AI Blog Writer

# AUTO BLOG WRITER — GitHub Actions + Google Gemini + Hashnode
name: Auto Blog Writer

on:
  push:
    paths:
      - "topics/**" # Only triggers when you add/edit a file in topics/

  workflow_dispatch: # Also run manually from GitHub UI
    inputs:
      topic_file:
        description: "Which topic file to process? (e.g. topics/my-topic.md)"
        type: string
        required: false

jobs:
  write-and-publish:
    name: "Write Blog Post with AI and Publish"
    runs-on: ubuntu-latest

    permissions:
      contents: write # Needed to commit the generated post back

    steps:
      - name: "1. Download the repo"
        uses: actions/checkout@v4
        with:
          persist-credentials: true
          fetch-depth: 2 # Need 2 commits to detect which files changed

      - name: "2. Set up Node.js"
        uses: actions/setup-node@v4
        with:
          node-version: "20"

      - name: "3. Find which topic file was just added or changed"
        id: find-topic
        run: |
          if [ -n "${{ inputs.topic_file }}" ]; then
            # Manual trigger — use the file they specified
            TOPIC_FILE="${{ inputs.topic_file }}"
          else
            # Auto trigger — find which topics/ file changed in this push
            TOPIC_FILE=$(git diff --name-only HEAD~1 HEAD -- 'topics/*.md' | head -1)
          fi

          if [ -z "$TOPIC_FILE" ]; then
            echo "No topic file found. Skipping."
            echo "found=false" >> $GITHUB_OUTPUT
          else
            echo "Found topic file: $TOPIC_FILE"
            echo "found=true"       >> $GITHUB_OUTPUT
            echo "file=$TOPIC_FILE" >> $GITHUB_OUTPUT
          fi

      - name: "4. Write and publish the blog post"
        if: steps.find-topic.outputs.found == 'true'
        env:
          GEMINI_API_KEY: ${{ secrets.GEMINI_API_KEY }}
          HASHNODE_API_KEY: ${{ secrets.HASHNODE_API_KEY }}
          HASHNODE_PUBLICATION_TOKEN: ${{ secrets.HASHNODE_PUBLICATION_TOKEN }}
          TOPIC_FILE: ${{ steps.find-topic.outputs.file }}
        run: node scripts/auto-blog-writer.js

      - name: "5. Commit generated post"
        if: steps.find-topic.outputs.found == 'true'
        run: |
          git config user.name  "Blog Writer Bot"
          git config user.email "adityatrivedi612@gmail.com"
          git add posts/
          git add .published.json || true
          
          if git diff --staged --quiet; then
            echo "Nothing to commit."
          else
            git commit -m "📝 Auto-generated blog post [skip ci]"
            git push
          fi