package Route

import (
	"bytes"
	"embed"
	"html/template"
	"net/http"
	"path"
	"sync"
)

type tempView struct {
	//assetFs        *embed.FS
	templateDir    string //模板存放目录
	templateSuffix string //模板后缀
}

var tempViewOnce sync.Once
var tempViewInstance *tempView

/**
@param templateDir string 模板存放目录
@param templateSuffix string 模板后缀 如".html"
*/
func newTempView(templateDir, templateSuffix string) *tempView {
	tempViewOnce.Do(func() {
		tempViewInstance = &tempView{
			templateDir:    templateDir,
			templateSuffix: templateSuffix,
		}
	})
	//tempViewInstance = &tempView{
	//	templateDir:    templateDir,
	//	templateSuffix: templateSuffix,
	//}
	return tempViewInstance
}

func (tv *tempView) Render(engine *Engine, assetFs *embed.FS, write http.ResponseWriter, data interface{}, tempName string) {
	var itemTempBuffer bytes.Buffer

	itemTempBuffer.WriteString(tv.templateDir)
	itemTempBuffer.WriteString(getPathSeparator())
	itemTempBuffer.WriteString(tempName)
	itemTempBuffer.WriteString(tv.templateSuffix)
	itemTemp := itemTempBuffer.String()
	itemTempBuffer.Reset()
	_, fileName := path.Split(itemTemp)

	engine.log.Debug("template path:%s", itemTemp)
	t, errd := template.ParseFS(assetFs, itemTemp)
	if errd != nil {
		_, _ = write.Write([]byte(errd.Error()))
	} else {
		err := t.ExecuteTemplate(write, fileName, data)
		if err != nil {
			_, _ = write.Write([]byte(err.Error()))
		}
	}

}

/**
批量模板解析
*/
func (tv *tempView) RenderMultiple(engine *Engine, asset *embed.FS, write http.ResponseWriter, data interface{}, tempName []string) {
	var tempPath []string
	if tempName == nil || len(tempName) == 0 {
		_, _ = write.Write([]byte("no template load"))
		return
	}

	for _, v := range tempName {
		var itemTempBuffer bytes.Buffer
		itemTempBuffer.WriteString(tv.templateDir)
		itemTempBuffer.WriteString(getPathSeparator())
		itemTempBuffer.WriteString(v)
		itemTempBuffer.WriteString(tv.templateSuffix)
		itemTemp := itemTempBuffer.String()
		itemTempBuffer.Reset()
		tempPath = append(tempPath, itemTemp)
	}
	engine.log.Debug("templateMultiple path:%+v", tempPath)
	t, errd := template.ParseFS(asset, tempPath...)
	if errd != nil {
		_, _ = write.Write([]byte(errd.Error()))
	} else {
		err := t.Execute(write, data)
		if err != nil {
			_, _ = write.Write([]byte(err.Error()))
		}
	}
}

/**
获取目录分隔
*/
func getPathSeparator() string {
	return "/"
}