// Copyright 2018 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

package main

import (
	"flag"
	"fmt"
	"log"
	"os"
	"path"

	"go.fuchsia.dev/fuchsia/tools/fidl/fidlgen_dart/codegen"
	fidl "go.fuchsia.dev/fuchsia/tools/fidl/lib/fidlgen"
)

type flagsDef struct {
	jsonPath     *string
	outAsyncPath *string
	outTestPath  *string
	dartfmt      *string

	deprecatedOutputBase  *string
	deprecatedIncludeBase *string
}

var flags = flagsDef{
	jsonPath: flag.String("json", "",
		"path to the FIDL intermediate representation."),
	outAsyncPath: flag.String("output-async", "",
		"output path for the async bindings."),
	outTestPath: flag.String("output-test", "",
		"output path for the test bindings."),
	dartfmt: flag.String("dartfmt", "",
		"path to the dartfmt tool"),
}

// valid returns true if the parsed flags are valid.
func (f flagsDef) valid() bool {
	return *f.jsonPath != ""
}

func printUsage() {
	program := path.Base(os.Args[0])
	message := `Usage: ` + program + ` [flags]

Dart FIDL backend, used to generate Dart bindings from JSON IR input (the
intermediate representation of a FIDL library).

Flags:
`
	fmt.Fprint(flag.CommandLine.Output(), message)
	flag.PrintDefaults()
}

func main() {
	flag.Parse()
	if !flag.Parsed() || !flags.valid() {
		printUsage()
		os.Exit(1)
	}

	fidl, err := fidl.ReadJSONIr(*flags.jsonPath)
	if err != nil {
		log.Fatal(err)
	}
	tree := codegen.Compile(fidl)

	generator := codegen.NewFidlGenerator()

	outAsyncPath := *flags.outAsyncPath
	if outAsyncPath != "" {
		err := generator.GenerateAsyncFile(tree, outAsyncPath, *flags.dartfmt)
		if err != nil {
			log.Fatalf("Error: %v", err)
		}
	}

	outTestPath := *flags.outTestPath
	if outTestPath != "" {
		err := generator.GenerateTestFile(tree, outTestPath, *flags.dartfmt)
		if err != nil {
			log.Fatalf("Error: %v", err)
		}
	}
}