collab: Extract contributor endpoints to their own module (#15251)

This PR extracts the contributor endpoints to their own module for
organizational purposes.

Release Notes:

- N/A

crates/collab/src/api/contributors.rs

@@ -0,0 +1,121 @@
+use std::sync::{Arc, OnceLock};
+
+use anyhow::anyhow;
+use axum::{
+    extract::{self, Query},
+    routing::get,
+    Extension, Json, Router,
+};
+use chrono::{NaiveDateTime, SecondsFormat};
+use serde::{Deserialize, Serialize};
+
+use crate::api::AuthenticatedUserParams;
+use crate::db::ContributorSelector;
+use crate::{AppState, Result};
+
+pub fn router() -> Router {
+    Router::new()
+        .route("/contributors", get(get_contributors).post(add_contributor))
+        .route("/contributor", get(check_is_contributor))
+}
+
+async fn get_contributors(Extension(app): Extension<Arc<AppState>>) -> Result<Json<Vec<String>>> {
+    Ok(Json(app.db.get_contributors().await?))
+}
+
+#[derive(Debug, Deserialize)]
+struct CheckIsContributorParams {
+    github_user_id: Option<i32>,
+    github_login: Option<String>,
+}
+
+impl CheckIsContributorParams {
+    fn as_contributor_selector(self) -> Result<ContributorSelector> {
+        if let Some(github_user_id) = self.github_user_id {
+            return Ok(ContributorSelector::GitHubUserId { github_user_id });
+        }
+
+        if let Some(github_login) = self.github_login {
+            return Ok(ContributorSelector::GitHubLogin { github_login });
+        }
+
+        Err(anyhow!(
+            "must be one of `github_user_id` or `github_login`."
+        ))?
+    }
+}
+
+#[derive(Debug, Serialize)]
+struct CheckIsContributorResponse {
+    signed_at: Option<String>,
+}
+
+async fn check_is_contributor(
+    Extension(app): Extension<Arc<AppState>>,
+    Query(params): Query<CheckIsContributorParams>,
+) -> Result<Json<CheckIsContributorResponse>> {
+    let params = params.as_contributor_selector()?;
+
+    if RenovateBot::is_renovate_bot(&params) {
+        return Ok(Json(CheckIsContributorResponse {
+            signed_at: Some(
+                RenovateBot::created_at()
+                    .and_utc()
+                    .to_rfc3339_opts(SecondsFormat::Millis, true),
+            ),
+        }));
+    }
+
+    Ok(Json(CheckIsContributorResponse {
+        signed_at: app
+            .db
+            .get_contributor_sign_timestamp(&params)
+            .await?
+            .map(|ts| ts.and_utc().to_rfc3339_opts(SecondsFormat::Millis, true)),
+    }))
+}
+
+/// The Renovate bot GitHub user (`renovate[bot]`).
+///
+/// https://api.github.com/users/renovate[bot]
+struct RenovateBot;
+
+impl RenovateBot {
+    const LOGIN: &'static str = "renovate[bot]";
+    const USER_ID: i32 = 29139614;
+
+    /// Returns the `created_at` timestamp for the Renovate bot user.
+    fn created_at() -> &'static NaiveDateTime {
+        static CREATED_AT: OnceLock<NaiveDateTime> = OnceLock::new();
+        CREATED_AT.get_or_init(|| {
+            chrono::DateTime::parse_from_rfc3339("2017-06-02T07:04:12Z")
+                .expect("failed to parse 'created_at' for 'renovate[bot]'")
+                .naive_utc()
+        })
+    }
+
+    /// Returns whether the given contributor selector corresponds to the Renovate bot user.
+    fn is_renovate_bot(contributor: &ContributorSelector) -> bool {
+        match contributor {
+            ContributorSelector::GitHubLogin { github_login } => github_login == Self::LOGIN,
+            ContributorSelector::GitHubUserId { github_user_id } => {
+                github_user_id == &Self::USER_ID
+            }
+        }
+    }
+}
+
+async fn add_contributor(
+    Extension(app): Extension<Arc<AppState>>,
+    extract::Json(params): extract::Json<AuthenticatedUserParams>,
+) -> Result<()> {
+    let initial_channel_id = app.config.auto_join_channel_id;
+    app.db
+        .add_contributor(
+            &params.github_login,
+            params.github_user_id,
+            params.github_email.as_deref(),
+            initial_channel_id,
+        )
+        .await
+}