//! `comment <number> [body sources] [repo]` — post a comment on an
//! issue or PR.
//!
//! Read-before-comment guard: before posting, refuse when forge still
//! has an unread notification for the thread — i.e. someone commented
//! since the caller last read it. Reading the thread
//! (`hive-forge comments <n>` / `view <n>`) marks the notification read
//! and clears the block; `--force` overrides. The unread signal is
//! forge's own notification read-state, not a local mirror — see
//! `crate::notify`.

use anyhow::{Result, bail};
use clap::Args as ClapArgs;
use serde_json::json;

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

#[derive(ClapArgs)]
pub struct Args {
    /// Issue or PR number.
    pub(crate) number: u64,
    /// Inline body text.
    #[arg(long, conflicts_with = "body_file")]
    body: Option<String>,
    /// Read body from a file. `-` means stdin.
    #[arg(long = "body-file")]
    body_file: Option<String>,
    /// Post even when the thread has unread activity (skips the
    /// read-before-comment guard).
    #[arg(long)]
    force: bool,
}

/// # Errors
///
/// Returns an error when the read-before-comment guard fires (the thread
/// has an unread notification and `--force` was not passed), and
/// propagates any I/O error from the body input (`--body-file`, stdin),
/// any transport error from the Forgejo REST call (network unreachable,
/// 4xx/5xx response, token missing/invalid), and any I/O error from
/// writing the response to stdout.
pub fn run(client: &Client, args: Args) -> Result<()> {
    let body = body::resolve_required(args.body.as_deref(), args.body_file.as_deref(), "comment")?;
    let repo = client.repo();

    if !args.force {
        // Degrade open: a transport failure checking notifications must
        // not block a legitimate comment — only a *confirmed* unread
        // thread refuses.
        match notify::unread_thread_id(client, repo, args.number) {
            Ok(Some(_)) => bail!(
                "hive-forge: {repo}#{0} has unread activity — someone commented since you last \
                 read it. Read it first (`hive-forge comments {0}`), then retry — or pass --force.",
                args.number
            ),
            Ok(None) => {}
            Err(e) => eprintln!(
                "hive-forge: warning: could not check notifications ({e}); posting anyway"
            ),
        }
    }

    let resp = client.post_json(
        &format!("/repos/{repo}/issues/{}/comments", args.number),
        &json!({ "body": body }),
    )?;
    print_json(&json!({
        "id": resp.get("id"),
        "url": resp.get("html_url"),
    }))
}