From 42d0ac7775eb7a9dc802fbe2b8bc25b7ad77a81d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Orhun=20Parmaks=C4=B1z?= <orhunparmaksiz@gmail.com>
Date: Sun, 1 Dec 2024 23:14:17 +0300
Subject: [PATCH] refactor(tui): separate the changelog generate/write logic

---
 git-cliff-core/src/changelog.rs | 46 +++++++++++---------
 git-cliff-core/src/template.rs  |  2 +-
 git-cliff-tui/src/event.rs      | 10 +++--
 git-cliff-tui/src/main.rs       | 72 +++++++++++++++----------------
 git-cliff-tui/src/state.rs      | 54 ++++++++++++++++++++---
 git-cliff/src/lib.rs            | 76 ++++++++++++++++++---------------
 git-cliff/src/main.rs           | 26 +++++++++--
 7 files changed, 183 insertions(+), 103 deletions(-)

diff --git a/git-cliff-core/src/changelog.rs b/git-cliff-core/src/changelog.rs
index 86a8e20300..328a3697da 100644
--- a/git-cliff-core/src/changelog.rs
+++ b/git-cliff-core/src/changelog.rs
@@ -28,31 +28,30 @@ use std::time::{
 };
 
 /// Changelog generator.
-#[derive(Debug)]
+#[derive(Clone, Debug)]
 pub struct Changelog<'a> {
 	/// Releases that the changelog will contain.
 	pub releases:       Vec<Release<'a>>,
+	/// Configuration.
+	pub config:         Config,
 	header_template:    Option<Template>,
 	body_template:      Template,
 	footer_template:    Option<Template>,
-	config:             &'a Config,
 	additional_context: HashMap<String, serde_json::Value>,
 }
 
 impl<'a> Changelog<'a> {
 	/// Constructs a new instance.
-	pub fn new(releases: Vec<Release<'a>>, config: &'a Config) -> Result<Self> {
-		let mut changelog = Changelog::build(releases, config)?;
-		changelog.add_remote_data()?;
-		changelog.process_commits();
-		changelog.process_releases();
-		Ok(changelog)
-	}
-
-	/// Builds a changelog from releases and config.
-	fn build(releases: Vec<Release<'a>>, config: &'a Config) -> Result<Self> {
+	///
+	/// Processes the commits/releases and fetches the remote data
+	/// if `process_data` is set to `true`.
+	pub fn new(
+		releases: Vec<Release<'a>>,
+		config: Config,
+		process_data: bool,
+	) -> Result<Self> {
 		let trim = config.changelog.trim.unwrap_or(true);
-		Ok(Self {
+		let mut changelog = Self {
 			releases,
 			header_template: match &config.changelog.header {
 				Some(header) => {
@@ -60,7 +59,7 @@ impl<'a> Changelog<'a> {
 				}
 				None => None,
 			},
-			body_template: get_body_template(config, trim)?,
+			body_template: get_body_template(&config, trim)?,
 			footer_template: match &config.changelog.footer {
 				Some(footer) => {
 					Some(Template::new("footer", footer.to_string(), trim)?)
@@ -69,12 +68,18 @@ impl<'a> Changelog<'a> {
 			},
 			config,
 			additional_context: HashMap::new(),
-		})
+		};
+		if process_data {
+			changelog.add_remote_data()?;
+			changelog.process_commits();
+			changelog.process_releases();
+		}
+		Ok(changelog)
 	}
 
 	/// Constructs an instance from a serialized context object.
-	pub fn from_context<R: Read>(input: &mut R, config: &'a Config) -> Result<Self> {
-		Changelog::build(serde_json::from_reader(input)?, config)
+	pub fn from_context<R: Read>(input: &mut R, config: Config) -> Result<Self> {
+		Changelog::new(serde_json::from_reader(input)?, config, false)
 	}
 
 	/// Adds a key value pair to the template context.
@@ -431,6 +436,7 @@ impl<'a> Changelog<'a> {
 
