/** @file
	Parser: @b hash parser class.

	Copyright (c) 2001-2005 ArtLebedev Group (http://www.artlebedev.com)
	Author: Alexandr Petrosian <paf@design.ru> (http://paf.design.ru)
*/

static const char * const IDENT_HASH_C="$Date: 2006/06/09 19:03:49 $";

#include "classes.h"
#include "pa_vmethod_frame.h"

#include "pa_request.h"
#include "pa_vhash.h"
#include "pa_vvoid.h"
#include "pa_sql_connection.h"
#include "pa_vtable.h"
#include "pa_vbool.h"
#include "pa_vmethod_frame.h"

// class

class MHash: public Methoded {
public: // VStateless_class
	Value* create_new_value(Pool&, HashStringValue&) { return new VHash(); }

public:
	MHash();
public: // Methoded
	bool used_directly() { return true; }
};

// global variable

DECLARE_CLASS_VAR(hash, new MHash, 0);

// externs

extern String cycle_data_name;

// methods

#ifndef DOXYGEN
class Hash_sql_event_handlers: public SQL_Driver_query_event_handlers {
	const String& statement_string; const char* statement_cstr;
	bool distinct;
	HashStringValue& rows_hash;
	HashStringValue* row_hash;
	int column_index;
	ArrayString columns;
	bool only_one_column;
	static VBool only_one_column_value;
public:
	Hash_sql_event_handlers(
		const String& astatement_string, const char* astatement_cstr,
		bool adistinct,
		HashStringValue& arows_hash): 
		statement_string(astatement_string), statement_cstr(astatement_cstr),
		distinct(adistinct),
		rows_hash(arows_hash),
		row_hash(0),
		column_index(0),
		only_one_column(false) {
	}
	bool add_column(SQL_Error& error, const char* str, size_t length) {
		try {
			columns+=new String(str, length, true);
			return false;
		} catch(...) {
			error=SQL_Error("exception occured in Hash_sql_event_handlers::add_column");
			return true;
		}
	}
	bool before_rows(SQL_Error& error) { 
		if(columns.count()<1) {
			error=SQL_Error("parser.runtime", "no columns");
			return true;
		}
		only_one_column=columns.count()==1;

		return false;
	}
	bool add_row(SQL_Error& /*error*/) {
		column_index=0;
		return false;
	}
	bool add_row_cell(SQL_Error& error, const char *ptr, size_t length) {
		try {
			String& cell=*new String;
			if(length)
				cell.append_know_length(ptr, length, String::L_TAINTED);
			bool duplicate=false;
			if(only_one_column) {
				duplicate=rows_hash.put_dont_replace(cell, &only_one_column_value);  // put. existed?
			} else if(column_index==0) {
				VHash* row_vhash=new VHash;
				row_hash=&row_vhash->hash();
				duplicate=rows_hash.put_dont_replace(cell, row_vhash); // put. existed?
			} else
				row_hash->put(*columns[column_index], new VString(cell));

			if(duplicate & !distinct) {
				error=SQL_Error("parser.runtime", "duplicate key");
				return true;
			}

			column_index++;
			return false;
		} catch(...) {
			error=SQL_Error("exception occured in Hash_sql_event_handlers::add_row_cell");
			return true;
		}
	}

};
VBool Hash_sql_event_handlers::only_one_column_value(true);

#endif

static void copy_all_overwrite_to(
								  HashStringValue::key_type key, 
								  HashStringValue::value_type value, 
								  HashStringValue* dest) {
	dest->put(key, value);
}
static void _create_or_add(Request& r, MethodParams& params) {
	if(params.count()) {
		Value& vsrc=params.as_no_junction(0, "param must be hash");
		if(HashStringValue* src=vsrc.get_hash()) {
			VHash& self=GET_SELF(r, VHash);
			HashStringValue* self_hash=&(self.hash());
			if(src==self_hash) // same: doing nothing
				return;
			src->for_each<HashStringValue*>(copy_all_overwrite_to, self_hash);

			if(VHash* vhash_src=static_cast<VHash*>(vsrc.as(VHASH_TYPE, false)))
			{
				if(Value* vdefault=vhash_src->get_default())
				{
					if(vdefault->is_defined())
					{
						self.set_default(vdefault);
					}
				}
			}
		}
	}
}

static void remove_key_from(
							HashStringValue::key_type key, 
							HashStringValue::value_type /*value*/, 
							HashStringValue* dest) {
	dest->remove(key);
}
static void _sub(Request& r, MethodParams& params) {
	Value& vsrc=params.as_no_junction(0, "param must be hash");
	if(HashStringValue* src=vsrc.get_hash()) {
		HashStringValue* self=&(GET_SELF(r, VHash).hash());
		if(src==self) { // same: clearing
			self->clear();
			return;
		}
		src->for_each<HashStringValue*>(remove_key_from, self);
	}
}

