//! `pr-commits <number> [repo]` — list a PR's commits as JSON
//! (sha, message, author date, author login), paginated.
//!
//! The forge stores a PR's commits against its branch ref, so this
//! returns them even for a PR whose shas were rewritten by a rebase
//! merge. The commit message and author date survive a rebase
//! unchanged, so a caller can match these rows against the linear
//! `main` history to recover the merged-final commits when the PR's
//! recorded shas no longer resolve.

use anyhow::Result;
use clap::Args as ClapArgs;
use serde_json::json;

use crate::client::Client;
use crate::verbs::print_json;

/// Page cap for the commit list. Forgejo serves up to 50 commits per
/// page; 40 pages (2000 commits) is far beyond any real PR.
const MAX_PAGES: u32 = 40;

#[derive(ClapArgs)]
pub struct Args {
    /// PR number.
    number: u64,
}

pub fn run(client: &Client, args: Args) -> Result<()> {
    let repo = client.repo();
    let commits = client.get_json_all(
        &format!("/repos/{repo}/pulls/{}/commits", args.number),
        MAX_PAGES,
    )?;
    let trimmed: Vec<_> = commits
        .iter()
        .map(|c| {
            let commit = c.get("commit");
            json!({
                "sha": c.get("sha"),
                "message": commit.and_then(|x| x.get("message")),
                "author_date": commit
                    .and_then(|x| x.get("author"))
                    .and_then(|a| a.get("date")),
                "author": c.get("author").and_then(|u| u.get("login")),
            })
        })
        .collect();
    print_json(&json!(trimmed))
}