package eth

import (
	"crypto/ecdsa"
	"fmt"
	"log"
	"m2pool-payment/internal/utils"
	"math/big"
	"strings"

	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/core/types"
	"github.com/ethereum/go-ethereum/crypto"
)

// BatchTransferItem 批量转账单项
type BatchTransferItem struct {
	ToAddress string  // 接收地址
	Amount    float64 // 转账金额
}

// BatchTransferResult 批量转账结果
type BatchTransferResult struct {
	TxHash      string  // 交易哈希
	Success     bool    // 是否成功
	TotalAmount float64 // 总转账金额
	Count       int     // 转账笔数
}

// usdt_batch_transfer 批量转账ERC20-USDT
// from: 发送地址
// items: 批量转账列表
// returns: 交易哈希和错误信息
func (e *ETHNode) USDTBatchTransfer(from string, items []BatchTransferItem) (*BatchTransferResult, error) {
	if len(items) == 0 {
		return nil, fmt.Errorf("批量转账列表不能为空")
	}

	// 统一转换为小写
	from = strings.ToLower(from)

	// 计算总金额
	var totalAmount float64
	for _, item := range items {
		if item.Amount <= 0 {
			return nil, fmt.Errorf("转账金额必须大于0")
		}
		totalAmount += item.Amount
	}

	// 1. 校验钱包USDT余额
	balance, err := e.getUSDTBalance(from)
	log.Printf("🔄 批量转账 - 检测钱包=%s，余额=%.2f USDT", from, balance)
	if err != nil {
		return nil, fmt.Errorf("获取余额失败: %w", err)
	}

	if balance < totalAmount {
		return nil, fmt.Errorf("余额不足: 余额=%.2f USDT < 需要=%.2f USDT", balance, totalAmount)
	}

	// 2. 通过from地址前往数据库查找出对应加密后的私钥，并解密真实的私钥
	originalKey := e.decodePrivatekey(from)
	if originalKey == "" {
		return nil, fmt.Errorf("无法获取私钥")
	}

	privateKey, err := crypto.HexToECDSA(originalKey)
	if err != nil {
		return nil, fmt.Errorf("解析私钥失败: %w", err)
	}

	// 3. 获得nonce
	nonce, err := e.RpcClient.PendingNonceAt(e.Ctx, common.HexToAddress(from))
	if err != nil {
		return nil, fmt.Errorf("获取nonce失败: %w", err)
	}

	// 4. 构造批量转账数据
	// 使用 transfer(address[], uint256[]) 或多次transfer调用
	// 这里使用多次transfer调用的方式，因为标准ERC20没有批量转账方法

	// 方法1: 构造多次transfer调用（适合少量转账）
	if len(items) <= 3 {
		return e.batchTransferMultipleCalls(from, privateKey, nonce, items)
	}

	// 方法2: 使用合约批量转账（需要部署代理合约，这里简化处理）
	// 注意：这里实现的是多次transaction方式
	return e.batchTransferSeparateTransactions(from, privateKey, nonce, items)
}

// batchTransferMultipleCalls 使用一个交易多次调用transfer（需要gas优化）
func (e *ETHNode) batchTransferMultipleCalls(from string, privateKey *ecdsa.PrivateKey, nonce uint64, items []BatchTransferItem) (*BatchTransferResult, error) {
	// 注意：标准ERC20不支持批量transfer，这里需要自定义合约
	// 或者使用多次独立交易
	log.Printf("⚠️ 标准ERC20不支持批量transfer，改用多次独立交易")

	// 回退到多次独立交易
	return e.batchTransferSeparateTransactions(from, privateKey, nonce, items)
}

