package util

import (
	"html/template"
	"os"
	"path/filepath"
	"sort"
	"strings"

	"github.com/gomarkdown/markdown"
	"github.com/gomarkdown/markdown/html"
	"github.com/gomarkdown/markdown/parser"
	"github.com/spf13/viper"
)

func GetMdStr(path string) template.HTML {
	fileMeta, err := os.Stat(path)
	if err != nil {
		return "读取错误"
	}
	if fileMeta.IsDir() {
		return GetDirStr(path)
	} else {
		context, err := os.ReadFile(path)
		if err != nil {
			return "error"
		}
		htmlContext := MdToHtml(context)
		html := template.HTML(htmlContext)
		return html
	}
}

func GetDirStr(path string) template.HTML {
	listResult := GetFileList(path)
	context := ""
	for i := 0; i < len(listResult); i++ {
		item := listResult[i]
		if !strings.HasPrefix(item.FileName, ".") && item.FileName != "assets" {
			context += "- [" + item.FileName + "](" + item.FilePath + ") \n"
		}
	}
	htmlContext := MdToHtml([]byte(context))
	html := template.HTML(htmlContext)
	return html
}

func GetFileList(path string) []FileModel {
	var result []FileModel
	fileMeta, err := os.Stat(path)
	if err != nil {
		return result
	}
	rootDir := viper.GetString("dir.root")
	if !fileMeta.IsDir() {
		path = filepath.Dir(path)
	}
	list, err := os.ReadDir(path)
	if err != nil {
		return result
	}
	for i := 0; i < len(list); i++ {
		item := list[i]
		fileInfo, err := item.Info()
		//fmt.Println(fileInfo.Name())
		if err != nil {
			continue
		}
		if strings.HasPrefix(fileInfo.Name(), ".") || fileInfo.Name() == "assets" {
			continue
		}
		if !strings.HasSuffix(path, "/") {
			path = path + "/"
		}
		filePath := strings.Replace(path+fileInfo.Name(), rootDir, "", -1)
		if !strings.HasPrefix(filePath, "/") {
			filePath = "/" + filePath
		}
		result = append(result, FileModel{FileName: fileInfo.Name(), FilePath: filePath})
	}
	// 用 age 排序，年龄相等的元素保持原始顺序
	sort.SliceStable(result, func(i, j int) bool {
		return result[i].FileName < result[j].FileName
	})
	return result
}

func MdToHtml(context []byte) []byte {
	// create markdown parser with extensions
	extensions := parser.CommonExtensions | parser.AutoHeadingIDs | parser.NoEmptyLineBeforeBlock
	p := parser.NewWithExtensions(extensions)
	doc := p.Parse(context)

	// create HTML renderer with extensions
	htmlFlags := html.CommonFlags | html.HrefTargetBlank
	opts := html.RendererOptions{Flags: htmlFlags}
	renderer := html.NewRenderer(opts)

	return markdown.Render(doc, renderer)
}