name: Daily Flake Update for Earth System

on:
  schedule:
    # Run daily at midnight UTC
    - cron: "0 0 * * *"
  workflow_dispatch: # Allow manual triggering

env:
  BRANCH_NAME: automated/flake-update
  PR_TITLE: "Automated: Update flake inputs"
  HYDRA_URL: "https://hydra.zoeys.computer"
  SYSTEM_NAME: "earth"
  HYDRA_PROJECT: "config"
  HYDRA_JOBSET: "config-build" 
  HYDRA_JOB: "x86_64-linux.earth"
  FORGEJO_API_URL: "${{ github.server_url }}/api/v1"

jobs:
  update-flake:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Install Nix
        uses: DeterminateSystems/nix-installer-action@main
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          extra-conf: |
            experimental-features = nix-command flakes
            access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}

      - name: Check for existing PR
        id: check-pr
        run: |
          # Get repository information
          REPO_OWNER=$(echo "$GITHUB_REPOSITORY" | cut -d '/' -f 1)
          REPO_NAME=$(echo "$GITHUB_REPOSITORY" | cut -d '/' -f 2)

          # Query Forgejo API for existing PRs
          PR_DATA=$(curl -s -H "Authorization: token ${{ secrets.GITHUB_TOKEN }}" \
            "${{ env.FORGEJO_API_URL }}/repos/${REPO_OWNER}/${REPO_NAME}/pulls?state=open&head=${REPO_OWNER}:${{ env.BRANCH_NAME }}")

          # Check if PR exists and extract PR number
          PR_COUNT=$(echo "$PR_DATA" | jq '. | length')

          if [[ "$PR_COUNT" -gt 0 ]]; then
            PR_NUMBER=$(echo "$PR_DATA" | jq -r '.[0].number')
            echo "Found existing PR #$PR_NUMBER"
            echo "pr_exists=true" >> $GITHUB_OUTPUT
            echo "pr_number=$PR_NUMBER" >> $GITHUB_OUTPUT
          else
            echo "No existing PR found"
            echo "pr_exists=false" >> $GITHUB_OUTPUT
            echo "pr_number=" >> $GITHUB_OUTPUT
          fi

      - name: Set up branch
        run: |
          git config --global user.name "Flake Update Bot"
          git config --global user.email "bot@example.com"

          if [[ "${{ steps.check-pr.outputs.pr_exists }}" == "true" ]]; then
            # Update existing branch
            git fetch origin ${{ env.BRANCH_NAME }}
            git checkout ${{ env.BRANCH_NAME }}
          else
            # Create new branch
            git checkout -b ${{ env.BRANCH_NAME }}
          fi

      - name: Update flake inputs
        id: flake-update
        run: |
          cd nixos
          nix flake update

          if [[ -z "$(git status --porcelain)" ]]; then
            echo "No changes to commit"
            echo "changes_made=false" >> $GITHUB_OUTPUT
            exit 0
          else
            git add flake.lock
            git commit -m "chore: update flake inputs"
            git push -f origin ${{ env.BRANCH_NAME }}
            echo "changes_made=true" >> $GITHUB_OUTPUT
          fi

      - name: Create or update PR
        id: create-pr
        if: steps.flake-update.outputs.changes_made == 'true'
        run: |
          # Get repository information
          REPO_OWNER=$(echo "$GITHUB_REPOSITORY" | cut -d '/' -f 1)
          REPO_NAME=$(echo "$GITHUB_REPOSITORY" | cut -d '/' -f 2)

          if [[ "${{ steps.check-pr.outputs.pr_exists }}" == "true" ]]; then
            echo "Updating existing PR #${{ steps.check-pr.outputs.pr_number }}"
            PR_NUMBER="${{ steps.check-pr.outputs.pr_number }}"

