#include "ScriptEngine.h"
#include "Game.h"
#include <pybind11/embed.h>
#include <iostream>
#include <fstream>

namespace py = pybind11;

// Static pointer used by the embedded module (set before interpreter starts).
static ZL::Game* s_game = nullptr;

// The embedded module must be defined at file scope before the interpreter
// is started.  It exposes a minimal surface: one function per scripting command.
PYBIND11_EMBEDDED_MODULE(game_api, m) {
    m.doc() = "Game scripting API";

    // npc_walk_to(index, x, y, z, on_arrived=None)
    // Tells the NPC at `index` to walk to (x,y,z).
    // on_arrived is an optional Python callable invoked once when the NPC arrives.
    // It can call npc_walk_to again (or anything else) to chain behaviour.
    m.def("npc_walk_to", [](int index, float x, float y, float z, py::object on_arrived) {
        if (!s_game) {
            std::cerr << "[script] game_api.npc_walk_to: engine not ready\n";
            return;
        }
        auto& npcs = s_game->npcs;
        if (index < 0 || index >= static_cast<int>(npcs.size())) {
            std::cerr << "[script] game_api.npc_walk_to: index " << index
                      << " out of range (0.." << npcs.size() - 1 << ")\n";
            return;
        }
        std::function<void()> cb;
        if (!on_arrived.is_none()) {
            cb = [on_arrived]() {
                try {
                    on_arrived();
                } catch (const py::error_already_set& e) {
                    std::cerr << "[script] on_arrived callback error:\n" << e.what() << "\n";
                }
            };
        }
        npcs[index]->setTarget(Eigen::Vector3f(x, y, z), std::move(cb));
    },
    py::arg("index"), py::arg("x"), py::arg("y"), py::arg("z"),
    py::arg("on_arrived") = py::none(),
    "Command NPC[index] to walk to (x,y,z). on_arrived is called when the NPC arrives.");
}

namespace ZL {

ScriptEngine::ScriptEngine() = default;
ScriptEngine::~ScriptEngine() = default;

void ScriptEngine::init(Game* game) {
    s_game = game;
    interpreter = std::make_unique<py::scoped_interpreter>();
    runScript("resources/start.py");
}

void ScriptEngine::runScript(const std::string& path) {
    std::ifstream file(path);
    if (!file.is_open()) {
        std::cerr << "[script] Could not open script: " << path << "\n";
        return;
    }
    std::string source((std::istreambuf_iterator<char>(file)),
                        std::istreambuf_iterator<char>());
    try {
        py::exec(source);
    } catch (const py::error_already_set& e) {
        std::cerr << "[script] Error in " << path << ":\n" << e.what() << "\n";
    }
}

} // namespace ZL