/** @file
	Parser: executor part of request class.

	Copyright (c) 2001 ArtLebedev Group (http://www.artlebedev.com)

	Author: Alexander Petrosyan <paf@design.ru> (http://design.ru/paf)

	$Id: execute.C,v 1.131 2001/03/27 18:24:38 paf Exp $
*/

#include "pa_config_includes.h"
#include "code.h"
#include "pa_array.h" 
#include "pa_request.h"
#include "pa_vstring.h"
#include "pa_vhash.h"
#include "pa_vunknown.h"
#include "pa_vcframe.h"
#include "pa_vmframe.h"
#include "pa_vobject.h"
#include "pa_vdouble.h"
#include "pa_vbool.h"
#include "pa_vtable.h"

#include <stdio.h>

#define PUSH(value) stack.push(value)
#define POP() static_cast<Value *>(stack.pop())
#define POP_NAME() static_cast<Value *>(stack.pop())->as_string()


char *opcode_name[]={
	// literals
	"VALUE",  "CURLY_CODE__STORE_PARAM",  "EXPR_CODE__STORE_PARAM",

	// actions
	"WITH_SELF",	"WITH_ROOT",	"WITH_READ",	"WITH_WRITE",
	"GET_CLASS",
	"CONSTRUCT_VALUE",  "CONSTRUCT_DOUBLE",
	"WRITE_VALUE",  "WRITE_EXPR_RESULT",  "STRING__WRITE",
	"GET_ELEMENT",	"GET_ELEMENT__WRITE",
	"CREATE_EWPOOL",	"REDUCE_EWPOOL",
	"CREATE_RWPOOL",	"REDUCE_RWPOOL",
  	"CREATE_SWPOOL",	"REDUCE_SWPOOL",
	"GET_METHOD_FRAME",
	"STORE_PARAM",
	"CALL",

	// expression ops: unary
	"NEG", "INV", "NOT", "DEF", "IN", "FEXISTS",
	// expression ops: binary
	"SUB", "ADD", "MUL", "DIV", "MOD",
	"BIN_AND", "BIN_OR", "BIN_XOR",
	"LOG_AND", "LOG_OR", "LOG_XOR",
	"NUM_LT", "NUM_GT", "NUM_LE", "NUM_GE", "NUM_EQ", "NUM_NE",
	"STR_LT", "STR_GT", "STR_LE", "STR_GE", "STR_EQ", "STR_NE",
	"IS"
};

void va_log_printf(Pool& pool, const char *fmt,va_list args) {
	return;
	char buf[MAX_STRING];
	vsnprintf(buf, MAX_STRING, fmt, args);
	SAPI::log(pool, "%s", buf);
}

void log_printf(Pool& pool, const char *fmt, ...) {
    va_list args;
    va_start(args,fmt);
    va_log_printf(pool,fmt,args);
    va_end(args);
}

void dump(Pool& pool, int level, const Array& ops) {
	if(0){
		int size=ops.size();
		//log_printf(pool, "size=%d\n", size);
		for(int i=0; i<size; i++) {
			Operation op;
			op.cast=ops.quick_get(i);
			log_printf(pool, "%8X\n", op.cast);
		}
	}

	int size=ops.size();
	//log_printf(pool, "size=%d\n", size);
	for(int i=0; i<size; i++) {
		Operation op;
		op.cast=ops.quick_get(i);
		log_printf(pool, "%*s%s", level*4, "", opcode_name[op.code]);

		if(op.code==OP_VALUE || op.code==OP_STRING__WRITE) {
			Value *value=static_cast<Value *>(ops.quick_get(++i));
			log_printf(pool, " \"%s\" %s", value->get_string()->cstr(), value->type());
		}
		//\log_printf(pool, "\n");

		if(op.code==OP_CURLY_CODE__STORE_PARAM || op.code==OP_EXPR_CODE__STORE_PARAM) {
			const Array *local_ops=reinterpret_cast<const Array *>(ops.quick_get(++i));
			dump(pool, level+1, *local_ops);
		}
	}
}

void Request::execute(const Array& ops) {
	if(1) {
		log_printf(pool(), "source----------------------------\n");
		dump(pool(), 0, ops);
		log_printf(pool(), "execution-------------------------\n");
	}

	int size=ops.size();
	//log_printf(pool(), "size=%d\n", size);
	for(int i=0; i<size; i++) {
		Operation op;
		op.cast=ops.quick_get(i);
		log_printf(pool(), "%d:%s", stack.top_index()+1, opcode_name[op.code]);

