package output

import (
	"encoding/csv"
	"encoding/json"
	"fmt"
	"os"
	"strings"
	"sync"
	"time"
	
	"github.com/shadow1ng/fscan/common/i18n"
)

// TXTWriter 文本格式写入器
type TXTWriter struct {
	file   *os.File
	mu     sync.Mutex
	closed bool
}

// NewTXTWriter 创建文本写入器
func NewTXTWriter(filePath string) (*TXTWriter, error) {
	file, err := os.OpenFile(filePath, DefaultFileFlags, DefaultFilePermissions)
	if err != nil {
		return nil, fmt.Errorf(i18n.GetText("output_create_file_failed"), "文本", err)
	}

	return &TXTWriter{
		file: file,
	}, nil
}

// WriteHeader 写入头部（文本格式无需头部）
func (w *TXTWriter) WriteHeader() error {
	return nil
}

// Write 写入扫描结果
func (w *TXTWriter) Write(result *ScanResult) error {
	w.mu.Lock()
	defer w.mu.Unlock()

	if w.closed {
		return fmt.Errorf(i18n.GetText("output_writer_closed"))
	}

	// 格式化 Details 为键值对字符串
	var details string
	if len(result.Details) > 0 {
		pairs := make([]string, 0, len(result.Details))
		for k, v := range result.Details {
			pairs = append(pairs, fmt.Sprintf(TxtKeyValueFormat, k, v))
		}
		details = strings.Join(pairs, TxtDetailsSeparator)
	}

	// 使用类似原有格式的文本输出
	txt := fmt.Sprintf(TxtOutputTemplate,
		result.Time.Format(TxtTimeFormat),
		result.Type,
		result.Target,
		result.Status,
	)
	if details != "" {
		txt += fmt.Sprintf(TxtDetailsFormat, details)
	}
	txt += TxtNewline

	_, err := w.file.WriteString(txt)
	return err
}

// Flush 刷新缓冲区
func (w *TXTWriter) Flush() error {
	w.mu.Lock()
	defer w.mu.Unlock()

	if w.closed {
		return nil
	}

	return w.file.Sync()
}

// Close 关闭写入器
func (w *TXTWriter) Close() error {
	w.mu.Lock()
	defer w.mu.Unlock()

	if w.closed {
		return nil
	}

	w.closed = true
	return w.file.Close()
}

// GetFormat 获取格式类型
func (w *TXTWriter) GetFormat() OutputFormat {
	return FormatTXT
}

// JSONWriter JSON格式写入器
type JSONWriter struct {
	file    *os.File
	encoder *json.Encoder
	mu      sync.Mutex
	closed  bool
}

// NewJSONWriter 创建JSON写入器
func NewJSONWriter(filePath string) (*JSONWriter, error) {
	file, err := os.OpenFile(filePath, DefaultFileFlags, DefaultFilePermissions)
	if err != nil {
		return nil, fmt.Errorf(i18n.GetText("output_create_file_failed"), "JSON", err)
	}

	encoder := json.NewEncoder(file)
	encoder.SetIndent(JSONIndentPrefix, JSONIndentString)

	return &JSONWriter{
		file:    file,
		encoder: encoder,
	}, nil
}

// WriteHeader 写入头部（JSON格式无需头部）
func (w *JSONWriter) WriteHeader() error {
	return nil
}

// Write 写入扫描结果
func (w *JSONWriter) Write(result *ScanResult) error {
	w.mu.Lock()
	defer w.mu.Unlock()

	if w.closed {
		return fmt.Errorf(i18n.GetText("output_writer_closed"))
	}

	return w.encoder.Encode(result)
}

// Flush 刷新缓冲区
func (w *JSONWriter) Flush() error {
	w.mu.Lock()
	defer w.mu.Unlock()

	if w.closed {
		return nil
	}

	return w.file.Sync()
}

// Close 关闭写入器
func (w *JSONWriter) Close() error {
	w.mu.Lock()
	defer w.mu.Unlock()

	if w.closed {
		return nil
	}

	w.closed = true
	return w.file.Close()
}

// GetFormat 获取格式类型
func (w *JSONWriter) GetFormat() OutputFormat {
	return FormatJSON
}

// CSVWriter CSV格式写入器
type CSVWriter struct {
	file      *os.File
	csvWriter *csv.Writer
	mu        sync.Mutex
	closed    bool
	headerWritten bool
}

// NewCSVWriter 创建CSV写入器
func NewCSVWriter(filePath string) (*CSVWriter, error) {
	file, err := os.OpenFile(filePath, DefaultFileFlags, DefaultFilePermissions)
	if err != nil {
		return nil, fmt.Errorf(i18n.GetText("output_create_file_failed"), "CSV", err)
	}

	csvWriter := csv.NewWriter(file)

	return &CSVWriter{
		file:      file,
		csvWriter: csvWriter,
	}, nil
}

// WriteHeader 写入CSV头部
func (w *CSVWriter) WriteHeader() error {
	w.mu.Lock()
	defer w.mu.Unlock()

	if w.headerWritten {
		return nil
	}

	headers := CSVHeaders
	err := w.csvWriter.Write(headers)
	if err != nil {
		return fmt.Errorf(i18n.GetText("output_write_header_failed"), err)
	}

	w.csvWriter.Flush()
	w.headerWritten = true
	return w.csvWriter.Error()
}

// Write 写入扫描结果
func (w *CSVWriter) Write(result *ScanResult) error {
	w.mu.Lock()
	defer w.mu.Unlock()

	if w.closed {
		return fmt.Errorf(i18n.GetText("output_writer_closed"))
	}

	// 确保头部已写入
	if !w.headerWritten {
		if err := w.writeHeaderUnsafe(); err != nil {
			return err
		}
	}

