//! Making an existing human forge account a site admin: the whole job of
//! `POST /api/forge/users/{name}/admin`, which `swarmctl forge make-admin`
//! calls.
//!
//! Never creates the account. A human's account is made by their first
//! authelia login to the forge (`oauth2_client` in
//! `nix/host-modules/hive-forge/default.nix`), so a missing one means that
//! login has not happened yet, and making it here would be a second way in.
//!
//! The decision is pure ([`plan`]), so the tests pin it; the IO on either side
//! only reads or acts. Same split as [`super::agent_token`].

use anyhow::{Context, Result};
use forgejo_api::structs::{EditUserOption, User};

use super::Client;
use super::agent_token::is_not_found;

/// What one request does about the account.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum Plan {
    /// The forge has no user by this name: its owner has not logged in yet.
    NoSuchUser,
    /// Already a site admin: nothing to send.
    AlreadyAdmin,
    /// An ordinary account: make it a site admin.
    Promote,
}

/// Decide from the account as the forge reports it (`None` when there is no
/// such user).
pub fn plan(user: Option<&User>) -> Plan {
    match user {
        None => Plan::NoSuchUser,
        Some(u) if u.is_admin == Some(true) => Plan::AlreadyAdmin,
        Some(_) => Plan::Promote,
    }
}

/// The `admin_edit_user` body that sets `admin` and nothing else.
///
/// Unlike [`super::repo_creation_lockdown`], no `login_name` + `source_id`:
/// in Forgejo 16 both are optional, and a `source_id` sets the account's login
/// type (`services/user/update.go`, `UpdateAuth`). `source_id = 0` would turn
/// an SSO-made account into a local one.
fn admin_edit() -> EditUserOption {
    EditUserOption {
        active: None,
        admin: Some(true),
        allow_create_organization: None,
        allow_git_hook: None,
        allow_import_local: None,
        description: None,
        email: None,
        full_name: None,
        hide_email: None,
        location: None,
        login_name: None,
        max_repo_creation: None,
        must_change_password: None,
        password: None,
        prohibit_login: None,
        pronouns: None,
        restricted: None,
        source_id: None,
        visibility: None,
        website: None,
    }
}

impl Client {
    /// Make the existing account `name` a site admin, and say what that took.
    /// The caller has already refused an agent's name.
    ///
    /// # Errors
    /// When the forge refuses the read or the edit.
    pub async fn make_site_admin(&self, name: &str) -> Result<Plan> {
        let user = match self.api.user_get(name).await {
            Ok(user) => Some(user),
            Err(e) if is_not_found(&e) => None,
            Err(e) => return Err(e).with_context(|| format!("read forge user {name}")),
        };
        let plan = plan(user.as_ref());
        if plan == Plan::Promote {
            self.api
                .admin_edit_user(name, admin_edit())
                .await
                .with_context(|| format!("make forge user {name} a site admin"))?;
            tracing::info!(%name, "swarm forge: made the user a site admin");
        }
        Ok(plan)
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    fn user(is_admin: Option<bool>) -> User {
        serde_json::from_value(serde_json::json!({
            "login": "mara",
            "is_admin": is_admin,
        }))
        .expect("a user decodes")
    }

    #[test]
    fn a_missing_user_is_not_created() {
        assert_eq!(plan(None), Plan::NoSuchUser);
    }

    #[test]
    fn an_admin_is_left_alone() {
        assert_eq!(plan(Some(&user(Some(true)))), Plan::AlreadyAdmin);
    }

    #[test]
    fn an_ordinary_user_is_promoted() {
        assert_eq!(plan(Some(&user(Some(false)))), Plan::Promote);
    }

    /// No flag in the answer: the edit is sent. On an admin it is a no-op;
    /// skipping it would report success for an ordinary account.
    #[test]
    fn an_unreported_admin_flag_is_promoted() {
        assert_eq!(plan(Some(&user(None))), Plan::Promote);
    }
}