Format files and commits as OSC 8 hyperlinks

Closes #257

3 files changed, 127 insertions, 6 deletions

diff --git a/src/features/hyperlinks.rs b/src/features/hyperlinks.rs
new file mode 100644
index 00000000..8fc58e9f
--- /dev/null
+++ b/src/features/hyperlinks.rs
@@ -0,0 +1,88 @@
+use std::borrow::Cow;
+
+use lazy_static::lazy_static;
+use regex::{Captures, Regex};
+
+use crate::config::Config;
+use crate::features::OptionValueFunction;
+use crate::git_config_entry::{GitConfigEntry, GitRemoteRepo};
+
+pub fn make_feature() -> Vec<(String, OptionValueFunction)> {
+    builtin_feature!([
+        (
+            "hyperlinks",
+            bool,
+            None,
+            _opt => true
+        )
+    ])
+}
+
+pub fn format_commit_line_with_osc8_commit_hyperlink<'a>(
+    line: &'a str,
+    config: &Config,
+) -> Cow<'a, str> {
+    if let Some(GitConfigEntry::GitRemote(GitRemoteRepo::GitHubRepo(repo))) =
+        config.git_config_entries.get("remote.origin.url")
+    {
+        COMMIT_LINE_REGEX.replace(line, |captures: &Captures| {
+            format_commit_line_captures_with_osc8_commit_hyperlink(captures, repo)
+        })
+    } else {
+        Cow::from(line)
+    }
+}
+
+/// Create a file hyperlink to `path`, displaying `text`.
+pub fn format_osc8_file_hyperlink<'a>(
+    relative_path: &'a str,
+    line_number: Option<usize>,
+    text: &str,
+    config: &Config,
+) -> Cow<'a, str> {
+    if let Some(GitConfigEntry::Path(workdir)) = config.git_config_entries.get("delta.__workdir__")
+    {
+        let absolute_path = workdir.join(relative_path);
+        let mut url = config
+            .hyperlinks_file_link_format
+            .replace("{path}", &absolute_path.to_string_lossy());
+        if let Some(n) = line_number {
+            url = url.replace("{line}", &format!("{}", n))
+        } else {
+            url = url.replace("{line}", "")
+        };
+        Cow::from(format!(
+            "{osc}8;;{url}{st}{text}{osc}8;;{st}",
+            url = url,
+            text = text,
+            osc = "\x1b]",
+            st = "\x1b\\"
+        ))
+    } else {
+        Cow::from(relative_path)
+    }
+}
+
+lazy_static! {
+    static ref COMMIT_LINE_REGEX: Regex = Regex::new("(.* )([0-9a-f]{40})(.*)").unwrap();
+}
+
+fn format_commit_line_captures_with_osc8_commit_hyperlink<'a, 'b>(
+    captures: &'a Captures,
+    github_repo: &'b str,
+) -> String {
+    let commit = captures.get(2).unwrap().as_str();
+    format!(
+        "{prefix}{osc}8;;{url}{st}{commit}{osc}8;;{st}{suffix}",
+        url = format_github_commit_url(commit, github_repo),
+        commit = commit,
+        prefix = captures.get(1).unwrap().as_str(),
+        suffix = captures.get(3).unwrap().as_str(),
+        osc = "\x1b]",
+        st = "\x1b\\"
+    )
+}
+
+fn format_github_commit_url(commit: &str, github_repo: &str) -> String {
+    format!("https://github.com/{}/commit/{}", github_repo, commit)
+}
diff --git a/src/features/line_numbers.rs b/src/features/line_numbers.rs
index b1d9b5b0..1543f46d 100644
--- a/src/features/line_numbers.rs
+++ b/src/features/line_numbers.rs
@@ -6,6 +6,7 @@ use regex::Regex;
 
 use crate::config;
 use crate::delta::State;
+use crate::features::hyperlinks;
 use crate::features::side_by_side;
 use crate::features::OptionValueFunction;
 use crate::style::Style;
@@ -112,6 +113,8 @@ pub fn format_and_paint_line_numbers<'a>(
             line_numbers_data.hunk_max_line_number_width,
             &minus_style,
             &plus_style,
+            &line_numbers_data.plus_file,
+            config,
         ));
     }
 
