implement sd card sink

include/lemlog/logger/sinks/sd-card.hpp

@@ -0,0 +1,19 @@
+#pragma once
+
+#include "lemlog/logger/logger.hpp"
+
+namespace logger {
+/**
+ * @brief SD card class. Outputs all data to the SD card connected to the brain.
+ */
+class SDCard : public Sink {
+    public:
+        SDCard(std::string filename = ".log", bool logTimestamp = true);
+        void send(Level level, std::string topic, std::string message) override;
+    private:
+        std::string formatTimestamp(long long ms);
+
+        std::string filename;
+        bool logTimestamp;
+};
+}

src/lemlog/logger/sinks/sd-card.cpp

@@ -0,0 +1,55 @@
+#include "lemlog/logger/sinks/sd-card.hpp"
+#include "pros/apix.h"
+#include <fstream>
+
+namespace logger {
+SDCard::SDCard(std::string filename, bool logTimestamp) : filename("/usd/" + filename), logTimestamp(logTimestamp) {}
+
+std::string SDCard::formatTimestamp(long long ms) {
+    // use the % operator to get the remainder of the division
+    long long minutes = ms / 60000;
+    ms %= 60000;
+    long long seconds = ms / 1000;
+    ms %= 1000;
+
+    std::string output = "";
+
+    if (minutes > 0) output += std::to_string(minutes) + "m ";
+    if (seconds > 0 || minutes > 0) output += std::to_string(seconds) + "s ";
+    output += std::to_string(ms) + "ms";
+
+    return output;
+}
+
+void SDCard::send(Level level, std::string topic, std::string message) {
+    // output: <time> [LEVEL] (topic) message
+    std::string output = "";
+
+    if (this->logTimestamp) output += this->formatTimestamp((long long) pros::millis());
+
+    switch (level) {
+        case (Level::DEBUG): {
+            output += " [DEBUG]";
+            break;
+        }
+        case (Level::INFO): {
+            output += " [INFO]";
+            break;
+        }
+        case (Level::WARN): {
+            output += " [WARN]";
+            break;
+        }
+        case (Level::ERROR): {
+            output += " [ERROR]";
+            break;
+        }
+    }
+
+    output += " (" + topic + ") " + message + "\n";
+
+    std::ofstream file(this->filename);
+    file << output;
+    file.close();
+}
+}