// Task 1 — RelationManager: the declaration registry for referential
// integrity relations. No enforcement, no LMDB index yet (later tasks).
//
// Modeled on tests/test_view_manager_paging.cpp: relations are keyed by
// their project-qualified name in a `_relations` system collection, and
// loadFromStore() must page explicitly since Query::limit defaults to 100
// and limit=0 returns nothing (not everything) — the same trap that has
// already shipped as a bug in ViewManager, PolicyManager and
// CollectionConfigManager.

#include <iostream>
#include <string>

#include <nlohmann/json.hpp>

#include "document.hpp"
#include "memory_store.hpp"
#include "relations/relation_manager.hpp"

using namespace smartbotic::database;

namespace {

int g_pass = 0;
int g_fail = 0;

void check(bool cond, const std::string& msg) {
    if (cond) { ++g_pass; }
    else { ++g_fail; std::cerr << "FAIL: " << msg << "\n"; }
}

struct Fixture {
    MemoryStore store;
    Fixture() : store(MemoryStore::Config{}) {
        store.start();
    }
    ~Fixture() { store.stop(); }
};

void test_relations_are_project_scoped_and_survive_reload() {
    Fixture f;                       // MemoryStore, started
    RelationManager rm(f.store);
    rm.loadFromStore();

    RelationInfo a;
    a.name = "default:exec_wf";
    a.child = "default:executions";
    a.childField = "workflowId";
    a.parent = "default:workflows";
    std::string err;
    check(rm.createRelation(a, err), "created in default");

    RelationInfo b = a;              // SAME bare name, different project
    b.name = "acme:exec_wf";
    b.child = "acme:executions";
    b.parent = "acme:workflows";
    check(rm.createRelation(b, err), "the same name in another project is allowed");

    check(rm.listRelations("default").size() == 1, "listing is project-filtered");
    check(rm.listRelations().size() == 2, "empty project lists everything");

    RelationManager fresh(f.store);   // restart
    fresh.loadFromStore();
    check(fresh.getRelation("default:exec_wf").has_value(), "survives reload");
    check(fresh.getRelation("acme:exec_wf").has_value(), "both survive");
}

void test_cross_project_relation_is_refused() {
    Fixture f;
    RelationManager rm(f.store);
    RelationInfo r;
    r.name = "default:bad";
    r.child = "default:executions";
    r.childField = "workflowId";
    r.parent = "acme:workflows";      // different env - no txn spans two
    std::string err;
    check(!rm.createRelation(r, err), "a cross-project relation is refused");
    check(err.find("project") != std::string::npos, "and says why");
}

void test_more_than_one_page_of_relations_loads() {
    Fixture f;
    RelationManager rm(f.store);
    for (int i = 0; i < 250; ++i) {          // Query::limit defaults to 100
        RelationInfo r;
        char buf[32];
        std::snprintf(buf, sizeof(buf), "default:r%03d", i);
        r.name = buf;
        r.child = "default:c";
        r.childField = "p";
        r.parent = "default:p";
        std::string err;
        rm.createRelation(r, err);
    }
    RelationManager fresh(f.store);
    fresh.loadFromStore();
    check(fresh.listRelations().size() == 250,
          "all 250 load - a bare Query would stop at 100, as it did for views, "
          "policies and collection configs");
}

// v2.11.0 T13 round 2 (review finding 3) — createRelation() refuses a
// cross-project declaration (test_cross_project_relation_is_refused,
// above), but loadFromStore() is the OTHER way a RelationInfo enters the
// cache and did not re-check it. A legacy or hand-written `_relations`
// document naming a cross-project parent must be skipped at load time too -
// arming it would resolve the bare parent name inside the CHILD's own
// project env (validate_on_write/RelationRef only ever resolve `parent`
// against the child's project), silently checking the wrong collection.
void test_load_skips_a_cross_project_relation_written_by_hand() {
    Fixture f;

    // Bypass createRelation()'s own guard entirely - write the raw document
    // straight into `_relations`, the way a legacy record or a hand-edited
    // one would exist on disk. `parent` names a DIFFERENT project than
    // `child`, which createRelation() would refuse today.
    nlohmann::json bad = {
        {"name", "default:bad_cross"},
        {"child", "default:executions"},
        {"child_field", "workflowId"},
        {"parent", "acme:workflows"},
        {"on_delete", "restrict"},
        {"validate_on_write", true},
        {"created_at", 0},
        {"updated_at", 0},
    };
    Document d;
    d.id = "default:bad_cross";
    d.collection = RelationManager::SYSTEM_COLLECTION;
    d.set_data(bad);
    f.store.insert(RelationManager::SYSTEM_COLLECTION, d);

    // A well-formed, same-project relation alongside it, to confirm one bad
    // record does not stop the rest of the load.
    RelationInfo good;
    good.name = "default:exec_wf";
    good.child = "default:executions";
    good.childField = "ownerId";
    good.parent = "default:users";
    {
        RelationManager rm(f.store);
        rm.loadFromStore();
        std::string err;
        check(rm.createRelation(good, err), "the well-formed sibling declares fine");
    }

    RelationManager fresh(f.store);
    fresh.loadFromStore();
    check(!fresh.getRelation("default:bad_cross").has_value(),
          "the cross-project relation was skipped, not armed with the wrong parent");
    check(fresh.getRelation("default:exec_wf").has_value(),
          "the well-formed sibling still loaded - one bad record did not stop the rest");
}

}  // namespace

int main() {
    std::cout << "=== test_relation_manager ===\n";
    test_relations_are_project_scoped_and_survive_reload();
    test_cross_project_relation_is_refused();
    test_more_than_one_page_of_relations_loads();
    test_load_skips_a_cross_project_relation_written_by_hand();
    std::cout << "passed: " << g_pass << ", failed: " << g_fail << "\n";
    return g_fail == 0 ? 0 : 1;
}