	// 序列化Details为JSON字符串
	details, err := json.Marshal(result.Details)
	if err != nil {
		details = []byte(EmptyJSONObject)
	}

	record := []string{
		result.Time.Format(DefaultTimeFormat),
		string(result.Type),
		result.Target,
		result.Status,
		string(details),
	}

	err = w.csvWriter.Write(record)
	if err != nil {
		return err
	}

	w.csvWriter.Flush()
	return w.csvWriter.Error()
}

// writeHeaderUnsafe 不安全的写入头部（内部使用，无锁）
func (w *CSVWriter) writeHeaderUnsafe() error {
	if w.headerWritten {
		return nil
	}

	headers := CSVHeaders
	err := w.csvWriter.Write(headers)
	if err != nil {
		return fmt.Errorf(i18n.GetText("output_write_header_failed"), err)
	}

	w.csvWriter.Flush()
	w.headerWritten = true
	return w.csvWriter.Error()
}

// Flush 刷新缓冲区
func (w *CSVWriter) Flush() error {
	w.mu.Lock()
	defer w.mu.Unlock()

	if w.closed {
		return nil
	}

	w.csvWriter.Flush()
	return w.csvWriter.Error()
}

// Close 关闭写入器
func (w *CSVWriter) Close() error {
	w.mu.Lock()
	defer w.mu.Unlock()

	if w.closed {
		return nil
	}

	w.csvWriter.Flush()
	err := w.csvWriter.Error()
	w.closed = true
	
	if fileErr := w.file.Close(); fileErr != nil && err == nil {
		err = fileErr
	}
	
	return err
}

// GetFormat 获取格式类型
func (w *CSVWriter) GetFormat() OutputFormat {
	return FormatCSV
}

// CSVReader CSV格式读取器
type CSVReader struct {
	filePath string
	mu       sync.Mutex
}

// NewCSVReader 创建CSV读取器
func NewCSVReader(filePath string) *CSVReader {
	return &CSVReader{
		filePath: filePath,
	}
}

// Read 读取所有结果
func (r *CSVReader) Read() ([]*ScanResult, error) {
	return r.ReadWithFilter(nil)
}

// ReadWithFilter 带过滤条件读取结果
func (r *CSVReader) ReadWithFilter(filter *ResultFilter) ([]*ScanResult, error) {
	r.mu.Lock()
	defer r.mu.Unlock()

	file, err := os.Open(r.filePath)
	if err != nil {
		return nil, fmt.Errorf(i18n.GetText("output_open_file_failed"), err)
	}
	defer file.Close()

	reader := csv.NewReader(file)
	records, err := reader.ReadAll()
	if err != nil {
		return nil, fmt.Errorf(i18n.GetText("output_read_file_failed"), err)
	}

	var results []*ScanResult
	for i, row := range records {
		// 跳过CSV头部
		if i == CSVHeaderRowIndex {
			continue
		}
		if len(row) < CSVMinColumns {
			continue // 数据不完整
		}

		result, err := r.parseCSVRow(row)
		if err != nil {
			continue // 跳过解析失败的行
		}

		// 应用过滤器
		if filter != nil && !r.matchFilter(result, filter) {
			continue
		}

		results = append(results, result)

		// 应用限制
		if filter != nil && filter.Limit > 0 && len(results) >= filter.Limit {
			break
		}
	}

	return results, nil
}

// parseCSVRow 解析CSV行
func (r *CSVReader) parseCSVRow(row []string) (*ScanResult, error) {
	// 解析时间
	t, err := parseTime(row[CSVTimeColumnIndex])
	if err != nil {
		return nil, err
	}

	// 解析Details
	var details map[string]interface{}
	if err := json.Unmarshal([]byte(row[CSVDetailsColumnIndex]), &details); err != nil {
		details = make(map[string]interface{})
	}

	return &ScanResult{
		Time:    t,
		Type:    ResultType(row[CSVTypeColumnIndex]),
		Target:  row[CSVTargetColumnIndex],
		Status:  row[CSVStatusColumnIndex],
		Details: details,
	}, nil
}

// matchFilter 检查结果是否匹配过滤器
func (r *CSVReader) matchFilter(result *ScanResult, filter *ResultFilter) bool {
	// 检查类型过滤
	if len(filter.Types) > 0 {
		found := false
		for _, t := range filter.Types {
			if result.Type == t {
				found = true
				break
			}
		}
		if !found {
			return false
		}
	}

	// 检查目标过滤
	if len(filter.Targets) > 0 {
		found := false
		for _, target := range filter.Targets {
			if strings.Contains(result.Target, target) {
				found = true
				break
			}
		}
		if !found {
			return false
		}
	}

	// 检查时间范围过滤
	if filter.TimeRange != nil {
		if result.Time.Before(filter.TimeRange.Start) || result.Time.After(filter.TimeRange.End) {
			return false
		}
	}

	return true
}

// Close 关闭读取器
func (r *CSVReader) Close() error {
	return nil // CSV读取器无需特殊关闭操作
}

// parseTime 解析时间字符串
func parseTime(timeStr string) (time.Time, error) {
	// 尝试多种时间格式
	formats := GetSupportedTimeFormats()

	for _, format := range formats {
		if t, err := time.Parse(format, timeStr); err == nil {
			return t, nil
		}
	}

	return time.Time{}, fmt.Errorf(i18n.GetText("output_parse_time_failed"), timeStr)
}