            # Update PR with comment about new update
            curl -s -X POST \
              -H "Authorization: token ${{ secrets.GITHUB_TOKEN }}" \
              -H "Content-Type: application/json" \
              -d '{"body": "Updated flake inputs with latest versions"}' \
              "${{ env.FORGEJO_API_URL }}/repos/${REPO_OWNER}/${REPO_NAME}/issues/${PR_NUMBER}/comments"

            echo "pr_number=$PR_NUMBER" >> $GITHUB_OUTPUT
          else
            echo "Creating new PR"

            # Create new PR using API
            PR_DATA=$(curl -s -X POST \
              -H "Authorization: token ${{ secrets.GITHUB_TOKEN }}" \
              -H "Content-Type: application/json" \
              -d '{
                "title": "'"${{ env.PR_TITLE }}"'",
                "body": "This is an automated PR to update flake inputs. It will be automatically merged if the Hydra build for the Earth system passes.",
                "head": "'"${{ env.BRANCH_NAME }}"'",
                "base": "main",
                "draft": true
              }' \
              "${{ env.FORGEJO_API_URL }}/repos/${REPO_OWNER}/${REPO_NAME}/pulls")

            PR_NUMBER=$(echo "$PR_DATA" | jq -r '.number')
            echo "Created PR #$PR_NUMBER"
            echo "pr_number=$PR_NUMBER" >> $GITHUB_OUTPUT
          fi

      - name: Wait for Hydra build to start
        run: |
          PR_NUMBER="${{ steps.check-pr.outputs.pr_number }}"
          if [[ -z "$PR_NUMBER" ]]; then
            PR_NUMBER="${{ steps.create-pr.outputs.pr_number }}"
          fi
          
          echo "Waiting for Hydra build to start (checking every 60 seconds, timeout after 30 minutes)..."
          MAX_ATTEMPTS=30
          ATTEMPT=0
          
          while [ $ATTEMPT -lt $MAX_ATTEMPTS ]; do
            ATTEMPT=$((ATTEMPT+1))
            
            # Get the latest commit SHA from the branch
            COMMIT_SHA=$(git rev-parse HEAD)
            
            # Check if Hydra build exists for this commit using API
            BUILD_STATUS=$(curl -s "${{ env.HYDRA_URL }}/api/jobsets?project=${{ env.HYDRA_PROJECT }}" || echo "")
            
            if [[ "$BUILD_STATUS" == *"${{ env.HYDRA_JOBSET }}"* ]]; then
              echo "Hydra jobset found! Monitoring build status..."
              break
            fi
            
            echo "Attempt $ATTEMPT/$MAX_ATTEMPTS: No Hydra build found yet, waiting 60 seconds..."
            sleep 60
          done
          
          if [ $ATTEMPT -ge $MAX_ATTEMPTS ]; then
            echo "Timeout waiting for Hydra build to start. PR will remain in draft state."
            exit 0
          fi

      - name: Monitor Hydra build
        id: hydra-build
        run: |
          PR_NUMBER="${{ steps.check-pr.outputs.pr_number }}"
          if [[ -z "$PR_NUMBER" ]]; then
            PR_NUMBER="${{ steps.create-pr.outputs.pr_number }}"
          fi
          
          echo "Monitoring Hydra build status (checking every 5 minutes, timeout after 6 hours)..."
          MAX_ATTEMPTS=72
          ATTEMPT=0
          
          while [ $ATTEMPT -lt $MAX_ATTEMPTS ]; do
            ATTEMPT=$((ATTEMPT+1))
            
            # Get latest evaluation ID
            EVAL_INFO=$(curl -s "${{ env.HYDRA_URL }}/jobset/${{ env.HYDRA_PROJECT }}/${{ env.HYDRA_JOBSET }}/evals" || echo "")
            LATEST_EVAL_ID=$(echo "$EVAL_INFO" | grep -o -E '"id":[0-9]+' | head -n 1 | cut -d ':' -f 2)
            
            if [[ -z "$LATEST_EVAL_ID" ]]; then
              echo "No evaluation found yet, continuing to wait..."
              sleep 300
              continue
            fi
            
            echo "Found latest evaluation ID: $LATEST_EVAL_ID"
            
