//
// php-armadillo/php_arma.hh
//
// @Author CismonX
//

#ifndef PHP_ARMA_HH
#define PHP_ARMA_HH

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <php.h>
#include <zend_exceptions.h>

#include <type_traits>

#define PHP_ARMA_VERSION         "0.0.1"

#if PHP_VERSION_ID >= 70400
#define ZEND_ACC_CTOR            0
#endif

extern zend_module_entry arma_module_entry;

/// Helper macros for method entry.

#define Z_OBJNAME_P(zval_p)                                     \
    ZSTR_VAL(Z_OBJCE_P(zval_p)->name)

#define PHP_ARMA_START_ME_1(name, t1)                           \
    template <typename t1>                                      \
    struct name##_me                                            \
    {                                                           \
        static constexpr zend_function_entry const val[] = {

#define PHP_ARMA_END_ME_1(name, t1)                             \
            PHP_FE_END                                          \
        };                                                      \
    };                                                          \
    template <typename t1>                                      \
    constexpr zend_function_entry const name##_me<t1>::val[];

#define PHP_ARMA_ME(cls, func, flags, ...)                      \
    ZEND_FENTRY(func, ZEND_MN(cls##_##func<__VA_ARGS__>), nullptr, flags)

#define PHP_ARMA_METHODS(name, ...)                             \
    name##_me<__VA_ARGS__>::val

/// Helper macros for class entry and object handlers

#define PHP_ARMA_DECLARE_CE(name)                               \
    struct name##_components                                    \
    {                                                           \
        static zend_class_entry     *ce;                        \
    }

#define PHP_ARMA_DECLARE_CE_HANDLERS(name)                      \
    struct name##_components                                    \
    {                                                           \
        static zend_class_entry     *ce;                        \
        static zend_object_handlers  handlers;                  \
    }

#define PHP_ARMA_DEFINE_CE(name, ...)                           \
    zend_class_entry *name##_components<__VA_ARGS__>::ce

#define PHP_ARMA_DEFINE_OBJECT_HANDLER(name, ...)               \
    zend_object_handlers name##_components<__VA_ARGS__>::handlers

#define PHP_ARMA_CE(name, ...)                                  \
    name##_components<__VA_ARGS__>::ce

#define PHP_ARMA_HANDLERS(name, ...)                            \
    &name##_components<__VA_ARGS__>::handlers

#define PHP_ARMA_HANDLER_SET(name, handler, func, ...)          \
    (PHP_ARMA_HANDLERS(name, __VA_ARGS__))->handler = func<__VA_ARGS__>

namespace php_arma
{
    /// Helper functions for initializing class entry and object handlers.

    template <typename F>
    zend_class_entry *ce_init(const char *name, const zend_function_entry *methods, F init_func)
    {
        char full_name[30] = { "Arma\\" };
        strcat(full_name, name);
        zend_class_entry tmp_ce;
        INIT_CLASS_ENTRY_EX(tmp_ce, full_name, strlen(full_name), methods);
        return init_func(&tmp_ce);
    }

    template <typename F, typename... Ts>
    zend_class_entry *ce_init(const char *name, const zend_function_entry *methods, F init_func, Ts... parents)
    {
        auto ce = ce_init(name, methods, init_func);
        zend_class_implements(ce, sizeof...(Ts), parents...);
        return ce;
    }

    template <typename>
    zend_class_entry *class_register(const char *name, const zend_function_entry *methods)
    {
        return ce_init(name, methods, zend_register_internal_class);
    }

    template <typename... Ts>
    zend_class_entry *class_register(const char *name, const zend_function_entry *methods, Ts... interfaces)
    {
        return ce_init(name, methods, zend_register_internal_class, interfaces...);
    }

    template <typename>
    zend_class_entry *interface_register(const char *name)
    {
        // Although methods are declared in interfaces as you see in the stubs,
        // nothing is declared in the internal interface implementation.
        return ce_init(name, nullptr, zend_register_internal_class);
    }

    template <typename... Ts>
    zend_class_entry *interface_register(const char *name, Ts... parents)
    {
        return ce_init(name, nullptr, zend_register_internal_class, parents...);
    }

    zend_always_inline
    void const_declare(zend_class_entry *ce, const char *name, zend_long val)
    {
        zend_declare_class_constant_long(ce, name, strlen(name), val);
    }

    zend_always_inline
    void property_declare(zend_class_entry *ce, const char *name)
    {
        zend_declare_property_null(ce, name, strlen(name), ZEND_ACC_PUBLIC);
    }

    zend_always_inline
    void object_handlers_init(zend_object_handlers *handlers)
    {
        memcpy(handlers, &std_object_handlers, sizeof(zend_object_handlers));
    }

    template <typename T>
    zend_object *to_zend_object(T *obj)
    {
        return reinterpret_cast<zend_object*>(obj + 1);
    }

    template <typename T>
    T *to_native_object(zend_object *zobj)
    {
        return reinterpret_cast<T*>(zobj) - 1;
    }

