logger_di_integration_example.cpp

Demonstrates how monitoring_system uses common_system interfaces and Result<T> pattern for error handling.

// BSD 3-Clause License
// Copyright (c) 2021-2025, 🍀☀🌕🌥 🌊
// See the LICENSE file in the project root for full license information.
 
#include <kcenon/monitoring/core/performance_monitor.h>
#include <kcenon/monitoring/core/result_types.h>
#include <kcenon/common/interfaces/logger_interface.h>
#include <kcenon/common/interfaces/monitoring_interface.h>
#include <iostream>
#include <memory>
#include <thread>
#include <chrono>
#include <iomanip>
 
using namespace kcenon::monitoring;
using namespace kcenon::common::interfaces;
 
class simple_console_logger : public ILogger {
private:
    log_level min_level_ = log_level::debug;
    std::atomic<size_t> log_count_{0};
 
public:
    explicit simple_console_logger(log_level min = log_level::debug)
        : min_level_(min) {}
 
    kcenon::common::VoidResult log(log_level level, const std::string& message) override {
        if (!is_enabled(level)) {
            return kcenon::common::ok();
        }
 
        auto now = std::chrono::system_clock::now();
        auto time = std::chrono::system_clock::to_time_t(now);
 
        // Thread-safe time conversion
        std::tm tm_buf;
#ifdef _WIN32
        localtime_s(&tm_buf, &time);
#else
        localtime_r(&time, &tm_buf);
#endif
 
        std::cout << "[" << std::put_time(&tm_buf, "%H:%M:%S")
                  << "] [" << to_string(level) << "] "
                  << message << std::endl;
 
        log_count_++;
        return kcenon::common::ok();
    }
 
    kcenon::common::VoidResult log(const log_entry& entry) override {
        std::string msg = entry.message;
        if (!entry.file.empty()) {
            msg += " [" + entry.file + ":" + std::to_string(entry.line) + " " + entry.function + "]";
        }
        return log(entry.level, msg);
    }
 
    bool is_enabled(log_level level) const override {
        return static_cast<int>(level) >= static_cast<int>(min_level_);
    }
 
    kcenon::common::VoidResult set_level(log_level level) override {
        min_level_ = level;
        return kcenon::common::ok();
    }
 
    log_level get_level() const override {
        return min_level_;
    }
 
    kcenon::common::VoidResult flush() override {
        std::cout << std::flush;
        return kcenon::common::ok();
    }
 
    size_t get_log_count() const { return log_count_.load(); }
};
 
void example_1_basic_monitoring() {
    std::cout << "\n=== Example 1: Basic Monitoring ===" << std::endl;
 
    // Create monitor
    auto monitor = std::make_shared<performance_monitor>();
 
    std::cout << "\nRecording metrics..." << std::endl;
 
    // Record metrics using Result pattern (updated API: record_counter, record_gauge)
    auto result1 = monitor->record_counter("requests_total", 100.0);
    if (result1.is_ok()) {
        std::cout << "  Metric 'requests_total' recorded" << std::endl;
    }
 
    auto result2 = monitor->record_counter("errors_total", 5.0);
    if (result2.is_ok()) {
        std::cout << "  Metric 'errors_total' recorded" << std::endl;
    }
 
    // Get metrics snapshot using collect()
    auto metrics = monitor->collect();
    if (metrics.is_ok()) {
        const auto& snapshot = metrics.value();
        std::cout << "  Retrieved " << snapshot.metrics.size() << " metrics" << std::endl;
    }
}
 
void example_2_error_handling() {
    std::cout << "\n=== Example 2: Error Handling ===" << std::endl;
 
    auto monitor = std::make_shared<performance_monitor>();
 
    // Record metric and check result (updated API: record_gauge)
    auto result = monitor->record_gauge("cpu_usage", 45.5);
    if (result.is_ok()) {
        std::cout << "  Metric recorded successfully" << std::endl;
    } else {
        const auto& err = result.error();
        std::cout << "  Error: " << err.message << std::endl;
    }
}
 
void example_3_threshold_monitoring() {
    std::cout << "\n=== Example 3: Threshold Monitoring ===" << std::endl;
 
    auto monitor = std::make_shared<performance_monitor>();
 
    std::cout << "\nConfiguring thresholds..." << std::endl;
 
    // Set thresholds
    monitor->set_cpu_threshold(80.0);
    monitor->set_memory_threshold(90.0);
    monitor->set_latency_threshold(std::chrono::milliseconds(1000));
 
