package partitioner

import (
	"fmt"
	"forever-files/db"
	"forever-files/types"
	"github.com/dustin/go-humanize"
)

func CalculatePartitions(store db.DB, targetSize int64) (partitions [][]types.FileMetadata, err error) {
	totalSize, err := store.GetTotalSize()
	if err != nil {
		return nil, fmt.Errorf("error getting total size: %w", err)
	}
	if targetSize <= 0 {
		targetSize = totalSize / 2
	}
	fmt.Printf("Total Size: %v\n", totalSize)
	fmt.Printf("Target Size: %v\n", targetSize)

	files, err := store.GetFiles()
	if err != nil {
		return nil, fmt.Errorf("error getting files: %w", err)
	}
	partitions = make([][]types.FileMetadata, 0)
	partitionSize := int64(0)
	partitionFiles := make([]types.FileMetadata, 0)
	leftOverFiles := make([]types.FileMetadata, 0)
	leftOverSize := int64(0)
	for _, file := range files {
		if partitionSize+file.Size > targetSize {
			fmt.Printf("Partition Size: %v\n", humanize.Bytes(uint64(partitionSize)))
			partitions = append(partitions, partitionFiles)
			partitionFiles = make([]types.FileMetadata, 0)
			partitionSize = 0
		}
		if partitionSize < targetSize && partitionSize+file.Size < targetSize {
			partitionFiles = append(partitionFiles, file)
			partitionSize += file.Size
		} else {
			leftOverFiles = append(leftOverFiles, file)
			leftOverSize += file.Size
		}
	}

	for _, partition := range partitions {
		fmt.Printf("Partition File Count: %v\n", len(partition))
	}
	fmt.Printf("Left Over File Count: %v\n", len(leftOverFiles))
	fmt.Printf("Left Over Size: %v\n", humanize.Bytes(uint64(leftOverSize)))

	return partitions, nil
}