package template

import (
	"gitee.com/h79/goutils/common/json"
	"gitee.com/h79/goutils/common/logger"
	"gitee.com/h79/goutils/common/result"
	"io/fs"
	"text/template"
)

type Format struct {
	engine  *Engine
	command template.FuncMap
	items   Items
}

type Option struct {
	Data map[string]interface{}
}

type HandlerFunc func(source interface{}, opt *Option) error

type CommandFunc func(source interface{}, opt *Option, handler HandlerFunc) error

func DefFormat() *Format {
	engine := DefEngine()
	return NewFormat(engine)
}

func NewFormat(engine *Engine) *Format {
	return &Format{
		engine:  engine,
		command: make(template.FuncMap),
	}
}

func (ft *Format) Load(path string) error {
	if err := json.Read(path, &ft.items); err != nil {
		return err
	}
	logger.Debug("Template: conf= %+v", ft.items)
	return nil
}

func (ft *Format) LoadTemplate(path string) {
	ft.engine.LoadGlob(path)
}

func (ft *Format) LoadString(str string) {
	ft.engine.LoadString(str)
}

func (ft *Format) LoadFS(f fs.FS, patterns ...string) {
	ft.engine.LoadFS(f, patterns...)
}

func (ft *Format) AddCommand(funcName string, funcCall CommandFunc) {
	ft.command[funcName] = funcCall
}

func (ft *Format) Format(format, appId, filter string, source interface{}, handler HandlerFunc) (*Data, error) {

	reply, exists := ft.items.ItMap[appId]
	if !exists {
		return nil, result.Error(result.ErrNotFound, "Not found config")
	}

	var tpl Content
	if format == "xml" {
		tpl, exists = reply.Xml[filter]
	} else if format == "json" {
		tpl, exists = reply.Json[filter]
	} else {
		return nil, result.Error(result.ErrException, "Not support the format")
	}
	if !exists {
		return nil, result.Error(result.ErrNotFound, "Not found the filter content")
	}
	var cmd CommandFunc = nil
	if f, ok := ft.command[tpl.Func]; ok {
		cmd = f.(CommandFunc)
	}
	return ft.FormatWith(cmd, tpl.Name, source, handler)
}

func (ft *Format) FormatWith(cmdFn CommandFunc, tplName string, source interface{}, handler HandlerFunc) (*Data, error) {
	opt := Option{
		Data: map[string]interface{}{},
	}
	if err := cmdFn(source, &opt, func(source interface{}, opt *Option) error {
		if handler != nil {
			return handler(source, opt)
		}
		return nil
	}); err != nil {
		return nil, err
	}
	return ft.engine.OUTPUT(tplName, opt.Data)
}