package template

import (
	"bytes"
	"fmt"
	"github.com/Sirupsen/logrus"
	"github.com/kujtimiihoxha/gk/utils"
	"path/filepath"
	"reflect"
	"strings"
	"text/template"
)

var engine Engine

type Engine interface {
	init()
	Execute(name string, model interface{}) (string, error)
	ExecuteString(data string, model interface{}) (string, error)
}

type DefaultEngine struct {
	t *template.Template
}

func funcMap() template.FuncMap {
	return template.FuncMap{
		"last": func(x int, a interface{}) bool {
			return x == reflect.ValueOf(a).Len()-1
		},
		"toSnakeCase": func(s string) string {
			return utils.ToLowerSnakeCase(s)
		},
		"toUpperFirstCamelCase": func(s string) string {
			return utils.ToUpperFirstCamelCase(s)
		},
		"toUpperFirst": func(s string) string {
			return utils.ToUpperFirst(s)
		},
		"fileSeparator": func() string {
			if filepath.Separator == '\\' {
				return "\\\\"
			}
			return string(filepath.Separator)
		},
		"toCamelCase": func(s string) string {
			return utils.ToCamelCase(s)
		},
	}
}
func NewEngine() Engine {
	if engine == nil {
		engine = &DefaultEngine{}
		engine.init()
	}
	return engine
}
func (e *DefaultEngine) init() {
	e.t = template.New("default")
	e.t.Funcs(funcMap())
	for n, v := range _bintree.Children["tmpl"].Children["partials"].Children {
		a, _ := v.Func()
		_, err := e.t.Parse(
			fmt.Sprintf(
				"{{define \"%s\"}} %s {{end}}",
				strings.Replace(n, ".tmpl", "", 1),
				string(a.bytes),
			),
		)
		if err != nil {
			logrus.Panic(err)
		}
	}
}

func (e *DefaultEngine) Execute(name string, model interface{}) (string, error) {
	d, err := Asset(fmt.Sprintf("tmpl/%s.tmpl", name))
	if err != nil {
		logrus.Panic(err)
	}
	tmp, err := e.t.Parse(string(d))
	if err != nil {
		logrus.Panic(err)
	}
	ret := bytes.NewBufferString("")
	err = tmp.Execute(ret, model)
	return ret.String(), err
}
func (e *DefaultEngine) ExecuteString(data string, model interface{}) (string, error) {
	tmp, err := e.t.Parse(data)
	if err != nil {
		logrus.Panic(err)
	}
	ret := bytes.NewBufferString("")
	err = tmp.Execute(ret, model)
	return ret.String(), err
}