// Copyright 2023 syzkaller project authors. All rights reserved.
// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.

package lore

import (
	"sort"
	"strings"
	"testing"
	"time"

	"github.com/google/go-cmp/cmp"
	"github.com/google/syzkaller/dashboard/dashapi"
	"github.com/google/syzkaller/pkg/email"
)

func TestThreadsCollection(t *testing.T) {
	messages := []string{
		// <A-Base> <-- <A-Child-1> <-- <A-Child-1-1>.
		`Date: Sun, 7 May 2017 19:54:00 -0700
Subject: Thread A
Message-ID: <A-Base>
From: UserA <a@user.com>
Content-Type: text/plain


Some text`,
		`Date: Sun, 7 May 2017 19:55:00 -0700
Subject: Re: Thread A
Message-ID: <A-Child-1>
From: UserB <b@user.com>
To: UserA <a@user.com>
Content-Type: text/plain
In-Reply-To: <A-Base>


Some reply`,
		`Date: Sun, 7 May 2017 19:56:00 -0700
Subject: Re: Re: Thread A
Message-ID: <A-Child-1-1>
From: UserC <c@user.com>
To: UserA <a@user.com>, UserB <b@user.com>
Content-Type: text/plain
In-Reply-To: <A-Child-1>


Some reply (2)`,
		// <Bug> with two children: <Bug-Reply1>, <Bug-Reply2>.
		`Date: Sun, 7 May 2017 19:57:00 -0700
Subject: [syzbot] Some bug
Message-ID: <Bug>
From: syzbot <syzbot+4564456@bar.com>
Content-Type: text/plain


Bug report`,
		`Date: Sun, 7 May 2017 19:58:00 -0700
Subject: Re: [syzbot] Some bug
Message-ID: <Bug-Reply1>
From: UserC <c@user.com>
To: syzbot <syzbot+4564456@bar.com>
In-Reply-To: <Bug>
Content-Type: text/plain


Bug report reply`,
		`Date: Sun, 7 May 2017 19:58:01 -0700
Subject: Re: [syzbot] Some bug
Message-ID: <Bug-Reply2>
From: UserD <d@user.com>
To: syzbot <syzbot+4564456@bar.com>
In-Reply-To: <Bug>B
Content-Type: text/plain


Bug report reply 2`,
		// And one PATCH without replies.
		`Date: Sun, 7 May 2017 19:58:01 -0700
Subject: [PATCH] Some bug fixed
Message-ID: <Patch>
From: UserE <e@user.com>
Cc: syzbot <syzbot+12345@bar.com>
Content-Type: text/plain


Patch`,
		// An orphaned reply from a human.
		`Date: Sun, 7 May 2017 19:57:00 -0700
Subject: Another bug discussion
In-Reply-To: <Unknown>
Message-ID: <Sub-Discussion>
From: person@email.com
Cc: syzbot <syzbot+4564456@bar.com>
Content-Type: text/plain


Bug report`,
		// An orphaned reply from a bot.
		`Date: Sun, 7 May 2017 19:57:00 -0700
Subject: Re: [syzbot] Some bug 3
In-Reply-To: <Unknown>
Message-ID: <Sub-Discussion-Bot>
From: syzbot+4564456@bar.com
To: all@email.com
Content-Type: text/plain


