/*
 * This file is a part of morm
 * and is distributed under the 2-Clause BSD licence.
 * Author: Tomasz Sowa <t.sowa@ttmath.org>
 */

/*
 * Copyright (c) 2018-2023, Tomasz Sowa
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 */

#include "dbexpression.h"
#include "model.h"


namespace morm
{


DbExpression::DbExpression()
{
}


DbExpression::~DbExpression()
{
}


bool DbExpression::can_field_be_generated(const FT & field_type)
{
	if( output_type == MORM_OUTPUT_TYPE_DB_INSERT )
	{
		return field_type.is_insertable();
	}
	else
	if(	output_type == MORM_OUTPUT_TYPE_DB_UPDATE )
	{
		return field_type.is_updatable();
	}
	else
	if( output_type == MORM_OUTPUT_TYPE_DB_PRIMARY_KEY ||
		output_type == MORM_OUTPUT_TYPE_JOIN_TABLES ||
		output_type == MORM_OUTPUT_TYPE_DB_INSERT_PRIMARY_KEY ||
		output_type == MORM_OUTPUT_TYPE_DB_UPDATE_PRIMARY_KEY )
	{
		return field_type.is_primary_key();
	}
	else
	{
		return true;
	}
}



void DbExpression::field_before()
{
	BaseExpression::field_before();

	if( !is_first_field )
	{
		if( output_type == MORM_OUTPUT_TYPE_DB_INSERT ||
			output_type == MORM_OUTPUT_TYPE_DB_UPDATE ||
			output_type == MORM_OUTPUT_TYPE_SELECT_COLUMNS )
		{
			(*out_stream) << ", ";
		}
		else
		if( output_type == MORM_OUTPUT_TYPE_DB_PRIMARY_KEY )
		{
			(*out_stream) << " AND ";
		}
		else
		if( output_type == MORM_OUTPUT_TYPE_DB_INSERT_PRIMARY_KEY ||
			output_type == MORM_OUTPUT_TYPE_DB_UPDATE_PRIMARY_KEY )
		{
			(*out_stream) << ", ";
		}
		else
		if( output_type == MORM_OUTPUT_TYPE_WHERE_EQ ||
			output_type == MORM_OUTPUT_TYPE_WHERE_GE ||
			output_type == MORM_OUTPUT_TYPE_WHERE_GT ||
			output_type == MORM_OUTPUT_TYPE_WHERE_LE ||
			output_type == MORM_OUTPUT_TYPE_WHERE_LT ||
			output_type == MORM_OUTPUT_TYPE_WHERE_NOT_EQ ||
			output_type == MORM_OUTPUT_TYPE_WHERE_IN ||
			output_type == MORM_OUTPUT_TYPE_WHERE_LIKE ||
			output_type == MORM_OUTPUT_TYPE_WHERE_ILIKE ||
			output_type == MORM_OUTPUT_TYPE_WHERE_IS_NULL ||
			output_type == MORM_OUTPUT_TYPE_WHERE_IS_NOT_NULL )
		{
			int conjunction = MORM_CONJUNCTION_AND;

			if( !conjunctions.empty() )
			{
				conjunction = conjunctions.back();
			}

			if( conjunction == MORM_CONJUNCTION_AND )
			{
				(*out_stream) << " AND ";
			}
			else
			if( conjunction == MORM_CONJUNCTION_OR )
			{
				(*out_stream) << " OR ";
			}
		}
	}
}

