name: Terragrunt CI/CD

on:
  pull_request:
    branches: [main, master]
    paths:
      - '**.tf'
      - '**.hcl'
      - '**.tfvars'
  push:
    branches: [main, master]
    paths:
      - '**.tf'
      - '**.hcl'
      - '**.tfvars'
  workflow_dispatch:
    inputs:
      environment:
        description: 'Environment to deploy'
        required: true
        type: choice
        options:
          - dev
          - staging
          - prod
      action:
        description: 'Action to perform'
        required: true
        type: choice
        options:
          - plan
          - apply
          - destroy

env:
  TF_VERSION: '1.5.0'
  TG_VERSION: '0.55.0'
  WORKING_DIR: 'environments'  # Base directory for environments

permissions:
  contents: read
  pull-requests: write
  id-token: write

jobs:
  detect-changes:
    name: Detect Changed Modules
    runs-on: ubuntu-latest
    outputs:
      matrix: ${{ steps.set-matrix.outputs.matrix }}
      has-changes: ${{ steps.set-matrix.outputs.has-changes }}
    steps:
      - name: Checkout
        uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Get Changed Files
        id: changed-files
        uses: tj-actions/changed-files@v42
        with:
          files: |
            **/*.tf
            **/*.hcl
            **/*.tfvars

      - name: Set Matrix
        id: set-matrix
        run: |
          # Find all directories with terragrunt.hcl that have changes
          changed_dirs=$(echo "${{ steps.changed-files.outputs.all_changed_files }}" | tr ' ' '\n' | xargs -I {} dirname {} | grep -E "environments/(dev|staging|prod)" | sort -u | jq -R -s -c 'split("\n")[:-1]')

          if [ "$changed_dirs" = "[]" ]; then
            echo "has-changes=false" >> $GITHUB_OUTPUT
          else
            echo "has-changes=true" >> $GITHUB_OUTPUT
            echo "matrix={\"directory\":$changed_dirs}" >> $GITHUB_OUTPUT
          fi

  validate:
    name: Validate
    runs-on: ubuntu-latest
    if: github.event_name == 'pull_request'
    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Setup Terraform
        uses: hashicorp/setup-terraform@v3
        with:
          terraform_version: ${{ env.TF_VERSION }}
          terraform_wrapper: false

      - name: Setup Terragrunt
        run: |
          wget -q https://github.com/gruntwork-io/terragrunt/releases/download/v${{ env.TG_VERSION }}/terragrunt_linux_amd64
          chmod +x terragrunt_linux_amd64
          sudo mv terragrunt_linux_amd64 /usr/local/bin/terragrunt
          terragrunt --version

      - name: Terragrunt Format Check
        run: terragrunt hclfmt --terragrunt-check
        working-directory: ${{ env.WORKING_DIR }}
        continue-on-error: true

      - name: Terragrunt Validate All
        run: terragrunt run-all validate --terragrunt-non-interactive
        working-directory: ${{ env.WORKING_DIR }}

  plan:
    name: Plan - ${{ matrix.directory }}
    runs-on: ubuntu-latest
    needs: [detect-changes, validate]
    if: needs.detect-changes.outputs.has-changes == 'true'
    strategy:
      matrix: ${{ fromJson(needs.detect-changes.outputs.matrix) }}
      fail-fast: false
    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Setup Terraform
        uses: hashicorp/setup-terraform@v3
        with:
          terraform_version: ${{ env.TF_VERSION }}
          terraform_wrapper: false

      - name: Setup Terragrunt
        run: |
          wget -q https://github.com/gruntwork-io/terragrunt/releases/download/v${{ env.TG_VERSION }}/terragrunt_linux_amd64
          chmod +x terragrunt_linux_amd64
          sudo mv terragrunt_linux_amd64 /usr/local/bin/terragrunt

      - name: Configure AWS Credentials
        uses: aws-actions/configure-aws-credentials@v4
        with:
          role-to-assume: ${{ secrets.AWS_ROLE_ARN }}
          aws-region: us-east-1

      - name: Terragrunt Plan
        id: plan
        run: |
          terragrunt run-all plan --terragrunt-non-interactive -out=tfplan 2>&1 | tee plan_output.txt
        working-directory: ${{ matrix.directory }}
        continue-on-error: true

      - name: Upload Plan Output
        uses: actions/upload-artifact@v4
        with:
          name: plan-${{ hashFiles(matrix.directory) }}
          path: ${{ matrix.directory }}/plan_output.txt
          retention-days: 5

      - name: Comment PR
        if: github.event_name == 'pull_request'
        uses: actions/github-script@v7
        with:
          script: |
            const fs = require('fs');
            const planPath = '${{ matrix.directory }}/plan_output.txt';
            let plan = 'Plan output not available';

            try {
              plan = fs.readFileSync(planPath, 'utf8');
              const maxLength = 65000;
              plan = plan.length > maxLength ? plan.substring(0, maxLength) + '\n... (truncated)' : plan;
            } catch (error) {
              plan = 'Error reading plan output: ' + error.message;
            }

            const output = `#### Terragrunt Plan for \`${{ matrix.directory }}\`
            <details><summary>Show Plan</summary>

            \`\`\`terraform
            ${plan}
            \`\`\`

            </details>

            *Workflow: ${{ github.workflow }}, Actor: @${{ github.actor }}*`;

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

  apply:
    name: Apply - ${{ matrix.directory }}
    runs-on: ubuntu-latest
    needs: [detect-changes]
    if: |
      (github.event_name == 'push' && (github.ref == 'refs/heads/main' || github.ref == 'refs/heads/master')) ||
      (github.event_name == 'workflow_dispatch' && github.event.inputs.action == 'apply')
    strategy:
      matrix:
        directory: ${{ github.event_name == 'workflow_dispatch' && fromJson(format('["environments/{0}"]', github.event.inputs.environment)) || fromJson(needs.detect-changes.outputs.matrix).directory }}
      fail-fast: false
      max-parallel: 1  # Apply one at a time
    environment:
      name: production  # Configure approval in GitHub settings
    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Setup Terraform
        uses: hashicorp/setup-terraform@v3
        with:
          terraform_version: ${{ env.TF_VERSION }}
          terraform_wrapper: false

      - name: Setup Terragrunt
        run: |
          wget -q https://github.com/gruntwork-io/terragrunt/releases/download/v${{ env.TG_VERSION }}/terragrunt_linux_amd64
          chmod +x terragrunt_linux_amd64
          sudo mv terragrunt_linux_amd64 /usr/local/bin/terragrunt

      - name: Configure AWS Credentials
        uses: aws-actions/configure-aws-credentials@v4
        with:
          role-to-assume: ${{ secrets.AWS_ROLE_ARN }}
          aws-region: us-east-1

      - name: Terragrunt Apply
        run: |
          terragrunt run-all apply --terragrunt-non-interactive -auto-approve
        working-directory: ${{ matrix.directory }}

      - name: Notify Success
        if: success()
        run: echo "✅ Terragrunt apply completed for ${{ matrix.directory }}"

      - name: Notify Failure
        if: failure()
        run: echo "❌ Terragrunt apply failed for ${{ matrix.directory }}"