Bug report`,
	}

	zone := time.FixedZone("", -7*60*60)
	expected := map[string]*Thread{
		"<A-Base>": {
			Subject:   "Thread A",
			MessageID: "<A-Base>",
			Type:      dashapi.DiscussionMention,
			Messages: []*email.Email{
				{
					MessageID: "<A-Base>",
					Subject:   "Thread A",
					Date:      time.Date(2017, time.May, 7, 19, 54, 0, 0, zone),
					Author:    "a@user.com",
					Cc:        []string{"a@user.com"},
				},
				{
					MessageID: "<A-Child-1>",
					Subject:   "Re: Thread A",
					Date:      time.Date(2017, time.May, 7, 19, 55, 0, 0, zone),
					Author:    "b@user.com",
					Cc:        []string{"a@user.com", "b@user.com"},
					InReplyTo: "<A-Base>",
				},
				{
					MessageID: "<A-Child-1-1>",
					Subject:   "Re: Re: Thread A",
					Date:      time.Date(2017, time.May, 7, 19, 56, 0, 0, zone),
					Author:    "c@user.com",
					Cc:        []string{"a@user.com", "b@user.com", "c@user.com"},
					InReplyTo: "<A-Child-1>",
				},
			},
		},
		"<Bug>": {
			Subject:   "[syzbot] Some bug",
			MessageID: "<Bug>",
			Type:      dashapi.DiscussionReport,
			BugIDs:    []string{"4564456"},
			Messages: []*email.Email{
				{
					MessageID: "<Bug>",
					BugIDs:    []string{"4564456"},
					Subject:   "[syzbot] Some bug",
					Date:      time.Date(2017, time.May, 7, 19, 57, 0, 0, zone),
					Author:    "syzbot@bar.com",
					OwnEmail:  true,
				},
				{
					MessageID: "<Bug-Reply1>",
					BugIDs:    []string{"4564456"},
					Subject:   "Re: [syzbot] Some bug",
					Date:      time.Date(2017, time.May, 7, 19, 58, 0, 0, zone),
					Author:    "c@user.com",
					Cc:        []string{"c@user.com"},
					InReplyTo: "<Bug>",
				},
				{
					MessageID: "<Bug-Reply2>",
					BugIDs:    []string{"4564456"},
					Subject:   "Re: [syzbot] Some bug",
					Date:      time.Date(2017, time.May, 7, 19, 58, 1, 0, zone),
					Author:    "d@user.com",
					Cc:        []string{"d@user.com"},
					InReplyTo: "<Bug>",
				},
			},
		},
		"<Patch>": {
			Subject:   "[PATCH] Some bug fixed",
			MessageID: "<Patch>",
			Type:      dashapi.DiscussionPatch,
			BugIDs:    []string{"12345"},
			Messages: []*email.Email{
				{
					MessageID: "<Patch>",
					BugIDs:    []string{"12345"},
					Subject:   "[PATCH] Some bug fixed",
					Date:      time.Date(2017, time.May, 7, 19, 58, 1, 0, zone),
					Author:    "e@user.com",
					Cc:        []string{"e@user.com"},
				},
			},
		},
		"<Sub-Discussion>": {
			Subject:   "Another bug discussion",
			MessageID: "<Sub-Discussion>",
			Type:      dashapi.DiscussionMention,
			BugIDs:    []string{"4564456"},
			Messages: []*email.Email{
				{
					MessageID: "<Sub-Discussion>",
					InReplyTo: "<Unknown>",
					Date:      time.Date(2017, time.May, 7, 19, 57, 0, 0, zone),
					BugIDs:    []string{"4564456"},
					Cc:        []string{"person@email.com"},
					Subject:   "Another bug discussion",
					Author:    "person@email.com",
				},
			},
		},
		"<Sub-Discussion-Bot>": nil,
	}

	emails := []*email.Email{}
	for _, m := range messages {
		msg, err := email.Parse(strings.NewReader(m), []string{"syzbot@bar.com"},
			[]string{}, []string{"bar.com"})
		if err != nil {
			t.Fatal(err)
		}
		msg.Body = ""
		emails = append(emails, msg)
	}

	threads := Threads(emails)
	got := map[string]*Thread{}

	for _, d := range threads {
		sort.Slice(d.Messages, func(i, j int) bool {
			return d.Messages[i].Date.Before(d.Messages[j].Date)
		})
		got[d.MessageID] = d
	}

	for key, val := range expected {
		if diff := cmp.Diff(val, got[key]); diff != "" {
			t.Fatalf("%s: %s", key, diff)
		}
	}

	if len(threads) > len(expected) {
		t.Fatalf("expected %d threads, got %d", len(expected), len(threads))
	}
}

func TestDiscussionType(t *testing.T) {
	tests := []struct {
		msg *email.Email
		ret dashapi.DiscussionType
	}{
		{
			msg: &email.Email{
				Subject: "[PATCH] Bla-bla",
			},
			ret: dashapi.DiscussionPatch,
		},
		{
			msg: &email.Email{
				Subject: "[patch v3] Bla-bla",
			},
			ret: dashapi.DiscussionPatch,
		},
		{
			msg: &email.Email{
				Subject: "[RFC PATCH] Bla-bla",
			},
			ret: dashapi.DiscussionPatch,
		},
		{
			msg: &email.Email{
				Subject: "[RESEND PATCH] Bla-bla",
			},
			ret: dashapi.DiscussionPatch,
		},
		{
			msg: &email.Email{
				Subject:  "[syzbot] Monthly ext4 report",
				OwnEmail: true,
			},
			ret: dashapi.DiscussionReminder,
		},
		{
			msg: &email.Email{
				Subject:  "[syzbot] WARNING in abcd",
				OwnEmail: true,
			},
			ret: dashapi.DiscussionReport,
		},
		{
			msg: &email.Email{
				Subject: "Some human-reported bug",
			},
			ret: dashapi.DiscussionMention,
		},
	}
	for _, test := range tests {
		got := DiscussionType(test.msg)
		if got != test.ret {
			t.Fatalf("expected %v got %v for %v", test.ret, got, test.msg)
		}
	}
}