// batchTransferSeparateTransactions 执行多次独立的transfer交易
func (e *ETHNode) batchTransferSeparateTransactions(from string, privateKey *ecdsa.PrivateKey, nonce uint64, items []BatchTransferItem) (*BatchTransferResult, error) {
	var totalAmount float64
	var txHashes []string
	var allSuccess bool = true

	for i, item := range items {
		// 构造单个transfer交易
		amountBigInt := utils.Float64ToBigIntUSDT(item.Amount)
		data, err := e.USDT.ABI.Pack("transfer", common.HexToAddress(strings.ToLower(item.ToAddress)), amountBigInt)
		if err != nil {
			log.Printf("❌ 批量转账第%d笔打包失败: %v", i+1, err)
			allSuccess = false
			continue
		}

		// 获取gas limit
		gasLimit, err := e.getGasLimit()
		if err != nil {
			log.Printf("❌ 批量转账第%d笔获取gasLimit失败: %v", i+1, err)
			allSuccess = false
			continue
		}

		// 获取gas费用
		maxFeePerGas, maxPriorityFeePerGas, err := e.getEIP1559GasFees()

		var txHash string
		if err != nil {
			// 回退到传统gas price
			gasPrice, err := e.getSuggestGasPrice()
			if err != nil {
				log.Printf("❌ 批量转账第%d笔获取gasPrice失败: %v", i+1, err)
				allSuccess = false
				continue
			}

			tx := types.NewTransaction(nonce+uint64(i), e.USDT.Address, big.NewInt(0), gasLimit, gasPrice, data)
			signedTx, err := types.SignTx(tx, types.NewEIP155Signer(e.NetId), privateKey)
			if err != nil {
				log.Printf("❌ 批量转账第%d笔签名失败: %v", i+1, err)
				allSuccess = false
				continue
			}

			txHash = signedTx.Hash().Hex()
			err = e.RpcClient.SendTransaction(e.Ctx, signedTx)
			if err != nil {
				log.Printf("❌ 批量转账第%d笔发送失败: %v", i+1, err)
				allSuccess = false
				continue
			}
		} else {
			// 使用EIP-1559交易
			ethBalance, err := e.getETHBlance(from)
			if err != nil {
				log.Printf("❌ 批量转账第%d笔获取ETH余额失败: %v", i+1, err)
				allSuccess = false
				continue
			}

			maxGasCost := new(big.Int).Mul(new(big.Int).SetUint64(gasLimit), maxFeePerGas)
			if ethBalance.Cmp(maxGasCost) == -1 {
				log.Printf("❌ 批量转账第%d笔ETH余额不足", i+1)
				allSuccess = false
				continue
			}

			tx := types.NewTx(&types.DynamicFeeTx{
				ChainID:   e.NetId,
				Nonce:     nonce + uint64(i),
				GasTipCap: maxPriorityFeePerGas,
				GasFeeCap: maxFeePerGas,
				Gas:       gasLimit,
				To:        &e.USDT.Address,
				Value:     big.NewInt(0),
				Data:      data,
			})

			signedTx, err := types.SignTx(tx, types.NewLondonSigner(e.NetId), privateKey)
			if err != nil {
				log.Printf("❌ 批量转账第%d笔签名失败: %v", i+1, err)
				allSuccess = false
				continue
			}

			txHash = signedTx.Hash().Hex()
			err = e.RpcClient.SendTransaction(e.Ctx, signedTx)
			if err != nil {
				log.Printf("❌ 批量转账第%d笔发送失败: %v", i+1, err)
				allSuccess = false
				continue
			}
		}

		txHashes = append(txHashes, txHash)
		totalAmount += item.Amount
		log.Printf("✅ 批量转账第%d笔已提交: %s, 金额=%.2f USDT, 收款地址=%s",
			i+1, txHash, item.Amount, strings.ToLower(item.ToAddress))
	}

	log.Printf("📊 批量转账完成: 总计%d笔, 成功%d笔, 总金额=%.2f USDT",
		len(items), len(txHashes), totalAmount)

	return &BatchTransferResult{
		TxHash:      strings.Join(txHashes, ","),
		Success:     allSuccess && len(txHashes) == len(items),
		TotalAmount: totalAmount,
		Count:       len(txHashes),
	}, nil
}