@@ -124,6 +127,8 @@ pub fn format_and_paint_line_numbers<'a>(
             line_numbers_data.hunk_max_line_number_width,
             &minus_style,
             &plus_style,
+            &line_numbers_data.plus_file,
+            config,
         ));
     }
     formatted_numbers
@@ -155,6 +160,7 @@ pub struct LineNumbersData<'a> {
     pub hunk_minus_line_number: usize,
     pub hunk_plus_line_number: usize,
     pub hunk_max_line_number_width: usize,
+    pub plus_file: String,
 }
 
 // Although it's probably unusual, a single format string can contain multiple placeholders. E.g.
@@ -178,11 +184,12 @@ impl<'a> LineNumbersData<'a> {
             hunk_minus_line_number: 0,
             hunk_plus_line_number: 0,
             hunk_max_line_number_width: 0,
+            plus_file: "".to_string(),
         }
     }
 
     /// Initialize line number data for a hunk.
-    pub fn initialize_hunk(&mut self, line_numbers: Vec<(usize, usize)>) {
+    pub fn initialize_hunk(&mut self, line_numbers: Vec<(usize, usize)>, plus_file: String) {
         // Typically, line_numbers has length 2: an entry for the minus file, and one for the plus
         // file. In the case of merge commits, it may be longer.
         self.hunk_minus_line_number = line_numbers[0].0;
@@ -190,6 +197,7 @@ impl<'a> LineNumbersData<'a> {
         let hunk_max_line_number = line_numbers.iter().map(|(n, d)| n + d).max().unwrap();
         self.hunk_max_line_number_width =
             1 + (hunk_max_line_number as f64).log10().floor() as usize;
+        self.plus_file = plus_file;
     }
 }
 
@@ -233,6 +241,8 @@ fn format_and_paint_line_number_field<'a>(
     min_field_width: usize,
     minus_number_style: &Style,
     plus_number_style: &Style,
+    plus_file: &str,
+    config: &config::Config,
 ) -> Vec<ansi_term::ANSIGenericString<'a, str>> {
     let mut ansi_strings = Vec::new();
     let mut suffix = "";
@@ -251,11 +261,15 @@ fn format_and_paint_line_number_field<'a>(
                 minus_number,
                 alignment_spec,
                 width,
+                None,
+                config,
             ))),
             Some("np") => ansi_strings.push(plus_number_style.paint(format_line_number(
                 plus_number,
                 alignment_spec,
                 width,
+                Some(plus_file),
+                config,
             ))),
             None => {}
             Some(_) => unreachable!(),
@@ -267,15 +281,29 @@ fn format_and_paint_line_number_field<'a>(
 }
 
 /// Return line number formatted according to `alignment` and `width`.
-fn format_line_number(line_number: Option<usize>, alignment: &str, width: usize) -> String {
-    let n = line_number
-        .map(|n| format!("{}", n))
-        .unwrap_or_else(|| "".to_string());
-    match alignment {
+fn format_line_number(
+    line_number: Option<usize>,
+    alignment: &str,
+    width: usize,
+    plus_file: Option<&str>,
+    config: &config::Config,
+) -> String {
+    let format_n = |n| match alignment {
         "<" => format!("{0:<1$}", n, width),
         "^" => format!("{0:^1$}", n, width),
         ">" => format!("{0:>1$}", n, width),
         _ => unreachable!(),
+    };
+    match (line_number, config.hyperlinks, plus_file) {
+        (None, _, _) => format_n(""),
+        (Some(n), true, Some(file)) => hyperlinks::format_osc8_file_hyperlink(
+            file,
+            line_number,
+            &format_n(&n.to_string()),
+            config,
+        )
+        .to_string(),
+        (Some(n), _, _) => format_n(&n.to_string()),
     }
 }
 
diff --git a/src/features/mod.rs b/src/features/mod.rs
index 58599ea6..67dbd6ba 100644
--- a/src/features/mod.rs
+++ b/src/features/mod.rs
@@ -39,6 +39,10 @@ pub fn make_builtin_features() -> HashMap<String, BuiltinFeature> {
             diff_so_fancy::make_feature().into_iter().collect(),
         ),
         (
+            "hyperlinks".to_string(),
+            hyperlinks::make_feature().into_iter().collect(),
+        ),
+        (
             "line-numbers".to_string(),
             line_numbers::make_feature().into_iter().collect(),
         ),
@@ -81,6 +85,7 @@ macro_rules! builtin_feature {
 pub mod color_only;
 pub mod diff_highlight;
 pub mod diff_so_fancy;
+pub mod hyperlinks;
 pub mod line_numbers;
 pub mod navigate;
 pub mod raw;