void DbExpression::put_name_value_separator()
{
	if( output_type == MORM_OUTPUT_TYPE_DB_PRIMARY_KEY ||
		output_type == MORM_OUTPUT_TYPE_WHERE_EQ ||
		output_type == MORM_OUTPUT_TYPE_DB_UPDATE ||
		output_type == MORM_OUTPUT_TYPE_DB_INSERT_PRIMARY_KEY ||
		output_type == MORM_OUTPUT_TYPE_DB_UPDATE_PRIMARY_KEY )
	{
		(*out_stream) << "=";
	}
	else
	if( output_type == MORM_OUTPUT_TYPE_WHERE_NOT_EQ )
	{
		(*out_stream) << "<>";
	}
	else
	if( output_type == MORM_OUTPUT_TYPE_WHERE_LT )
	{
		(*out_stream) << "<";
	}
	else
	if( output_type == MORM_OUTPUT_TYPE_WHERE_GT )
	{
		(*out_stream) << ">";
	}
	else
	if( output_type == MORM_OUTPUT_TYPE_WHERE_LE )
	{
		(*out_stream) << "<=";
	}
	else
	if( output_type == MORM_OUTPUT_TYPE_WHERE_GE )
	{
		(*out_stream) << ">=";
	}
	else
	if( output_type == MORM_OUTPUT_TYPE_WHERE_IN )
	{
		(*out_stream) << " IN ";
	}
	else
	if( output_type == MORM_OUTPUT_TYPE_WHERE_LIKE )
	{
		(*out_stream) << " LIKE ";
	}
	else
	if( output_type == MORM_OUTPUT_TYPE_WHERE_ILIKE )
	{
		(*out_stream) << " ILIKE ";
	}
	else
	if( output_type == MORM_OUTPUT_TYPE_WHERE_IS_NULL )
	{
		(*out_stream) << " IS NULL ";
	}
	else
	if( output_type == MORM_OUTPUT_TYPE_WHERE_IS_NOT_NULL )
	{
		(*out_stream) << " IS NOT NULL ";
	}
}


void DbExpression::schema_table_separator()
{
	(*out_stream) << '.';
}


void DbExpression::table_field_separator()
{
	(*out_stream) << '.';
}


void DbExpression::alias_names_separator()
{
	(*out_stream) << '.';
}


void DbExpression::before_schema_name()
{
	(*out_stream) << '"';
}


void DbExpression::after_schema_name()
{
	(*out_stream) << '"';
}


void DbExpression::before_table_name()
{
	(*out_stream) << '"';
}


void DbExpression::after_table_name()
{
	(*out_stream) << '"';
}


void DbExpression::before_field_name()
{
	(*out_stream) << '"';
}


void DbExpression::after_field_name()
{
	(*out_stream) << '"';
}


void DbExpression::before_alias_name()
{
	(*out_stream) << '"';
}


void DbExpression::after_alias_name()
{
	(*out_stream) << '"';
}




void DbExpression::before_field_value_string(const FT & field_type, ModelEnv * model_env)
{
	(*out_stream) << "'";

	if( model_env && model_env->use_escaping_for_like && model_env->add_prefix_percent )
		(*out_stream) << '%';
}


void DbExpression::after_field_value_string(const FT & field_type, ModelEnv * model_env)
{
	if( model_env && model_env->use_escaping_for_like && model_env->add_postfix_percent )
		(*out_stream) << '%';

	(*out_stream) << "'";
}


void DbExpression::prepare_to_where_clause()
{
	work_mode = MORM_WORK_MODE_MODEL_FIELDS_VALUES;
	conjunctions.clear();
	is_first_field = true;
}


DbExpression & DbExpression::group_or(pt::TextStream & stream)
{
	out_stream = &stream;
	field_before();
	(*out_stream) << "(";
	is_first_field = true;
	conjunctions.push_back(MORM_CONJUNCTION_OR);
	out_stream = nullptr;

	return *this;
}

DbExpression & DbExpression::group_and(pt::TextStream & stream)
{
	out_stream = &stream;
	field_before();
	(*out_stream) << "(";
	is_first_field = true;
	conjunctions.push_back(MORM_CONJUNCTION_AND);
	out_stream = nullptr;

	return *this;
}

DbExpression & DbExpression::group_end(pt::TextStream & stream)
{
	out_stream = &stream;

	if( !conjunctions.empty() )
	{
		conjunctions.pop_back();
		(*out_stream) << ")";
		field_after();
	}

