Adding publishing workflow for GitHub and NuGet

.github/workflows/publish.yml

@@ -0,0 +1,98 @@
+name: Publish NuGet package
+
+on:
+  push:
+    tags:
+      - '*'
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  packages: write
+  id-token: write
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@v4
+
+      - name: Verify publishing credentials
+        if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags/')
+        shell: bash
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          NUGET_USER: ${{ secrets.NUGET_USER }}
+        run: |
+          if [[ -z "$GITHUB_TOKEN" ]]; then
+            echo "GitHub Packages token is not available."
+            exit 1
+          fi
+
+          if [[ -z "$NUGET_USER" ]]; then
+            echo "The NUGET_USER secret is missing or empty."
+            exit 1
+          fi
+
+      - name: Set up .NET SDKs
+        uses: actions/setup-dotnet@v4
+        with:
+          dotnet-version: |
+            5.0.x
+            6.0.x
+            7.0.x
+            8.0.x
+            10.0.x
+
+      - name: Restore dependencies
+        run: dotnet restore ImgBBApi.csproj
+
+      - name: Create NuGet package
+        shell: bash
+        run: |
+          PACKAGE_VERSION_ARGS=()
+          if [[ "$GITHUB_REF_TYPE" == "tag" ]]; then
+            PACKAGE_VERSION_ARGS=(-p:PackageVersion="${GITHUB_REF_NAME#v}")
+          fi
+
+          dotnet pack ImgBBApi.csproj \
+            --configuration Release \
+            --no-restore \
+            --output ./artifacts \
+            "${PACKAGE_VERSION_ARGS[@]}"
+
+      - name: Upload package artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: ImgBBApi-nuget-package
+          path: ./artifacts/*.nupkg
+          if-no-files-found: error
+
+      - name: Publish to GitHub Packages
+        if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags/')
+        run: |
+          for package in ./artifacts/*.nupkg; do
+            dotnet nuget push "$package" \
+              --source "https://nuget.pkg.github.com/${{ github.repository_owner }}/index.json" \
+              --api-key "${{ secrets.GITHUB_TOKEN }}" \
+              --skip-duplicate
+          done
+
+      - name: NuGet login
+        if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags/')
+        uses: NuGet/login@v1
+        id: nuget-login
+        with:
+          user: ${{ secrets.NUGET_USER }}
+
+      - name: Publish to NuGet.org
+        if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags/')
+        run: |
+          for package in ./artifacts/*.nupkg; do
+            dotnet nuget push "$package" \
+              --source "https://api.nuget.org/v3/index.json" \
+              --api-key "${{ steps.nuget-login.outputs.NUGET_API_KEY }}" \
+              --skip-duplicate
+          done