From 345c410a6239df1c1c7e99864c7e5f220722e5e4 Mon Sep 17 00:00:00 2001
From: orhun <orhunparmaksiz@gmail.com>
Date: Tue, 1 Jun 2021 22:47:30 +0300
Subject: [PATCH] refactor(bin): add changelog module

---
 git-cliff-core/src/template.rs |  4 +-
 git-cliff/src/changelog.rs     | 91 ++++++++++++++++++++++++++++++++++
 git-cliff/src/main.rs          | 63 ++---------------------
 3 files changed, 97 insertions(+), 61 deletions(-)
 create mode 100644 git-cliff/src/changelog.rs

diff --git a/git-cliff-core/src/template.rs b/git-cliff-core/src/template.rs
index 4888193..3a58234 100644
--- a/git-cliff-core/src/template.rs
+++ b/git-cliff-core/src/template.rs
@@ -39,10 +39,10 @@ impl Template {
 	}
 
 	/// Renders the template.
-	pub fn render(&self, release: Release) -> Result<String> {
+	pub fn render(&self, release: &Release) -> Result<String> {
 		Ok(self
 			.tera
-			.render("template", &TeraContext::from_serialize(&release)?)?)
+			.render("template", &TeraContext::from_serialize(release)?)?)
 	}
 }
 
diff --git a/git-cliff/src/changelog.rs b/git-cliff/src/changelog.rs
new file mode 100644
index 00000000..d9eec71
--- /dev/null
+++ b/git-cliff/src/changelog.rs
@@ -0,0 +1,91 @@
+use git_cliff_core::commit::Commit;
+use git_cliff_core::config::ChangelogConfig as Config;
+use git_cliff_core::error::Result;
+use git_cliff_core::release::ReleaseRoot;
+use git_cliff_core::template::Template;
+use std::io::Write;
+
+/// Changelog generator.
+#[derive(Debug)]
+pub struct Changelog<'a> {
+	release_root: ReleaseRoot<'a>,
+	template:     Template,
+	config:       &'a Config,
+}
+
+impl<'a> Changelog<'a> {
+	/// Constructs a new instance.
+	pub fn new(release_root: ReleaseRoot<'a>, config: &'a Config) -> Result<Self> {
+		let mut changelog = Self {
+			release_root,
+			template: Template::new(config.body.to_string())?,
+			config,
+		};
+		changelog.process_commits();
+		changelog.process_releases();
+		Ok(changelog)
+	}
+
+	/// Processes the commits and omits the ones that doesn't match the
+	/// criteria set by configuration file.
+	fn process_commits(&mut self) {
+		let config = &self.config;
+		self.release_root.releases.iter_mut().for_each(|release| {
+			release.commits = release
+				.commits
+				.iter()
+				.filter_map(|commit| {
+					match commit.process(&config.commit_parsers, config.filter_group)
+					{
+						Ok(commit) => Some(commit),
+						Err(e) => {
+							debug!("Cannot process commit: {} ({})", commit.id, e);
+							None
+						}
+					}
+				})
+				.collect::<Vec<Commit>>();
+		});
+	}
+
+	/// Processes the releases and filters them out based on the configuration.
+	fn process_releases(&mut self) {
+		self.release_root.releases = self
+			.release_root
+			.releases
+			.clone()
+			.into_iter()
+			.rev()
+			.filter(|release| {
+				if release.commits.is_empty() {
+					debug!(
+						"Release {} doesn't have any commits",
+						release
+							.version
+							.as_ref()
+							.cloned()
+							.unwrap_or_else(|| String::from("[?]"))
+					);
+					false
+				} else if let Some(version) = &release.version {
+					!self.config.skip_tags_regex.is_match(version)
+				} else {
+					true
+				}
+			})
+			.collect();
+	}
+
+	pub fn generate<W: Write>(&self, out: &mut W) -> Result<()> {
+		if !self.config.header.is_empty() {
+			writeln!(out, "{}", self.config.header)?;
+		}
+		for release in &self.release_root.releases {
+			write!(out, "{}", self.template.render(release)?)?;
+		}
+		if !self.config.footer.is_empty() {
+			writeln!(out, "{}", self.config.footer)?;
+		}
+		Ok(())
+	}
+}
diff --git a/git-cliff/src/main.rs b/git-cliff/src/main.rs
index 0ce336c..3b043e6 100644
--- a/git-cliff/src/main.rs
+++ b/git-cliff/src/main.rs
@@ -1,6 +1,8 @@
 mod args;
+mod changelog;
 
 use args::Opt;
+use changelog::Changelog;
 use git_cliff_core::commit::Commit;
 use git_cliff_core::config::Config;
 use git_cliff_core::error::Result;
@@ -9,12 +11,8 @@ use git_cliff_core::release::{
 	ReleaseRoot,
 };
 use git_cliff_core::repo::Repository;
-use git_cliff_core::template::Template;
 use std::env;
-use std::io::{
-	self,
-	Write,
-};
+use std::io;
 use structopt::StructOpt;
 #[macro_use]
 extern crate log;
@@ -64,58 +62,5 @@ fn main() -> Result<()> {
 		}
 	}
 
-	release_root.releases.iter_mut().for_each(|release| {
-		release.commits = release
-			.commits
-			.iter()
-			.filter_map(|commit| {
-				match commit.process(
-					&config.changelog.commit_parsers,
-					config.changelog.filter_group,
-				) {
-					Ok(commit) => Some(commit),
-					Err(e) => {
-						debug!("Cannot process commit: {} ({})", commit.id, e);
-						None
-					}
-				}
-			})
-			.collect::<Vec<Commit>>();
-	});
-	release_root.releases = release_root
-		.releases
-		.into_iter()
-		.rev()
-		.filter(|release| {
-			if release.commits.is_empty() {
-				debug!(
-					"Release {} doesn't have any commits",
-					release
-						.version
-						.as_ref()
-						.cloned()
-						.unwrap_or_else(|| String::from("[?]"))
-				);
-				false
-			} else if let Some(version) = &release.version {
-				!config.changelog.skip_tags_regex.is_match(version)
-			} else {
-				true
-			}
-		})
-		.collect();
-
-	let stdout = &mut io::stdout();
-	let template = Template::new(config.changelog.body)?;
-	if !config.changelog.header.is_empty() {
-		writeln!(stdout, "{}", config.changelog.header)?;
-	}
-	for release in release_root.releases {
-		write!(stdout, "{}", template.render(release)?)?;
-	}
-	if !config.changelog.footer.is_empty() {
-		writeln!(stdout, "{}", config.changelog.footer)?;
-	}
-
-	Ok(())
+	Changelog::new(release_root, &config.changelog)?.generate(&mut io::stdout())
 }