eq2go/old/common/database/database_result.hpp

// Copyright (C) 2007 EQ2EMulator Development Team - GPL v3 License

#pragma once

#include <map>
#include <string>
#include <string_view>
#include <cstdlib>
#include <mysql.h>

#include "../types.hpp"
#include "../log.hpp"

using namespace std;

// Return this instead of NULL for string functions to prevent crashes
static const char* empty_str = "";

// Database result wrapper class for MySQL query results with type-safe accessors
class DatabaseResult
{
public:
	// Constructor - initializes empty result set
	DatabaseResult() : field_map(), result(0), num_fields(0), row(0)
	{
	}

	// Destructor - frees MySQL result and clears field mappings
	virtual ~DatabaseResult()
	{
		if (result != NULL)
			mysql_free_result(result);
		if (field_map.size()) {
			field_map.clear();
		}
	}

	// Store MySQL result set and build field name to index mapping
	bool StoreResult(MYSQL_RES* res, uint8 field_count, uint8 row_count)
	{
		if (result != NULL)
			mysql_free_result(result);
		if (field_map.size()) {
			field_map.clear();
		}

		result = res;
		num_rows = row_count;
		num_fields = field_count;

		if (!num_rows || !num_fields) {
			mysql_free_result(res);
			result = NULL;
			return false;
		}

		const MYSQL_FIELD* fields = mysql_fetch_fields(result);
		for (uint8 i = 0; i < num_fields; ++i) {
			field_map.emplace(std::make_pair(std::string_view(fields[i].name), i));
		}

		return true;
	}

	// Advance to next row in result set
	bool Next()
	{
		return (result != NULL && (row = mysql_fetch_row(result)) != NULL);
	}

	// Get total number of rows in result set
	const unsigned int GetNumRows() { return num_rows; }

	// Check if field value at index is NULL
	bool IsNull(unsigned int index)
	{
		const char* value = GetFieldValue(index);
		return value == NULL;
	}

	// Check if field value by name is NULL
	bool IsNullStr(const char* field_name)
	{
		const char* value = GetFieldValueStr(field_name);
		return value == NULL;
	}

	// Type-safe getters by index
	int8 GetInt8(unsigned int index)
	{
		const char* value = GetFieldValue(index);
		return value == NULL ? 0 : atoi(value);
	}

	sint8 GetSInt8(unsigned int index)
	{
		const char* value = GetFieldValue(index);
		return value == NULL ? 0 : atoi(value);
	}

	int16 GetInt16(unsigned int index)
	{
		const char* value = GetFieldValue(index);
		return value == NULL ? 0 : atoi(value);
	}

	sint16 GetSInt16(unsigned int index)
	{
		const char* value = GetFieldValue(index);
		return value == NULL ? 0 : atoi(value);
	}

	int32 GetInt32(unsigned int index)
	{
		const char* value = GetFieldValue(index);
		return value == NULL ? 0U : strtoul(value, NULL, 10);
	}

	sint32 GetSInt32(unsigned int index)
	{
		const char* value = GetFieldValue(index);
		return value == NULL ? 0 : atoi(value);
	}

	uint64 GetInt64(unsigned int index)
	{
		const char* value = GetFieldValue(index);
		return value == NULL ? 0UL : strtoull(value, NULL, 10);
	}

	sint64 GetSInt64(unsigned int index)
	{
		const char* value = GetFieldValue(index);
		return value == NULL ? 0L : strtoll(value, NULL, 10);
	}

	float GetFloat(unsigned int index)
	{
		const char* value = GetFieldValue(index);
		return value == NULL ? 0.0F : atof(value);
	}

	char GetChar(unsigned int index)
	{
		const char* value = GetFieldValue(index);
		return value == NULL ? '\0' : value[0];
	}

	const char* GetString(unsigned int index)
	{
		const char* value = GetFieldValue(index);
		return value == NULL ? empty_str : value;
	}

	// Type-safe getters by field name
	int8 GetInt8Str(const char* field_name)
	{
		const char* value = GetFieldValueStr(field_name);
		return value == NULL ? 0 : atoi(value);
	}

	sint8 GetSInt8Str(const char* field_name)
	{
		const char* value = GetFieldValueStr(field_name);
		return value == NULL ? 0 : atoi(value);
	}

	int16 GetInt16Str(const char* field_name)
	{
		const char* value = GetFieldValueStr(field_name);
		return value == NULL ? 0 : atoi(value);
	}

	sint16 GetSInt16Str(const char* field_name)
	{
		const char* value = GetFieldValueStr(field_name);
		return value == NULL ? 0 : atoi(value);
	}

	int32 GetInt32Str(const char* field_name)
	{
		const char* value = GetFieldValueStr(field_name);
		return value == NULL ? 0U : strtoul(value, NULL, 10);
	}

	sint32 GetSInt32Str(const char* field_name)
	{
		const char* value = GetFieldValueStr(field_name);
		return value == NULL ? 0 : atoi(value);
	}

	uint64 GetInt64Str(const char* field_name)
	{
		const char* value = GetFieldValueStr(field_name);
		return value == NULL ? 0UL : strtoull(value, NULL, 10);
	}

	sint64 GetSInt64Str(const char* field_name)
	{
		const char* value = GetFieldValueStr(field_name);
		return value == NULL ? 0L : strtoll(value, NULL, 10);
	}

	float GetFloatStr(const char* field_name)
	{
		const char* value = GetFieldValueStr(field_name);
		return value == NULL ? 0.0F : atof(value);
	}

	char GetCharStr(const char* field_name)
	{
		const char* value = GetFieldValueStr(field_name);
		return value == NULL ? '\0' : value[0];
	}

	const char* GetStringStr(const char* field_name)
	{
		const char* value = GetFieldValueStr(field_name);
		return value == NULL ? empty_str : value;
	}

	// Get raw field value by index with bounds checking
	const char* GetFieldValue(unsigned int index)
	{
		if (index >= num_fields) {
			LogWrite(DATABASE__ERROR, 0, "Database Result", "Attempt to access field at index %u but there %s only %u field%s", index, num_fields == 1 ? "is" : "are", num_fields, num_fields == 1 ? "" : "s");
			return NULL;
		}
		return row[index];
	}

	// Get raw field value by name with field mapping lookup
	const char* GetFieldValueStr(const char* field_name)
	{
		const auto& map_iterator = field_map.find(std::string_view(field_name));
		if (map_iterator != field_map.end()) {
			return row[map_iterator->second];
		}
		LogWrite(DATABASE__ERROR, 0, "Database Result", "Unknown field name '%s'", field_name);
		return NULL;
	}

private:
	MYSQL_RES* result;							// MySQL result set from query
	MYSQL_ROW row;								// Current row data
	unsigned int num_rows;						// Total number of rows in result
	unsigned int num_fields;					// Total number of fields per row
	std::map<std::string_view, uint8> field_map;	// Field name to index mapping for fast lookups
};