static void copy_all_dontoverwrite_to(
								  HashStringValue::key_type key, 
								  HashStringValue::value_type value, 
								  HashStringValue* dest) {
	dest->put_dont_replace(key, value);
}
static void _union(Request& r, MethodParams& params) {
	// dest = copy of self
	Value& result=*new VHash(GET_SELF(r, VHash).hash());
	// dest += b
	Value& vsrc=params.as_no_junction(0, "param must be hash");
	if(HashStringValue* src=vsrc.get_hash())
		src->for_each<HashStringValue*>(copy_all_dontoverwrite_to, result.get_hash());

	// return result
	r.write_no_lang(result);
}

#ifndef DOXYGEN
struct Copy_intersection_to_info {
	HashStringValue* b;
	HashStringValue* dest;
};
#endif
static void copy_intersection_to(
								 HashStringValue::key_type key, 
								 HashStringValue::value_type value, 
								 Copy_intersection_to_info *info) {
	if(info->b->get(key))
		info->dest->put_dont_replace(key, value);
}
static void _intersection(Request& r, MethodParams& params) {
	Value& result=*new VHash;
	// dest += b
	Value& vb=params.as_no_junction(0, "param must be hash");
	if(HashStringValue* b=vb.get_hash()) {
		Copy_intersection_to_info info={b, result.get_hash()};
		GET_SELF(r, VHash).hash().for_each<Copy_intersection_to_info*>(copy_intersection_to, &info);
	}

	// return result
	r.write_no_lang(result);
}

static bool intersects(
					   HashStringValue::key_type key, 
					   HashStringValue::value_type /*value*/, 
					   HashStringValue* b) {
	return b->get(key)!=0;
}

static void _intersects(Request& r, MethodParams& params) {
	bool result=false;

	Value& vb=params.as_no_junction(0, "param must be hash");
	if(HashStringValue* b=vb.get_hash())
		result=GET_SELF(r, VHash).hash().first_that<HashStringValue*>(intersects, b)!=0;

	// return result
	r.write_no_lang(*new VBool(result));
}


extern String sql_bind_name;
extern String sql_limit_name;
extern String sql_offset_name;
extern String sql_default_name;
extern String sql_distinct_name;
extern int marshal_binds(HashStringValue& hash, SQL_Driver::Placeholder*& placeholders);
extern void unmarshal_bind_updates(HashStringValue& hash, int placeholder_count, SQL_Driver::Placeholder* placeholders);

static void _sql(Request& r, MethodParams& params) {
	Value& statement=params.as_junction(0, "statement must be code");

	HashStringValue* bind=0;
	ulong limit=0;
	ulong offset=0;
	bool distinct=false;
	if(params.count()>1) {
		Value& voptions=params.as_no_junction(1, "options must be hash, not code");
		if(voptions.is_defined() && !voptions.is_string())
			if(HashStringValue* options=voptions.get_hash()) {
				int valid_options=0;
				if(Value* vbind=options->get(sql_bind_name)) {
					valid_options++;
					bind=vbind->get_hash();
				}
				if(Value* vlimit=options->get(sql_limit_name)) {
					valid_options++;
					limit=(ulong)r.process_to_value(*vlimit).as_double();
				}
				if(Value* voffset=options->get(sql_offset_name)) {
					valid_options++;
					offset=(ulong)r.process_to_value(*voffset).as_double();
				}
				if(Value* vdistinct=options->get(sql_distinct_name)) {
					valid_options++;
					distinct=r.process_to_value(*vdistinct).as_bool();
				}
				if(valid_options!=options->count())
					throw Exception("parser.runtime",
						0,
						"called with invalid option");
			} else
				throw Exception("parser.runtime",
					0,
					"options must be hash");
	}

	SQL_Driver::Placeholder* placeholders=0;
	uint placeholders_count=0;
	if(bind)
		placeholders_count=marshal_binds(*bind, placeholders);

