From 222ed138e492221fa21cf16b66f8d95f87d6877b Mon Sep 17 00:00:00 2001
From: pep <pep@bouah.net>
Date: Sat, 3 May 2025 23:53:38 +0200
Subject: [PATCH] forgejo-hook: impl Hook::try_from_event

Utilize X-Forgejo-Event http header to facilitate conversion.

Signed-off-by: pep <pep@bouah.net>
---
 forgejo-hooks/Cargo.toml   |  2 +-
 forgejo-hooks/src/error.rs | 48 ++++++++++++++++++++++++++++++++++++++
 forgejo-hooks/src/lib.rs   | 39 +++++++++++++++++++++++++++++++
 3 files changed, 88 insertions(+), 1 deletion(-)
 create mode 100644 forgejo-hooks/src/error.rs

diff --git a/forgejo-hooks/Cargo.toml b/forgejo-hooks/Cargo.toml
index 8bfee68..7341bae 100644
--- a/forgejo-hooks/Cargo.toml
+++ b/forgejo-hooks/Cargo.toml
@@ -7,7 +7,7 @@ license = "AGPL-3.0+"
 [dependencies]
 chrono = { version = "0.4", default-features = false, features = ["serde"] }
 serde = { version = "1.0", features = ["derive"] }
+serde_json = "1.0"
 
 [dev-dependencies]
-serde_json = "1.0"
 serde_path_to_error = "0.1.16"
diff --git a/forgejo-hooks/src/error.rs b/forgejo-hooks/src/error.rs
new file mode 100644
index 0000000..78035fe
--- /dev/null
+++ b/forgejo-hooks/src/error.rs
@@ -0,0 +1,48 @@
+// Copyright (C) 2025-2099 The crate authors.
+//
+// This program is free software: you can redistribute it and/or modify it
+// under the terms of the GNU Affero General Public License as published by the
+// Free Software Foundation, either version 3 of the License, or (at your
+// option) any later version.
+//
+// This program is distributed in the hope that it will be useful, but WITHOUT
+// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License
+// for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+use std::error::Error as StdError;
+use std::io::Error as IoError;
+
+#[derive(Debug)]
+pub enum Error {
+	UnknownHookType,
+	Io(IoError),
+	SerdeJson(serde_json::Error),
+}
+
+impl StdError for Error {}
+
+impl std::fmt::Display for Error {
+	fn fmt(&self, fmt: &mut std::fmt::Formatter) -> std::fmt::Result {
+		match self {
+			Error::UnknownHookType => write!(fmt, "Unknown hook type"),
+			Error::Io(e) => write!(fmt, "Io error: {}", e),
+			Error::SerdeJson(e) => write!(fmt, "serde_json error: {}", e),
+		}
+	}
+}
+
+impl From<IoError> for Error {
+	fn from(err: IoError) -> Error {
+		Error::Io(err)
+	}
+}
+
+impl From<serde_json::Error> for Error {
+	fn from(err: serde_json::Error) -> Error {
+		Error::SerdeJson(err)
+	}
+}
diff --git a/forgejo-hooks/src/lib.rs b/forgejo-hooks/src/lib.rs
index 3eac78d..068910a 100644
--- a/forgejo-hooks/src/lib.rs
+++ b/forgejo-hooks/src/lib.rs
@@ -13,9 +13,12 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program. If not, see <https://www.gnu.org/licenses/>.
 
+mod error;
 #[cfg(test)]
 mod tests;
 
+pub use error::Error;
+
 use chrono::{DateTime, Utc};
 use serde::Deserialize;
 
@@ -295,6 +298,18 @@ impl From<Push> for Hook {
 	}
 }
 
+impl From<AddedBranch> for Hook {
+	fn from(branch: AddedBranch) -> Self {
+		Self::AddedBranch(branch)
+	}
+}
+
+impl From<RemovedBranch> for Hook {
+	fn from(branch: RemovedBranch) -> Self {
+		Self::RemovedBranch(branch)
+	}
+}
+
 impl From<Issue> for Hook {
 	fn from(issue: Issue) -> Self {
 		Self::Issue(issue)
@@ -309,3 +324,27 @@ pub enum Hook {
 	RemovedBranch(RemovedBranch),
 	Issue(Issue),
 }
+
+/// Deserializes the payload into a struct
+fn parse_payload<Output>(payload: &[u8]) -> Result<Output, serde_json::Error>
+where
+	for<'a> Output: Deserialize<'a>,
+{
+	serde_json::from_slice(payload)
+}
+
+impl Hook {
+	/// Generate the proper struct based on the event type provided by Forgejo. Generally found in
+	/// the "X-Forgejo-Event" http header, which is not the same as the "X-Forgejo-Event-Type"
+	/// header.
+	pub fn try_from_event(event: &str, payload: &[u8]) -> Result<Hook, Error> {
+		Ok(match event {
+			"create" => parse_payload::<AddedBranch>(payload).map(Hook::from),
+			"delete" => parse_payload::<RemovedBranch>(payload).map(Hook::from),
+			"push" => parse_payload::<Push>(payload).map(Hook::from),
+			"issues" => parse_payload::<Issue>(payload).map(Hook::from),
+			"issue_comment" => parse_payload::<Issue>(payload).map(Hook::from),
+			_ => return Err(Error::UnknownHookType),
+		}?)
+	}
+}