name: Nix Flake Update

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

env:
  BRANCH_NAME: auto-update-flake-${{ github.run_number }}
  HYDRA_INSTANCE: https://hydra.zoeys.computer
  HYDRA_PROJECT: config
  HYDRA_JOBSET: pr-${{ github.run_number }}

jobs:
  check-existing-pr:
    runs-on: ubuntu-latest
    outputs:
      pr_exists: ${{ steps.check-pr.outputs.pr_exists }}
      pr_number: ${{ steps.check-pr.outputs.pr_number }}
    steps:
      - name: Check for existing PR
        id: check-pr
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          existing_pr=$(gh pr list --repo ${{ github.repository }} --head "auto-update-flake-" --state open --json number --jq '.[0].number')
          if [ -n "$existing_pr" ]; then
            echo "pr_exists=true" >> $GITHUB_OUTPUT
            echo "pr_number=$existing_pr" >> $GITHUB_OUTPUT
          else
            echo "pr_exists=false" >> $GITHUB_OUTPUT
          fi

  update-flake:
    needs: check-existing-pr
    if: needs.check-existing-pr.outputs.pr_exists == 'false'
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repository
        uses: actions/checkout@v3
        with:
          fetch-depth: 0  # Fetch all history for all branches and tags

      - name: Install Nix
        uses: cachix/install-nix-action@v30

      - name: Update flake dependencies
        id: update-flake
        run: |
          git config user.name github-actions
          git config user.email github-actions@github.com
          nix flake update --accept-flake-config
          git diff
          if [[ -n $(git status -s) ]]; then
            echo "CHANGED=true" >> $GITHUB_OUTPUT
            echo "Changes detected:"
            git status -s
          else
            echo "CHANGED=false" >> $GITHUB_OUTPUT
            echo "No changes detected."
          fi

      - name: Create branch and commit changes
        if: steps.update-flake.outputs.CHANGED == 'true'
        run: |
          git checkout -b ${{ env.BRANCH_NAME }}
          git add .
          git commit -m "chore: update flake dependencies"
          git push -u origin ${{ env.BRANCH_NAME }}

      - name: Create Pull Request
        if: steps.update-flake.outputs.CHANGED == 'true'
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          gh pr create --title "Auto-update Nix flake dependencies" \
                       --body "This PR updates the Nix flake dependencies." \
                       --base main \
                       --head ${{ env.BRANCH_NAME }}

      - name: Get Hydra session token
        id: hydra-session
        run: |
          response=$(curl -X POST -i \
            '${{ env.HYDRA_INSTANCE }}/login' \
            -H 'accept: application/json' \
            -H 'Content-Type: application/json' \
            -H 'Origin: ${{ env.HYDRA_INSTANCE }}' \
            -d '{
              "username": "${{ secrets.HYDRA_USERNAME }}",
              "password": "${{ secrets.HYDRA_PASSWORD }}"
            }')
          session_cookie=$(echo "$response" | grep -i 'set-cookie' | sed -n 's/.*hydra_session=\([^;]*\).*/\1/p')
          echo "SESSION_COOKIE=$session_cookie" >> $GITHUB_OUTPUT

      - name: Create Hydra jobset
        if: steps.update-flake.outputs.CHANGED == 'true'
        env:
          SESSION_COOKIE: ${{ steps.hydra-session.outputs.SESSION_COOKIE }}
        run: |
          curl -X PUT -H "Content-Type: application/json" \
            -H "Cookie: hydra_session=$SESSION_COOKIE" \
            -d '{
              "enabled": 1,
              "visible": false,
              "keepnr": 3,
              "schedulingshares": 100,
              "checkinterval": 60,
              "description": "PR #${{ github.event.pull_request.number }} - Auto-update flake dependencies",
              "flake": "github:${{ github.repository }}/${{ env.BRANCH_NAME }}",
              "type": 1
            }' \
            "${{ env.HYDRA_INSTANCE }}/jobset/${{ env.HYDRA_PROJECT }}/${{ env.HYDRA_JOBSET }}"

      - name: Trigger Hydra build
        if: steps.update-flake.outputs.CHANGED == 'true'
        env:
          SESSION_COOKIE: ${{ steps.hydra-session.outputs.SESSION_COOKIE }}
        run: |
          curl -X POST -H "Content-Type: application/json" \
            -H "Cookie: hydra_session=$SESSION_COOKIE" \
            -H "Origin: ${{ env.HYDRA_INSTANCE }}" \
            -d '{"jobsets": ["${{ env.HYDRA_PROJECT }}:${{ env.HYDRA_JOBSET }}"]}' \
            "${{ env.HYDRA_INSTANCE }}/api/push"