	Temp_lang temp_lang(r, String::L_SQL);
	const String& statement_string=r.process_to_string(statement);
	const char* statement_cstr=
		statement_string.cstr(String::L_UNSPECIFIED, r.connection());
	HashStringValue& hash=GET_SELF(r, VHash).hash();
	hash.clear();	
	Hash_sql_event_handlers handlers(
		statement_string, statement_cstr, 
		distinct,
		hash);
	r.connection()->query(
		statement_cstr, 
		placeholders_count, placeholders,
		offset, limit,
		handlers,
		statement_string);

	if(bind)
		unmarshal_bind_updates(*bind, placeholders_count, placeholders);
}

static void keys_collector(
			   HashStringValue::key_type key, 
			   HashStringValue::value_type, 
			   Table *table) {
	Table::element_type row(new ArrayString);
	*row+=new String(key, String::L_TAINTED);
	*table+=row;
}
static void _keys(Request& r, MethodParams& params) {
	const String* keys_column_name;
	if(params.count()>0)
		keys_column_name=&params.as_string(0, "column name must be string");
	else 
		keys_column_name=new String("key");

	Table::columns_type columns(new ArrayString);
	*columns+=keys_column_name;
	Table* table=new Table(columns);

	GET_SELF(r, VHash).hash().for_each<Table*>(keys_collector, table);

	r.write_no_lang(*new VTable(table));
}

static void _count(Request& r, MethodParams&) {
	r.write_no_lang(*new VInt(GET_SELF(r, VHash).hash().count()));
}

static void _delete(Request& r, MethodParams& params) {

	GET_SELF(r, VHash).hash().remove(params.as_string(0, "key must be string"));
}

#ifndef DOXYGEN
struct Foreach_info {
	Request *r;
	const String* key_var_name;
	const String* value_var_name;
	Value* body_code;
	Value* delim_maybe_code;

	VString* vkey;
	bool need_delim;
};
#endif
static bool one_foreach_cycle(						   
			      HashStringValue::key_type akey, 
			      HashStringValue::value_type avalue, 
			      Foreach_info *info) {
	info->vkey->set_string(*new String(akey, String::L_TAINTED));
	Value& ncontext=*info->r->get_method_frame()->caller();
	ncontext.put_element(ncontext, *info->key_var_name, info->vkey, false);
	ncontext.put_element(ncontext, *info->value_var_name, avalue, false);

	StringOrValue sv_processed=info->r->process(*info->body_code);
	Request::Skip lskip=info->r->get_skip(); info->r->set_skip(Request::SKIP_NOTHING);
	const String* s_processed=sv_processed.get_string();
	if(info->delim_maybe_code && s_processed && s_processed->length()) { // delimiter set and we have body
		if(info->need_delim) // need delim & iteration produced string?
			info->r->write_pass_lang(info->r->process(*info->delim_maybe_code));
		info->need_delim=true;
	}
	info->r->write_pass_lang(sv_processed);

	return lskip==Request::SKIP_BREAK;
}
static void _foreach(Request& r, MethodParams& params) {
	Temp_hash_value<const String::Body, void*> 
		cycle_data_setter(r.classes_conf, cycle_data_name, /*any not null flag*/&r);

	Foreach_info info={
		&r,
		&params.as_string(0, "key-var name must be string"),
		&params.as_string(1, "value-var name must be string"),
		&params.as_junction(2, "body must be code"),
		params.count()>3?params.get(3):0,
		/*vkey=*/new VString,
		false
	};

	VHash& self=GET_SELF(r, VHash);
	HashStringValue& hash=self.hash();
	VHash_lock lock(self);
	hash.first_that<Foreach_info*>(one_foreach_cycle, &info);
}

// constructor

MHash::MHash(): Methoded("hash") 
{
	// ^hash::create[[copy_from]]
	add_native_method("create", Method::CT_DYNAMIC, _create_or_add, 0, 1);
	// ^hash.add[add_from]
	add_native_method("add", Method::CT_DYNAMIC, _create_or_add, 1, 1);
	// ^hash.sub[sub_from]
	add_native_method("sub", Method::CT_DYNAMIC, _sub, 1, 1);
	// ^a.union[b] = hash
	add_native_method("union", Method::CT_DYNAMIC, _union, 1, 1);
	// ^a.intersection[b] = hash
	add_native_method("intersection", Method::CT_DYNAMIC, _intersection, 1, 1);
	// ^a.intersects[b] = bool
	add_native_method("intersects", Method::CT_DYNAMIC, _intersects, 1, 1);

	// ^a.delete[key]
	add_native_method("delete", Method::CT_DYNAMIC, _delete, 1, 1);

	// ^hash:sql[query][options hash]
	add_native_method("sql", Method::CT_DYNAMIC, _sql, 1, 2);

	// ^hash._keys[[column name]]
	add_native_method("_keys", Method::CT_DYNAMIC, _keys, 0, 1);	

	// ^hash._count[]
	add_native_method("_count", Method::CT_DYNAMIC, _count, 0, 0);	

	// ^hash.foreach[key;value]{code}[delim]
	add_native_method("foreach", Method::CT_DYNAMIC, _foreach, 2+1, 2+1+1);
}