name: 'Save Cache'
description: 'Archives and uploads cache to GitHub Releases. Supports both single and multiple cache paths/keys/buckets.'

inputs:
  cache_path:
    description: 'Single path where cache is saved (use cache_paths for multiple)'
    required: false
    type: string
  cache_paths:
    description: 'Multiline list of paths where caches are saved (one per line)'
    required: false
    type: string
    default: ""
  cache_key:
    description: 'Unique key for the cache (use cache_keys for multiple)'
    required: false
    type: string
  cache_keys:
    description: 'Multiline list of unique keys for caches (one per line, must match cache_paths)'
    required: false
    type: string
    default: ""
  cache_bucket:
    description: 'Single tag name for the release (use cache_buckets for multiple)'
    required: false
    default: 'general-cache'
  cache_buckets:
    description: 'Multiline list of tag names for releases (one per line, must match cache_paths)'
    required: false
    type: string
    default: ""
  compression_level:
    description: 'Compression level (0-9). 0 = No compression, 1 = Fast, 19 = Best.'
    required: false
    type: number
    default: 6
  github_token:
    description: 'GitHub token for release upload authentication'
    required: true
    type: string

runs:
  using: 'composite'
  steps:
    - name: Archive, Split, and Upload Cache
      shell: bash
      env:
        GITHUB_TOKEN: ${{ inputs.github_token }}
        TARGET_REPO: "${{ github.repository }}"
      run: |
        # Validate and parse inputs
        PATHS_INPUT="${{ inputs.cache_paths }}"
        KEYS_INPUT="${{ inputs.cache_keys }}"
        BUCKETS_INPUT="${{ inputs.cache_buckets }}"
        
        # If multiple inputs are empty, fall back to single inputs
        if [ -z "$PATHS_INPUT" ]; then
          PATHS_INPUT="${{ inputs.cache_path }}"
        fi
        if [ -z "$KEYS_INPUT" ]; then
          KEYS_INPUT="${{ inputs.cache_key }}"
        fi
        if [ -z "$BUCKETS_INPUT" ]; then
          BUCKETS_INPUT="${{ inputs.cache_bucket }}"
        fi
        
        # Split inputs into arrays
        IFS=$'\n' read -rd '' -a PATHS_ARRAY <<<"$PATHS_INPUT" || true
        IFS=$'\n' read -rd '' -a KEYS_ARRAY <<<"$KEYS_INPUT" || true
        IFS=$'\n' read -rd '' -a BUCKETS_ARRAY <<<"$BUCKETS_INPUT" || true
        
        # Validate array lengths match
        if [[ ${#PATHS_ARRAY[@]} -ne ${#KEYS_ARRAY[@]} ]] || [[ ${#PATHS_ARRAY[@]} -ne ${#BUCKETS_ARRAY[@]} ]]; then
          echo "::error::Mismatch in array lengths: paths=${#PATHS_ARRAY[@]}, keys=${#KEYS_ARRAY[@]}, buckets=${#BUCKETS_ARRAY[@]}"
          exit 1
        fi
        
        # Git configuration for releases
        git config user.name "github-actions[bot]"
        git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
        
        # Helper function to handle release creation
        ensure_release() {
          local tag_name="$1"
          
          git fetch --tags --force
          
          if gh release view "$tag_name" --repo "$TARGET_REPO" >/dev/null 2>&1; then
            echo "Release '$tag_name' already exists. Ready for upload."
            gh release edit "$tag_name" --latest=false --repo "$TARGET_REPO" >/dev/null 2>&1 || true
            return 0
          fi