      - name: Wait for Hydra build
        if: steps.update-flake.outputs.CHANGED == 'true'
        id: wait-for-build
        env:
          SESSION_COOKIE: ${{ steps.hydra-session.outputs.SESSION_COOKIE }}
        run: |
          max_attempts=60  # 30 minutes (30 * 2 minutes)
          attempt=0
          build_status="unknown"
          set -e  # Exit immediately if a command exits with a non-zero status
          while [ $attempt -lt $max_attempts ]; do
            echo "Attempt $((attempt + 1))/$max_attempts"
            response=$(curl -s -H "Cookie: hydra_session=$SESSION_COOKIE" \
              "${{ env.HYDRA_INSTANCE }}/api/jobsets?project=${{ env.HYDRA_PROJECT }}")
            jobset=$(echo "$response" | jq -r '.[] | select(.name == "${{ env.HYDRA_JOBSET }}")')
            
            if [ -z "$jobset" ]; then
              echo "Jobset ${{ env.HYDRA_JOBSET }} not found. Waiting..."
              sleep 120
              attempt=$((attempt + 1))
              continue
            fi

            
            nrscheduled=$(echo "$jobset" | jq -r '.nrscheduled')
            nrfailed=$(echo "$jobset" | jq -r '.nrfailed')
            nrsucceeded=$(echo "$jobset" | jq -r '.nrsucceeded')
            nrtotal=$(echo "$jobset" | jq -r '.nrtotal')
            
            echo "Status: nrscheduled=$nrscheduled, nrfailed=$nrfailed, nrsucceeded=$nrsucceeded, nrtotal=$nrtotal"
            
            if [ "$nrtotal" = "0" ]; then
              echo "Build not started yet. Waiting..."
            elif [ "$nrfailed" != "0" ]; then
              build_status="failed"
              break
            elif [ "$nrsucceeded" = "$nrtotal" ] && [ "$nrtotal" != "0" ]; then
              build_status="succeeded"
              break
            elif [ "$nrscheduled" = "0" ] && [ "$nrsucceeded" != "0" ] && [ "$nrsucceeded" = "$nrtotal" ]; then
              build_status="succeeded"
              break
            else
              echo "Build in progress. Waiting..."
            fi
            
            sleep 120  # Wait for 2 minutes before checking again
            attempt=$((attempt + 1))
          done
          
          if [ "$build_status" = "unknown" ]; then
            echo "Timeout reached. Considering build as failed."
            build_status="failed"
          fi
          
          echo "BUILD_SUCCESS=$([ "$build_status" = "succeeded" ] && echo "true" || echo "false")" >> $GITHUB_OUTPUT
          if [ "$build_status" = "succeeded" ]; then
            echo "Build succeeded!"
            exit 0
          else
            echo "Build failed or timed out."
            exit 1
          fi

      - name: Merge PR if build succeeds
        if: steps.update-flake.outputs.CHANGED == 'true' && steps.wait-for-build.outputs.BUILD_SUCCESS == 'true'
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          gh pr merge ${{ steps.create-pr.outputs.pr_number }} --merge

      - name: Exit if build fails
        if: steps.update-flake.outputs.CHANGED == 'true' && steps.wait-for-build.outputs.BUILD_SUCCESS != 'true'
        run: exit 1

  retry-update:
    needs: check-existing-pr
    if: needs.check-existing-pr.outputs.pr_exists == 'true'
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repository
        uses: actions/checkout@v3
        with:
          fetch-depth: 0

      - name: Install Nix
        uses: cachix/install-nix-action@v30

      - name: Checkout PR branch
        run: |
          pr_number="${{ needs.check-existing-pr.outputs.pr_number }}"
          branch_name=$(gh pr view $pr_number --json headRefName -q .headRefName)
          git checkout $branch_name
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}

      - name: Update flake dependencies
        id: update-flake
        run: |
          git config user.name github-actions
          git config user.email github-actions@github.com
          nix flake update --accept-flake-config
          git diff
          if [[ -n $(git status -s) ]]; then
            echo "CHANGED=true" >> $GITHUB_OUTPUT
            git add .
            git commit -m "Auto-update flake dependencies (retry)"
            git push origin HEAD
          else
            echo "CHANGED=false" >> $GITHUB_OUTPUT
            echo "No changes detected."
          fi

      - name: Get Hydra session token
        id: hydra-session
        run: |
          response=$(curl -X POST -i \
            '${{ env.HYDRA_INSTANCE }}/login' \
            -H 'accept: application/json' \
            -H 'Content-Type: application/json' \
            -H 'Origin: ${{ env.HYDRA_INSTANCE }}' \
            -d '{
              "username": "${{ secrets.HYDRA_USERNAME }}",
              "password": "${{ secrets.HYDRA_PASSWORD }}"
            }')
          session_cookie=$(echo "$response" | grep -i 'set-cookie' | sed -n 's/.*hydra_session=\([^;]*\).*/\1/p')
          echo "SESSION_COOKIE=$session_cookie" >> $GITHUB_OUTPUT

