linkedin-post.yml

name: Cross-post to LinkedIn

on:
  push:
    branches: [main]
    paths:
      - 'blog/posts/*.json'
  workflow_dispatch:

jobs:
  linkedin-post:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 2
          token: ${{ secrets.SYNC_PAT }}

      - name: Find new/changed post files
        id: posts
        run: |
          CHANGED=$(git diff --name-only --diff-filter=AM HEAD~1 HEAD -- 'blog/posts/*.json' | head -1)
          echo "file=$CHANGED" >> $GITHUB_OUTPUT
          if [ -z "$CHANGED" ]; then
            echo "skip=true" >> $GITHUB_OUTPUT
          else
            echo "skip=false" >> $GITHUB_OUTPUT
          fi

      - name: Post to LinkedIn
        if: steps.posts.outputs.skip == 'false'
        env:
          LINKEDIN_ENABLED: ${{ vars.LINKEDIN_ENABLED }}
          LINKEDIN_ACCESS_TOKEN: ${{ secrets.LINKEDIN_ACCESS_TOKEN }}
          LINKEDIN_ORG_ID: ${{ vars.LINKEDIN_ORG_ID }}
          POST_FILE: ${{ steps.posts.outputs.file }}
        run: |
          set -e

          if [ "$LINKEDIN_ENABLED" != "true" ]; then
            echo "LINKEDIN_ENABLED is not 'true' — skipping."
            exit 0
          fi

          TITLE=$(jq -r '.title' "$POST_FILE")
          EXCERPT=$(jq -r '.excerpt' "$POST_FILE")
          SLUG=$(jq -r '.slug' "$POST_FILE")
          LINKEDIN_REQUESTED=$(jq -r '.linkedinRequested // false' "$POST_FILE")
          EXISTING_URL=$(jq -r '.linkedinUrl // empty' "$POST_FILE")
          COVER_IMAGE=$(jq -r '.coverImage // ""' "$POST_FILE")

          if [ "$LINKEDIN_REQUESTED" != "true" ]; then
            echo "LinkedIn posting not requested for this post. Skipping."
            exit 0
          fi

          if [ -n "$EXISTING_URL" ]; then
            echo "Post already cross-posted to LinkedIn: $EXISTING_URL. Skipping."
            exit 0
          fi

          if [ -z "$LINKEDIN_ACCESS_TOKEN" ]; then
            echo "LinkedIn access token not configured. Skipping."
            exit 0
          fi

          if [ -z "$LINKEDIN_ORG_ID" ]; then
            echo "LINKEDIN_ORG_ID repo variable not set. Skipping."
            exit 1
          fi

          AUTHOR_URN="urn:li:organization:$LINKEDIN_ORG_ID"
          SITE_URL="https://actionresearchprojects.github.io"
          POST_URL="${SITE_URL}/blog/#${SLUG}"

          POST_TEXT=$(printf '%s\n\n%s\n\nRead more: %s' "$TITLE" "$EXCERPT" "$POST_URL")

          if [ -n "$COVER_IMAGE" ] && [ "$COVER_IMAGE" != "null" ]; then
            BODY=$(jq -n \
              --arg author "$AUTHOR_URN" \
              --arg text "$POST_TEXT" \
              --arg url "$POST_URL" \
              --arg title "$TITLE" \
              --arg desc "$EXCERPT" \
              '{
                "author": $author,
                "commentary": $text,
                "visibility": "PUBLIC",
                "distribution": {
                  "feedDistribution": "MAIN_FEED",
                  "targetEntities": [],
                  "thirdPartyDistributionChannels": []
                },
                "content": {
                  "article": {
                    "source": $url,
                    "title": $title,
                    "description": $desc
                  }
                },
                "lifecycleState": "PUBLISHED",
                "isReshareDisabledByAuthor": false
              }')
          else
            BODY=$(jq -n \
              --arg author "$AUTHOR_URN" \
              --arg text "$POST_TEXT" \
              '{
                "author": $author,
                "commentary": $text,
                "visibility": "PUBLIC",
                "distribution": {
                  "feedDistribution": "MAIN_FEED",
                  "targetEntities": [],
                  "thirdPartyDistributionChannels": []
                },
                "lifecycleState": "PUBLISHED",
                "isReshareDisabledByAuthor": false
              }')
          fi

          echo "Posting to LinkedIn..."
          HTTP_CODE=$(curl -s \
            -o /tmp/li_response.txt \
            -D /tmp/li_headers.txt \
            -w "%{http_code}" \
            -X POST "https://api.linkedin.com/rest/posts" \
            -H "Authorization: Bearer $LINKEDIN_ACCESS_TOKEN" \
            -H "Content-Type: application/json" \
            -H "LinkedIn-Version: 202401" \
            -H "X-Restli-Protocol-Version: 2.0.0" \
            -d "$BODY")

          RESPONSE_BODY=$(cat /tmp/li_response.txt)

          if [ "$HTTP_CODE" -ge 200 ] && [ "$HTTP_CODE" -lt 300 ]; then
            echo "Successfully posted to LinkedIn!"

            POST_URN=$(grep -i "^x-restli-id:" /tmp/li_headers.txt | awk '{print $2}' | tr -d '\r\n')
            if [ -n "$POST_URN" ]; then
              LINKEDIN_URL="https://www.linkedin.com/feed/update/${POST_URN}"
              echo "LinkedIn post URL: $LINKEDIN_URL"

              jq --arg url "$LINKEDIN_URL" '. + {linkedinUrl: $url}' "$POST_FILE" > tmp.json && mv tmp.json "$POST_FILE"

              SLUG_VAL=$(jq -r '.slug' "$POST_FILE")
              jq --arg slug "$SLUG_VAL" --arg url "$LINKEDIN_URL" \
                'map(if .slug == $slug then . + {linkedinUrl: $url} else . end)' \
                blog/posts.json > tmp.json && mv tmp.json blog/posts.json

              git config user.name "github-actions[bot]"
              git config user.email "github-actions[bot]@users.noreply.github.com"
              git add "$POST_FILE" blog/posts.json
              git commit -m "Add LinkedIn URL to post: ${TITLE}" || true
              git push || true
            fi
          else
            echo "Failed to post to LinkedIn (HTTP $HTTP_CODE)"
            echo "Response: $RESPONSE_BODY"
            exit 1
          fi