1 files changed, 116 insertions, 0 deletions
diff --git a/src/labeller.cc b/src/labeller.cc
new file mode 100644
index 0000000..64da2d7
--- /dev/null
+++ b/src/labeller.cc
@@ -0,0 +1,116 @@
+#include "labeller.h"
+#include "settings.h"
+#include <fstream>
+
+
+namespace backend {
+    struct labeller_impl {
+        std::vector<std::string> labels;
+        std::vector<label> annotations;
+        // Bool in undo/redo buffers is whether was applied or deleted
+        std::vector<std::pair<bool, label>> undoBuffer;
+        std::vector<std::pair<bool, label>> redoBuffer;
+        std::filesystem::path savepath;
+    };
+
+    labeller::labeller(const std::filesystem::path& savepath) {
+        data = std::shared_ptr<labeller_impl>(new labeller_impl);
+        data->labels = settings::getLabels();
+        data->savepath = savepath;
+    }
+
+    std::pair<label, label> labeller::getSurrounding(double time) const {
+        std::pair<label, label> labs;
+        if(!data->annotations.empty()) {
+            auto above = data->annotations.rbegin();
+            auto below = above;
+            auto rit = above;
+            while(++rit != data->annotations.rend()) {
+                if(rit->time > time && (above->time <= time || rit->time < above->time)) above = rit;
+                if(rit->time <= time && (below->time > time || rit->time > below->time)) below = rit;
+            }
+            if(below->time <= time) labs.first = *below;
+            if(above->time > time) labs.second = *above;
+        }
+        return labs;
+    }
+
+    std::vector<std::string> labeller::getLabels() const {
+        return data->labels;
+    }
+
+    void appLab(std::vector<label>& annotations, label lab) {
+        annotations.push_back(lab);
+    }
+
+    void labeller::applyLabel(std::string name, double time) {
+        label lab(name, time);
+        appLab(data->annotations, lab);
+        data->undoBuffer.push_back({true, lab});
+        data->redoBuffer.clear();
+    }
+
+    double abs(double x) {
+        if(x < 0) x *= -1;
+        return x;
+    }
+
+    label delLab(std::vector<label>& annotations, double time) {
+        if(annotations.empty()) {
+            return label();
+        }
+        auto closest = annotations.rbegin();
+        auto rit = closest;
+        while(++rit != annotations.rend()) {
+            if(abs(rit->time - time) < abs(closest->time - time)) {
+                closest = rit;
+            }
+        }
+        label c(*closest);
+        annotations.erase(closest.base());
+        return c;
+    }
+
+    void labeller::deleteLabel(double time) {
+        label deleted = delLab(data->annotations, time);
+        data->undoBuffer.push_back({false, deleted});
+        data->redoBuffer.clear();
+    }
+
+    // Pops action from 'from', applies, and appends to 'to'.
+    void handleUndoRedo(std::vector<std::pair<bool, label>>& from, std::vector<std::pair<bool, label>>& to, std::vector<label>& annotations) {
+        if(! from.empty()) {
+            auto elem = from.back();
+            from.pop_back();
+            if(elem.first) { // It was applied, so we must unapply
+                delLab(annotations, elem.second.time);
+            } else {
+                appLab(annotations, elem.second);
+            }
+            to.push_back({! elem.first, elem.second});
+        }
+    }
+
+    void labeller::undo() {
+        handleUndoRedo(data->undoBuffer, data->redoBuffer, data->annotations);
+    }
+
+    void labeller::redo() {
+        handleUndoRedo(data->redoBuffer, data->undoBuffer, data->annotations);
+    }
+
+    bool compareLabels(label l1, label l2) {
+        return (l1.time < l2.time);
+    }
+
+    void labeller::save() const {
+        std::ofstream out;
+        out.open(data->savepath);
+        std::vector<label> a(data->annotations);
+        std::sort(a.begin(), a.end(), compareLabels);
+        for(label l : a) {
+            out << l.name << "," << l.time << std::endl;
+        }
+        out.close();
+    }
+}