feat: inital commit

.gitignore

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+__test__/_temp
+_temp/
+lib/
+node_modules/
+.vscode/
+.idea/

README.md

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+# Maven Cache V1
+
+This is a more advanced maven cache action.
+
+## Usage
+
+```
+- name: Cache Maven repository
+  uses: https://git.kvant.cloud/actions/maven-cache@v1
+  with:
+    root-cache-key: 'm2-cache-project-name' # this should be unique
+```

action.yml

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+name: 'Maven Cache'
+description: 'The .m2/repository caching mechanism'
+
+inputs:
+  root-cache-key:
+    description: 'The unique root key for the cache. For example `m2-cache-project-name`.'
+    required: true
+
+runs:
+  using: 'composite'
+  steps:
+    - name: Generate cache keys
+      id: generate-cache-keys
+      shell: bash
+      run: |
+        CURRENT_BRANCH="${{ github.head_ref || github.ref_name }}"
+        CURRENT_MONTH=$(/bin/date -u "+%Y-%m")
+        CURRENT_DAY=$(/bin/date -u "+%d")
+        echo "m2-monthly-cache-key=${{ inputs.root-cache-key }}-${CURRENT_MONTH}" >> $GITHUB_OUTPUT
+        echo "m2-monthly-branch-cache-key=${{ inputs.root-cache-key }}-${CURRENT_MONTH}-${CURRENT_BRANCH}" >> $GITHUB_OUTPUT
+        echo "m2-cache-key=${{ inputs.root-cache-key }}-${CURRENT_MONTH}-${CURRENT_BRANCH}-${CURRENT_DAY}" >> $GITHUB_OUTPUT
+
+    - name: Cache Maven repository
+      id: cache-maven-repository
+      uses: actions/cache@v4
+      with:
+        path: ~/.m2/repository
+        # The cache is per branch but in case we don't find a branch for a given branch, we will get a cache from another branch.
+        key: ${{ steps.generate-cache-keys.outputs.m2-cache-key }}
+        restore-keys: |
+          ${{ steps.generate-cache-keys.outputs.m2-monthly-branch-cache-key }}
+          ${{ steps.generate-cache-keys.outputs.m2-monthly-cache-key }}