1 files changed, 133 insertions, 0 deletions
diff --git a/crates/discord-bot/src/commands/track.rs b/crates/discord-bot/src/commands/track.rs
new file mode 100644
index 0000000..f071ebf
--- /dev/null
+++ b/crates/discord-bot/src/commands/track.rs
@@ -0,0 +1,133 @@
+use crate::{config::Config, consts::NIXPKGS_REMOTE, http::GitHubClientExt};
+
+use std::sync::Arc;
+
+use eyre::Result;
+use log::debug;
+use serenity::builder::{
+	CreateCommand, CreateCommandOption, CreateEmbed, CreateInteractionResponseFollowup,
+};
+use serenity::model::{
+	application::{
+		CommandInteraction, CommandOptionType, InstallationContext, ResolvedOption, ResolvedValue,
+	},
+	Timestamp,
+};
+use serenity::prelude::Context;
+
+const REPO_OWNER: &str = "NixOS";
+const REPO_NAME: &str = "nixpkgs";
+
+pub async fn respond<T>(
+	ctx: &Context,
+	http: &Arc<T>,
+	config: &Config,
+	command: &CommandInteraction,
+) -> Result<()>
+where
+	T: GitHubClientExt,
+{
+	// this will probably take a while
+	command.defer(&ctx).await?;
+
+	let options = command.data.options();
+	let Some(ResolvedOption {
+		value: ResolvedValue::Integer(pr),
+		..
+	}) = options.first()
+	else {
+		let resp = CreateInteractionResponseFollowup::new()
+			.content("PR numbers aren't negative or that big...");
+		command.create_followup(&ctx, resp).await?;
+
+		return Ok(());
+	};
+
+	let Ok(id) = u64::try_from(*pr) else {
+		let resp = CreateInteractionResponseFollowup::new()
+			.content("PR numbers aren't negative or that big...");
+		command.create_followup(&ctx, resp).await?;
+
+		return Ok(());
+	};
+
+	// find out what commit our PR was merged in
+	let pull_request = http.pull_request(REPO_OWNER, REPO_NAME, id).await?;
+	if !pull_request.merged {
+		let response = CreateInteractionResponseFollowup::new()
+			.content("It looks like that PR isn't merged yet! Try again when it is 😄");
+		command.create_followup(&ctx, response).await?;
+
+		return Ok(());
+	}
+
+	// seems older PRs may not have this
+	let Some(commit_sha) = pull_request.merge_commit_sha else {
+		let response = CreateInteractionResponseFollowup::new()
+			.content("It seems this pull request is very old. I can't track it");
+		command.create_followup(&ctx, response).await?;
+
+		return Ok(());
+	};
+
+	let status_results = git_tracker::collect_statuses_in(
+		&config.nixpkgs_path,
+		&commit_sha,
+		&config.nixpkgs_branches,
+	)?;
+
+	// find branches containing our PR and trim the remote ref prefix
+	let found_branches: Vec<String> = status_results
+		.iter()
+		.filter(|&(_, has_pr)| *has_pr)
+		.map(|(branch_name, _)| {
+			// remove the ref prefix that we add in our Config struct
+			let start_pos = format!("{NIXPKGS_REMOTE}/").len();
+			branch_name[start_pos..].to_string()
+		})
+		.collect();
+
+	// if we didn't find any, bail
+	if found_branches.is_empty() {
+		let response = CreateInteractionResponseFollowup::new()
+			.content("This PR has been merged...but I can't seem to find it anywhere. I might not be tracking it's base branch");
+		command.create_followup(&ctx, response).await?;
+
+		return Ok(());
+	}
+
+	let mut embed = CreateEmbed::new()
+		.title(format!("Nixpkgs PR #{} Status", pull_request.number))
+		.url(&pull_request.html_url)
+		.description(&pull_request.title)
+		.fields(
+			found_branches
+				.iter()
+				.map(|branch_name| (branch_name, "✅", true)),
+		);
+
+	if let Some(merged_at) = pull_request.merged_at {
+		if let Ok(timestamp) = Timestamp::parse(&merged_at) {
+			embed = embed.timestamp(timestamp);
+		} else {
+			debug!("Couldn't parse timestamp from GitHub! Ignoring.");
+		}
+	} else {
+		debug!("Couldn't find `merged_at` information for a supposedly merged PR! Ignoring.");
+	}
+
+	let resp = CreateInteractionResponseFollowup::new().embed(embed);
+	command.create_followup(&ctx, resp).await?;
+
+	Ok(())
+}
+
+pub fn register() -> CreateCommand {
+	CreateCommand::new("track")
+		.description("Track a nixpkgs PR")
+		.add_integration_type(InstallationContext::User)
+		.add_option(
+			CreateCommandOption::new(CommandOptionType::Integer, "pull_request", "PR to track")
+				.required(true),
+		)
+}