          if ! git rev-parse "$tag_name" >/dev/null 2>&1; then
            echo "Tag '$tag_name' not found. Creating backdated tag and release..."
            GIT_COMMITTER_DATE="2015-01-01T12:00:00" git tag -a "$tag_name" -m "Build Cache Storage"
            if git push origin "$tag_name" --force; then
              gh release create "$tag_name" --title "Build Cache" --notes "Automated storage for build assets" --latest=false --repo "$TARGET_REPO" || true
              gh release edit "$tag_name" --latest=false --repo "$TARGET_REPO" >/dev/null 2>&1 || true
            else
              echo "Push failed, tag might have been created by a parallel job. Continuing..."
            fi
          else
            echo "Tag '$tag_name' already exists but release is missing. Creating release..."
            gh release create "$tag_name" --title "Build Cache" --notes "Automated storage for build assets" --latest=false --repo "$TARGET_REPO" || true
            gh release edit "$tag_name" --latest=false --repo "$TARGET_REPO" >/dev/null 2>&1 || true
          fi
        }
        
        upload_with_retry() {
          local file=$1
          local tag_name=$2
          local max_attempts=3
          local timeout_duration="30m"  # Increased timeout for large files
          
          for ((i=1; i<=max_attempts; i++)); do
            echo "  Attempt $i for $file..."
            
            if timeout $timeout_duration gh release upload "$tag_name" "$file" --clobber --repo "$TARGET_REPO"; then
              echo "  ✅ Successfully uploaded $file"
              return 0
            else
              local exit_code=$?
              if [ $exit_code -eq 124 ]; then
                echo "  ⚠ Attempt $i timed out (timeout after $timeout_duration). Retrying..."
              else
                echo "  ⚠ Attempt $i failed with exit code $exit_code. Retrying..."
              fi
            fi
            
            if [ $i -lt $max_attempts ]; then
              sleep 5
            fi
          done
          return 1
        }
        
        # Process each cache entry
        for ((idx=0; idx<${#PATHS_ARRAY[@]}; idx++)); do
          CACHE_PATH="${PATHS_ARRAY[$idx]}"
          CACHE_KEY="${KEYS_ARRAY[$idx]}"
          CACHE_BUCKET="${BUCKETS_ARRAY[$idx]}"
          
          [ -z "$CACHE_PATH" ] && continue
          
          TAG_NAME="$CACHE_BUCKET"
          BASE_FILENAME="cache-$CACHE_KEY"
          
          if [ "${{ inputs.compression_level }}" -eq 0 ]; then
            FILENAME="$BASE_FILENAME.tar"
          else
            FILENAME="$BASE_FILENAME.tzst"
          fi
          
          echo "::group:: [$((idx+1))/${#PATHS_ARRAY[@]}] Checking Release State ($CACHE_BUCKET)"
          ensure_release "$TAG_NAME"
          echo "::endgroup::"
          
          echo "::group:: [$((idx+1))/${#PATHS_ARRAY[@]}] Archiving Path: $CACHE_PATH"
          
          if [ ! -d "$CACHE_PATH" ] && [ ! -f "$CACHE_PATH" ]; then
            echo "⚠️ Target path not found. Skipping cache save."
            echo "::endgroup::"
            continue
          fi

          # Print concise summary: total size, top-level entries, and one-level-deep for largest entries
          summarize_dir() {
            local path="$1"
            local top_n=${2:-10}
            local sub_n=${3:-5}
            if [ ! -e "$path" ]; then
              echo "Path $path not found"
              return
            fi
            echo "--- Cache save summary for: $path ---"
            du -sh "$path" || true
            du -h --max-depth=1 "$path" 2>/dev/null | sort -hr | head -n $top_n || true
            echo "Showing one-level-deep details for top entries (up to $sub_n each):"
            while read -r line; do
              entry_path=$(echo "$line" | awk '{print $2}')
              [ -z "$entry_path" ] && continue
              if [ "$entry_path" = "$path" ]; then
                continue
              fi
              echo "-> $entry_path :"
              du -h --max-depth=1 "$entry_path" 2>/dev/null | sort -hr | head -n $sub_n || true
            done < <(du -h --max-depth=1 "$path" 2>/dev/null | sort -hr | head -n $top_n)
            echo "-------------------------------------"
          }

