name: Terraform CI/CD

on:
  push:
    branches:
      - dev
    paths:
      - 'terraform/**'
  pull_request:
    branches:
      - dev
    paths:
      - 'terraform/**'

env:
  TF_WORKING_DIR: terraform/prod
  # Backend S3 (Scaleway)
  AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }}
  AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
  # Terraform variables
  TF_VAR_proxmox_url: ${{ secrets.PROXMOX_URL }}
  TF_VAR_proxmox_api_token: ${{ secrets.PROXMOX_API_TOKEN }}
  TF_VAR_tailscale_auth_key: ${{ secrets.TAILSCALE_AUTH_KEY }}

jobs:
  # ===========================================================================
  # Validation - Runs on all pushes and PRs
  # ===========================================================================
  validate:
    name: Validate
    runs-on: self-hosted
    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Setup Terraform
        uses: hashicorp/setup-terraform@v3
        with:
          terraform_version: "1.9"

      - name: Setup TFLint
        uses: terraform-linters/setup-tflint@v4

      - name: Terraform Format Check
        id: fmt
        run: terraform fmt -check -recursive -diff
        working-directory: ${{ env.TF_WORKING_DIR }}
        continue-on-error: true

      - name: TFLint Init
        run: tflint --init
        working-directory: ${{ env.TF_WORKING_DIR }}

      - name: TFLint
        id: lint
        run: tflint --recursive --format compact
        working-directory: ${{ env.TF_WORKING_DIR }}
        continue-on-error: true

      - name: Terraform Init
        id: init
        run: terraform init -input=false
        working-directory: ${{ env.TF_WORKING_DIR }}

      - name: Terraform Validate
        id: validate
        run: terraform validate -no-color
        working-directory: ${{ env.TF_WORKING_DIR }}

      - name: Validation Summary
        if: always()
        run: |
          echo "## Validation Results" >> $GITHUB_STEP_SUMMARY
          echo "" >> $GITHUB_STEP_SUMMARY
          echo "| Check | Status |" >> $GITHUB_STEP_SUMMARY
          echo "|-------|--------|" >> $GITHUB_STEP_SUMMARY
          echo "| Format | ${{ steps.fmt.outcome == 'success' && '✅' || '❌' }} |" >> $GITHUB_STEP_SUMMARY
          echo "| TFLint | ${{ steps.lint.outcome == 'success' && '✅' || '⚠️' }} |" >> $GITHUB_STEP_SUMMARY
          echo "| Init | ${{ steps.init.outcome == 'success' && '✅' || '❌' }} |" >> $GITHUB_STEP_SUMMARY
          echo "| Validate | ${{ steps.validate.outcome == 'success' && '✅' || '❌' }} |" >> $GITHUB_STEP_SUMMARY

      - name: Check Validation Status
        if: steps.fmt.outcome == 'failure' || steps.init.outcome == 'failure' || steps.validate.outcome == 'failure'
        run: exit 1

  # ===========================================================================
  # Plan - Runs on PRs and pushes to dev
  # ===========================================================================
  plan:
    name: Plan
    runs-on: self-hosted
    needs: validate
    outputs:
      plan_exitcode: ${{ steps.plan.outputs.exitcode }}
    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Setup Terraform
        uses: hashicorp/setup-terraform@v3
        with:
          terraform_version: "1.9"

      - name: Terraform Init
        run: terraform init -input=false
        working-directory: ${{ env.TF_WORKING_DIR }}

      - name: Terraform Plan
        id: plan
        run: |
          terraform plan -input=false -no-color -detailed-exitcode -out=tfplan 2>&1 | tee plan_output.txt
          echo "exitcode=$?" >> $GITHUB_OUTPUT
        working-directory: ${{ env.TF_WORKING_DIR }}
        continue-on-error: true

      - name: Upload Plan
        uses: actions/upload-artifact@v4
        with:
          name: tfplan
          path: ${{ env.TF_WORKING_DIR }}/tfplan
          retention-days: 7

      - name: Plan Summary
        if: always()
        run: |
          echo "## Terraform Plan" >> $GITHUB_STEP_SUMMARY
          echo "" >> $GITHUB_STEP_SUMMARY
          echo '```' >> $GITHUB_STEP_SUMMARY
          cat plan_output.txt >> $GITHUB_STEP_SUMMARY
          echo '```' >> $GITHUB_STEP_SUMMARY
        working-directory: ${{ env.TF_WORKING_DIR }}

      - name: Comment PR with Plan
        if: github.event_name == 'pull_request'
        uses: actions/github-script@v7
        with:
          script: |
            const fs = require('fs');
            const plan = fs.readFileSync('${{ env.TF_WORKING_DIR }}/plan_output.txt', 'utf8');
            const maxLength = 60000;
            const truncated = plan.length > maxLength 
              ? plan.substring(0, maxLength) + '\n... (truncated)'
              : plan;
            
            const body = `## 🔍 Terraform Plan
            
            <details>
            <summary>Click to expand</summary>
            
            \`\`\`hcl
            ${truncated}
            \`\`\`
            
            </details>
            
            **Exit code:** \`${{ steps.plan.outputs.exitcode }}\`
            - \`0\` = No changes
            - \`1\` = Error
            - \`2\` = Changes detected
            `;
            
            github.rest.issues.createComment({
              issue_number: context.issue.number,
              owner: context.repo.owner,
              repo: context.repo.repo,
              body: body
            });

      - name: Check Plan Status
        if: steps.plan.outputs.exitcode == '1'
        run: exit 1

  # ===========================================================================
  # Apply - Runs on push to dev OR after PR merge
  # ===========================================================================
  apply:
    name: Apply
    runs-on: self-hosted
    needs: plan
    if: |
      (github.event_name == 'push' && github.ref == 'refs/heads/dev') &&
      needs.plan.outputs.plan_exitcode == '2'
    environment: production
    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Setup Terraform
        uses: hashicorp/setup-terraform@v3
        with:
          terraform_version: "1.9"

      - name: Terraform Init
        run: terraform init -input=false
        working-directory: ${{ env.TF_WORKING_DIR }}

      - name: Download Plan
        uses: actions/download-artifact@v4
        with:
          name: tfplan
          path: ${{ env.TF_WORKING_DIR }}

      - name: Terraform Apply
        run: terraform apply -input=false -auto-approve tfplan
        working-directory: ${{ env.TF_WORKING_DIR }}

      - name: Apply Summary
        if: always()
        run: |
          echo "## ✅ Terraform Apply Complete" >> $GITHUB_STEP_SUMMARY
          echo "" >> $GITHUB_STEP_SUMMARY
          echo "Infrastructure has been updated successfully." >> $GITHUB_STEP_SUMMARY