    /// Helper functions for creating objects.

    template <typename T, typename F>
    zend_object *object_create(zend_class_entry *ce, F init)
    {
        auto obj = reinterpret_cast<T*>(ecalloc(1,
            sizeof(T) + sizeof(zend_object) + zend_object_properties_size(ce)));
        auto handlers = init(obj);
        auto zobj = to_zend_object(obj);
        zend_object_std_init(zobj, ce);
        zobj->handlers = handlers ? handlers : &std_object_handlers;
        return zobj;
    }

    zend_always_inline
    zend_object *object_create(zend_class_entry *ce, const zend_object_handlers *handlers = &std_object_handlers)
    {
        auto zobj = reinterpret_cast<zend_object*>(ecalloc(1,
            sizeof(zend_object) + zend_object_properties_size(ce)));
        zend_object_std_init(zobj, ce);
        object_properties_init(zobj, ce);
        zobj->handlers = handlers;
        return zobj;
    }

    /// Helper functions for handling scalar types.

    template <typename>
    struct false_type : std::false_type {};

    template <typename T>
    void assert_bad_type()
    {
        static_assert(false_type<T>::value, "Type should be zend_long, double or cx_double");
    }

    template <typename T>
    bool zval_is_scalar(zval *zv)
    {
        assert_bad_type<T>();
    }

    template <> zend_always_inline
    bool zval_is_scalar<double>(zval *zv)
    {
        return Z_TYPE_P(zv) == IS_DOUBLE;
    }

    template <> zend_always_inline
    bool zval_is_scalar<zend_long>(zval *zv)
    {
        return Z_TYPE_P(zv) == IS_LONG;
    }

    template <typename>
    struct scalar_type {};

    template <>
    struct scalar_type<double> {
        static const int value = IS_DOUBLE;
    };

    template <>
    struct scalar_type<zend_long> {
        static const int value = IS_LONG;
    };

    template <typename T>
    const char *scalar_type_name()
    {
        assert_bad_type<T>();
    }

    template <> zend_always_inline
    const char *scalar_type_name<double>()
    {
        return zend_get_type_by_const(IS_DOUBLE);
    }

    template <> zend_always_inline
    const char *scalar_type_name<zend_long>()
    {
        return zend_get_type_by_const(IS_LONG);
    }

    template <typename T>
    T zval_get_scalar(zval *zv)
    {
        assert_bad_type<T>();
    }

    template <> zend_always_inline
    double zval_get_scalar<double>(zval *zv)
    {
        return Z_DVAL_P(zv);
    }

    template <> zend_always_inline
    zend_long zval_get_scalar<zend_long>(zval *zv)
    {
        return Z_LVAL_P(zv);
    }

    zend_always_inline
    void zval_set_scalar(zval *zv, double val)
    {
        ZVAL_DOUBLE(zv, val);
    }

    zend_always_inline
    void zval_set_scalar(zval *zv, zend_long val)
    {
        ZVAL_LONG(zv, val);
    }

    zend_always_inline
    const char *zval_get_type_name(zval *zv)
    {
        if (Z_TYPE_P(zv) == IS_OBJECT) {
            return ZSTR_VAL(Z_OBJCE_P(zv)->name);
        } else {
            return zend_get_type_by_const(Z_TYPE_P(zv));
        }
    }

    /// Helper functions for throwing exceptions when errors occur.

    zend_always_inline
    void ex_bad_type(const char *expected, const char *got)
    {
        zend_throw_exception_ex(zend_ce_type_error, -1, "Bad type, expected %s, %s given.", expected, got);
    }

    template <typename T>
    bool zval_check_scalar(zval *zv)
    {
        if (!zval_is_scalar<T>(zv)) {
            ex_bad_type(scalar_type_name<T>(), zval_get_type_name(zv));
            return false;
        }
        return true;
    }

    zend_always_inline
    void object_set_property(zend_object *obj, size_t idx, zval *val)
    {
        zval_ptr_dtor(OBJ_PROP_NUM(obj, idx));
        ZVAL_COPY(OBJ_PROP_NUM(obj, idx), val);
    }
}

#endif // !PHP_ARMA_HH