          summarize_dir "$CACHE_PATH" 10 5 || true
          
          DIR_NAME=$(dirname "$CACHE_PATH")
          BASE_NAME=$(basename "$CACHE_PATH")
          
          if [ "${{ inputs.compression_level }}" -eq 0 ]; then
            tar --posix -h -cvf "$FILENAME" -C "$DIR_NAME" "$BASE_NAME" > /dev/null 2>&1
          else
            tar --posix -h -I "zstd -T0 -${{ inputs.compression_level }}" -cvf "$FILENAME" -C "$DIR_NAME" "$BASE_NAME" > /dev/null 2>&1
          fi
          
          FILE_SIZE=$(stat -c%s "$FILENAME")
          echo "Archive created: $FILENAME ($FILE_SIZE bytes)"
          # Create SHA256 checksum and upload alongside the archive/parts
          if command -v sha256sum >/dev/null 2>&1; then
            sha256sum "$FILENAME" | awk '{print $1}' > "$FILENAME.sha256"
          else
            # fallback using openssl
            openssl dgst -sha256 "$FILENAME" | awk '{print $2}' > "$FILENAME.sha256" || true
          fi
          echo "Checksum written: $FILENAME.sha256"
          echo "::endgroup::"
          
          echo "::group:: [$((idx+1))/${#PATHS_ARRAY[@]}] Uploading Assets ($CACHE_BUCKET)"
          MAX_SIZE=2000000000 # ~1.86GB
          
          # Check if cache has changed by comparing with previous release asset
          SKIP_UPLOAD=false
          if gh release view "$TAG_NAME" --repo "$TARGET_REPO" >/dev/null 2>&1; then
            echo "Checking if cache has changed..."
            # Try to get the size of the previous asset with the same name
            PREV_SIZE=$(gh release view "$TAG_NAME" --repo "$TARGET_REPO" --json assets --jq ".assets[] | select(.name == \"$FILENAME\") | .size" 2>/dev/null || echo "0")
            if [ "$PREV_SIZE" = "$FILE_SIZE" ]; then
              echo "⚠️ Cache size unchanged ($FILE_SIZE bytes). Skipping upload to save bandwidth."
              SKIP_UPLOAD=true
            fi
          fi
          
          if [ "$SKIP_UPLOAD" = "true" ]; then
            rm -f "$FILENAME"
            echo "::endgroup::"
            continue
          fi
          
          if [ "$FILE_SIZE" -gt "$MAX_SIZE" ]; then
            echo "⚠️ File > 2GB. Splitting into 1.5GB chunks..."
            split -b 1500M -a 2 "$FILENAME" "${FILENAME}.part"
            for part in "${FILENAME}".part*; do
              echo "  Uploading $part..."
              if ! upload_with_retry "$part" "$TAG_NAME"; then
                echo "::warning::Failed to upload part $part after 3 attempts. Continuing with next cache..."
              fi
              rm -f "$part"
            done
            # Upload checksum for the original archive
            echo "  Uploading checksum $FILENAME.sha256..."
            if ! upload_with_retry "$FILENAME.sha256" "$TAG_NAME"; then
              echo "::warning::Failed to upload checksum $FILENAME.sha256"
            fi
            rm -rf "$FILENAME"
          else
            echo "  File size: $((FILE_SIZE / 1024 / 1024))MB"
            echo "  Uploading $FILENAME..."
            if ! upload_with_retry "$FILENAME" "$TAG_NAME"; then
              echo "::warning::Failed to upload $FILENAME after 3 attempts. The cache will not be available for next run."
            fi
            # Upload checksum alongside the archive
            echo "  Uploading checksum $FILENAME.sha256..."
            if ! upload_with_retry "$FILENAME.sha256" "$TAG_NAME"; then
              echo "::warning::Failed to upload checksum $FILENAME.sha256"
            fi
            rm -f "$FILENAME"
            rm -f "$FILENAME.sha256"
          fi
          echo "::endgroup::"
        done