1 files changed, 263 insertions, 0 deletions

diff --git a/src/sub_commands/list.rs b/src/sub_commands/list.rs
new file mode 100644
index 0000000..49cbf6d
--- /dev/null
+++ b/src/sub_commands/list.rs
@@ -0,0 +1,263 @@
+use anyhow::{bail, Context, Result};
+
+use super::send::event_is_patch_set_root;
+#[cfg(not(test))]
+use crate::client::Client;
+#[cfg(test)]
+use crate::client::MockConnect;
+use crate::{
+    cli_interactor::{Interactor, InteractorPrompt, PromptChoiceParms, PromptConfirmParms},
+    client::Connect,
+    git::{Repo, RepoActions},
+    repo_ref::{self, RepoRef, REPO_REF_KIND},
+    sub_commands::send::{event_is_cover_letter, event_to_cover_letter, PATCH_KIND},
+    Cli,
+};
+
+#[derive(Debug, clap::Args)]
+pub struct SubCommandArgs {
+    /// TODO ignore merged, and closed
+    #[arg(long, action)]
+    open_only: bool,
+}
+
+#[allow(clippy::too_many_lines)]
+pub async fn launch(_cli_args: &Cli, _args: &SubCommandArgs) -> Result<()> {
+    let git_repo = Repo::discover().context("cannot find a git repository")?;
+
+    let root_commit = git_repo
+        .get_root_commit()
+        .context("failed to get root commit of the repository")?;
+
+    // TODO: check for empty repo
+    // TODO: check for existing maintaiers file
+    // TODO: check for other claims
+
+    #[cfg(not(test))]
+    let client = Client::default();
+    #[cfg(test)]
+    let client = <MockConnect as std::default::Default>::default();
+
+    let repo_ref = repo_ref::fetch(
+        &git_repo,
+        root_commit.to_string(),
+        &client,
+        client.get_fallback_relays().clone(),
+    )
+    .await?;
+
+    println!("finding PRs...");
+
+    let pr_events: Vec<nostr::Event> =
+        find_pr_events(&client, &repo_ref, &root_commit.to_string()).await?;
+
+    let selected_index = Interactor::default().choice(
+        PromptChoiceParms::default()
+            .with_prompt("All PRs")
+            .with_choices(
+                pr_events
+                    .iter()
+                    .map(|e| {
+                        if let Ok(cl) = event_to_cover_letter(e) {
+                            cl.title
+                        } else if let Ok(msg) = tag_value(e, "description") {
+                            msg.split('\n').collect::<Vec<&str>>()[0].to_string()
+                        } else {
+                            e.id.to_string()
+                        }
+                    })
+                    .collect(),
+            ),
+    )?;
+
+    println!("finding commits...");
+
+    let commits_events: Vec<nostr::Event> =
+        find_commits_for_pr_event(&client, &pr_events[selected_index], &repo_ref).await?;
+
+    confirm_checkout(&git_repo)?;
+
+    let most_recent_pr_patch_chain = get_most_recent_patch_with_ancestors(commits_events)
+        .context("cannot get most recent patch for PR")?;
+
+    let branch_name: String = event_to_cover_letter(&pr_events[selected_index])
+        .context("cannot assign a branch name as event is not a patch set root")?
+        .branch_name;
+
+    let applied = git_repo
+        .apply_patch_chain(&branch_name, most_recent_pr_patch_chain)
+        .context("cannot apply patch chain")?;
+
+    if applied.is_empty() {
+        println!("checked out PR branch. no new commits to pull");
+    } else {
+        println!(
+            "checked out PR branch. pulled {} new commits",
+            applied.len(),
+        );
+    }
+    Ok(())
+}
+
+fn confirm_checkout(git_repo: &Repo) -> Result<()> {
+    if !Interactor::default().confirm(
+        PromptConfirmParms::default()
+            .with_prompt("check out branch?")
+            .with_default(true),
+    )? {
+        bail!("Exiting...");
+    }
+
+    if git_repo.has_outstanding_changes()? {
+        bail!(
+            "cannot pull PR branch when repository is not clean. discard or stash (un)staged changes and try again."
+        );
+    }
+    Ok(())
+}
+
+pub fn tag_value(event: &nostr::Event, tag_name: &str) -> Result<String> {
+    Ok(event
+        .tags
+        .iter()
+        .find(|t| t.as_vec()[0].eq(tag_name))
+        .context(format!("tag '{tag_name}'not present"))?