		switch(op.code) {
		// param in next instruction
		case OP_VALUE:
			{
				Value *value=static_cast<Value *>(ops.quick_get(++i));
				log_printf(pool(), " \"%s\" %s", value->get_string()->cstr(), value->type());
				PUSH(value);
				break;
			}
		case OP_CURLY_CODE__STORE_PARAM:
		case OP_EXPR_CODE__STORE_PARAM:
			{
				VMethodFrame *frame=static_cast<VMethodFrame *>(stack.top_value());
				// code
				const Array *local_ops=reinterpret_cast<const Array *>(ops.quick_get(++i));
				log_printf(pool(), " (%d)\n", local_ops->size());
				dump(pool(), 1, *local_ops);
				
				// when called method of some object, specifying object literally,
				// e.g ^t.menu, code of curly params must be executed 
				// in r/w context of that object.
				// otherwise in current r/w context.
				//
				// when they evaluate expression parameter,
				// the object expression result
				// does not need to be written into calling frame
				// it must go into any expressions using that parameter
				// hence, zeroing junction.wcontext being created
				// later, in .process we would test that field 
				// in decision "which wwrapper to use"
				Junction& j=*NEW Junction(pool(), 
					*self, 0, 0,
					root, 
					wcontext->somebody_entered_some_object()>1?
						&frame->junction.self /* ^t.menu{} */:rcontext/* ^if() */, 
					op.code==OP_EXPR_CODE__STORE_PARAM?
						0:wcontext->somebody_entered_some_object()>1?
							frame/* ^t.menu{} */:wcontext/* ^if() */, 
					local_ops);
				
				Value *value=NEW VJunction(j);

				// store param
				frame->store_param(frame->name(), value);
				break;
			}
		case OP_GET_CLASS:
			{
				// maybe they do ^class:method[] call, remember the fact
				wcontext->set_somebody_entered_some_class();

				const String& name=POP_NAME();
				Value *value=static_cast<Value *>(classes().get(name));
				if(!value) 
					THROW(0,0,
						&name,
						": undefined class"); 

				PUSH(value);
				break;
			}
			
		// OP_WITH
		case OP_WITH_SELF: 
			{
				PUSH(self);
				break;
			}
		case OP_WITH_ROOT: 
			{
				PUSH(root);
				break;
			}
		case OP_WITH_READ: 
			{
				PUSH(rcontext);
				break;
			}
		case OP_WITH_WRITE: 
			{
				PUSH(wcontext);
				break;
			}
			
		// OTHER ACTIONS BUT WITHs
		case OP_CONSTRUCT_VALUE:
			{
				Value *value=POP();
				const String& name=POP_NAME();
				Value *ncontext=POP();
				ncontext->put_element(name, value);
				value->set_name(name);
				break;
			}
		case OP_CONSTRUCT_EXPR:
			{
				Value *value=POP();
				const String& name=POP_NAME();
				Value *ncontext=POP();
				ncontext->put_element(name, value->as_expr_result());
				value->set_name(name);
				break;
			}
		case OP_WRITE_VALUE:
			{
				Value *value=POP();
				write_assign_lang(*value);
				break;
			}
		case OP_WRITE_EXPR_RESULT:
			{
				Value *value=POP();
				write_expr_result(*value->as_expr_result());
				break;
			}
		case OP_STRING__WRITE:
			{
				VString *vstring=static_cast<VString *>(ops.quick_get(++i));
				log_printf(pool(), " \"%s\"", vstring->string().cstr());
				write_no_lang(vstring->string());
				break;
			}
			
		case OP_GET_ELEMENT:
			{
				// maybe they do ^object.method[] call, remember the fact
				wcontext->inc_somebody_entered_some_object();

				Value *value=get_element();
				PUSH(value);
				break;
			}

		case OP_GET_ELEMENT__WRITE:
			{
				Value *value=get_element();
				write_assign_lang(*value);
				break;
			}


		case OP_CREATE_EWPOOL:
			{
				PUSH(wcontext);
				wcontext=NEW WWrapper(pool(), 0 /* empty */, true /* constructing */);
				break;
			}
		case OP_REDUCE_EWPOOL:
			{
				Value *value=wcontext->result();
				wcontext=static_cast<WContext *>(POP());
				PUSH(value);
				break;
			}
			
