package report

import (
	"context"
	"fmt"
	"math/big"
	"os"
	"time"

	"github.com/shopspring/decimal"
	"github.com/wormhole-foundation/wormhole-explorer/common/domain"
	"github.com/wormhole-foundation/wormhole-explorer/common/prices"
	sdk "github.com/wormhole-foundation/wormhole/sdk/vaa"
	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
	"go.uber.org/zap"
)

type TransferReportJob struct {
	database    *mongo.Database
	pageSize    int64
	logger      *zap.Logger
	pricesCache *prices.CoinPricesCache
	outputPath  string
}

type transactionResult struct {
	ID                string    `bson:"_id"`
	SourceChain       int       `bson:"sourceChain"`
	EmitterAddress    string    `bson:"emitterAddress"`
	Sequence          string    `bson:"sequence"`
	DestinationChain  int       `bson:"destinationChain"`
	TokenChain        int       `bson:"tokenChain"`
	TokenAddress      string    `bson:"tokenAddress"`
	TokenAddressHexa  string    `bson:"tokenAddressHexa"`
	Amount            string    `bson:"amount"`
	SourceWallet      string    `bson:"sourceWallet"`
	DestinationWallet string    `bson:"destinationWallet"`
	Fee               string    `bson:"fee"`
	Timestamp         time.Time `bson:"timestamp"`
	AppIds            []string  `bson:"appIds"`
}

// NewTransferReportJob creates a new transfer report job.
func NewTransferReportJob(database *mongo.Database, pageSize int64, pricesCache *prices.CoinPricesCache, outputPath string, logger *zap.Logger) *TransferReportJob {
	return &TransferReportJob{database: database, pageSize: pageSize, pricesCache: pricesCache, outputPath: outputPath, logger: logger}
}

// Run runs the transfer report job.
func (j *TransferReportJob) Run(ctx context.Context) error {

	file, err := os.Create(j.outputPath)
	if err != nil {
		return err
	}

	defer file.Close()

	//start backfilling
	page := int64(0)
	for {
		j.logger.Info("Processing page", zap.Int64("page", page))

		trxs, err := j.findTransactionsByPage(ctx, page, j.pageSize)
		if err != nil {
			j.logger.Error("Failed to get transactions", zap.Error(err))
			break
		}

		if len(trxs) == 0 {
			j.logger.Info("Empty page", zap.Int64("page", page))
			break
		}
		for _, t := range trxs {
			j.logger.Debug("Processing transaction", zap.String("id", t.ID))

			if t.TokenAddressHexa == "" {
				j.writeRecord(t, t.Amount, nil, nil, file)
				continue
			}

			tokenAddress, err := sdk.StringToAddress(t.TokenAddressHexa)
			if err != nil {
				j.logger.Error("Failed to get transactions",
					zap.String("id", t.ID),
					zap.String("TokenAddressHexa", t.TokenAddressHexa),
					zap.Error(err))
				continue
			}

			m, ok := domain.GetTokenByAddress(sdk.ChainID(t.TokenChain), tokenAddress.String())
			if ok {
				tokenPrice, err := j.pricesCache.GetPriceByTime(m.CoingeckoID, t.Timestamp)
				if err != nil {
					continue
				}
				if t.Amount == "" {
					j.writeRecord(t, t.Amount, nil, nil, file)
					continue
				}
				amount := new(big.Int)
				amount, ok := amount.SetString(t.Amount, 10)
				if !ok {
					j.logger.Error("amount is not a number",
						zap.String("id", t.ID),
						zap.String("amount", t.Amount),
					)
					j.writeRecord(t, "", nil, nil, file)
					continue
				}

				priceUSD := prices.CalculatePriceUSD(tokenPrice, amount, m.Decimals)

				j.writeRecord(t, t.Amount, m, &priceUSD, file)
			} else {
				j.writeRecord(t, t.Amount, nil, nil, file)
			}

