#include "PreparedStatement.h"

PreparedStatement::PreparedStatement(sqlite3_stmt* stmt) : stmt(stmt) {

}

PreparedStatement::~PreparedStatement() {

	sqlite3_finalize(stmt);

}

void PreparedStatement::setBoolean(int parameterIndex, relpipe::reader::boolean_t value) {

	int result = sqlite3_bind_int(stmt, parameterIndex, value);

	if (result != SQLITE_OK) throw SqlException(L"Unable to set SQLite parameter.");

}

void PreparedStatement::setInteger(int parameterIndex, relpipe::reader::integer_t value) {

	int result = sqlite3_bind_int64(stmt, parameterIndex, value);

	if (result != SQLITE_OK) throw SqlException(L"Unable to set SQLite parameter.");

}

void PreparedStatement::setString(int parameterIndex, std::string value) {

	int result = sqlite3_bind_text(stmt, parameterIndex, value.c_str(), -1, SQLITE_TRANSIENT);

	if (result != SQLITE_OK) throw SqlException(L"Unable to set SQLite parameter.");

}

void PreparedStatement::setNull(int parameterIndex) {

	int result = sqlite3_bind_null(stmt, parameterIndex);

	if (result != SQLITE_OK) throw SqlException(L"Unable to set SQLite parameter.");

}

bool PreparedStatement::next() {

	int result = sqlite3_step(stmt);

	if (result == SQLITE_ROW) return true;

	else if (result == SQLITE_DONE) return false;

	else throw SqlException(L"Error while iterating over SQLite result.");

}

void PreparedStatement::reset() {

	int result = sqlite3_reset(stmt);

	if (result != SQLITE_OK) throw SqlException(L"Unable to reset SQLite prepared statement.");

}

int PreparedStatement::getColumnCount() {

	return sqlite3_column_count(stmt);

}

std::string PreparedStatement::getColumName(int columnIndex) {

	const char* name = sqlite3_column_name(stmt, columnIndex);

	if (name) return name;

	else throw SqlException(L"Unable to get SQLite column name.");

}

relpipe::writer::TypeId PreparedStatement::getColumType(int columnIndex, relpipe::writer::TypeId defaultType) {

	const char* type = sqlite3_column_decltype(stmt, columnIndex);

	// TODO: sqlite3_column_decltype returns value only for columns of existing tables, not for dynamic expressions – SQLite uses dynamic types

	// maybe we could write a function/module that returns result set metadata for given query (before executing it)

	// or use at least explicit casts in SQL and modify sqlite3_column_decltype() function or add some new one to return such casted type

	// 

	// fprintf(stderr, "%d → %s\n", columnIndex, type);

	// SELECT typeof(1+1); == "integer"

	// https://www.sqlite.org/c3ref/column_decltype.html – sqlite3_column_decltype

	// https://www.sqlite.org/c3ref/column_blob.html – sqlite3_column_type

	// https://www.sqlite.org/datatype3.html – Datatypes In SQLite Version 3

	// https://dba.stackexchange.com/questions/203220/sqlite-what-is-the-use-of-specifying-data-types

	// https://www.mail-archive.com/sqlite-users@mailinglists.sqlite.org/msg118093.html

	if (type == nullptr) return relpipe::writer::TypeId::STRING;

	else if (strcmp(type, "integer") == 0) return relpipe::writer::TypeId::INTEGER;

	else if (strcmp(type, "text") == 0) return relpipe::writer::TypeId::STRING;

	else return defaultType;

	// TODO: support also other data types

}

std::string PreparedStatement::getString(int columnIndex) {

	const char* value = (const char*) sqlite3_column_text(stmt, columnIndex);

		return value ? value : ""; // TODO: support NULL values (when supported in relpipe format)

}