntaxes.bin")),
            asset_from_cache(&cache_path.join("themes.bin"), "theme set", COMPRESS_THEMES)?,
        ))
    }

    pub fn from_binary() -> Self {
        HighlightingAssets::new(
            SerializedSyntaxSet::FromBinary(get_serialized_integrated_syntaxset()),
            get_integrated_themeset(),
        )
    }

    pub fn set_fallback_theme(&mut self, theme: &'static str) {
        self.fallback_theme = Some(theme);
    }

    /// Return the collection of syntect syntax definitions.
    pub fn get_syntax_set(&self) -> Result<&SyntaxSet> {
        self.syntax_set_cell
            .get_or_try_init(|| self.serialized_syntax_set.deserialize())
    }

    /// Use [Self::get_syntaxes] instead
    #[deprecated]
    pub fn syntaxes(&self) -> &[SyntaxReference] {
        self.get_syntax_set()
            .expect(".syntaxes() is deprecated, use .get_syntaxes() instead")
            .syntaxes()
    }

    pub fn get_syntaxes(&self) -> Result<&[SyntaxReference]> {
        Ok(self.get_syntax_set()?.syntaxes())
    }

    fn get_theme_set(&self) -> &LazyThemeSet {
        &self.theme_set
    }

    pub fn themes(&self) -> impl Iterator<Item = &str> {
        self.get_theme_set().themes()
    }

    /// Use [Self::get_syntax_for_path] instead
    #[deprecated]
    pub fn syntax_for_file_name(
        &self,
        file_name: impl AsRef<Path>,
        mapping: &SyntaxMapping,
    ) -> Option<&SyntaxReference> {
        self.get_syntax_for_path(file_name, mapping)
            .ok()
            .map(|syntax_in_set| syntax_in_set.syntax)
    }

    /// Detect the syntax based on, in order:
    ///  1. Syntax mappings with [MappingTarget::MapTo] and [MappingTarget::MapToUnknown]
    ///     (e.g. `/etc/profile` -> `Bourne Again Shell (bash)`)
    ///  2. The file name (e.g. `Dockerfile`)
    ///  3. Syntax mappings with [MappingTarget::MapExtensionToUnknown]
    ///     (e.g. `*.conf`)
    ///  4. The file name extension (e.g. `.rs`)
    ///
    /// When detecting syntax based on syntax mappings, the full path is taken
    /// into account. When detecting syntax based on file name, no regard is
    /// taken to the path of the file. Only the file name itself matters. When
    /// detecting syntax based on file name extension, only the file name
    /// extension itself matters.
    ///
    /// Returns [Error::UndetectedSyntax] if it was not possible detect syntax
    /// based on path/file name/extension (or if the path was mapped to
    /// [MappingTarget::MapToUnknown] or [MappingTarget::MapExtensionToUnknown]).
    /// In this case it is appropriate to fall back to other methods to detect
    /// syntax. Such as using the contents of the first line of the file.
    ///
    /// Returns [Error::UnknownSyntax] if a syntax mapping exist, but the mapped
    /// syntax does not exist.
    pub fn get_syntax_for_path(
        &self,
        path: impl AsRef<Path>,
        mapping: &SyntaxMapping,
    ) -> Result<SyntaxReferenceInSet> {
        let path = path.as_ref();

        let syntax_match = mapping.get_syntax_for(path);

        if let Some(MappingTarget::MapToUnknown) = syntax_match {
            return Err(Error::UndetectedSyntax(path.to_string_lossy().into()));
        }

        if let Some(MappingTarget::MapTo(syntax_name)) = syntax_match {
            return self
                .find_syntax_by_name(syntax_name)?
                .ok_or_else(|| Error::UnknownSyntax(syntax_name.to_owned()));
        }

        let file_name = path.file_name().unwrap_or_default();

        match (
            self.get_syntax_for_file_name(file_name, &mapping.ignored_suffixes)?,
            syntax_match,
        ) {
            (Some(syntax), _) => Ok(syntax),

            (_, Some(MappingTarget::MapExtensionToUnknown)) => {
                Err(Error::UndetectedSyntax(path.to_string_lossy().into()))
            }

            _ => self
                .get_syntax_for_file_extension(file_name, &mapping.ignored_suffixes)?
                .ok_or_else(