From 7024acac06885f9d9e24125afef04231aebdd113 Mon Sep 17 00:00:00 2001
From: flow <flowlnlnln@gmail.com>
Date: Thu, 28 Jul 2022 22:34:24 -0300
Subject: [PATCH] feat: add override helper functions

These help us keep track of relevant metadata information about
overrides, so that we know what they are when we update a pack.

Signed-off-by: flow <flowlnlnln@gmail.com>
---
 launcher/CMakeLists.txt                       |  2 +
 .../modplatform/helpers/OverrideUtils.cpp     | 59 +++++++++++++++++++
 launcher/modplatform/helpers/OverrideUtils.h  | 20 +++++++
 3 files changed, 81 insertions(+)
 create mode 100644 launcher/modplatform/helpers/OverrideUtils.cpp
 create mode 100644 launcher/modplatform/helpers/OverrideUtils.h

diff --git a/launcher/CMakeLists.txt b/launcher/CMakeLists.txt
index 7bd92fac9..2ff700ad1 100644
--- a/launcher/CMakeLists.txt
+++ b/launcher/CMakeLists.txt
@@ -461,6 +461,8 @@ set(API_SOURCES
     modplatform/helpers/NetworkModAPI.cpp
     modplatform/helpers/HashUtils.h
     modplatform/helpers/HashUtils.cpp
+    modplatform/helpers/OverrideUtils.h
+    modplatform/helpers/OverrideUtils.cpp
 )
 
 set(FTB_SOURCES
diff --git a/launcher/modplatform/helpers/OverrideUtils.cpp b/launcher/modplatform/helpers/OverrideUtils.cpp
new file mode 100644
index 000000000..3496a2863
--- /dev/null
+++ b/launcher/modplatform/helpers/OverrideUtils.cpp
@@ -0,0 +1,59 @@
+#include "OverrideUtils.h"
+
+#include <QDirIterator>
+
+#include "FileSystem.h"
+
+namespace Override {
+
+void createOverrides(QString name, QString parent_folder, QString override_path)
+{
+    QString file_path(FS::PathCombine(parent_folder, name + ".txt"));
+    if (QFile::exists(file_path))
+        QFile::remove(file_path);
+
+    FS::ensureFilePathExists(file_path);
+
+    QFile file(file_path);
+    file.open(QFile::WriteOnly);
+
+    QDirIterator override_iterator(override_path, QDirIterator::Subdirectories);
+    while (override_iterator.hasNext()) {
+        auto override_file_path = override_iterator.next();
+        QFileInfo info(override_file_path);
+        if (info.isFile()) {
+            // Absolute path with temp directory -> relative path
+            override_file_path = override_file_path.split(name).last().remove(0, 1);
+
+            file.write(override_file_path.toUtf8());
+            file.write("\n");
+        }
+    }
+
+    file.close();
+}
+
+QStringList readOverrides(QString name, QString parent_folder)
+{
+    QString file_path(FS::PathCombine(parent_folder, name + ".txt"));
+
+    QFile file(file_path);
+    if (!file.exists())
+        return {};
+
+    QStringList previous_overrides;
+
+    file.open(QFile::ReadOnly);
+
+    QString entry;
+    do {
+        entry = file.readLine();
+        previous_overrides.append(entry.trimmed());
+    } while (!entry.isEmpty());
+
+    file.close();
+
+    return previous_overrides;
+}
+
+}  // namespace Override
diff --git a/launcher/modplatform/helpers/OverrideUtils.h b/launcher/modplatform/helpers/OverrideUtils.h
new file mode 100644
index 000000000..73f059d6d
--- /dev/null
+++ b/launcher/modplatform/helpers/OverrideUtils.h
@@ -0,0 +1,20 @@
+#pragma once
+
+#include <QString>
+
+namespace Override {
+
+/** This creates a file in `parent_folder` that holds information about which
+ *  overrides are in `override_path`.
+ *
+ *  If there's already an existing such file, it will be ovewritten.
+ */
+void createOverrides(QString name, QString parent_folder, QString override_path);
+
+/** This reads an existing overrides archive, returning a list of overrides.
+ *
+ *  If there's no such file in `parent_folder`, it will return an empty list.
+ */
+QStringList readOverrides(QString name, QString parent_folder);
+
+}  // namespace Override