feat(tags): add tag merging (#322)

* added merge tag context menu option, created modal, and created merge_tag logic

* forgot to close out the modal

* added ability to re-assign current tag

* ruff/mypy checks

tagstudio/src/core/library.py

@@ -1895,6 +1895,31 @@ class Library:
         for t in self.tags:
             self._map_tag_strings_to_tag_id(t)
 
+    def merge_tag(self, source_tag: Tag, target_tag: Tag) -> None:
+        source_tag_id: int = source_tag.id
+        target_tag_id: int = target_tag.id
+
+        if source_tag.name not in target_tag.aliases:
+            target_tag.aliases.append(source_tag.name)
+
+        for alias in source_tag.aliases:
+            if alias not in target_tag.aliases:
+                target_tag.aliases.append(alias)
+
+        for subtag_id in source_tag.subtag_ids:
+            if subtag_id not in target_tag.subtag_ids:
+                target_tag.subtag_ids.append(subtag_id)
+
+        for entry in self.entries:
+            for field in entry.fields:
+                if self.get_field_attr(field, "type") == "tag_box":
+                    if source_tag_id in self.get_field_attr(field, "content"):
+                        self.get_field_attr(field, "content").remove(source_tag_id)
+                        if target_tag_id not in self.get_field_attr(field, "content"):
+                            self.get_field_attr(field, "content").append(target_tag_id)
+
+        self.remove_tag(source_tag_id)
+
     def get_tag_ref_count(self, tag_id: int) -> tuple[int, int]:
         """Returns an int tuple (entry_ref_count, subtag_ref_count) of Tag reference counts."""
         entry_ref_count: int = 0

tagstudio/src/qt/modals/merge_tag.py

@@ -0,0 +1,63 @@
+from PySide6.QtWidgets import QDialog, QVBoxLayout, QLabel, QComboBox, QPushButton
+from PySide6.QtCore import Qt
+import logging
+
+
+class MergeTagModal(QDialog):
+    def __init__(self, library, current_tag):
+        super().__init__()
+        self.lib = library
+        self.current_tag = current_tag
+        self.init_ui()
+
+    def init_ui(self):
+        layout = QVBoxLayout()
+
+        layout.addWidget(QLabel("Selected tag:"))
+        self.selected_tag_dropdown = QComboBox(self)
+        for tag in self.lib.tags:
+            self.selected_tag_dropdown.addItem(tag.display_name(self.lib), tag)
+        self.selected_tag_dropdown.setCurrentIndex(self.find_current_tag_index())
+        self.selected_tag_dropdown.currentIndexChanged.connect(self.update_current_tag)
+        layout.addWidget(self.selected_tag_dropdown)
+
+        arrow_label = QLabel("↓")
+        arrow_label.setAlignment(Qt.AlignCenter)
+        layout.addWidget(arrow_label)
+
+        layout.addWidget(QLabel("Select tag to merge with:"))
+        self.tag2_dropdown = QComboBox(self)
+        self.update_tag2_dropdown()
+        layout.addWidget(self.tag2_dropdown)
+
+        self.merge_button = QPushButton("Merge", self)
+        layout.addWidget(self.merge_button)
+
+        self.merge_button.clicked.connect(self.merge_tags)
+
+        self.setLayout(layout)
+
+    def find_current_tag_index(self):
+        for index in range(self.selected_tag_dropdown.count()):
+            if self.selected_tag_dropdown.itemData(index) == self.current_tag:
+                return index
+        return 0
+
+    def update_current_tag(self):
+        self.current_tag = self.selected_tag_dropdown.currentData()
+        self.update_tag2_dropdown()
+
+    def update_tag2_dropdown(self):
+        self.tag2_dropdown.clear()
+        for tag in self.lib.tags:
+            if tag.id != self.current_tag.id:
+                self.tag2_dropdown.addItem(tag.display_name(self.lib), tag)
+
+    def merge_tags(self):
+        target_tag = self.tag2_dropdown.currentData()
+        if target_tag and self.current_tag != target_tag:
+            self.lib.merge_tag(self.current_tag, target_tag)
+            self.accept()
+        else:
+            logging.error("MergeTagModal: Invalid tag selection.")
+            self.reject()

tagstudio/src/qt/widgets/tag.py

@@ -15,6 +15,7 @@ from PySide6.QtWidgets import QWidget, QVBoxLayout, QHBoxLayout, QPushButton
 
 from src.core.library import Library, Tag
 from src.core.palette import ColorType, get_tag_color
+from src.qt.modals.merge_tag import MergeTagModal
 
 
 ERROR = f"[ERROR]"
@@ -77,6 +78,10 @@ class TagWidget(QWidget):
         add_to_search_action = QAction("Add to Search", self)
         self.bg_button.addAction(add_to_search_action)
 
+        merge_tag_action = QAction("Merge Tag", self)
+        merge_tag_action.triggered.connect(self.show_merge_tag_modal)
+        self.bg_button.addAction(merge_tag_action)
+
         self.inner_layout = QHBoxLayout()
         self.inner_layout.setObjectName("innerLayout")
         self.inner_layout.setContentsMargins(2, 2, 2, 2)
@@ -234,6 +239,9 @@ class TagWidget(QWidget):
     # 		pass
     # 	# self.bg.clicked.connect(lambda checked=False, filepath=filepath: open_file(filepath))
     # 	# self.bg.clicked.connect(function)
+    def show_merge_tag_modal(self):
+        modal = MergeTagModal(self.lib, self.tag)
+        modal.exec_()
 
     def enterEvent(self, event: QEnterEvent) -> None:
         if self.has_remove: