action.yml

name: Backport Pull Request from Comment
description: Launches a Backport Job from a GitHub Comment on an Issue
author: Connor Adsit <cadsit@microsoft.com>
inputs:
  pull_request_url:
    description: URL of the pull request from the issue comment event
    required: true
  comment_author:
    description: Author of the PR comment
    required: true
  comment_body:
    description: Message of the comment on a PR
    required: true
  github_repository:
    description: GitHub Repository where the comment was written
    required: true
  ado_organization:
    description: Azure DevOps organization that hosts the backport job
    required: true
  ado_project:
    description: Azure DevOps project that hosts the backport job
    required: true
  backport_pipeline_id:
    description: ID of the backport yaml pipeline in Azure DevOps
    required: true
  ado_build_pat:
    description: PAT of an account that can launch builds on the backport pipeline in Azure DevOps
    required: true
  github_account_pat:
    description: PAT for a github account that has write access to source repository
    required: true
  use_fork:
    description: The action should create a PR from a fork
    required: false
    default: 'false'

runs:
  using: "composite"
  steps:
    - name: Gather Parameters
      id: get_parameters
      run: |
        $statusCode = 0
        $message = ""
        try {
          ($repoOwner, $repoName) = "${{ inputs.github_repository }}".Split("/")
          $headers = $headers = @{ Authorization = "token ${{ inputs.github_account_pat }}"}
          $uri = "https://api.github.com/repos/$repoOwner/$repoName/collaborators/${{ inputs.comment_author }}/permission"
          Write-Host "Checking $repoOwner membership for ${{ inputs.comment_author }} via $uri"
          $response = Invoke-WebRequest -Headers $headers -Uri $uri
          $content = $response.Content | ConvertFrom-Json
          $accessType = $content.permission
          Write-Host "Found membership: $accessType"
          if (-not ($accessType.Equals("admin") -or $accessType.Equals("write"))) {
            throw "${{ inputs.comment_author }}/permission does not have sufficient permissions for ${{ inputs.github_repository }}"
          }

          Write-Host "Parsing ${{ inputs.comment_body }}"
          ($botName, $backport, $backportTargetBranch) = [System.Text.RegularExpressions.Regex]::Split("${{ inputs.comment_body }}", "\s+")

          Write-Host "Grabbing PR details from ${{ inputs.pull_request_url }}"
          $response = Invoke-WebRequest -UseBasicParsing -Headers $headers -Uri "${{ inputs.pull_request_url }}" | ConvertFrom-Json
          $backportPRNumber = $response.number

          $parameters = @{
            BackportRepoName = "$repoName";
            BackportRepoOrg = "$repoOwner";
            BackportTargetBranch = "$backportTargetBranch";
            BackportPRNumber = "$backportPRNumber";
            BackportHeadSHA = "$($response.head.sha)";
            UseFork = "${{ inputs.use_fork }}" -eq "true";
          } | ConvertTo-Json -Compress

          $json = $parameters.Replace("`"","'")
          Write-Host "Setting output variables"
          echo "::set-output name=parameters::$json"
          echo "::set-output name=pr_number::$backportPRNumber"
        } catch {
          Write-Host $_.Exception.Message
          $statusCode = 1
        }
        return $statusCode
      shell: pwsh

    - name: Launch ADO Build
      id: ado_build
      run: |
        $message = ""
        $statusCode = 0
        try {
          $launchURI = "https://dev.azure.com/${{ inputs.ado_organization }}/${{ inputs.ado_project }}/_apis/pipelines/${{ inputs.backport_pipeline_id }}/runs?api-version=6.0-preview.1"
          Write-Host "Grabbing parameters from prior step"
          $parameters = ConvertFrom-Json "${{ steps.get_parameters.outputs.parameters }}"
          Write-Host "$parameters"
          $jsonBody = @{
              previewRun = false;
              templateParameters = $parameters;
              resources = @{
                repositories = @{
                  self = @{
                    refName = "refs/heads/dev/cadsit/backport-bot"
                  }
                }
              };
            } | ConvertTo-Json -Depth 10

          Write-Host "Posting to $launchURI"
          Write-Host $jsonBody
          $encoded = [Convert]::ToBase64String([System.Text.Encoding]::UTF8.GetBytes(":${{ inputs.ado_build_pat }}"))
          $headers = @{ Authorization = "Basic $encoded"}

          $response = Invoke-WebRequest -UseBasicParsing -Method POST -Headers $headers -ContentType "application/json" -Uri $launchURI -Body $jsonBody
          $responseJson = ConvertFrom-Json $response.Content
          echo "Job successfully launched"
          $message = "Backport Job to branch **$($parameters.BackportTargetBranch)** Created! The magic is happening [here](https://dev.azure.com/${{ inputs.ado_organization }}/${{ inputs.ado_project }}/_build/results?buildId=$($responseJson.id))"
        } catch {
          Write-Host $_.Exception.Message
          $message = "I couldn't create a backport to **$($parameters.BackportTargetBranch)** for you. :( Please check the Action logs for more details."
          $statusCode = 1
        } finally {
          $jsonBody = @{
            body = $message
          } | ConvertTo-Json

          $headers = @{ Authorization = "token ${{ inputs.github_account_pat }}"}
          $uri = "https://api.github.com/repos/${{ inputs.github_repository }}/issues/${{ steps.get_parameters.outputs.pr_number }}/comments"


          Write-Host "Posting to $uri"
          Write-Host "$jsonBody"
          Invoke-WebRequest -UseBasicParsing -Headers $headers -Method POST -Uri $uri -Body $jsonBody
        }
        return $statusCode
      shell: pwsh