Enhance sync workflow with state management and download delta tracking

Added steps to restore and save the sync state using caching, enabling incremental download tracking. Updated the workflow to calculate and log download deltas, improving efficiency and clarity in reporting new downloads to PostHog.

Author: decker502

.github/workflows/sync-github-downloads.yml

@@ -10,6 +10,17 @@ jobs:
   sync:
     runs-on: ubuntu-latest
     steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Restore previous sync state
+        uses: actions/cache/restore@v4
+        with:
+          path: .sync-state.json
+          key: posthog-sync-state-${{ github.repository_id }}
+          restore-keys: |
+            posthog-sync-state-
+
       - name: Fetch release data and sync to PostHog
         env:
           POSTHOG_API_KEY: ${{ secrets.POSTHOG_API_KEY }}
@@ -26,6 +37,21 @@ jobs:
             POSTHOG_HOST="https://us.i.posthog.com"
             echo "Using default POSTHOG_HOST: ${POSTHOG_HOST}"
           fi
+
+          # 获取当前同步时间（ISO 8601 格式）
+          sync_timestamp=$(date -u +"%Y-%m-%dT%H:%M:%S.000Z")
+          echo "Sync timestamp: ${sync_timestamp}"
+
+          # 加载上次同步的状态（用于计算增量）
+          if [ -f .sync-state.json ] && [ "$(cat .sync-state.json)" != "{}" ]; then
+            echo "Loaded previous sync state"
+            echo "true" > .has-previous-state
+          else
+            echo '{}' > .sync-state.json
+            echo "false" > .has-previous-state
+            echo "No previous sync state, starting fresh"
+          fi
+
           # 获取所有 releases
           releases=$(curl -s -H "Authorization: token ${GITHUB_TOKEN}" \
             "https://api.github.com/repos/mantra-hq/mantra-releases/releases?per_page=100")
@@ -43,7 +69,6 @@ jobs:
             echo "$release" | jq -c '.assets[]' | while read -r asset; do
               asset_name=$(echo "$asset" | jq -r '.name')
               download_count=$(echo "$asset" | jq -r '.download_count')
-              asset_created=$(echo "$asset" | jq -r '.created_at')
               
               # 跳过签名文件
               if [[ "$asset_name" == *.sig ]]; then
@@ -68,21 +93,38 @@ jobs:
                 platform="linux"
                 arch="x64"
               fi
+
+              # 计算增量下载数
+              asset_key="${version}:${asset_name}"
+              previous_count=$(jq -r --arg key "$asset_key" '.[$key] // 0' .sync-state.json)
+              download_delta=$((download_count - previous_count))
               
-              # 发送到 PostHog
+              # 更新状态文件
+              jq --arg key "$asset_key" --argjson val "$download_count" \
+                '.[$key] = $val' .sync-state.json > .sync-state.tmp && mv .sync-state.tmp .sync-state.json
+
+              # 跳过无增量的记录（首次同步除外）
+              has_previous=$(cat .has-previous-state)
+              if [ "$download_delta" -le 0 ] && [ "$has_previous" = "true" ]; then
+                echo "  - ${asset_name}: no new downloads (total: ${download_count})"
+                continue
+              fi
+
+              # 发送到 PostHog（使用当前同步时间）
               response=$(curl -s -w "\n%{http_code}" -X POST "${POSTHOG_HOST}/capture/" \
                 -H "Content-Type: application/json" \
                 -d "{
                   \"api_key\": \"${POSTHOG_API_KEY}\",
                   \"event\": \"github_release_download\",
                   \"distinct_id\": \"github-release-sync\",
-                  \"timestamp\": \"${asset_created}\",
+                  \"timestamp\": \"${sync_timestamp}\",
                   \"properties\": {
                     \"version\": \"${version}\",
                     \"asset_name\": \"${asset_name}\",
                     \"platform\": \"${platform}\",
                     \"arch\": \"${arch}\",
                     \"download_count\": ${download_count},
+                    \"download_delta\": ${download_delta},
                     \"published_at\": \"${published_at}\"
                   }
                 }")
@@ -91,13 +133,19 @@ jobs:
               response_body=$(echo "$response" | head -n -1)
               
               if [ "$http_code" = "200" ]; then
-                echo "  ✓ ${asset_name}: ${download_count} downloads (${platform}/${arch})"
+                echo "  ✓ ${asset_name}: +${download_delta} new downloads (total: ${download_count}) (${platform}/${arch})"
               else
                 echo "  ✗ Failed: ${asset_name} (HTTP ${http_code})"
                 echo "    Response: ${response_body}"
               fi
             done
           done
-          
+
           echo ""
           echo "Sync completed!"
+
+      - name: Save sync state
+        uses: actions/cache/save@v4
+        with:
+          path: .sync-state.json
+          key: posthog-sync-state-${{ github.repository_id }}