    // Check thresholds
    auto threshold_result = monitor->check_thresholds();
    if (threshold_result.is_ok()) {
        bool exceeded = threshold_result.value();
        std::cout << "  Thresholds exceeded: " << (exceeded ? "Yes" : "No") << std::endl;
 
        auto thresholds = monitor->get_thresholds();
        std::cout << "  CPU threshold: " << thresholds.cpu_threshold << "%" << std::endl;
        std::cout << "  Memory threshold: " << thresholds.memory_threshold << "%" << std::endl;
        std::cout << "  Latency threshold: " << thresholds.latency_threshold.count() << "ms" << std::endl;
    }
}
 
void example_4_multiple_monitors() {
    std::cout << "\n=== Example 4: Multiple Monitors ===" << std::endl;
 
    // Create multiple monitors
    auto monitor1 = std::make_shared<performance_monitor>("monitor1");
    auto monitor2 = std::make_shared<performance_monitor>("monitor2");
 
    std::cout << "\nMonitor 1 recording metrics..." << std::endl;
    monitor1->record_counter("monitor1_metric", 100.0);
 
    std::cout << "Monitor 2 recording metrics..." << std::endl;
    monitor2->record_counter("monitor2_metric", 200.0);
 
    // Get metrics from both using collect()
    auto metrics1 = monitor1->collect();
    auto metrics2 = monitor2->collect();
 
    if (metrics1.is_ok() && metrics2.is_ok()) {
        const auto& snapshot1 = metrics1.value();
        const auto& snapshot2 = metrics2.value();
        std::cout << "  Monitor 1: " << snapshot1.metrics.size() << " metrics" << std::endl;
        std::cout << "  Monitor 2: " << snapshot2.metrics.size() << " metrics" << std::endl;
    }
}
 
void example_5_metrics_with_tags() {
    std::cout << "\n=== Example 5: Metrics with Tags ===" << std::endl;
 
    auto monitor = std::make_shared<performance_monitor>();
 
    // Record metrics with tags (updated API: record_histogram with tags)
    tag_map tags{
        {"service", "api"},
        {"region", "us-east-1"},
        {"instance", "i-12345"}
    };
 
    auto result = monitor->record_histogram("request_latency", 150.0, tags);
    if (result.is_ok()) {
        std::cout << "  Metric with tags recorded successfully" << std::endl;
    }
 
    // Get all tagged metrics
    auto all_metrics = monitor->get_all_tagged_metrics();
    std::cout << "  Total tagged metrics: " << all_metrics.size() << std::endl;
}
 
void example_6_monitoring_workflow() {
    std::cout << "\n=== Example 6: Monitoring Workflow ===" << std::endl;
 
    auto monitor = std::make_shared<performance_monitor>();
    auto logger = std::make_shared<simple_console_logger>();
 
    std::cout << "\nSimulating application workload..." << std::endl;
 
    // Simulate application metrics (updated API: record_gauge)
    for (int i = 0; i < 5; ++i) {
        auto result = monitor->record_gauge("requests", static_cast<double>(i * 10));
        if (result.is_ok()) {
            logger->log(log_level::info, "Recorded metric: requests = " + std::to_string(i * 10));
        }
        std::this_thread::sleep_for(std::chrono::milliseconds(100));
    }
 
    // Check thresholds and log results
    auto threshold_result = monitor->check_thresholds();
    if (threshold_result.is_ok()) {
        bool exceeded = threshold_result.value();
        logger->log(log_level::info, "Thresholds exceeded: " + std::string(exceeded ? "Yes" : "No"));
    }
 
    // Get metrics and log summary
    auto metrics = monitor->collect();
    if (metrics.is_ok()) {
        const auto& snapshot = metrics.value();
        logger->log(log_level::info, "Collected " + std::to_string(snapshot.metrics.size()) + " metrics");
    }
 
    std::cout << "\n  Workflow completed successfully" << std::endl;
    std::cout << "  Logger events: " << logger->get_log_count() << std::endl;
}
 
int main() {
    std::cout << "========================================================" << std::endl;
    std::cout << "Monitoring System - Integration Examples" << std::endl;
    std::cout << "Using common_system interfaces and Result<T> pattern" << std::endl;
    std::cout << "========================================================" << std::endl;
 
    try {
        example_1_basic_monitoring();
        example_2_error_handling();
        example_3_threshold_monitoring();
        example_4_multiple_monitors();
        example_5_metrics_with_tags();
        example_6_monitoring_workflow();
 
        std::cout << "\n========================================================" << std::endl;
        std::cout << "All integration examples completed!" << std::endl;
        std::cout << "Key Points:" << std::endl;
        std::cout << "    common_system interfaces used" << std::endl;
        std::cout << "    Result<T> pattern for error handling" << std::endl;
        std::cout << "    Interface-based loose coupling" << std::endl;
        std::cout << "    Comprehensive monitoring" << std::endl;
        std::cout << "========================================================" << std::endl;
 
    } catch (const std::exception& e) {
        std::cerr << "Error: " << e.what() << std::endl;
        return 1;
    }
 
    return 0;
}