package compliance

import (
	"bytes"
	"fmt"
	"os"
	"path/filepath"
	"sort"

	"github.com/ethereum/go-ethereum/core"
	"github.com/ethereum/go-ethereum/core/types"

	"github.com/cerc-io/eth-statediff-compliance/internal/statediff"
)

// arg 0 is filename
func WriteDiffs(outputDir string,
	chain *core.BlockChain,
	blocks []*types.Block,
) {
	sdb := chain.StateCache()
	builder := statediff.MakeBuilder(sdb)

	// For each block, run the builder and output to a file
	for i, block := range blocks {
		args := statediff.Args{
			NewStateRoot: block.Root(),
			BlockNumber:  block.Number(),
			BlockHash:    block.Hash(),
		}
		if i != 0 {
			args.OldStateRoot = blocks[i-1].Root()
		}

		diff, err := builder.BuildStateDiffObject(args, statediff.Params{})
		if err != nil {
			panic(err)
		}

		writeDiff(outputDir, i, &diff)
	}
}

// Sorts contained state nodes, storage nodes, and IPLDs
// Outputs them to respective files in given dir
func writeDiff(outputDir string, number int, diff *statediff.StateObject) {
	sort.Slice(diff.IPLDs, func(i, j int) bool {
		return diff.IPLDs[i].CID < diff.IPLDs[j].CID
	})
	sort.Slice(diff.Nodes, func(i, j int) bool {
		return bytes.Compare(
			diff.Nodes[i].AccountWrapper.LeafKey,
			diff.Nodes[j].AccountWrapper.LeafKey,
		) < 0
	})
	for _, node := range diff.Nodes {
		sort.Slice(node.StorageDiff, func(i, j int) bool {
			return bytes.Compare(
				node.StorageDiff[i].LeafKey,
				node.StorageDiff[j].LeafKey,
			) < 0
		})
	}

	// open file and dump sorted node CIDs
	ipldsPath := filepath.Join(outputDir, fmt.Sprintf("%d_diff.txt", number))
	f, err := os.Create(ipldsPath)
	if err != nil {
		panic(err)
	}
	defer f.Close()
	for _, item := range diff.IPLDs {
		if _, err = f.WriteString("ipld," + item.CID + "\n"); err != nil {
			panic(err)
		}
	}
	for _, item := range diff.Nodes {
		if _, err = f.WriteString("state," + item.AccountWrapper.CID + "\n"); err != nil {
			panic(err)
		}
		for _, storage := range item.StorageDiff {
			if _, err = f.WriteString("storage," + storage.CID + "\n"); err != nil {
				panic(err)
			}
		}
	}
}