	out_stream = nullptr;
	return *this;
}


DbExpression & DbExpression::page(pt::TextStream & stream, size_t page_number, size_t page_size)
{
	stream << " LIMIT " << (page_number*page_size) << "," << page_size << " ";
	return *this;
}


void DbExpression::generate_rows_counter_column_name(ModelEnv & model_env, pt::TextStream & str)
{
	str << model_env.table_name;

	if( model_env.table_index > 1 )
	{
		str << model_env.table_index;
	}

	str << DbExpression::COLUMN_ROWS_COUNTER_POSTFIX;
}


void DbExpression::add_additional_columns(Model & model)
{
	if( model.model_env )
	{
		if(	model.model_env->select_flags.is_with_rows_counter() )
		{
			add_rows_counter_column(model);
		}
	}
}


void DbExpression::add_rows_counter_column(Model & model)
{
	if( out_stream && model.model_env )
	{
		field_before();
		(*out_stream) << "COUNT(*) OVER() AS ";
		before_field_name();

		if( model.model_env->rows_counter_column_name.empty() )
		{
			pt::TextStream str;
			generate_rows_counter_column_name(*model.model_env, str);
			esc(str, *out_stream);

			/*
			 * for autogenerated selects we don't have to copy the rows_counter_column_name
			 * because a field() method will use an index instead of this name
			 */
			if( !model.model_env->has_autogenerated_select )
			{
				str.to_str(model.model_env->rows_counter_column_name);
			}
		}
		else
		{
			esc(model.model_env->rows_counter_column_name, *out_stream);
		}

		after_field_name();
		field_after();
	}
}



void DbExpression::prepare_declare_cursor_query(const pt::TextStream & cursor_name, bool scroll_cursor, pt::TextStream & out_stream)
{
	out_stream << "DECLARE " << cursor_name;

	if( scroll_cursor )
		out_stream << " SCROLL";

	out_stream << " CURSOR FOR ";
}


void DbExpression::prepare_fetch_next_query(const pt::TextStream & cursor_name, pt::TextStream & out_stream)
{
	out_stream << "FETCH NEXT FROM " << cursor_name;
}


void DbExpression::prepare_fetch_prior_query(const pt::TextStream & cursor_name, pt::TextStream & out_stream)
{
	out_stream << "FETCH PRIOR FROM " << cursor_name;
}


void DbExpression::prepare_fetch_first_query(const pt::TextStream & cursor_name, pt::TextStream & out_stream)
{
	out_stream << "FETCH FIRST FROM " << cursor_name;
}


void DbExpression::prepare_fetch_last_query(const pt::TextStream & cursor_name, pt::TextStream & out_stream)
{
	out_stream << "FETCH LAST FROM " << cursor_name;
}


void DbExpression::prepare_fetch_absotule_query(const pt::TextStream & cursor_name, long position, pt::TextStream & out_stream)
{
	out_stream << "FETCH ABSOLUTE " << position << " FROM " << cursor_name;
}


void DbExpression::prepare_fetch_relative_query(const pt::TextStream & cursor_name, long position, pt::TextStream & out_stream)
{
	out_stream << "FETCH RELATIVE " << position << " FROM " << cursor_name;
}


void DbExpression::prepare_fetch_forward_count_query(const pt::TextStream & cursor_name, size_t len, pt::TextStream & out_stream)
{
	out_stream << "FETCH FORWARD " << len << " FROM " << cursor_name;
}


void DbExpression::prepare_fetch_backward_count_query(const pt::TextStream & cursor_name, size_t len, pt::TextStream & out_stream)
{
	out_stream << "FETCH BACKWARD " << len << " FROM " << cursor_name;
}


void DbExpression::prepare_fetch_all_query(const pt::TextStream & cursor_name, pt::TextStream & out_stream)
{
	out_stream << "FETCH ALL FROM " << cursor_name;
}


}