 	/// Adds information about the remote to the template context.
 	pub fn add_remote_context(&mut self) -> Result<()> {
+		debug!("Adding remote context...");
 		self.additional_context.insert(
 			"remote".to_string(),
 			serde_json::to_value(self.config.remote.clone())?,
@@ -1024,7 +1030,7 @@ mod test {
 	#[test]
 	fn changelog_generator() -> Result<()> {
 		let (config, releases) = get_test_data();
-		let mut changelog = Changelog::new(releases, &config)?;
+		let mut changelog = Changelog::new(releases, config, true)?;
 		changelog.bump_version()?;
 		changelog.releases[0].timestamp = 0;
 		let mut out = Vec::new();
@@ -1143,7 +1149,7 @@ chore(deps): fix broken deps
 ",
 			),
 		));
-		let changelog = Changelog::new(releases, &config)?;
+		let changelog = Changelog::new(releases, config, true)?;
 		let mut out = Vec::new();
 		changelog.generate(&mut out)?;
 		assert_eq!(
@@ -1247,7 +1253,7 @@ chore(deps): fix broken deps
 				{% endfor %}{% endfor %}"#
 				.to_string(),
 		);
-		let mut changelog = Changelog::new(releases, &config)?;
+		let mut changelog = Changelog::new(releases, config, true)?;
 		changelog.add_context("custom_field", "Hello")?;
 		let mut out = Vec::new();
 		changelog.generate(&mut out)?;
diff --git a/git-cliff-core/src/template.rs b/git-cliff-core/src/template.rs
index 0d280082a3..1d43b985d4 100644
--- a/git-cliff-core/src/template.rs
+++ b/git-cliff-core/src/template.rs
@@ -20,7 +20,7 @@ use tera::{
 };
 
 /// Wrapper for [`Tera`].
-#[derive(Debug)]
+#[derive(Clone, Debug)]
 pub struct Template {
 	/// Template name.
 	name:          String,
diff --git a/git-cliff-tui/src/event.rs b/git-cliff-tui/src/event.rs
index 46f50c9092..4d113051e6 100644
--- a/git-cliff-tui/src/event.rs
+++ b/git-cliff-tui/src/event.rs
@@ -122,17 +122,21 @@ pub fn handle_key_events(
 		KeyCode::Char('c') | KeyCode::Char('C') => {
 			if key_event.modifiers == KeyModifiers::CONTROL {
 				state.quit();
-			} else if let Some(clipboard) = &mut state.clipboard {
-				if let Err(e) = clipboard.set_contents(state.changelog.clone()) {
-					eprintln!("Failed to set clipboard contents: {e}");
+			} else if let Some(contents) = state.get_changelog_contents()? {
+				if let Some(clipboard) = &mut state.clipboard {
+					if let Err(e) = clipboard.set_contents(contents) {
+						eprintln!("Failed to set clipboard contents: {e}");
+					}
 				}
 			}
 		}
 		KeyCode::Char('k') | KeyCode::Char('K') | KeyCode::Up => {
 			state.list_state.select_previous();
+			state.process_changelog()?;
 		}
 		KeyCode::Char('j') | KeyCode::Char('J') | KeyCode::Down => {
 			state.list_state.select_next();
+			state.process_changelog()?;
 		}
 		KeyCode::Char('h') | KeyCode::Char('H') | KeyCode::Left => {
 			state.markdown.scroll_index =
diff --git a/git-cliff-tui/src/main.rs b/git-cliff-tui/src/main.rs
index e32bbc5295..5f390d7f9d 100644
--- a/git-cliff-tui/src/main.rs
+++ b/git-cliff-tui/src/main.rs
@@ -1,9 +1,6 @@
-use std::{
-	path::{
-		Path,
-		PathBuf,
-	},
-	thread,
+use std::path::{
+	Path,
+	PathBuf,
 };
 
