name: Run Terraform plan in production

on:
  pull_request:
    branches: [ production ]
    paths: [ 'terraform/**' ]

defaults:
  run:
    working-directory: terraform/production

jobs:
  terraform:
    name: Terraform plan
    runs-on: ubuntu-latest
    environment: production
    steps:
      - name: Checkout
        uses: actions/checkout@v2

      - name: Terraform format
        id: format
        run: terraform fmt -check

      - name: Terraform init
        id: init
        env:
          AWS_ACCESS_KEY_ID: ${{ secrets.TERRAFORM_STATE_ACCESS_KEY }}
          AWS_SECRET_ACCESS_KEY: ${{ secrets.TERRAFORM_STATE_SECRET_ACCESS_KEY }}
        run: terraform init

      - name: Terraform validate
        id: validation
        run: terraform validate -no-color

      - name: Terraform plan
        id: plan
        env:
          AWS_ACCESS_KEY_ID: ${{ secrets.TERRAFORM_STATE_ACCESS_KEY }}
          AWS_SECRET_ACCESS_KEY: ${{ secrets.TERRAFORM_STATE_SECRET_ACCESS_KEY }}
          TF_VAR_cf_user: ${{ secrets.CF_USERNAME }}
          TF_VAR_cf_password: ${{ secrets.CF_PASSWORD }}
        run: terraform plan -no-color -input=false 2>&1 | tee plan_output.txt

      - name: Read Terraform plan output file
        id: terraform_output
        uses: juliangruber/read-file-action@v1
        if: ${{ always() }}
        with:
          path: ./terraform/production/plan_output.txt

      # inspiration: https://learn.hashicorp.com/tutorials/terraform/github-actions#review-actions-workflow
      - name: Update PR
        uses: actions/github-script@v4
        # we would like to update the PR even when a prior step failed
        if: ${{ always() }}
        with:
          script: |
            const output = `Terraform Format and Style: ${{ steps.format.outcome }}
            Terraform Initialization: ${{ steps.init.outcome }}
            Terraform Validation: ${{ steps.validation.outcome }}
            Terraform Plan: ${{ steps.plan.outcome }}

            <details><summary>Show Plan</summary>

            \`\`\`\n
            ${{ steps.terraform_output.outputs.content }}
            \`\`\`

            </details>

            *Pusher: @${{ github.actor }}, Action: \`${{ github.event_name }}\`*`;

            github.issues.createComment({
              issue_number: context.issue.number,
              owner: context.repo.owner,
              repo: context.repo.repo,
              body: output
            })