//! `verify_invariants()` over a graph where one `merge` declaration matches
//! two members of the context it names and another matches none.

use mizan_core as mizan;
use mizan_core::graph_check::verify_invariants;
use mizan_core::prelude::*;
use mizan_core::RequestHandle;
use serde::{Deserialize, Serialize};

#[derive(Mizan, Serialize, Deserialize, Debug, Clone)]
pub struct Profile {
    pub user_id: i64,
    pub name: String,
}

#[derive(Mizan, Serialize, Deserialize, Debug, Clone)]
pub struct Status {
    pub ok: bool,
}

#[mizan::context("user")]
pub struct UserCtx;

#[mizan::client(context = UserCtx)]
pub async fn user_profile(_req: &RequestHandle<'_>, user_id: i64) -> Profile {
    Profile {
        user_id,
        name: format!("user-{user_id}"),
    }
}

/// Same output shape as `user_profile`.
#[mizan::client(context = UserCtx)]
pub async fn user_card(_req: &RequestHandle<'_>, user_id: i64) -> Profile {
    Profile {
        user_id,
        name: format!("card-{user_id}"),
    }
}

#[mizan::client(merge = UserCtx)]
pub async fn rename_user(_req: &RequestHandle<'_>, user_id: i64, name: String) -> Profile {
    Profile { user_id, name }
}

/// No member of `user` returns this shape.
#[mizan::client(merge = UserCtx)]
pub async fn mark_seen(_req: &RequestHandle<'_>, user_id: i64) -> Status {
    Status { ok: user_id > 0 }
}

#[test]
#[should_panic(expected = "Merge resolution needs exactly one match")]
fn a_merge_matching_several_members_is_ambiguous() {
    verify_invariants();
}

#[test]
#[should_panic(expected = "user_card")]
fn an_ambiguous_merge_names_every_candidate_member() {
    verify_invariants();
}

#[test]
#[should_panic(expected = "no member of that context has output type")]
fn a_merge_matching_no_member_has_no_slot() {
    verify_invariants();
}