+        .as_vec()[1]
+        .clone())
+}
+
+pub fn get_most_recent_patch_with_ancestors(
+    mut patches: Vec<nostr::Event>,
+) -> Result<Vec<nostr::Event>> {
+    patches.sort_by_key(|e| e.created_at);
+
+    let first_patch = patches.first().context("no patches found")?;
+
+    let patches_with_youngest_created_at: Vec<&nostr::Event> = patches
+        .iter()
+        .filter(|p| p.created_at.eq(&first_patch.created_at))
+        .collect();
+
+    let latest_commit_id = tag_value(
+        // get the first patch which isn't a parent of a patch event created at the same
+        // time
+        patches_with_youngest_created_at
+            .clone()
+            .iter()
+            .find(|p| {
+                if let Ok(commit) = tag_value(p, "commit") {
+                    !patches_with_youngest_created_at.iter().any(|p2| {
+                        if let Ok(parent) = tag_value(p2, "parent-commit") {
+                            commit.eq(&parent)
+                        } else {
+                            false // skip 
+                        }
+                    })
+                } else {
+                    false // skip 
+                }
+            })
+            .context("cannot find patches_with_youngest_created_at")?,
+        "commit",
+    )?;
+
+    let mut res = vec![];
+
+    let mut commit_id_to_search = latest_commit_id;
+
+    while let Some(event) = patches.iter().find(|e| {
+        if let Ok(commit) = tag_value(e, "commit") {
+            commit.eq(&commit_id_to_search)
+        } else {
+            false // skip
+        }
+    }) {
+        res.push(event.clone());
+        commit_id_to_search = tag_value(event, "parent-commit")?;
+    }
+    Ok(res)
+}
+
+pub async fn find_pr_events(
+    #[cfg(test)] client: &crate::client::MockConnect,
+    #[cfg(not(test))] client: &Client,
+    repo_ref: &RepoRef,
+    root_commit: &str,
+) -> Result<Vec<nostr::Event>> {
+    Ok(client
+        .get_events(
+            repo_ref.relays.clone(),
+            vec![
+                nostr::Filter::default()
+                    .kind(nostr::Kind::Custom(PATCH_KIND))
+                    .custom_tag(nostr::Alphabet::T, vec!["root"])
+                    .identifiers(
+                        repo_ref
+                            .maintainers
+                            .iter()
+                            .map(|m| format!("{REPO_REF_KIND}:{m}:{}", repo_ref.identifier)),
+                    ),
+                // also pick up prs from the same repo but no target at our maintainers repo events
+                nostr::Filter::default()
+                    .kind(nostr::Kind::Custom(PATCH_KIND))
+                    .custom_tag(nostr::Alphabet::T, vec!["root"])
+                    .reference(root_commit),
+            ],
+        )
+        .await
+        .context("cannot get pr events")?
+        .iter()
+        .filter(|e| {
+            event_is_patch_set_root(e)
+                && (e
+                    .tags
+                    .iter()
+                    .any(|t| t.as_vec().len() > 1 && t.as_vec()[1].eq(root_commit))
+                    || e.tags.iter().any(|t| {
+                        t.as_vec().len() > 1
+                            && repo_ref
+                                .maintainers
+                                .iter()
+                                .map(|m| format!("{REPO_REF_KIND}:{m}:{}", repo_ref.identifier))
+                                .any(|d| t.as_vec()[1].eq(&d))
+                    }))
+        })
+        .map(std::borrow::ToOwned::to_owned)
+        .collect::<Vec<nostr::Event>>())
+}
+
+pub async fn find_commits_for_pr_event(
+    #[cfg(test)] client: &crate::client::MockConnect,
+    #[cfg(not(test))] client: &Client,
+    pr_event: &nostr::Event,
+    repo_ref: &RepoRef,
+) -> Result<Vec<nostr::Event>> {
+    let mut patch_events: Vec<nostr::Event> = client
+        .get_events(
+            repo_ref.relays.clone(),
+            vec![
+                nostr::Filter::default()
+                    .kind(nostr::Kind::Custom(PATCH_KIND))
+                    // this requires every patch to reference the root event
+                    // this will not pick up v2,v3 patch sets
+                    // TODO: fetch commits for v2.. patch sets
+                    .event(pr_event.id),
+            ],
+        )
+        .await
+        .context("cannot fetch patch events")?
+        .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()))
+        })
+        .map(std::borrow::ToOwned::to_owned)
+        .collect();
+
+    if !event_is_cover_letter(pr_event) {
+        patch_events.push(pr_event.clone());
+    }
+    Ok(patch_events)
+}