package file_download

import (
	"bytes"
	"errors"
	"fmt"
	"io"

	"github.com/unidoc/unioffice/document"

	"net/http"
	"net/url"
	"os"
	"path/filepath"
	"strings"
	"time"
)

// 下载文件
func DownloadFile(url string, validFunc func(resp *http.Response) error) ([]byte, string, error) {
	// 设置超时
	client := &http.Client{
		Timeout: 30 * time.Second,
	}

	// 发送请求
	resp, err := client.Get(url)
	if err != nil {
		return nil, "", err
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		return nil, "", fmt.Errorf("HTTP %d: %s", resp.StatusCode, resp.Status)
	}

	if validFunc != nil {
		err = validFunc(resp)
		if err != nil {
			return nil, "", err
		}
	}

	// 读取文件数据
	data, err := io.ReadAll(resp.Body)
	if err != nil {
		return nil, "", err
	}

	// 获取文件名
	filename := getFilenameFromURL(url, resp)

	return data, filename, nil
}

// 从 URL 或响应头获取文件名
func getFilenameFromURL(urlStr string, resp *http.Response) string {
	// 1. 尝试从 Content-Disposition 头获取
	contentDisposition := resp.Header.Get("Content-Disposition")
	if contentDisposition != "" {
		if strings.Contains(contentDisposition, "filename=") {
			parts := strings.Split(contentDisposition, "filename=")
			if len(parts) > 1 {
				filename := strings.Trim(parts[1], `"' `)
				return sanitizeFilename(filename)
			}
		}
	}

	// 2. 从 URL 路径获取
	parsedURL, err := url.Parse(urlStr)
	if err == nil {
		path := parsedURL.Path
		if path != "" {
			filename := filepath.Base(path)
			if filename != "" && filename != "." && filename != "/" {
				return sanitizeFilename(filename)
			}
		}
	}

	// 3. 生成默认文件名
	return fmt.Sprintf("word_%d.docx", time.Now().Unix())
}

// 清理文件名
func sanitizeFilename(filename string) string {
	// 移除非法字符
	illegalChars := []string{"/", "\\", ":", "*", "?", "\"", "<", ">", "|"}
	for _, char := range illegalChars {
		filename = strings.ReplaceAll(filename, char, "_")
	}

	// 确保有扩展名
	if !strings.Contains(filename, ".") {
		filename += ".docx"
	}

	return filename
}

// 从URL获取Word文件的纯文本内容
func GetWordTextFromURL(url string, validFunc func(resp *http.Response) error) (string, string, error) {
	// 1. 下载文件
	data, fileName, err := DownloadFile(url, validFunc)
	if err != nil {
		return "", "", fmt.Errorf("下载失败: %w", err)
	}

	// 2. 解析Word文件
	text, err := parseWordContent(data)
	if err != nil {
		return "", "", fmt.Errorf("解析失败: %w", err)
	}

	return text, fileName, nil
}

// 解析Word内容 - 简单版本，只提取文字
func parseWordContent(data []byte) (string, error) {
	// 创建reader
	reader := bytes.NewReader(data)

	// 打开Word文档
	doc, err := document.Read(reader, int64(len(data)))
	if err != nil {
		return "", err
	}
	defer doc.Close()

	// 提取所有文字
	var textBuilder strings.Builder

	// 遍历所有段落
	for _, paragraph := range doc.Paragraphs() {
		// 遍历段落中的所有文本块
		for _, run := range paragraph.Runs() {
			textBuilder.WriteString(run.Text())
		}
		// 每个段落后面加换行
		textBuilder.WriteString("\n")
	}

	// 返回清理过的文本
	result := strings.TrimSpace(textBuilder.String())
	return result, nil
}

// 解析 Word 文件内容
func parseWordFile(filePath string) (map[string]interface{}, error) {
	ext := strings.ToLower(filepath.Ext(filePath))

	result := map[string]interface{}{
		"filepath": filePath,
		"format":   ext,
	}

	// 解析 .docx 文件
	if ext == ".docx" {
		doc, err := document.Open(filePath)
		if err != nil {
			return nil, err
		}
		defer doc.Close()

		// 提取段落文本
		var paragraphs []string
		for _, p := range doc.Paragraphs() {
			text := ""
			for _, run := range p.Runs() {
				text += run.Text()
			}
			if strings.TrimSpace(text) != "" {
				paragraphs = append(paragraphs, text)
			}
		}

		// 提取表格内容
		var tables []map[string]interface{}
		for _, table := range doc.Tables() {
			tableData := make(map[string]interface{})
			var rows []map[int]string

			for _, row := range table.Rows() {
				rowData := make(map[int]string)
				for cellIdx, cell := range row.Cells() {
					cellText := ""
					for _, p := range cell.Paragraphs() {
						for _, run := range p.Runs() {
							cellText += run.Text()
						}
					}
					rowData[cellIdx] = cellText
				}
				rows = append(rows, rowData)
			}

			tableData["rows"] = rows
			tableData["row_count"] = len(rows)
			tables = append(tables, tableData)
		}

		result["paragraphs"] = paragraphs
		result["tables"] = tables
		result["paragraph_count"] = len(paragraphs)
		result["table_count"] = len(tables)

	} else if ext == ".doc" {
		// 对于 .doc 文件，可能需要其他库或转换
		// 这里简单读取为二进制文件
		data, err := os.ReadFile(filePath)
		if err != nil {
			return nil, err
		}
		result["binary_size"] = len(data)
		result["note"] = ".doc 文件需要专门的解析库"
	}

	// 获取文件信息
	fileInfo, _ := os.Stat(filePath)
	if fileInfo != nil {
		result["filesize"] = fileInfo.Size()
		result["modified"] = fileInfo.ModTime()
	}

	return result, nil
}

// 判断是否为 Word 文件
func IsWordFile(resp *http.Response) error {
	contentType := resp.Header.Get("Content-Type")
	wordContentTypes := []string{
		"application/msword",
		"application/vnd.openxmlformats-officedocument.wordprocessingml.document",
		"application/vnd.ms-word",
		"application/octet-stream", // 有些服务器可能返回这个
	}

	contentType = strings.ToLower(contentType)
	for _, ct := range wordContentTypes {
		if strings.Contains(contentType, ct) {
			return nil
		}
	}
	return errors.New("错误的文件类型")
}