// SPDX-License-Identifier: LGPL-3.0-only
// SPDX-FileCopyrightText: Copyright (C) 2026 Catcrafts®

// Describe gives `crafter-debug help` what an agent needs to call a command
// right the first time: each field's name and type, its default taken from
// the member initializer, Required fields marked with no default, a narrow
// integer's range, an enum's names, a nested aggregate's own fields. A type
// that contains itself is described a few levels deep instead of forever.
import std;
import Crafter.Debug.Core;
using namespace Crafter::Debug;

namespace Game {
    enum class Mode : std::uint8_t { Idle, Build };

    struct Vec3 {
        float x = 0;
        float y = 1;
        float z = 0;
    };

    struct Aim {
        Required<std::uint8_t> slot;
        float yaw = 45;
        Vec3 at;
        std::optional<std::string> label;
        Mode mode = Mode::Build;
        std::vector<std::int32_t> ids;
    };

    struct Node {
        std::vector<Node> children;
    };
}

namespace {
    std::int32_t failures = 0;

    void Check(bool ok, std::string_view what) {
        std::println("{} {}", ok ? "PASS" : "FAIL", what);
        if (!ok) ++failures;
    }
}

int main() {
    const Value description = Describe<Game::Aim>();
    std::println("{}", description.DumpPretty());
    Check(description.Find("type")->AsString() == "object" && description.Find("name")->AsString().ends_with("Aim"), "an aggregate describes as a named object");
    const std::span<const Value> fields = description.Find("fields")->Items();
    Check(fields.size() == 6, "one entry per field");
    const auto field = [&](std::string_view name) -> const Value& {
        for (const Value& f : fields) {
            if (f.Find("name")->AsString() == name) return f;
        }
        throw std::runtime_error(std::format("no field {}", name));
    };
    Check(field("slot").Find("required") != nullptr && field("slot").Find("default") == nullptr, "a Required field is marked required, with no default");
    Check(field("slot").Find("type")->Find("maximum")->AsInteger() == 255, "a narrow integer carries its range");
    Check(field("yaw").Find("default")->AsNumber() == 45, "a default comes from the member initializer");
    Check(field("at").Find("type")->Find("fields")->Size() == 3 && field("at").Find("default")->Find("y")->AsNumber() == 1, "a nested aggregate describes its fields and default");
    Check(field("label").Find("type")->Find("nullable") != nullptr && field("label").Find("default")->IsNull(), "an optional is nullable and defaults to null");
    Check(field("mode").Find("type")->Find("values")->Size() == 2 && field("mode").Find("default")->AsString() == "Build", "an enum lists its names");
    Check(field("ids").Find("type")->Find("items")->Find("type")->AsString() == "integer", "a vector describes its items");
    Check(!Describe<Game::Node>().Dump().empty(), "a type that contains itself is described without recursing forever");

    return failures == 0 ? 0 : 1;
}