package logger

import (
	"compress/gzip"
	"fmt"
	"io"
	"os"
	"path/filepath"
	"sync"
	"time"
)

const (
	MaxFileSize = 1 * 1024 * 1024 // 1MB
	LogDir      = "logs"
)

// TransactionLogger 交易日志记录器
type TransactionLogger struct {
	mu     sync.Mutex
	files  map[string]*logFile // address -> logFile
	logDir string
}

// logFile 单个日志文件
type logFile struct {
	file    *os.File
	size    int64
	address string
	logDir  string
	mu      sync.Mutex
}

var (
	txLogger *TransactionLogger
	once     sync.Once
)

// InitTransactionLogger 初始化交易日志系统
func InitTransactionLogger(logDir string) error {
	var err error
	once.Do(func() {
		if logDir == "" {
			logDir = LogDir
		}

		// 创建日志目录
		err = os.MkdirAll(logDir, 0755)
		if err != nil {
			return
		}

		txLogger = &TransactionLogger{
			files:  make(map[string]*logFile),
			logDir: logDir,
		}
	})

	return err
}

// getOrCreateLogFile 获取或创建日志文件
func (tl *TransactionLogger) getOrCreateLogFile(address string) (*logFile, error) {
	tl.mu.Lock()
	defer tl.mu.Unlock()

	// 如果已存在，返回现有的
	if lf, exists := tl.files[address]; exists {
		return lf, nil
	}

	// 创建新的日志文件
	lf := &logFile{
		address: address,
		logDir:  tl.logDir,
	}

	// 打开或创建文件
	filePath := filepath.Join(tl.logDir, fmt.Sprintf("%s.log", address))
	file, err := os.OpenFile(filePath, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0644)
	if err != nil {
		return nil, fmt.Errorf("创建日志文件失败: %w", err)
	}

	// 获取当前文件大小
	info, err := file.Stat()
	if err != nil {
		file.Close()
		return nil, fmt.Errorf("获取文件信息失败: %w", err)
	}

	lf.file = file
	lf.size = info.Size()
	tl.files[address] = lf

	return lf, nil
}

// write 写入日志
func (lf *logFile) write(content string) error {
	lf.mu.Lock()
	defer lf.mu.Unlock()

	// 检查是否需要轮转
	if lf.size >= MaxFileSize {
		if err := lf.rotate(); err != nil {
			return fmt.Errorf("日志轮转失败: %w", err)
		}
	}

	// 写入内容
	n, err := lf.file.WriteString(content + "\n")
	if err != nil {
		return fmt.Errorf("写入日志失败: %w", err)
	}

	lf.size += int64(n)

	// 立即刷新到磁盘
	lf.file.Sync()

	return nil
}

// rotate 日志轮转：压缩当前文件，创建新文件
func (lf *logFile) rotate() error {
	// 关闭当前文件
	if lf.file != nil {
		lf.file.Close()
	}

	// 生成备份文件名（带时间戳）
	timestamp := time.Now().Format("20060102_150405")
	oldPath := filepath.Join(lf.logDir, fmt.Sprintf("%s.log", lf.address))
	backupPath := filepath.Join(lf.logDir, fmt.Sprintf("%s_%s.log", lf.address, timestamp))

	// 重命名当前文件
	if err := os.Rename(oldPath, backupPath); err != nil {
		return fmt.Errorf("重命名日志文件失败: %w", err)
	}

	// 压缩备份文件
	go func() {
		if err := compressFile(backupPath); err != nil {
			fmt.Printf("⚠️ 压缩日志文件失败 %s: %v\n", backupPath, err)
		} else {
			// 删除原文件
			os.Remove(backupPath)
		}
	}()

	// 创建新文件
	file, err := os.OpenFile(oldPath, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0644)
	if err != nil {
		return fmt.Errorf("创建新日志文件失败: %w", err)
	}

	lf.file = file
	lf.size = 0

	return nil
}

// compressFile 压缩文件
func compressFile(filePath string) error {
	// 打开原文件
	srcFile, err := os.Open(filePath)
	if err != nil {
		return err
	}
	defer srcFile.Close()

	// 创建压缩文件
	gzPath := filePath + ".gz"
	gzFile, err := os.Create(gzPath)
	if err != nil {
		return err
	}
	defer gzFile.Close()

	// 创建 gzip writer
	gzWriter := gzip.NewWriter(gzFile)
	defer gzWriter.Close()

	// 复制数据
	_, err = io.Copy(gzWriter, srcFile)
	return err
}

// LogTopup 记录充值消息
func LogTopup(toAddress string, status string, amount float64, txHash string, blockHeight uint64) {
	if txLogger == nil {
		return
	}

	lf, err := txLogger.getOrCreateLogFile(toAddress)
	if err != nil {
		fmt.Printf("⚠️ 获取日志文件失败: %v\n", err)
		return
	}

	timestamp := time.Now().Format("2006-01-02 15:04:05")
	content := fmt.Sprintf("%s [topup]-[%s] | 金额: %.6f | 交易哈希: %s | 区块高度: %d | ToAddress: %s",
		timestamp, status, amount, txHash, blockHeight, toAddress)

	if err := lf.write(content); err != nil {
		fmt.Printf("⚠️ 写入日志失败: %v\n", err)
	}
}

// LogWithdraw 记录提现消息
func LogWithdraw(toAddress string, status string, amount float64, fromAddress string, txHash string, blockHeight uint64) {
	if txLogger == nil {
		return
	}

	// 使用 toAddress 作为文件名
	lf, err := txLogger.getOrCreateLogFile(toAddress)
	if err != nil {
		fmt.Printf("⚠️ 获取日志文件失败: %v\n", err)
		return
	}

	timestamp := time.Now().Format("2006-01-02 15:04:05")
	content := fmt.Sprintf("%s [withdraw]-[%s] | 金额: %.6f | FromAddress: %s | ToAddress: %s | 交易哈希: %s | 区块高度: %d",
		timestamp, status, amount, fromAddress, toAddress, txHash, blockHeight)

	if err := lf.write(content); err != nil {
		fmt.Printf("⚠️ 写入日志失败: %v\n", err)
	}
}

// LogPay 记录支付消息
func LogPay(toAddress string, status string, amount float64, fromAddress string, txHash string, blockHeight uint64, orderId string, queueId string) {
	if txLogger == nil {
		return
	}

	// 使用 toAddress 作为文件名
	lf, err := txLogger.getOrCreateLogFile(toAddress)
	if err != nil {
		fmt.Printf("⚠️ 获取日志文件失败: %v\n", err)
		return
	}

	timestamp := time.Now().Format("2006-01-02 15:04:05")
	content := fmt.Sprintf("%s [pay]-[%s] | 金额: %.6f | FromAddress: %s | ToAddress: %s | 交易哈希: %s | 区块高度: %d | OrderId: %s | QueueId: %s",
		timestamp, status, amount, fromAddress, toAddress, txHash, blockHeight, orderId, queueId)

	if err := lf.write(content); err != nil {
		fmt.Printf("⚠️ 写入日志失败: %v\n", err)
	}
}

// Close 关闭所有日志文件
func CloseTransactionLogger() {
	if txLogger == nil {
		return
	}

	txLogger.mu.Lock()
	defer txLogger.mu.Unlock()

	for _, lf := range txLogger.files {
		if lf.file != nil {
			lf.file.Close()
		}
	}
}