# The GitHub Actions docs (https://docs.github.com/en/actions/reference/workflow-syntax-for-github-actions#on)
   # describe other options for 'on', 'pull_request' is a good default.
   on: [pull_request]
   env:
      # If you use private modules you'll need this env variable to use 
      # the same ssh-agent socket value across all jobs & steps. 
      SSH_AUTH_SOCK: /tmp/ssh_agent.sock
   jobs:
     infracost:
       name: Infracost
       runs-on: ubuntu-latest

       env:
         TF_ROOT: examples/terraform-project/code
         # If you're using Terraform Cloud/Enterprise and have variables stored on there
         # you can specify the following to automatically retrieve the variables:
         #   INFRACOST_TERRAFORM_CLOUD_TOKEN: ${{ secrets.TFC_TOKEN }}
         #   INFRACOST_TERRAFORM_CLOUD_HOST: app.terraform.io # Change this if you're using Terraform Enterprise

         steps:
           # If you use private modules, add an environment variable or secret
           # called GIT_SSH_KEY with your private key, so Infracost can access
           # private repositories (similar to how Terraform/Terragrunt does).
           # - name: add GIT_SSH_KEY
           #   run: |
           #     ssh-agent -a $SSH_AUTH_SOCK
           #     mkdir -p ~/.ssh
           #     echo "${{ secrets.GIT_SSH_KEY }}" | tr -d '\r' | ssh-add -
           #     ssh-keyscan github.com >> ~/.ssh/known_hosts
            
           - name: Setup Infracost
             uses: infracost/actions/setup@v2
             # See https://github.com/infracost/actions/tree/master/setup for other inputs
             # If you can't use this action, see Docker images in https://infracost.io/cicd
             with:
               api-key: ${{ secrets.INFRACOST_API_KEY }}

           # Checkout the base branch of the pull request (e.g. main/master).
           - name: Checkout base branch
             uses: actions/checkout@v2
             with:
               ref: '${{ github.event.pull_request.base.ref }}'

           # Generate Infracost JSON file as the baseline.
           - name: Generate Infracost cost estimate baseline
             run: |
               infracost breakdown --path=${TF_ROOT} \
                                   --format=json \
                                   --out-file=/tmp/infracost-base.json

           # Checkout the current PR branch so we can create a diff.
           - name: Checkout PR branch
             uses: actions/checkout@v2

           # Generate an Infracost diff and save it to a JSON file.
           - name: Generate Infracost diff
             run: |
               infracost diff --path=${TF_ROOT} \
                              --format=json \
                              --compare-to=/tmp/infracost-base.json \
                              --out-file=/tmp/infracost.json

           # Posts a comment to the PR using the 'update' behavior.
           # This creates a single comment and updates it. The "quietest" option.
           # The other valid behaviors are:
           #   delete-and-new - Delete previous comments and create a new one.
           #   hide-and-new - Minimize previous comments and create a new one.
           #   new - Create a new cost estimate comment on every push.
           # See https://www.infracost.io/docs/features/cli_commands/#comment-on-pull-requests for other options.
           - name: Post Infracost comment
             run: |
                 infracost comment github --path=/tmp/infracost.json \
                                          --repo=$GITHUB_REPOSITORY \
                                          --github-token=${{github.token}} \
                                          --pull-request=${{github.event.pull_request.number}} \
                                          --behavior=update