            # Get build status for the specific job from evaluation
            EVAL_BUILDS=$(curl -s "${{ env.HYDRA_URL }}/eval/$LATEST_EVAL_ID/builds" || echo "")
            
            # Look for our specific job in the evaluation
            if [[ "$EVAL_BUILDS" == *"${{ env.HYDRA_JOB }}"* ]]; then
              # Extract buildstatus for our job
              JOB_STATUS=$(echo "$EVAL_BUILDS" | grep -o -E '"buildstatus":[0-9]+' | head -n 1 | cut -d ':' -f 2)
              
              if [[ "$JOB_STATUS" == "0" ]]; then
                echo "Build succeeded (status: $JOB_STATUS)!"
                echo "build_success=true" >> $GITHUB_OUTPUT
                break
              elif [[ "$JOB_STATUS" == "1" || "$JOB_STATUS" == "2" || "$JOB_STATUS" == "3" || "$JOB_STATUS" == "4" || 
                      "$JOB_STATUS" == "6" || "$JOB_STATUS" == "7" || "$JOB_STATUS" == "9" || "$JOB_STATUS" == "10" || 
                      "$JOB_STATUS" == "11" ]]; then
                echo "Build failed (status: $JOB_STATUS)!"
                echo "build_success=false" >> $GITHUB_OUTPUT
                break
              fi
            fi
            
            echo "Attempt $ATTEMPT/$MAX_ATTEMPTS: Build still in progress or not found, waiting 5 minutes..."
            sleep 300
          done
          
          if [ $ATTEMPT -ge $MAX_ATTEMPTS ]; then
            echo "Timeout waiting for build to complete. PR will remain in draft state."
            echo "build_success=false" >> $GITHUB_OUTPUT
          fi

      - name: Mark PR ready for review or merge if build succeeded
        if: steps.hydra-build.outputs.build_success == 'true'
        run: |
          PR_NUMBER="${{ steps.check-pr.outputs.pr_number }}"
          if [[ -z "$PR_NUMBER" ]]; then
            PR_NUMBER="${{ steps.create-pr.outputs.pr_number }}"
          fi

          # Get repository information
          REPO_OWNER=$(echo "$GITHUB_REPOSITORY" | cut -d '/' -f 1)
          REPO_NAME=$(echo "$GITHUB_REPOSITORY" | cut -d '/' -f 2)

          # Mark PR as ready for review (not draft)
          curl -s -X PATCH \
            -H "Authorization: token ${{ secrets.GITHUB_TOKEN }}" \
            -H "Content-Type: application/json" \
            -d '{"draft": false}' \
            "${{ env.FORGEJO_API_URL }}/repos/${REPO_OWNER}/${REPO_NAME}/pulls/${PR_NUMBER}"

          # Add comment about successful build
          curl -s -X POST \
            -H "Authorization: token ${{ secrets.GITHUB_TOKEN }}" \
            -H "Content-Type: application/json" \
            -d '{"body": "Hydra build succeeded! Merging PR."}' \
            "${{ env.FORGEJO_API_URL }}/repos/${REPO_OWNER}/${REPO_NAME}/issues/${PR_NUMBER}/comments"

          # Merge the PR
          curl -s -X POST \
            -H "Authorization: token ${{ secrets.GITHUB_TOKEN }}" \
            -H "Content-Type: application/json" \
            -d '{
              "merge_method": "merge",
              "commit_title": "'"${{ env.PR_TITLE }}"'",
              "commit_message": "Automated merge after successful Hydra build for the Earth system."
            }' \
            "${{ env.FORGEJO_API_URL }}/repos/${REPO_OWNER}/${REPO_NAME}/pulls/${PR_NUMBER}/merge"