 use crate::{
@@ -60,6 +57,9 @@ fn main() -> Result<()> {
 		}
 	}
 
+	// Generate the changelog.
+	state.generate_changelog()?;
+
 	// Initialize the terminal user interface.
 	let events = EventHandler::new(250);
 	let mut terminal = ratatui::init();
@@ -104,37 +104,37 @@ fn main() -> Result<()> {
 			Event::Mouse(_) => {}
 			Event::Resize(_, _) => {}
 			Event::Generate | Event::AutoGenerate => {
-				if event == Event::AutoGenerate && !state.autoload {
-					continue;
-				}
-				let sender = events.sender.clone();
-				let args = state.args.clone();
-				state.is_generating = true;
-				state.args.config = PathBuf::from(
-					state.configs[state.list_state.selected().unwrap_or_default()]
-						.file
-						.clone(),
-				);
-				thread::spawn(move || {
-					let mut output = Vec::new();
-					sender
-						.send(match git_cliff::run(args, &mut output) {
-							Ok(()) => Event::RenderMarkdown(
-								String::from_utf8_lossy(&output).to_string(),
-							),
-							Err(e) => Event::Error(e.to_string()),
-						})
-						.expect("failed to send event");
-				});
+				// if event == Event::AutoGenerate && !state.autoload {
+				// 	continue;
+				// }
+				// let sender = events.sender.clone();
+				// let args = state.args.clone();
+				// state.is_generating = true;
+				// state.args.config = PathBuf::from(
+				// 	state.configs[state.list_state.selected().
+				// unwrap_or_default()] 		.file
+				// 		.clone(),
+				// );
+				// thread::spawn(move || {
+				// 	let mut output = Vec::new();
+				// 	sender
+				// 		.send(match git_cliff::run(args, &mut output) {
+				// 			Ok(()) => Event::RenderMarkdown(
+				// 				String::from_utf8_lossy(&output).to_string(),
+				// 			),
+				// 			Err(e) => Event::Error(e.to_string()),
+				// 		})
+				// 		.expect("failed to send event");
+				// });
 			}
-			Event::RenderMarkdown(changelog) => {
-				state.is_generating = false;
-				state.changelog = changelog;
-				state.markdown.component = Some(md_tui::parser::parse_markdown(
-					None,
-					&state.changelog,
-					state.markdown.area.width,
-				));
+			Event::RenderMarkdown(_) => {
+				// state.is_generating = false;
+				// state.changelog = changelog;
+				// state.markdown.component =
+				// Some(md_tui::parser::parse_markdown( 	None,
+				// 	&state.changelog,
+				// 	state.markdown.area.width,
+				// ));
 			}
 			Event::Error(e) => {
 				state.error = Some(e);
diff --git a/git-cliff-tui/src/state.rs b/git-cliff-tui/src/state.rs
index e5a7d00217..c517b6ecd7 100644
--- a/git-cliff-tui/src/state.rs
+++ b/git-cliff-tui/src/state.rs
@@ -1,5 +1,6 @@
 use copypasta::ClipboardContext;
 use git_cliff::args::Args;
+use git_cliff::core::changelog::Changelog;
 use git_cliff::core::embed::BuiltinConfig;
 use md_tui::nodes::root::ComponentRoot;
 use ratatui::layout::Rect;
@@ -32,7 +33,7 @@ pub struct Markdown {
 
 /// Is the application running?
 /// Application state.
-pub struct State {
+pub struct State<'a> {
 	/// git-cliff arguments.
 	pub args:           Args,
 	/// Is the application running?
@@ -41,8 +42,8 @@ pub struct State {
 	pub configs:        Vec<Config>,
 	/// The state of the list.
 	pub list_state:     ListState,
-	/// Changelog contents.
-	pub changelog:      String,
+	/// Changelog.
+	pub changelog:      Option<Changelog<'a>>,
 	/// Error message.
 	pub error:          Option<String>,
 	/// Rendered markdown.
@@ -59,7 +60,7 @@ pub struct State {
 	pub is_generating:  bool,
 }
 
-impl State {
+impl<'a> State<'a> {
 	/// Constructs a new instance.
 	pub fn new(args: Args) -> Result<Self> {
 		let configs = BuiltinConfig::iter()
@@ -78,7 +79,7 @@ impl State {
 				list_state.select_first();
 				list_state
 			},
-			changelog: String::new(),
+			changelog: None,
 			error: None,
 			markdown: Markdown::default(),
 			autoload: true,
@@ -93,6 +94,49 @@ impl State {
 		})
 	}
 