		}
		page++
	}
	return nil
}

func (*TransferReportJob) writeRecord(trx transactionResult, fAmount string, m *domain.TokenMetadata, priceUSD *decimal.Decimal, file *os.File) error {
	// vaaId, sourceChain,emitterAddress,sequence,sourceWallet, destinationChain,destinationWallet,tokenChain,tokenAddress,amount,decimals,notionalUSD,fee,coinGeckoId,symbol
	var notionalUSD, decimals, symbol, coingeckoID string
	if m != nil {
		decimals = fmt.Sprintf("%d", m.Decimals)
		symbol = m.Symbol.String()
		coingeckoID = m.CoingeckoID
	}
	if priceUSD != nil {
		notionalUSD = priceUSD.Truncate(10).String()
	}
	line := fmt.Sprintf("%s,%d,%s,%s,%s,%d,%s,%d,%s,%s,%s,%s,%s,%s,%s\n",
		trx.ID, trx.SourceChain, trx.EmitterAddress, trx.Sequence, trx.SourceWallet, trx.DestinationChain,
		trx.DestinationWallet, trx.TokenChain, trx.TokenAddress, fAmount, decimals,
		notionalUSD, trx.Fee, coingeckoID, symbol)
	_, err := file.WriteString(line)
	return err
}

func (j *TransferReportJob) findTransactionsByPage(ctx context.Context, page, pageSize int64) ([]transactionResult, error) {

	vaas := j.database.Collection("vaas")

	skip := page * pageSize

	// Build the aggregation pipeline
	var pipeline mongo.Pipeline

	pipeline = append(pipeline, bson.D{
		{Key: "$sort", Value: bson.D{
			bson.E{Key: "timestamp", Value: -1},
			bson.E{Key: "_id", Value: -1},
		}},
	})

	pipeline = append(pipeline, bson.D{
		{Key: "$lookup", Value: bson.D{
			{Key: "from", Value: "parsedVaa"},
			{Key: "localField", Value: "_id"},
			{Key: "foreignField", Value: "_id"},
			{Key: "as", Value: "parsedVaa"},
		}},
	})

	pipeline = append(pipeline, bson.D{
		{Key: "$lookup", Value: bson.D{
			{Key: "from", Value: "globalTransactions"},
			{Key: "localField", Value: "_id"},
			{Key: "foreignField", Value: "_id"},
			{Key: "as", Value: "globalTransactions"},
		}},
	})

	// Skip initial results
	pipeline = append(pipeline, bson.D{
		{Key: "$skip", Value: skip},
	})

	// Limit size of results
	pipeline = append(pipeline, bson.D{
		{Key: "$limit", Value: pageSize},
	})

	// add nested fields
	pipeline = append(pipeline, bson.D{
		{"$addFields", bson.D{
			{"standardizedProperties", bson.M{"$arrayElemAt": []interface{}{"$parsedVaa.rawStandardizedProperties", 0}}},
			{"globalTransactions", bson.M{"$arrayElemAt": []interface{}{"$globalTransactions", 0}}},
			{"appIds", bson.M{"$arrayElemAt": []interface{}{"$parsedVaa.appIds", 0}}},
			{"parsedPayload", bson.M{"$arrayElemAt": []interface{}{"$parsedVaa.parsedPayload", 0}}},
		}},
	})

	pipeline = append(pipeline, bson.D{
		{Key: "$project", Value: bson.D{
			{Key: "appIds", Value: "$appIds"},
			{Key: "sourceChain", Value: "$emitterChain"},
			{Key: "emitterAddress", Value: "$emitterAddr"},
			{Key: "sequence", Value: "$sequence"},
			{Key: "destinationChain", Value: "$standardizedProperties.toChain"},
			{Key: "tokenChain", Value: "$standardizedProperties.tokenChain"},
			{Key: "tokenAddress", Value: "$standardizedProperties.tokenAddress"},
			{Key: "amount", Value: "$standardizedProperties.amount"},
			{Key: "sourceWallet", Value: "$globalTransactions.originTx.from"},
			{Key: "destinationWallet", Value: "$standardizedProperties.toAddress"},
			{Key: "fee", Value: "$standardizedProperties.fee"},
			{Key: "timestamp", Value: "$timestamp"},
			{Key: "tokenAddressHexa", Value: "$parsedPayload.tokenAddress"},
		}}})

	// Execute the aggregation pipeline
	cur, err := vaas.Aggregate(ctx, pipeline)
	if err != nil {
		j.logger.Error("failed execute aggregation pipeline", zap.Error(err))
		return nil, err
	}

	// Read results from cursor
	var documents []transactionResult
	err = cur.All(ctx, &documents)
	if err != nil {
		j.logger.Error("failed to decode cursor", zap.Error(err))
		return nil, err
	}

	return documents, nil
}