		case OP_CREATE_RWPOOL:
			{
				Value *ncontext=POP();
				PUSH(rcontext);
				rcontext=ncontext;
				PUSH(wcontext);
				wcontext=NEW WWrapper(pool(), ncontext, false /* not constructing */);
				break;
			}
		case OP_REDUCE_RWPOOL:
			{
				const String *string=wcontext->get_string();
				Value *value;
				if(string)
					value=NEW VString(*string);
				else
					value=NEW VUnknown(pool());
				wcontext=static_cast<WContext *>(POP());
				rcontext=POP();
				PUSH(value);
				break;
			}
		case OP_CREATE_SWPOOL:
			{
				PUSH(wcontext);
				wcontext=NEW WWrapper(pool(), 0 /* empty */, false /* not constructing */);
				break;
			}
		case OP_REDUCE_SWPOOL:
			{
				// from "$a $b" part of expression taking only string value,
				// ignoring any other content of wcontext
				const String *string=wcontext->get_string();
				Value *value;
				if(string)
					value=NEW VString(*string);
				else
					NEW VUnknown(pool());
				wcontext=static_cast<WContext *>(POP());
				PUSH(value);
				break;
			}

		// CALL
		case OP_GET_METHOD_FRAME:
			{
				Value *value=POP();
				// info: 
				//	code compiled so that this one's always method-junction, 
				//	not a code-junction
				Junction *junction=value->get_junction();
				if(!junction)
					THROW(0,0,
						&value->name(),
						"(%s) not a method or junction, can not call it",
							value->type()); 

				VMethodFrame *frame=NEW VMethodFrame(pool(), *junction);
				frame->set_name(value->name());
				PUSH(frame);
				break;
			}
		case OP_STORE_PARAM:
			{
				Value *value=POP();
				VMethodFrame *frame=static_cast<VMethodFrame *>(stack.top_value());
				frame->store_param(frame->name(), value);
				break;
			}

		case OP_CALL:
			{
				log_printf(pool(), "->\n");
				VMethodFrame *frame=static_cast<VMethodFrame *>(POP());
				frame->fill_unspecified_params();
				PUSH(self);  
				PUSH(root);  
				PUSH(rcontext);  
				PUSH(wcontext); 
				
				VStateless_class *called_class=frame->junction.self.get_class();
				// is context object or class & is it my class or my parent's class?
				VStateless_class *read_class=rcontext->get_class();
				if(read_class && read_class->is_or_derived_from(*called_class)) // yes
					self=rcontext; // class dynamic call
				else // no, not me or relative of mine (total stranger)
					if(
						wcontext->constructing() && // constructing?
						wcontext->somebody_entered_some_class()) { // ^class:method[..]?
						// yes, this is a constructor call
						// some stateless_object derivates with constructors
						if(called_class==table_class)
							self=NEW VTable(pool());
						else // stateful object
							self=NEW VObject(pool(), *called_class);
						frame->write(*self, 
							String::UL_NO  // not used, always an object, not string
						);
					} else 
						self=&frame->junction.self; // no, static or simple dynamic call

				frame->set_self(*self);
				root=rcontext=wcontext=frame;
				{
					// take object or class from any wrappers
					// and substitute class alias to the class they are called AS
					Temp_alias temp_alias(*self->get_aliased(), *frame->junction.vclass);

					const Method& method=*frame->junction.method;
					if(method.native_code) { // native code?
						method.check_actual_numbered_params(
							frame->junction.self, 
							frame->name(), frame->numbered_params());
						(*method.native_code)(
							*this, 
							frame->name(), frame->numbered_params()); // execute it
					} else // parser code
						execute(*method.parser_code); // execute it
				}
				Value *value=wcontext->result();

				wcontext=static_cast<WContext *>(POP());  
				rcontext=POP();  
				root=POP();  
				self=static_cast<VAliased *>(POP());

				PUSH(value);
				log_printf(pool(), "<-returned");
				break;
			}

		// expression ops: unary
		case OP_NEG:
			{
				Value *operand=POP();
				Value *value=NEW VDouble(pool(), -operand->as_double());
				PUSH(value);
				break;
			}
		case OP_INV:
			{
				Value *operand=POP();
				Value *value=NEW VDouble(pool(), ~(int)operand->as_double());
				PUSH(value);
				break;
			}
		case OP_NOT:
			{
				Value *operand=POP();
				Value *value=NEW VBool(pool(), !operand->as_bool());
				PUSH(value);
				break;
			}
		case OP_DEF:
			{
				Value *operand=POP();
				Value *value=NEW VBool(pool(), operand->is_defined());
				PUSH(value);
				break;
			}
		case OP_IN:
			{
				Value *operand=POP();
				const char *path=operand->as_string().cstr();
				Value *value=NEW VBool(pool(), info.uri && strcmp(path, info.uri)<=0);
				PUSH(value);
				break;
			}
		case OP_FEXISTS:
			{
				Value *operand=POP();
				Value *value=NEW VBool(pool(), 
					file_readable(absolute(operand->as_string())));
				PUSH(value);
				break;
			}

