use models::pull_request::pull_requests;

use crate::errors::PullError;

pub fn is_author(pull: &pull_requests::Model, uid: Option<i64>) -> bool {
    uid.is_some_and(|uid| uid == pull.author_id)
}

pub fn require_open(pull: &pull_requests::Model) -> Result<(), PullError> {
    if pull.has_merged {
        return Err(PullError::Conflict(
            "pull request already merged".to_string(),
        ));
    }
    if pull.closed_at.is_some() {
        return Err(PullError::Conflict("pull request is closed".to_string()));
    }
    Ok(())
}

pub fn require_unlocked(pull: &pull_requests::Model) -> Result<(), PullError> {
    if pull.is_locked {
        return Err(PullError::Conflict(
            "pull request is locked; only repository administrators may act".to_string(),
        ));
    }
    Ok(())
}

/// 作者或有写权限的管理员可以改标题/正文/关闭/合并。
pub fn require_can_manage(
    pull: &pull_requests::Model,
    caller: Option<i64>,
    admin: bool,
) -> Result<i64, PullError> {
    let uid = caller.ok_or(PullError::Unauthorized)?;
    if admin || is_author(pull, Some(uid)) {
        return Ok(uid);
    }
    Err(PullError::Forbidden)
}