Re-add entities and assets

src/entities/song.h

@@ -0,0 +1,79 @@
+#pragma once
+#include "rapidjson/document.h"
+#include "rapidjson/filereadstream.h"
+#include <cstdio>
+#include <string>      // Added: needed for std::string
+#include <vector>      // Added: needed for std::vector
+#include <cassert>     // Added: needed for assert
+
+struct Note {
+    std::string name;
+    int midi;
+    int duration_ticks;
+    int ticks;
+};
+
+struct Instrument {
+    std::string family;
+    int number;
+};
+
+struct Track {
+    std::string name;
+    Instrument instrument;
+    std::vector<Note> notes;
+};
+
+struct Header {
+    std::string name;
+};
+
+struct Song {
+    Header header;
+    std::vector<Track> tracks;
+};
+
+Song parseSong(const rapidjson::Document& doc) {
+    assert(doc.IsObject());
+
+    Song song;
+
+    if (doc.HasMember("header") && doc["header"].IsObject()) {
+        const auto& h = doc["header"].GetObject();
+        Header header;
+        header.name = h["name"].GetString();
+        song.header = header;
+    }
+
+    if (doc.HasMember("tracks") && doc["tracks"].IsArray()) {
+        const auto& a = doc["tracks"].GetArray();
+        for (auto& t : a) {
+            Track track;
+            track.name = t["name"].GetString();
+
+            if (t.HasMember("instrument") && t["instrument"].IsObject()) {  // Fixed: added closing parenthesis
+                const auto& i = t["instrument"].GetObject();
+                Instrument instrument;
+                instrument.family = i["family"].GetString();
+                instrument.number = i["number"].GetInt();
+                track.instrument = instrument;
+            }  // Fixed: removed extra closing parenthesis
+
+            if (t.HasMember("notes") && t["notes"].IsArray()) {
+                const auto& notes = t["notes"].GetArray();
+                for (auto& n : notes) {
+                    Note note;
+                    note.name = n["name"].GetString();
+                    note.midi = n["midi"].GetInt();
+                    note.duration_ticks = n["durationTicks"].GetInt();
+                    note.ticks = n["ticks"].GetInt();
+                    track.notes.push_back(note);
+                }
+            }
+
+            song.tracks.push_back(track);
+        }
+    }
+
+    return song;
+}