		// expression ops: binary
		case OP_SUB: 
			{
				Value *b=POP();  Value *a=POP();
				Value *value=NEW VDouble(pool(), a->as_double() - b->as_double());
				PUSH(value);
				break;
			}
		case OP_ADD: 
			{
				Value *b=POP();  Value *a=POP();
				Value *value=NEW VDouble(pool(), a->as_double() + b->as_double());
				PUSH(value);
				break;
			}
		case OP_MUL: 
			{
				Value *b=POP();  Value *a=POP();
				Value *value=NEW VDouble(pool(), a->as_double() * b->as_double());
				PUSH(value);
				break;
			}
		case OP_DIV: 
			{
				Value *b=POP();  Value *a=POP();
				Value *value=NEW VDouble(pool(), a->as_double() / b->as_double());
				PUSH(value);
				break;
			}
		case OP_MOD: 
			{
				Value *b=POP();  Value *a=POP();
				Value *value=NEW VDouble(pool(), 
					(int)a->as_double() %
					(int)b->as_double());
				PUSH(value);
				break;
			}
		case OP_BIN_AND:
			{
				Value *b=POP();  Value *a=POP();
				Value *value=NEW VDouble(pool(), 
					(int)a->as_double() &
					(int)b->as_double());
				PUSH(value);
				break;
			}
		case OP_BIN_OR:
			{
				Value *b=POP();  Value *a=POP();
				Value *value=NEW VDouble(pool(), 
					(int)a->as_double() |
					(int)b->as_double());
				PUSH(value);
				break;
			}
		case OP_BIN_XOR:
			{
				Value *b=POP();  Value *a=POP();
				Value *value=NEW VDouble(pool(), 
					(int)a->as_double() ^
					(int)b->as_double());
				PUSH(value);
				break;
			}
		case OP_LOG_AND:
			{
				Value *b=POP();  Value *a=POP();
				Value *value=NEW VBool(pool(), a->as_bool() && b->as_bool());
				PUSH(value);
				break;
			}
		case OP_LOG_OR:
			{
				Value *b=POP();  Value *a=POP();
				Value *value=NEW VBool(pool(), a->as_bool() || b->as_bool());
				PUSH(value);
				break;
			}
		case OP_LOG_XOR:
			{
				Value *b=POP();  Value *a=POP();
				Value *value=NEW VBool(pool(), a->as_bool() ^ b->as_bool());
				PUSH(value);
				break;
			}
		case OP_NUM_LT: 
			{
				Value *b=POP();  Value *a=POP();
				Value *value=NEW VBool(pool(), a->as_double() < b->as_double());
				PUSH(value);
				break;
			}
		case OP_NUM_GT: 
			{
				Value *b=POP();  Value *a=POP();
				Value *value=NEW VBool(pool(), a->as_double() > b->as_double());
				PUSH(value);
				break;
			}
		case OP_NUM_LE: 
			{
				Value *b=POP();  Value *a=POP();
				Value *value=NEW VBool(pool(), a->as_double() <= b->as_double());
				PUSH(value);
				break;
			}
		case OP_NUM_GE: 
			{
				Value *b=POP();  Value *a=POP();
				Value *value=NEW VBool(pool(), a->as_double() >= b->as_double());
				PUSH(value);
				break;
			}
		case OP_NUM_EQ: 
			{
				Value *b=POP();  Value *a=POP();
				Value *value=NEW VBool(pool(), a->as_double() == b->as_double());
				PUSH(value);
				break;
			}
		case OP_NUM_NE: 
			{
				Value *b=POP();  Value *a=POP();
				Value *value=NEW VBool(pool(), a->as_double() != b->as_double());
				PUSH(value);
				break;
			}
		case OP_STR_LT: 
			{
				Value *b=POP();  Value *a=POP();
				Value *value=NEW VBool(pool(), a->as_string() < b->as_string());
				PUSH(value);
				break;
			}
		case OP_STR_GT: 
			{
				Value *b=POP();  Value *a=POP();
				Value *value=NEW VBool(pool(), a->as_string() > b->as_string());
				PUSH(value);
				break;
			}
		case OP_STR_LE: 
			{
				Value *b=POP();  Value *a=POP();
				Value *value=NEW VBool(pool(), a->as_string() <= b->as_string());
				PUSH(value);
				break;
			}
		case OP_STR_GE: 
			{
				Value *b=POP();  Value *a=POP();
				Value *value=NEW VBool(pool(), a->as_string() >= b->as_string());
				PUSH(value);
				break;
			}
		case OP_STR_EQ: 
			{
				Value *b=POP();  Value *a=POP();
				Value *value=NEW VBool(pool(), a->as_string() == b->as_string());
				PUSH(value);
				break;
			}
		case OP_STR_NE: 
			{
				Value *b=POP();  Value *a=POP();
				Value *value=NEW VBool(pool(), a->as_string() != b->as_string());
				PUSH(value);
				break;
			}
		case OP_IS:
			{
				Value *b=POP();  Value *a=POP();
				Value *value=NEW VBool(pool(), b->as_string() == a->type());
				PUSH(value);
				break;
			}

