// Copyright 2020 The Chromium OS 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 cmd

import (
	"fmt"
	"os"
	"path/filepath"
	"sort"

	"github.com/golang/protobuf/jsonpb"
	"github.com/maruel/subcommands"
	tnProto "go.chromium.org/chromiumos/config/go/api/test/harness/tnull/v1"
	rtd "go.chromium.org/chromiumos/config/go/api/test/rtd/v1"
	"go.chromium.org/luci/common/errors"
)

type gen struct {
	subcommands.CommandRunBase
	dest string
}

func GenerateFullRequest() *subcommands.Command {
	return &subcommands.Command{
		UsageLine: "generate-full-request -output_json /path/to/output/json",
		ShortDesc: "create an Invocation requesting every TNull test, as a JSON file.",
		CommandRun: func() subcommands.CommandRun {
			g := &gen{}
			g.Flags.StringVar(&g.dest, "output_json", "", "Path to contain a JSON-encoded rtd.Invocation object")
			return g
		},
	}
}

func (g *gen) Run(a subcommands.Application, args []string, env subcommands.Env) int {
	lookup, err := extractTestsFromSpecification()
	if err != nil {
		fmt.Fprintf(a.GetErr(), "%s\n", err)
		return 1
	}
	err = WriteJSONInvocation(lookup.Lookup, g.dest)
	if err != nil {
		fmt.Fprintf(a.GetErr(), "%s\n", err)
		return 1
	}
	return 0
}

// WriteJSONInvocation writes a JSON encoded Invocation proto to destFile.
func WriteJSONInvocation(tests map[string]*tnProto.Steps, destFile string) error {
	reqs := []*rtd.Request{}
	for _, name := range mapKeysToSortedList(tests) {
		req := rtd.Request{
			Name: "request_" + filepath.Base(name),
			Test: name,
		}
		reqs = append(reqs, &req)
	}
	Inv := rtd.Invocation{
		Requests: reqs,
	}
	dir := filepath.Dir(destFile)
	// Create the directory if it doesn't exist.
	if err := os.MkdirAll(dir, 0777); err != nil {
		return errors.Annotate(err, "write JSON pb").Err()
	}

	w, err := os.Create(destFile)
	if err != nil {
		return errors.Annotate(err, "write JSON pb").Err()
	}
	defer w.Close()

	marshaler := jsonpb.Marshaler{Indent: "  "}
	if err := marshaler.Marshal(w, &Inv); err != nil {
		return errors.Annotate(err, "write JSON pb").Err()
	}
	return nil
}

func mapKeysToSortedList(m map[string]*tnProto.Steps) []string {
	keys := make([]string, 0, len(m))
	for k := range m {
		keys = append(keys, k)
	}
	sort.Strings(keys)
	return keys
}