      - name: Create Hydra jobset
        if: steps.update-flake.outputs.CHANGED == 'true'
        env:
          SESSION_COOKIE: ${{ steps.hydra-session.outputs.SESSION_COOKIE }}
        run: |
          curl -X PUT -H "Content-Type: application/json" \
            -H "Cookie: hydra_session=$SESSION_COOKIE" \
            -d '{
              "enabled": 1,
              "visible": false,
              "keepnr": 3,
              "schedulingshares": 100,
              "checkinterval": 60,
              "description": "PR #${{ github.event.pull_request.number }} - Auto-update flake dependencies",
              "flake": "github:${{ github.repository }}/${{ env.BRANCH_NAME }}",
              "type": 1
            }' \
            "${{ env.HYDRA_INSTANCE }}/jobset/${{ env.HYDRA_PROJECT }}/${{ env.HYDRA_JOBSET }}"

      - name: Trigger Hydra build
        if: steps.update-flake.outputs.CHANGED == 'true'
        env:
          SESSION_COOKIE: ${{ steps.hydra-session.outputs.SESSION_COOKIE }}
        run: |
          curl -X POST -H "Content-Type: application/json" \
            -H "Cookie: hydra_session=$SESSION_COOKIE" \
            -H "Origin: ${{ env.HYDRA_INSTANCE }}" \
            -d '{"jobsets": ["${{ env.HYDRA_PROJECT }}:${{ env.HYDRA_JOBSET }}"]}' \
            "${{ env.HYDRA_INSTANCE }}/api/push"

      - name: Wait for Hydra build
        if: steps.update-flake.outputs.CHANGED == 'true'
        id: wait-for-build
        env:
          SESSION_COOKIE: ${{ steps.hydra-session.outputs.SESSION_COOKIE }}
        run: |
          max_attempts=60  # 30 minutes (30 * 2 minutes)
          attempt=0
          build_status="unknown"
          set -e  # Exit immediately if a command exits with a non-zero status
          while [ $attempt -lt $max_attempts ]; do
            echo "Attempt $((attempt + 1))/$max_attempts"
            response=$(curl -s -H "Cookie: hydra_session=$SESSION_COOKIE" \
              "${{ env.HYDRA_INSTANCE }}/api/jobsets?project=${{ env.HYDRA_PROJECT }}")
            jobset=$(echo "$response" | jq -r '.[] | select(.name == "${{ env.HYDRA_JOBSET }}")')
            
            if [ -z "$jobset" ]; then
              echo "Jobset ${{ env.HYDRA_JOBSET }} not found. Waiting..."
              sleep 120
              attempt=$((attempt + 1))
              continue
            fi

            nrscheduled=$(echo "$jobset" | jq -r '.nrscheduled')
            nrfailed=$(echo "$jobset" | jq -r '.nrfailed')
            nrsucceeded=$(echo "$jobset" | jq -r '.nrsucceeded')
            nrtotal=$(echo "$jobset" | jq -r '.nrtotal')
            
            echo "Status: nrscheduled=$nrscheduled, nrfailed=$nrfailed, nrsucceeded=$nrsucceeded, nrtotal=$nrtotal"
            
            if [ "$nrtotal" = "0" ]; then
              echo "Build not started yet. Waiting..."
            elif [ "$nrfailed" != "0" ]; then
              build_status="failed"
              break
            elif [ "$nrsucceeded" = "$nrtotal" ] && [ "$nrtotal" != "0" ]; then
              build_status="succeeded"
              break
            elif [ "$nrscheduled" = "0" ] && [ "$nrsucceeded" != "0" ] && [ "$nrsucceeded" = "$nrtotal" ]; then
              build_status="succeeded"
              break
            else
              echo "Build in progress. Waiting..."
            fi
            
            sleep 120  # Wait for 2 minutes before checking again
            attempt=$((attempt + 1))
          done
          
          if [ "$build_status" = "unknown" ]; then
            echo "Timeout reached. Considering build as failed."
            build_status="failed"
          fi
          
          echo "BUILD_SUCCESS=$([ "$build_status" = "succeeded" ] && echo "true" || echo "false")" >> $GITHUB_OUTPUT
          if [ "$build_status" = "succeeded" ]; then
            echo "Build succeeded!"
            exit 0
          else
            echo "Build failed or timed out."
            exit 1
          fi

      - name: Merge PR if build succeeds
        if: steps.update-flake.outputs.CHANGED == 'true' && steps.wait-for-build.outputs.BUILD_SUCCESS == 'true'
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          gh pr merge ${{ needs.check-existing-pr.outputs.pr_number }} --merge

      - name: Exit if build fails
        if: steps.update-flake.outputs.CHANGED == 'true' && steps.wait-for-build.outputs.BUILD_SUCCESS != 'true'
        run: exit 1