#include "mwscriptbindings.hpp"

#include <components/lua/luastate.hpp>
#include <components/misc/strings/lower.hpp>

#include "../mwbase/environment.hpp"
#include "../mwbase/scriptmanager.hpp"
#include "../mwbase/world.hpp"
#include "../mwscript/globalscripts.hpp"
#include "../mwworld/esmstore.hpp"

#include "object.hpp"

#include <stdexcept>

namespace MWLua
{
    struct MWScriptRef
    {
        ESM::RefId mId;
        sol::optional<GObject> mObj;

        MWScript::Locals& getLocals()
        {
            if (mObj)
                return mObj->ptr().getRefData().getLocals();
            else
                return MWBase::Environment::get().getScriptManager()->getGlobalScripts().getLocals(mId);
        }
    };
    struct MWScriptVariables
    {
        MWScriptRef mRef;
    };
}

namespace sol
{
    template <>
    struct is_automagical<MWLua::MWScriptRef> : std::false_type
    {
    };
    template <>
    struct is_automagical<MWLua::MWScriptVariables> : std::false_type
    {
    };
    template <>
    struct is_automagical<ESM::Global> : std::false_type
    {
    };
}

namespace MWLua
{

    sol::table initMWScriptBindings(const Context& context)
    {
        sol::table api(context.mLua->sol(), sol::create);

        api["getGlobalScript"]
            = [](std::string_view recordId, sol::optional<GObject> player) -> sol::optional<MWScriptRef> {
            if (player.has_value() && player->ptr() != MWBase::Environment::get().getWorld()->getPlayerPtr())
                throw std::runtime_error("Second argument must either be a player or be missing");
            auto scriptId = ESM::RefId::deserializeText(recordId);
            if (MWBase::Environment::get().getScriptManager()->getGlobalScripts().getScriptIfPresent(scriptId))
                return MWScriptRef{ scriptId, sol::nullopt };
            else
                return sol::nullopt;
        };
        api["getLocalScript"] = [](const GObject& obj, sol::optional<GObject> player) -> sol::optional<MWScriptRef> {
            if (player.has_value() && player->ptr() != MWBase::Environment::get().getWorld()->getPlayerPtr())
                throw std::runtime_error("Second argument must either be a player or be missing");
            auto scriptId = obj.ptr().getRefData().getLocals().getScriptId();
            if (scriptId.empty())
                return sol::nullopt;
            return MWScriptRef{ scriptId, obj };
        };

        // In multiplayer it will be possible to have several instances (per player) of a single script,
        // so we will likely add functions returning Lua table of scripts.
        // api["getGlobalScripts"] = [](std::string_view recordId) -> list of scripts
        // api["getLocalScripts"] = [](const GObject& obj) -> list of scripts

        sol::state_view& lua = context.mLua->sol();
        sol::usertype<MWScriptRef> mwscript = context.mLua->sol().new_usertype<MWScriptRef>("MWScript");
        sol::usertype<MWScriptVariables> mwscriptVars
            = context.mLua->sol().new_usertype<MWScriptVariables>("MWScriptVariables");
        mwscript[sol::meta_function::to_string]
            = [](const MWScriptRef& s) { return std::string("MWScript{") + s.mId.toDebugString() + "}"; };
        mwscript["recordId"] = sol::readonly_property([](const MWScriptRef& s) { return s.mId.serializeText(); });
        mwscript["variables"] = sol::readonly_property([](const MWScriptRef& s) { return MWScriptVariables{ s }; });
        mwscript["object"] = sol::readonly_property([](const MWScriptRef& s) -> sol::optional<GObject> {
            if (s.mObj)
                return s.mObj;
            const MWScript::GlobalScriptDesc* script
                = MWBase::Environment::get().getScriptManager()->getGlobalScripts().getScriptIfPresent(s.mId);
            if (!script)
                throw std::runtime_error("Invalid MWScriptRef");
            const MWWorld::Ptr* ptr = script->getPtrIfPresent();
            if (ptr && !ptr->isEmpty())
                return GObject(*ptr);
            else
                return sol::nullopt;
        });
        mwscript["player"] = sol::readonly_property(
            [](const MWScriptRef&) { return GObject(MWBase::Environment::get().getWorld()->getPlayerPtr()); });
        mwscriptVars[sol::meta_function::index]
            = [](MWScriptVariables& s, std::string_view var) -> sol::optional<double> {
            if (s.mRef.getLocals().hasVar(s.mRef.mId, var))
                return s.mRef.getLocals().getVarAsDouble(s.mRef.mId, Misc::StringUtils::lowerCase(var));
            else
                return sol::nullopt;
        };
        mwscriptVars[sol::meta_function::new_index] = [](MWScriptVariables& s, std::string_view var, double val) {
            MWScript::Locals& locals = s.mRef.getLocals();
            if (!locals.setVar(s.mRef.mId, Misc::StringUtils::lowerCase(var), val))
                throw std::runtime_error(
                    "No variable \"" + std::string(var) + "\" in mwscript " + s.mRef.mId.toDebugString());
        };

        using GlobalStore = MWWorld::Store<ESM::Global>;
        sol::usertype<GlobalStore> globalStoreT = lua.new_usertype<GlobalStore>("ESM3_GlobalStore");
        const GlobalStore* globalStore = &MWBase::Environment::get().getWorld()->getStore().get<ESM::Global>();
        globalStoreT[sol::meta_function::to_string] = [](const GlobalStore& store) {
            return "ESM3_GlobalStore{" + std::to_string(store.getSize()) + " globals}";
        };
        globalStoreT[sol::meta_function::length] = [](const GlobalStore& store) { return store.getSize(); };
        globalStoreT[sol::meta_function::index]
            = sol::overload([](const GlobalStore& store, std::string_view globalId) -> sol::optional<float> {
                  auto g = store.search(ESM::RefId::deserializeText(globalId));
                  if (g == nullptr)
                      return sol::nullopt;
                  char varType = MWBase::Environment::get().getWorld()->getGlobalVariableType(globalId);
                  if (varType == 's' || varType == 'l')
                  {
                      return static_cast<float>(MWBase::Environment::get().getWorld()->getGlobalInt(globalId));
                  }
                  else
                  {
                      return MWBase::Environment::get().getWorld()->getGlobalFloat(globalId);
                  }
              });
        globalStoreT[sol::meta_function::new_index]
            = sol::overload([](const GlobalStore& store, std::string_view globalId, float val) {
                  auto g = store.search(ESM::RefId::deserializeText(globalId));
                  if (g == nullptr)
                      throw std::runtime_error("No variable \"" + std::string(globalId) + "\" in GlobalStore");
                  char varType = MWBase::Environment::get().getWorld()->getGlobalVariableType(globalId);
                  if (varType == 's' || varType == 'l')
                  {
                      MWBase::Environment::get().getWorld()->setGlobalInt(globalId, static_cast<int>(val));
                  }
                  else
                  {
                      MWBase::Environment::get().getWorld()->setGlobalFloat(globalId, val);
                  }
              });
        globalStoreT[sol::meta_function::pairs] = lua["ipairsForArray"].template get<sol::function>();
        globalStoreT[sol::meta_function::ipairs] = lua["ipairsForArray"].template get<sol::function>();
        api["getGlobalVariables"] = [globalStore](sol::optional<GObject> player) {
            if (player.has_value() && player->ptr() != MWBase::Environment::get().getWorld()->getPlayerPtr())
                throw std::runtime_error("First argument must either be a player or be missing");

            return globalStore;
        };
        return LuaUtil::makeReadOnly(api);
    }

}