+	/// Generates the changelog.
+	pub fn generate_changelog(&mut self) -> Result<()> {
+		self.changelog = Some(git_cliff::generate_changelog(&mut self.args)?);
+		Ok(())
+	}
+
+	/// Returns the changelog contents.
+	pub fn get_changelog_contents(&mut self) -> Result<Option<String>> {
+		if let Some(changelog) = &self.changelog {
+			let config = git_cliff::core::embed::BuiltinConfig::parse(
+				self.configs[self.list_state.selected().unwrap_or_default()]
+					.file
+					.clone(),
+			)?
+			.0;
+			let changelog =
+				Changelog::new(changelog.releases.clone(), config.clone(), false)?;
+			let mut output = Vec::new();
+			git_cliff::write_changelog(
+				self.args.clone(),
+				changelog.clone(),
+				&mut output,
+			)?;
+			let contents = String::from_utf8(output)?;
+			self.changelog = Some(changelog);
+			Ok(Some(contents))
+		} else {
+			Ok(None)
+		}
+	}
+
+	/// Processes the changelog contents.
+	pub fn process_changelog(&mut self) -> Result<()> {
+		if let Some(contents) = &self.get_changelog_contents()? {
+			self.markdown.component = Some(md_tui::parser::parse_markdown(
+				None,
+				&contents,
+				self.markdown.area.width,
+			));
+		}
+		Ok(())
+	}
+
 	/// Handles the tick event of the terminal.
 	pub fn tick(&mut self) {
 		if self.is_generating {
diff --git a/git-cliff/src/lib.rs b/git-cliff/src/lib.rs
index b38fb3792b..4b3ce1bb2b 100644
--- a/git-cliff/src/lib.rs
+++ b/git-cliff/src/lib.rs
@@ -58,7 +58,7 @@ use std::time::{
 
 /// Checks for a new version on crates.io
 #[cfg(feature = "update-informer")]
-fn check_new_version() {
+pub fn check_new_version() {
 	use update_informer::Check;
 	let pkg_name = env!("CARGO_PKG_NAME");
 	let pkg_version = env!("CARGO_PKG_VERSION");
@@ -77,6 +77,21 @@ fn check_new_version() {
 	}
 }
 
+/// Initializes the configuration file.
+pub fn init_config(name: Option<String>) -> Result<()> {
+	let contents = match name {
+		Some(ref name) => BuiltinConfig::get_config(name.to_string())?,
+		None => EmbeddedConfig::get_config()?,
+	};
+	info!(
+		"Saving the configuration file{} to {:?}",
+		name.map(|v| format!(" ({v})")).unwrap_or_default(),
+		DEFAULT_CONFIG
+	);
+	fs::write(DEFAULT_CONFIG, contents)?;
+	return Ok(());
+}
+
 /// Processes the tags and commits for creating release entries for the
 /// changelog.
 ///
@@ -350,34 +365,15 @@ fn process_repository<'a>(
 	Ok(releases)
 }
 
-/// Runs `git-cliff`.
-pub fn run<W: io::Write>(mut args: Args, mut out: W) -> Result<()> {
-	// Check if there is a new version available.
-	#[cfg(feature = "update-informer")]
-	check_new_version();
-
-	// Create the configuration file if init flag is given.
-	if let Some(init_config) = args.init {
-		let contents = match init_config {
-			Some(ref name) => BuiltinConfig::get_config(name.to_string())?,
-			None => EmbeddedConfig::get_config()?,
-		};
-		info!(
-			"Saving the configuration file{} to {:?}",
-			init_config.map(|v| format!(" ({v})")).unwrap_or_default(),
-			DEFAULT_CONFIG
-		);
-		fs::write(DEFAULT_CONFIG, contents)?;
-		return Ok(());
-	}
-
+/// Processes the command-line arguments and generates the changelog.
+pub fn generate_changelog(args: &mut Args) -> Result<Changelog<'static>> {
 	// Retrieve the built-in configuration.
 	let builtin_config =
 		BuiltinConfig::parse(args.config.to_string_lossy().to_string());
 
 	// Set the working directory.
 	if let Some(ref workdir) = args.workdir {
-		args.config = workdir.join(args.config);
+		args.config = workdir.join(&args.config);
 		match args.repository.as_mut() {
 			Some(repository) => {
 				repository
@@ -386,7 +382,7 @@ pub fn run<W: io::Write>(mut args: Args, mut out: W) -> Result<()> {
 			}
 			None => args.repository = Some(vec![workdir.clone()]),
 		}
-		if let Some(changelog) = args.prepend {
+		if let Some(changelog) = &args.prepend {
 			args.prepend = Some(workdir.join(changelog));
 		}
 	}
@@ -424,7 +420,6 @@ pub fn run<W: io::Write>(mut args: Args, mut out: W) -> Result<()> {
 	}
 
 	// Update the configuration based on command line arguments and vice versa.
-	let output = args.output.clone().or(config.changelog.output.clone());
 	match args.strip {
 		Some(Strip::Header) => {
 			config.changelog.header = None;
@@ -446,6 +441,8 @@ pub fn run<W: io::Write>(mut args: Args, mut out: W) -> Result<()> {
 			)));
 		}
 	}
+
+	let output = args.output.clone().or(config.changelog.output.clone());
 	if output.is_some() &&
 		args.prepend.is_some() &&
 		output.as_ref() == args.prepend.as_ref()
@@ -544,13 +541,13 @@ pub fn run<W: io::Write>(mut args: Args, mut out: W) -> Result<()> {
 	}
 