		default:
			THROW(0,0,
				0,
				"unhandled '%s' opcode", opcode_name[op.code]); 
		}
		//\log_printf(pool(), "\n");
	}
}

Value *Request::get_element() {
	const String& name=POP_NAME();
	Value *ncontext=POP();
	Value *value=ncontext->get_element(name);

	if(value)
		value=&process(*value, &name); // process possible code-junction
	else {
		value=NEW VUnknown(pool());
		value->set_name(name);
	}

	return value;
}

/**
	intercept_string:
	- true:
		they want result=string value, 
		possible object result goes to wcontext
	- false:
		they want any result[string|object]
		nothing goes to wcontext.
		used in @c (expression) params evaluation
*/
Value& Request::process(Value& value, const String *name, bool intercept_string) {
	Value *result;
	Junction *junction=value.get_junction();
	if(junction && junction->code) { // is it a code-junction?
		// process it
		log_printf(pool(), "ja->\n");
		PUSH(self);  
		PUSH(root);  
		PUSH(rcontext);  
		PUSH(wcontext);
		
		WContext *frame;
		// for expression method params
		// wcontext is set 0
		// using the fact in decision "which wwrapper to use"
		bool using_code_frame=intercept_string && junction->wcontext;
		if(using_code_frame) {
			// almost plain wwrapper about junction wcontext, 
			// BUT intercepts string writes
			frame=NEW VCodeFrame(pool(), *junction->wcontext);  
		} else {
			// plain wwrapper
			frame=NEW WWrapper(pool(), 0/*empty*/, false/*not constructing*/);
		}
		
		wcontext=frame;
		self=&junction->self;
		root=junction->root;
		rcontext=junction->rcontext;
		execute(*junction->code);
		if(using_code_frame) {
			// CodeFrame soul:
			//   string writes were intercepted
			//   returning them as the result of getting code-junction
			result=NEW VString(*frame->get_string());
		} else 
			result=frame->result();
		
		wcontext=static_cast<WContext *>(POP());  
		rcontext=POP();  
		root=POP();  
		self=static_cast<VAliased *>(POP());
		
		log_printf(pool(), "<-ja returned");
	} else
		result=&value;

	if(name)
		result->set_name(*name);
	return *result;
}

const String *Request::execute_method(Value& aself, const Method& method, bool return_cstr) {
	PUSH(self);  
	PUSH(root);  
	PUSH(rcontext);  
	PUSH(wcontext);
	
	// initialize contexts
	root=rcontext=self=&aself;
	wcontext=NEW WWrapper(pool(), &aself, false /* not constructing */);
	
	// execute!	
	execute(*method.parser_code);
	
	// result
	const String *result;
	if(return_cstr)
		result=&wcontext->as_string();
	else
		result=0; // ignore result
	
	wcontext=static_cast<WContext *>(POP());  
	rcontext=POP();  
	root=POP();  
	self=static_cast<VAliased *>(POP());
	
	// return
	return result;
}

const String *Request::execute_method(Value& aself, 
							  const String& method_name, bool return_cstr) {
	if(Value *value=aself.get_element(method_name))
		if(Junction *junction=value->get_junction())
			if(const Method *method=junction->method) 
				return execute_method(aself, *method, return_cstr);

	return 0;
}