// Copyright 2017 Google LLC. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// gnostic_go_generator is a sample Gnostic plugin that generates Go
// code that supports an API.
package main

import (
	"log"
	"path/filepath"

	"github.com/golang/protobuf/proto"
	openapiv2 "github.com/googleapis/gnostic/openapiv2"
	openapiv3 "github.com/googleapis/gnostic/openapiv3"
	plugins "github.com/googleapis/gnostic/plugins"
	"github.com/googleapis/gnostic/printer"
)

// generate a simple report of an OpenAPI document's contents
func printDocumentV2(code *printer.Code, document *openapiv2.Document) {
	code.Print("Swagger: %+v", document.Swagger)
	code.Print("Host: %+v", document.Host)
	code.Print("BasePath: %+v", document.BasePath)
	if document.Info != nil {
		code.Print("Info:")
		code.Indent()
		if document.Info.Title != "" {
			code.Print("Title: %s", document.Info.Title)
		}
		if document.Info.Description != "" {
			code.Print("Description: %s", document.Info.Description)
		}
		if document.Info.Version != "" {
			code.Print("Version: %s", document.Info.Version)
		}
		code.Outdent()
	}
	code.Print("Paths:")
	code.Indent()
	for _, pair := range document.Paths.Path {
		v := pair.Value
		if v.Get != nil {
			code.Print("GET %+v", pair.Name)
		}
		if v.Post != nil {
			code.Print("POST %+v", pair.Name)
		}
	}
	code.Outdent()
}

// generate a simple report of an OpenAPI document's contents
func printDocumentV3(code *printer.Code, document *openapiv3.Document) {
	code.Print("OpenAPI: %+v", document.Openapi)
	code.Print("Servers: %+v", document.Servers)
	if document.Info != nil {
		code.Print("Info:")
		code.Indent()
		if document.Info.Title != "" {
			code.Print("Title: %s", document.Info.Title)
		}
		if document.Info.Description != "" {
			code.Print("Description: %s", document.Info.Description)
		}
		if document.Info.Version != "" {
			code.Print("Version: %s", document.Info.Version)
		}
		code.Outdent()
	}
	code.Print("Paths:")
	code.Indent()
	for _, pair := range document.Paths.Path {
		v := pair.Value
		if v.Get != nil {
			code.Print("GET %+v", pair.Name)
		}
		if v.Post != nil {
			code.Print("POST %+v", pair.Name)
		}
	}
	code.Outdent()
}

// This is the main function for the plugin.
func main() {
	env, err := plugins.NewEnvironment()
	env.RespondAndExitIfError(err)
	code := &printer.Code{}
	for _, model := range env.Request.Models {
		switch model.TypeUrl {
		case "openapi.v2.Document":
			documentv2 := &openapiv2.Document{}
			err = proto.Unmarshal(model.Value, documentv2)
			if err == nil {
				printDocumentV2(code, documentv2)
			}
		case "openapi.v3.Document":
			documentv3 := &openapiv3.Document{}
			err = proto.Unmarshal(model.Value, documentv3)
			if err == nil {
				printDocumentV3(code, documentv3)
			}
		}
	}
	outputName := filepath.Join(
		filepath.Dir(env.Request.SourceName), "summary.txt")
	log.Printf("generating %+v", outputName)
	f := &plugins.File{
		Name: outputName,
		Data: []byte(code.String()),
	}
	env.Response.Files = append(env.Response.Files, f)
	env.RespondAndExit()
}