package main

import (
	"bytes"
	"fmt"
	"google.golang.org/protobuf/compiler/protogen"
	"text/template"
)

type generateRouterMethod struct {
	MethodName string
	InputName  string
	OutputName string
	API        string
	Author     string
	Describe   string
	Method     string
}

type generateRouters struct {
	StructName string
	BaseURL    string
	GenTo      string
	Methods    []generateRouterMethod
}

const routerGenerateTpl = `type AutoGen{{.StructName}}Impl interface { ` + `{{range .Methods}}
	{{.MethodName}}(ctx *core.Context, req *{{.InputName}}) (resp *{{.OutputName}}, err error){{end}}
}
var (
	AutoGen{{.StructName}} = &core.Routers{
			BaseURL: "{{.BaseURL}}",
			Apis: core.RouterMap{ {{range .Methods}}
				"{{.MethodName}}": {
					API:      "{{.API}}",
					Method:   "{{.Method}}",
					Author:   "{{.Author}}",
					Describe: "{{.Describe}}",
				},{{end}}
			},
	}
)
`

func GenerateRouterMap(srv *protogen.Service) (string, error) {
	var generate = new(generateRouters)
	generate.StructName = srv.GoName
	generate.BaseURL = GetCommentBaseURL(srv.Comments)
	generate.GenTo = GetCommentGenerateTo(srv.Comments)

	for _, method := range srv.Methods {
		generate.Methods = append(generate.Methods, generateRouterMethod{
			MethodName: method.GoName,
			InputName:  method.Input.GoIdent.GoName,
			OutputName: method.Output.GoIdent.GoName,
			API:        GetCommentApiURL(method),
			Author:     GetCommentAuthor(method.Comments),
			Describe:   GetCommentDescribe(method.Comments),
			Method:     GetCommentHttpMethod(method.Comments),
		})
	}

	tpl, err := template.New("group_router").Parse(routerGenerateTpl)
	if err != nil {
		return "", fmt.Errorf("parse %s group router template failed: %v", srv.GoName, err)
	}

	tpl.DefinedTemplates()
	var buf bytes.Buffer
	if err = tpl.Execute(&buf, generate); err != nil {
		return "", fmt.Errorf("execute %s group router template failed: %v", srv.GoName, err)
	}

	return buf.String(), nil
}