exduckdb

#include "duckdb/execution/operator/projection/physical_projection.hpp"
#include "duckdb/execution/operator/projection/physical_tableinout_function.hpp"

#include "duckdb/execution/operator/scan/physical_table_scan.hpp"
#include "duckdb/planner/expression/bound_constant_expression.hpp"
#include "duckdb/planner/expression/bound_reference_expression.hpp"
#include "duckdb/execution/physical_plan_generator.hpp"
#include "duckdb/planner/operator/logical_get.hpp"
#include "duckdb/function/table/table_scan.hpp"

namespace duckdb {

unique_ptr<TableFilterSet> CreateTableFilterSet(TableFilterSet &table_filters, vector<column_t> &column_ids) {
	// create the table filter map
	auto table_filter_set = make_unique<TableFilterSet>();
	for (auto &table_filter : table_filters.filters) {
		// find the relative column index from the absolute column index into the table
		idx_t column_index = INVALID_INDEX;
		for (idx_t i = 0; i < column_ids.size(); i++) {
			if (table_filter.first == column_ids[i]) {
				column_index = i;
				break;
			}
		}
		if (column_index == INVALID_INDEX) {
			throw InternalException("Could not find column index for table filter");
		}
		table_filter_set->filters[column_index] = move(table_filter.second);
	}
	return table_filter_set;
}

unique_ptr<PhysicalOperator> PhysicalPlanGenerator::CreatePlan(LogicalGet &op) {
	if (!op.children.empty()) {
		// this is for table producing functions that consume subquery results
		D_ASSERT(op.children.size() == 1);
		auto node = make_unique<PhysicalTableInOutFunction>(op.returned_types, op.function, move(op.bind_data),
		                                                    op.column_ids, op.estimated_cardinality);
		node->children.push_back(CreatePlan(move(op.children[0])));
		return move(node);
	}

	unique_ptr<TableFilterSet> table_filters;
	if (!op.table_filters.filters.empty()) {
		table_filters = CreateTableFilterSet(op.table_filters, op.column_ids);
	}

	if (op.function.dependency) {
		op.function.dependency(dependencies, op.bind_data.get());
	}
	// create the table scan node
	if (!op.function.projection_pushdown) {
		// function does not support projection pushdown
		auto node = make_unique<PhysicalTableScan>(op.returned_types, op.function, move(op.bind_data), op.column_ids,
		                                           op.names, move(table_filters), op.estimated_cardinality);
		// first check if an additional projection is necessary
		if (op.column_ids.size() == op.returned_types.size()) {
			bool projection_necessary = false;
			for (idx_t i = 0; i < op.column_ids.size(); i++) {
				if (op.column_ids[i] != i) {
					projection_necessary = true;
					break;
				}
			}
			if (!projection_necessary) {
				// a projection is not necessary if all columns have been requested in-order
				// in that case we just return the node

				return move(node);
			}
		}
		// push a projection on top that does the projection
		vector<LogicalType> types;
		vector<unique_ptr<Expression>> expressions;
		for (auto &column_id : op.column_ids) {
			if (column_id == COLUMN_IDENTIFIER_ROW_ID) {
				types.push_back(LogicalType::BIGINT);
				expressions.push_back(make_unique<BoundConstantExpression>(Value::BIGINT(0)));
			} else {
				auto type = op.returned_types[column_id];
				types.push_back(type);
				expressions.push_back(make_unique<BoundReferenceExpression>(type, column_id));
			}
		}

		auto projection = make_unique<PhysicalProjection>(move(types), move(expressions), op.estimated_cardinality);
		projection->children.push_back(move(node));
		return move(projection);
	} else {
		return make_unique<PhysicalTableScan>(op.types, op.function, move(op.bind_data), op.column_ids, op.names,
		                                      move(table_filters), op.estimated_cardinality);
	}
}

} // namespace duckdb