use module_auth::AuthUser;

use crate::state::AppState;

#[derive(Clone, Debug, PartialEq, Eq)]
pub struct WorkAuthorSummary {
    pub display_name: String,
    pub public_user_code: Option<String>,
}

/// 中文注释：作品作者的真相源是 owner_user_id；历史昵称字段只作为账号资料不可读时的兼容回退。
pub fn resolve_work_author_by_user_id(
    state: &AppState,
    owner_user_id: &str,
    fallback_display_name: Option<&str>,
    fallback_public_user_code: Option<&str>,
) -> WorkAuthorSummary {
    let fallback_display_name =
        normalize_optional_text(fallback_display_name).unwrap_or_else(|| "玩家".to_string());
    let fallback_public_user_code = normalize_optional_text(fallback_public_user_code);

    let Some(owner_user_id) = normalize_optional_text(Some(owner_user_id)) else {
        return WorkAuthorSummary {
            display_name: fallback_display_name,
            public_user_code: fallback_public_user_code,
        };
    };

    match state.auth_user_service().get_user_by_id(&owner_user_id) {
        Ok(Some(user)) => map_auth_user_to_work_author_summary(user, fallback_display_name),
        Ok(None) | Err(_) => WorkAuthorSummary {
            display_name: fallback_display_name,
            public_user_code: fallback_public_user_code,
        },
    }
}

fn map_auth_user_to_work_author_summary(
    user: AuthUser,
    fallback_display_name: String,
) -> WorkAuthorSummary {
    WorkAuthorSummary {
        display_name: normalize_optional_text(Some(user.display_name.as_str()))
            .unwrap_or(fallback_display_name),
        public_user_code: normalize_optional_text(Some(user.public_user_code.as_str())),
    }
}

fn normalize_optional_text(value: Option<&str>) -> Option<String> {
    value
        .map(str::trim)
        .filter(|value| !value.is_empty())
        .map(ToOwned::to_owned)
}