#include "pocketpy/interpreter/vm.h"
#include "pocketpy/common/memorypool.h"
#include "pocketpy/common/sstream.h"
#include "pocketpy/pocketpy.h"

static unsigned char* pk_default_import_file(const char* path){
    return NULL;
}

static void pk_default_stdout(const char* s){
    fprintf(stdout, "%s", s);
    fflush(stdout);
}

static void pk_default_stderr(const char* s){
    fprintf(stderr, "%s", s);
    fflush(stderr);
}

void pk_TypeInfo__ctor(pk_TypeInfo *self, py_Name name, Type base, PyObject* obj, const PyVar* module, bool subclass_enabled){
    memset(self, 0, sizeof(pk_TypeInfo));
    
    self->name = name;
    self->base = base;

    self->self = PyVar__fromobj(obj);
    self->module = module ? *module : PY_NULL;
    self->subclass_enabled = subclass_enabled;

    c11_vector__ctor(&self->annotated_fields, sizeof(py_Name));
}

void pk_TypeInfo__dtor(pk_TypeInfo *self){
    c11_vector__dtor(&self->annotated_fields);
}

// static int _py_print(const py_Ref args, int argc){
//     int length = py_tuple__len(args+0);
//     py_Str* sep;
//     py_Str* end;

//     int err;
//     err = py_tostr(args+1, &sep);
//     if(err) return err;
//     err = py_tostr(args+2, &end);
//     if(err) return err;

//     pk_SStream ss;
//     pk_SStream__ctor(&ss);

//     for(int i=0; i<length; i++){
//         const py_Ref item = py_tuple__getitem(args+0, i);
//         py_Str tmp;
//         int err = py_str(item, &tmp);
//         if(!err){
//             pk_SStream__write_Str(&ss, &tmp);
//             py_Str__dtor(&tmp);
//             if(i != length-1){
//                 pk_SStream__write_Str(&ss, sep);
//             }
//         }else{
//             py_Str__dtor(&tmp);
//             pk_SStream__dtor(&ss);
//             return err;
//         }
//     }
//     pk_SStream__write_Str(&ss, end);
//     py_Str out = pk_SStream__submit(&ss);
//     pk_current_vm->_stdout(py_Str__data(&out));
//     py_Str__dtor(&out);
//     return 0;
// }

static void do_builtin_bindings(){
    // py_Ref builtins = py_getmodule("builtins");
    // py_newfunction(py_reg(0), _py_print,
    //     "print(*args, sep=' ', end='\\n')",
    //     BindType_FUNCTION
    // );
    // py_setdict(builtins, py_name("hello"), py_reg(0));
}

void pk_VM__ctor(pk_VM* self){
    self->top_frame = NULL;

    pk_NameDict__ctor(&self->modules);
    c11_vector__ctor(&self->types, sizeof(pk_TypeInfo));

    self->StopIteration = PY_NULL;
    self->builtins = PY_NULL;
    self->main = PY_NULL;

    self->_ceval_on_step = NULL;
    self->_import_file = pk_default_import_file;
    self->_stdout = pk_default_stdout;
    self->_stderr = pk_default_stderr;

    self->last_error = NULL;
    self->last_retval = PY_NULL;

    self->__curr_class = NULL;
    self->__cached_object_new = NULL;
    self->__dynamic_func_decl = NULL;

    pk_ManagedHeap__ctor(&self->heap, self);
    ValueStack__ctor(&self->stack);

    self->True = (PyVar){.type=tp_bool, .is_ptr=true, .extra=1,
        ._obj=pk_ManagedHeap__gcnew(&self->heap, tp_bool, 0, 0),
    };
    self->False = (PyVar){.type=tp_bool, .is_ptr=true, .extra=0,
        ._obj=pk_ManagedHeap__gcnew(&self->heap, tp_bool, 0, 0),
    };
    self->None = (PyVar){.type=tp_none_type, .is_ptr=true,
        ._obj=pk_ManagedHeap__gcnew(&self->heap, tp_none_type, 0, 0),
    };
    self->NotImplemented = (PyVar){.type=tp_not_implemented_type, .is_ptr=true,
        ._obj=pk_ManagedHeap__gcnew(&self->heap, tp_not_implemented_type, 0, 0),
    };
    self->Ellipsis = (PyVar){.type=tp_ellipsis, .is_ptr=true,
        ._obj=pk_ManagedHeap__gcnew(&self->heap, tp_ellipsis, 0, 0),
    };

    /* Init Builtin Types */
    // 0: unused
    pk_TypeInfo__ctor(c11_vector__emplace(&self->types), 0, 0, NULL, NULL, false);
    #define validate(t, expr) if(t != (expr)) abort()

    validate(tp_object, pk_VM__new_type(self, "object", 0, NULL, true));
    validate(tp_type, pk_VM__new_type(self, "type", 1, NULL, false));

    validate(tp_int, pk_VM__new_type(self, "int", tp_object, NULL, false));
    validate(tp_float, pk_VM__new_type(self, "float", tp_object, NULL, false));
    validate(tp_bool, pk_VM__new_type(self, "bool", tp_object, NULL, false));
    validate(tp_str, pk_VM__new_type(self, "str", tp_object, NULL, false));

    validate(tp_list, pk_VM__new_type(self, "list", tp_object, NULL, false));
    validate(tp_tuple, pk_VM__new_type(self, "tuple", tp_object, NULL, false));

    validate(tp_slice, pk_VM__new_type(self, "slice", tp_object, NULL, false));
    validate(tp_range, pk_VM__new_type(self, "range", tp_object, NULL, false));
    validate(tp_module, pk_VM__new_type(self, "module", tp_object, NULL, false));

