Add auto snapshot update workflow

.github/workflows/auto_snapshot_update.yml

@@ -0,0 +1,98 @@
+# Experimental workflow to automate updating to a new Minecraft snapshot.
+name: Auto Snapshot Update
+
+on:
+  workflow_dispatch:
+    inputs:
+      mc_version:
+        description: "Minecraft version to update to"
+        required: true
+      yarn_mappings:
+        description: "Yarn mappings version"
+        required: true
+      fabric_loader:
+        description: "Fabric Loader version"
+        required: true
+      fapi_version:
+        description: "Fabric API version"
+        required: true
+
+permissions:
+  contents: write
+
+jobs:
+  update:
+    runs-on: ubuntu-latest
+    steps:
+
+    - name: Checkout repository
+      uses: actions/checkout@v4
+      with:
+        # Include all branches in case the new snapshot branch already exists.
+        fetch-depth: 0
+
+    - name: Set up Python 3.12
+      uses: actions/setup-python@v5
+      with:
+        python-version: "3.12"
+
+    - name: Set up Java 21
+      uses: actions/setup-java@v4
+      with:
+        java-version: "21"
+        distribution: "microsoft"
+
+    - name: Grant execute permission for gradlew
+      run: chmod +x gradlew
+
+    - name: Setup Gradle
+      uses: gradle/actions/setup-gradle@v4
+      with:
+        build-scan-publish: true
+        build-scan-terms-of-use-url: "https://gradle.com/help/legal-terms-of-use"
+        build-scan-terms-of-use-agree: "yes"
+
+    - name: Create and checkout new snapshot branch
+      run: |
+        BRANCH_NAME="${{ github.event.inputs.mc_version }}"
+        CURRENT_BRANCH=$(git rev-parse --abbrev-ref HEAD)
+        
+        if [ "$CURRENT_BRANCH" = "$BRANCH_NAME" ]; then
+          echo "Already on branch $BRANCH_NAME. Skipping branch creation."
+        elif git show-ref --quiet refs/heads/$BRANCH_NAME; then
+          echo "Branch $BRANCH_NAME already exists but is not currently checked out. Failing the workflow."
+          exit 1
+        else
+          git checkout -b $BRANCH_NAME
+          echo "Created and checked out new branch: $BRANCH_NAME"
+        fi
+      shell: bash
+
+    - name: Run migrateMappings task
+      run: |
+        ./gradlew migrateMappings --mappings ${{ github.event.inputs.yarn_mappings }}
+      shell: bash
+
+    - name: Replace src/main/java with remapped files
+      run: |
+        rm -rf ./src/main/java
+        mv ./remappedSrc ./src/main/java
+      shell: bash
+
+    - name: Update version constants
+      run: |
+        python scripts/update_version_constants.py "${{ github.event.inputs.mc_version }}" "${{ github.event.inputs.yarn_mappings }}" "${{ github.event.inputs.fabric_loader }}" "${{ github.event.inputs.fapi_version }}"
+      shell: bash
+
+    # To fix any style issues that the migration scripts might cause
+    - name: Run spotlessApply task
+      run: ./gradlew spotlessApply
+
+    - name: Commit and push changes
+      run: |
+        git config --global user.name "Wurst-Bot"
+        git config --global user.email "[email protected]"
+        git add .
+        git commit -m "[Wurst-Bot] Update to ${{ github.event.inputs.mc_version }}"
+        git push --set-upstream origin ${{ github.event.inputs.mc_version }}
+      shell: bash

scripts/update_version_constants.py

@@ -0,0 +1,43 @@
+import argparse
+
+if __name__ == "__main__":
+	parser = argparse.ArgumentParser()
+	parser.add_argument("mc_version", help="Minecraft version")
+	parser.add_argument("yarn_mappings", help="Yarn mappings version")
+	parser.add_argument("fabric_loader", help="Fabric Loader version")
+	parser.add_argument("fapi_version", help="Fabric API version")
+	args = parser.parse_args()
+
+	# Read gradle.properties
+	print("Updating gradle.properties...")
+	with open("gradle.properties", "r") as f:
+		lines = f.readlines()
+
+	# Define replacements
+	replacements = {
+		"minecraft_version": lambda v: args.mc_version,
+		"yarn_mappings": lambda v: args.yarn_mappings,
+		"loader_version": lambda v: args.fabric_loader,
+		"fabric_version": lambda v: args.fapi_version,
+		"mod_version": lambda v: v[: v.index("MC") + 2] + args.mc_version,
+	}
+
+	# Update lines
+	for i, line in enumerate(lines):
+		if line.startswith("#"):
+			continue
+		parts = line.split("=")
+		if len(parts) != 2:
+			continue
+		key = parts[0]
+		if key.strip() not in replacements:
+			continue
+		old_value = parts[1]
+		new_value = replacements[key.strip()](old_value)
+		print(f"{key}={old_value} -> {new_value}")
+		lines[i] = f"{key}={new_value}\n"
+
+	# Save modified gradle.properties
+	with open("gradle.properties", "w") as f:
+		f.writelines(lines)
+	print("gradle.properties updated.")