feat(pull) pull commits for checked out pr branch

- find pr event which matches branch name
- fetch and apply latest commits

1 files changed, 114 insertions, 0 deletions

diff --git a/src/sub_commands/pull.rs b/src/sub_commands/pull.rs
new file mode 100644
index 0000000..a6513e8
--- /dev/null
+++ b/src/sub_commands/pull.rs
@@ -0,0 +1,114 @@
+use anyhow::{bail, Context, Result};
+
+#[cfg(not(test))]
+use crate::client::Client;
+#[cfg(test)]
+use crate::client::MockConnect;
+use crate::{
+    client::Connect,
+    git::{Repo, RepoActions},
+    repo_ref,
+    sub_commands::prs::{
+        create::{PATCH_KIND, PR_KIND},
+        list::{get_most_recent_patch_with_ancestors, tag_value},
+    },
+};
+
+pub async fn launch() -> Result<()> {
+    let git_repo = Repo::discover().context("cannot find a git repository")?;
+
+    let (main_or_master_branch_name, _) = git_repo
+        .get_main_or_master_branch()
+        .context("no main or master branch")?;
+
+    let root_commit = git_repo
+        .get_root_commit(main_or_master_branch_name)
+        .context("failed to get root commit of the repository")?;
+
+    let branch_name = git_repo
+        .get_checked_out_branch_name()
+        .context("cannot get checked out branch name")?;
+
+    if branch_name == main_or_master_branch_name {
+        bail!("checkout a branch associated with a PR first")
+    }
+    #[cfg(not(test))]
+    let client = Client::default();
+    #[cfg(test)]
+    let client = <MockConnect as std::default::Default>::default();
+
+    let repo_ref = repo_ref::fetch(
+        root_commit.to_string(),
+        &client,
+        client.get_more_fallback_relays().clone(),
+    )
+    .await?;
+
+    println!("finding PR event...");
+
+    let pr_event: nostr::Event = client
+        .get_events(
+            repo_ref.relays.clone(),
+            vec![
+                nostr::Filter::default()
+                    .kind(nostr::Kind::Custom(PR_KIND))
+                    .reference(format!("r-{root_commit}")),
+            ],
+        )
+        .await?
+        .iter()
+        .find(|e| {
+            e.kind.as_u64() == PR_KIND
+                && e.tags
+                    .iter()
+                    .any(|t| t.as_vec().len() > 1 && t.as_vec()[1].eq(&format!("r-{root_commit}")))
+                && tag_value(e, "branch-name")
+                    .unwrap_or_default()
+                    .eq(&branch_name)
+        })
+        .context("cannot find a PR event associated with the checked out branch name")?
+        .to_owned();
+
+    println!("found PR event. finding commits...");
+
+    let commits_events: Vec<nostr::Event> = client
+        .get_events(
+            repo_ref.relays.clone(),
+            vec![
+                nostr::Filter::default()
+                    .kind(nostr::Kind::Custom(PATCH_KIND))
+                    .event(pr_event.id)
+                    .reference(format!("r-{root_commit}")),
+            ],
+        )
+        .await?
+        .iter()
+        .filter(|e| {
+            e.kind.as_u64() == PATCH_KIND
+                && e.tags
+                    .iter()
+                    .any(|t| t.as_vec().len() > 2 && t.as_vec()[1].eq(&pr_event.id.to_string()))
+                && e.tags
+                    .iter()
+                    .any(|t| t.as_vec().len() > 1 && t.as_vec()[1].eq(&format!("r-{root_commit}")))
+        })
+        .map(std::borrow::ToOwned::to_owned)
+        .collect();
+
+    // TODO: are there outstanding changes to prevent checking out a new branch?
+
+    let most_recent_pr_patch_chain = get_most_recent_patch_with_ancestors(commits_events)
+        .context("cannot get most recent patch for PR")?;
+
+    let applied = git_repo
+        .apply_patch_chain(&branch_name, most_recent_pr_patch_chain)
+        .context("cannot apply patch chain")?;
+
+    if applied.is_empty() {
+        println!("branch already up-to-date");
+    } else {
+        println!("applied {} new commits", applied.len(),);
+    }
+
+    Ok(())
+}