    validate(tp_function, pk_VM__new_type(self, "function", tp_object, NULL, false));
    validate(tp_nativefunc, pk_VM__new_type(self, "nativefunc", tp_object, NULL, false));
    validate(tp_bound_method, pk_VM__new_type(self, "bound_method", tp_object, NULL, false));

    validate(tp_super, pk_VM__new_type(self, "super", tp_object, NULL, false));
    validate(tp_exception, pk_VM__new_type(self, "Exception", tp_object, NULL, true));
    validate(tp_bytes, pk_VM__new_type(self, "bytes", tp_object, NULL, false));
    validate(tp_mappingproxy, pk_VM__new_type(self, "mappingproxy", tp_object, NULL, false));

    validate(tp_dict, pk_VM__new_type(self, "dict", tp_object, NULL, true));
    validate(tp_property, pk_VM__new_type(self, "property", tp_object, NULL, false));
    validate(tp_star_wrapper, pk_VM__new_type(self, "star_wrapper", tp_object, NULL, false));

    validate(tp_staticmethod, pk_VM__new_type(self, "staticmethod", tp_object, NULL, false));
    validate(tp_classmethod, pk_VM__new_type(self, "classmethod", tp_object, NULL, false));

    validate(tp_none_type, pk_VM__new_type(self, "NoneType", tp_object, NULL, false));
    validate(tp_not_implemented_type, pk_VM__new_type(self, "NotImplementedType", tp_object, NULL, false));
    validate(tp_ellipsis, pk_VM__new_type(self, "ellipsis", tp_object, NULL, false));

    validate(tp_op_call, pk_VM__new_type(self, "__op_call", tp_object, NULL, false));
    validate(tp_op_yield, pk_VM__new_type(self, "__op_yield", tp_object, NULL, false));

    validate(tp_syntax_error, pk_VM__new_type(self, "SyntaxError", tp_exception, NULL, false));
    validate(tp_stop_iteration, pk_VM__new_type(self, "StopIteration", tp_exception, NULL, false));
    #undef validate

    self->StopIteration = c11__at(pk_TypeInfo, &self->types, tp_stop_iteration)->self;
    self->builtins = *py_newmodule("builtins", NULL);
    
    /* Setup Public Builtin Types */
    Type public_types[] = {
        tp_object, tp_type,
        tp_int, tp_float, tp_bool, tp_str,
        tp_list, tp_tuple,
        tp_slice, tp_range,
        tp_bytes, tp_dict, tp_property,
        tp_exception, tp_stop_iteration, tp_syntax_error
    };

    for(int i=0; i<PK_ARRAY_COUNT(public_types); i++){
        Type t = public_types[i];
        pk_TypeInfo* ti = c11__at(pk_TypeInfo, &self->types, t);
        py_setdict(&self->builtins, ti->name, &ti->self);
    }
    py_setdict(&self->builtins, py_name("NotImplemented"), &self->NotImplemented);

    /* Do Buildin Bindings*/
    do_builtin_bindings();
    self->main = *py_newmodule("__main__", NULL);
}

void pk_VM__dtor(pk_VM* self){
    PK_DECREF(self->__dynamic_func_decl);
    // destroy all objects
    pk_ManagedHeap__dtor(&self->heap);
    // clear frames
    // ...
    pk_NameDict__dtor(&self->modules);
    c11_vector__dtor(&self->types);
    ValueStack__clear(&self->stack);
}

void pk_VM__push_frame(pk_VM* self, Frame* frame){
    frame->f_back = self->top_frame;
    self->top_frame = frame;
}

void pk_VM__pop_frame(pk_VM* self){
    assert(self->top_frame);
    Frame* frame = self->top_frame;
    self->top_frame = frame->f_back;
    Frame__delete(frame);
}

pk_FrameResult pk_VM__run_top_frame(pk_VM* self){
    return RES_RETURN;
}

Type pk_VM__new_type(pk_VM* self, const char* name, Type base, const PyVar* module, bool subclass_enabled){
    Type type = self->types.count;
    pk_TypeInfo* ti = c11_vector__emplace(&self->types);
    PyObject* typeobj = pk_ManagedHeap__gcnew(&self->heap, tp_type, 0, sizeof(Type));
    Type* value = PyObject__value(typeobj);
    *value = type;
    pk_TypeInfo__ctor(ti, py_name(name), base, typeobj, module, subclass_enabled);
    return type;
}

/****************************************/
void PyObject__delete(PyObject *self){
    pk_TypeInfo* ti = c11__getitem(pk_TypeInfo*, &pk_current_vm->types, self->type);
    if(ti->dtor) ti->dtor(PyObject__value(self));
    if(self->slots == -1) pk_NameDict__dtor(PyObject__dict(self));
    if(self->gc_is_large){
        free(self);
    }else{
        PoolObject_dealloc(self);
    }
}

void pk_ManagedHeap__mark(pk_ManagedHeap* self){
    // for(int i=0; i<self->no_gc.count; i++){
    //     PyObject* obj = c11__getitem(PyObject*, &self->no_gc, i);
    //     vm->__obj_gc_mark(obj);
    // }
    // vm->callstack.apply([vm](Frame& frame) {
    //     frame._gc_mark(vm);
    // });
    // vm->obj_gc_mark(vm->__last_exception);
    // vm->obj_gc_mark(vm->__curr_class);
    // vm->obj_gc_mark(vm->__c.error);
    // vm->__stack_gc_mark(vm->s_data.begin(), vm->s_data.end());
    // if(self->_gc_marker_ex) self->_gc_marker_ex((pkpy_VM*)vm);
}