name: Container Registry Prune

on:
  schedule:
    - cron: '0 3 * * 0' # Weekly: Sundays at 03:00 UTC
  workflow_dispatch:
    inputs:
      registries:
        description: 'Comma-separated registries to prune (ghcr,dockerhub)'
        required: false
        default: 'ghcr,dockerhub'
      keep_days:
        description: 'Number of days to retain images (unprotected)'
        required: false
        default: '30'
      dry_run:
        description: 'If true, only logs candidates and does not delete (default: false for active cleanup)'
        required: false
        default: 'false'
      keep_last_n:
        description: 'Keep last N newest images (global)'
        required: false
        default: '30'

permissions:
  packages: write
  contents: read

jobs:
  prune:
    runs-on: ubuntu-latest
    env:
      OWNER: ${{ github.repository_owner }}
      IMAGE_NAME: charon
      REGISTRIES: ${{ github.event.inputs.registries || 'ghcr,dockerhub' }}
      KEEP_DAYS: ${{ github.event.inputs.keep_days || '30' }}
      KEEP_LAST_N: ${{ github.event.inputs.keep_last_n || '30' }}
      DRY_RUN: ${{ github.event.inputs.dry_run || 'false' }}
      PROTECTED_REGEX: '["^v","^latest$","^main$","^develop$"]'
    steps:
      - name: Checkout
        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6

      - name: Install tools
        run: |
          sudo apt-get update && sudo apt-get install -y jq curl

      - name: Run container prune
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          DOCKERHUB_USERNAME: ${{ secrets.DOCKERHUB_USERNAME }}
          DOCKERHUB_TOKEN: ${{ secrets.DOCKERHUB_TOKEN }}
        run: |
          chmod +x scripts/prune-container-images.sh
          ./scripts/prune-container-images.sh 2>&1 | tee prune-${{ github.run_id }}.log

      - name: Summarize prune results (space reclaimed)
        if: ${{ always() }}
        run: |
          set -euo pipefail
          SUMMARY_FILE=prune-summary.env
          LOG_FILE=prune-${{ github.run_id }}.log

          human() {
            local bytes=${1:-0}
            if [ -z "$bytes" ] || [ "$bytes" -eq 0 ]; then
              echo "0 B"
              return
            fi
            awk -v b="$bytes" 'function human(x){ split("B KiB MiB GiB TiB",u," "); i=0; while(x>1024){x/=1024;i++} printf "%0.2f %s", x, u[i+1]} END{human(b)}'
          }

          if [ -f "$SUMMARY_FILE" ]; then
            TOTAL_CANDIDATES=$(grep -E '^TOTAL_CANDIDATES=' "$SUMMARY_FILE" | cut -d= -f2 || echo 0)
            TOTAL_CANDIDATES_BYTES=$(grep -E '^TOTAL_CANDIDATES_BYTES=' "$SUMMARY_FILE" | cut -d= -f2 || echo 0)
            TOTAL_DELETED=$(grep -E '^TOTAL_DELETED=' "$SUMMARY_FILE" | cut -d= -f2 || echo 0)
            TOTAL_DELETED_BYTES=$(grep -E '^TOTAL_DELETED_BYTES=' "$SUMMARY_FILE" | cut -d= -f2 || echo 0)

            {
              echo "## Container prune summary"
              echo "- candidates: ${TOTAL_CANDIDATES} (≈ $(human "${TOTAL_CANDIDATES_BYTES}"))"
              echo "- deleted: ${TOTAL_DELETED} (≈ $(human "${TOTAL_DELETED_BYTES}"))"
            } >> "$GITHUB_STEP_SUMMARY"

            printf 'PRUNE_SUMMARY: candidates=%s candidates_bytes=%s deleted=%s deleted_bytes=%s\n' \
              "${TOTAL_CANDIDATES}" "${TOTAL_CANDIDATES_BYTES}" "${TOTAL_DELETED}" "${TOTAL_DELETED_BYTES}"
            echo "Deleted approximately: $(human "${TOTAL_DELETED_BYTES}")"
            echo "space_saved=$(human "${TOTAL_DELETED_BYTES}")" >> "$GITHUB_OUTPUT"
          else
            deleted_bytes=$(grep -oE '\( *approx +[0-9]+ bytes\)' "$LOG_FILE" | sed -E 's/.*approx +([0-9]+) bytes.*/\1/' | awk '{s+=$1} END {print s+0}' || true)
            deleted_count=$(grep -cE 'deleting |DRY RUN: would delete' "$LOG_FILE" || true)

            {
              echo "## Container prune summary"
              echo "- deleted (approx): ${deleted_count} (≈ $(human "${deleted_bytes}"))"
            } >> "$GITHUB_STEP_SUMMARY"

            printf 'PRUNE_SUMMARY: deleted_approx=%s deleted_bytes=%s\n' "${deleted_count}" "${deleted_bytes}"
            echo "Deleted approximately: $(human "${deleted_bytes}")"
            echo "space_saved=$(human "${deleted_bytes}")" >> "$GITHUB_OUTPUT"
          fi

      - name: Upload prune artifacts
        if: ${{ always() }}
        uses: actions/upload-artifact@b7c566a772e6b6bfb58ed0dc250532a479d7789f # v6
        with:
          name: prune-log-${{ github.run_id }}
          path: |
            prune-${{ github.run_id }}.log
            prune-summary.env