 	// Generate changelog from context.
-	let mut changelog: Changelog = if let Some(context_path) = args.from_context {
+	let changelog: Changelog = if let Some(context_path) = &args.from_context {
 		let mut input: Box<dyn io::Read> = if context_path == Path::new("-") {
 			Box::new(io::stdin())
 		} else {
 			Box::new(File::open(context_path)?)
 		};
-		let mut changelog = Changelog::from_context(&mut input, &config)?;
+		let mut changelog = Changelog::from_context(&mut input, config)?;
 		changelog.add_remote_context()?;
 		changelog
 	} else {
@@ -592,10 +589,22 @@ pub fn run<W: io::Write>(mut args: Args, mut out: W) -> Result<()> {
 				&args,
 			)?);
 		}
-		Changelog::new(releases, &config)?
+		Changelog::new(releases, config.clone(), true)?
 	};
 
-	// Print the result.
+	Ok(changelog)
+}
+
+/// Writes the changelog to a file.
+pub fn write_changelog<W: io::Write>(
+	args: Args,
+	mut changelog: Changelog<'_>,
+	mut out: W,
+) -> Result<()> {
+	let output = args
+		.output
+		.clone()
+		.or(changelog.config.changelog.output.clone());
 	if args.bump.is_some() || args.bumped_version {
 		let next_version = if let Some(next_version) = changelog.bump_version()? {
 			next_version
@@ -605,7 +614,7 @@ pub fn run<W: io::Write>(mut args: Args, mut out: W) -> Result<()> {
 			warn!("There is nothing to bump.");
 			last_version
 		} else if changelog.releases.is_empty() {
-			config.bump.get_initial_tag()
+			changelog.config.bump.get_initial_tag()
 		} else {
 			return Ok(());
 		};
@@ -623,9 +632,8 @@ pub fn run<W: io::Write>(mut args: Args, mut out: W) -> Result<()> {
 		let mut out = io::BufWriter::new(File::create(path)?);
 		changelog.prepend(changelog_before, &mut out)?;
 	}
-	if output.is_some() || args.prepend.is_none() {
-		changelog.generate(&mut out)?;
-	}
 
-	Ok(())
+	Ok(if output.is_some() || args.prepend.is_none() {
+		changelog.generate(&mut out)?;
+	})
 }
diff --git a/git-cliff/src/main.rs b/git-cliff/src/main.rs
index 201dfa497f..4461dc067f 100644
--- a/git-cliff/src/main.rs
+++ b/git-cliff/src/main.rs
@@ -1,6 +1,10 @@
 use clap::Parser;
 use git_cliff::args::Args;
-use git_cliff::logger;
+use git_cliff::{
+	check_new_version,
+	init_config,
+	logger,
+};
 use git_cliff_core::error::Result;
 use std::env;
 use std::fs::File;
@@ -21,7 +25,7 @@ mod profiler;
 
 fn main() -> Result<()> {
 	// Parse the command line arguments
-	let args = Args::parse();
+	let mut args = Args::parse();
 
 	// Launch the TUI if the flag is set.
 	if args.tui {
@@ -59,7 +63,19 @@ fn main() -> Result<()> {
 		_profiler_guard = Some(());
 	}
 
-	// Run git-cliff
+	// Check if there is a new version available.
+	#[cfg(feature = "update-informer")]
+	check_new_version();
+
+	// Create the configuration file if init flag is given.
+	if let Some(path) = &args.init {
+		init_config(path.clone())?;
+	}
+
+	// Generate a changelog.
+	let changelog = git_cliff::generate_changelog(&mut args)?;
+
+	// Get output file.
 	let out: Box<dyn io::Write> = if let Some(path) = &args.output {
 		if path == Path::new("-") {
 			Box::new(io::stdout())
@@ -69,7 +85,9 @@ fn main() -> Result<()> {
 	} else {
 		Box::new(io::stdout())
 	};
-	let exit_code = match git_cliff::run(args, out) {
+
+	// Write the changelog.
+	let exit_code = match git_cliff::write_changelog(args, changelog, out) {
 		Ok(_) => 0,
 		Err(e) => {
 			log::error!("{}", e);