// Copyright 2023 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT

package integration

import (
	"io"
	"net"
	"net/smtp"
	"net/url"
	"strings"
	"testing"
	"time"

	issues_model "code.gitea.io/gitea/models/issues"
	"code.gitea.io/gitea/models/unittest"
	user_model "code.gitea.io/gitea/models/user"
	"code.gitea.io/gitea/modules/setting"
	"code.gitea.io/gitea/services/mailer/incoming"
	incoming_payload "code.gitea.io/gitea/services/mailer/incoming/payload"
	sender_service "code.gitea.io/gitea/services/mailer/sender"
	token_service "code.gitea.io/gitea/services/mailer/token"
	"code.gitea.io/gitea/tests"

	"github.com/stretchr/testify/assert"
)

func TestIncomingEmail(t *testing.T) {
	onGiteaRun(t, func(t *testing.T, u *url.URL) {
		user := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: 2})
		issue := unittest.AssertExistsAndLoadBean(t, &issues_model.Issue{ID: 1})

		t.Run("Payload", func(t *testing.T) {
			defer tests.PrintCurrentTest(t)()

			comment := unittest.AssertExistsAndLoadBean(t, &issues_model.Comment{ID: 1})

			_, err := incoming_payload.CreateReferencePayload(user)
			assert.Error(t, err)

			issuePayload, err := incoming_payload.CreateReferencePayload(issue)
			assert.NoError(t, err)
			commentPayload, err := incoming_payload.CreateReferencePayload(comment)
			assert.NoError(t, err)

			_, err = incoming_payload.GetReferenceFromPayload(t.Context(), []byte{1, 2, 3})
			assert.Error(t, err)

			ref, err := incoming_payload.GetReferenceFromPayload(t.Context(), issuePayload)
			assert.NoError(t, err)
			assert.IsType(t, ref, new(issues_model.Issue))
			assert.Equal(t, issue.ID, ref.(*issues_model.Issue).ID)

			ref, err = incoming_payload.GetReferenceFromPayload(t.Context(), commentPayload)
			assert.NoError(t, err)
			assert.IsType(t, ref, new(issues_model.Comment))
			assert.Equal(t, comment.ID, ref.(*issues_model.Comment).ID)
		})

		t.Run("Token", func(t *testing.T) {
			defer tests.PrintCurrentTest(t)()

			payload := []byte{1, 2, 3, 4, 5}

			token, err := token_service.CreateToken(token_service.ReplyHandlerType, user, payload)
			assert.NoError(t, err)
			assert.NotEmpty(t, token)

			ht, u, p, err := token_service.ExtractToken(t.Context(), token)
			assert.NoError(t, err)
			assert.Equal(t, token_service.ReplyHandlerType, ht)
			assert.Equal(t, user.ID, u.ID)
			assert.Equal(t, payload, p)
		})

		t.Run("Handler", func(t *testing.T) {
			t.Run("Reply", func(t *testing.T) {
				t.Run("Comment", func(t *testing.T) {
					defer tests.PrintCurrentTest(t)()

					handler := &incoming.ReplyHandler{}

					payload, err := incoming_payload.CreateReferencePayload(issue)
					assert.NoError(t, err)

					assert.Error(t, handler.Handle(t.Context(), &incoming.MailContent{}, nil, payload))
					assert.NoError(t, handler.Handle(t.Context(), &incoming.MailContent{}, user, payload))

					content := &incoming.MailContent{
						Content: "reply by mail",
						Attachments: []*incoming.Attachment{
							{
								Name:    "attachment.txt",
								Content: []byte("test"),
							},
						},
					}

					assert.NoError(t, handler.Handle(t.Context(), content, user, payload))

					comments, err := issues_model.FindComments(t.Context(), &issues_model.FindCommentsOptions{
						IssueID: issue.ID,
						Type:    issues_model.CommentTypeComment,
					})
					assert.NoError(t, err)
					assert.NotEmpty(t, comments)
					comment := comments[len(comments)-1]
					assert.Equal(t, user.ID, comment.PosterID)
					assert.Equal(t, content.Content, comment.Content)
					assert.NoError(t, comment.LoadAttachments(t.Context()))
					assert.Len(t, comment.Attachments, 1)
					attachment := comment.Attachments[0]
					assert.Equal(t, content.Attachments[0].Name, attachment.Name)
					assert.EqualValues(t, 4, attachment.Size)
				})

				t.Run("CodeComment", func(t *testing.T) {
					defer tests.PrintCurrentTest(t)()

					comment := unittest.AssertExistsAndLoadBean(t, &issues_model.Comment{ID: 6})
					issue := unittest.AssertExistsAndLoadBean(t, &issues_model.Issue{ID: comment.IssueID})

					handler := &incoming.ReplyHandler{}
					content := &incoming.MailContent{
						Content: "code reply by mail",
						Attachments: []*incoming.Attachment{
							{
								Name:    "attachment.txt",
								Content: []byte("test"),
							},
						},
					}

					payload, err := incoming_payload.CreateReferencePayload(comment)
					assert.NoError(t, err)

					assert.NoError(t, handler.Handle(t.Context(), content, user, payload))

					comments, err := issues_model.FindComments(t.Context(), &issues_model.FindCommentsOptions{
						IssueID: issue.ID,
						Type:    issues_model.CommentTypeCode,
					})
					assert.NoError(t, err)
					assert.NotEmpty(t, comments)
					comment = comments[len(comments)-1]
					assert.Equal(t, user.ID, comment.PosterID)
					assert.Equal(t, content.Content, comment.Content)
					assert.NoError(t, comment.LoadAttachments(t.Context()))
					assert.Len(t, comment.Attachments, 1)
					attachment := comment.Attachments[0]
					assert.Equal(t, content.Attachments[0].Name, attachment.Name)
					assert.EqualValues(t, 4, attachment.Size)
				})
			})

			t.Run("Unsubscribe", func(t *testing.T) {
				defer tests.PrintCurrentTest(t)()

				watching, err := issues_model.CheckIssueWatch(t.Context(), user, issue)
				assert.NoError(t, err)
				assert.True(t, watching)

				handler := &incoming.UnsubscribeHandler{}

				content := &incoming.MailContent{
					Content: "unsub me",
				}

				payload, err := incoming_payload.CreateReferencePayload(issue)
				assert.NoError(t, err)

				assert.NoError(t, handler.Handle(t.Context(), content, user, payload))

				watching, err = issues_model.CheckIssueWatch(t.Context(), user, issue)
				assert.NoError(t, err)
				assert.False(t, watching)
			})
		})

		if setting.IncomingEmail.Enabled {
			// This test connects to the configured email server and is currently only enabled for MySql integration tests.
			// It sends a reply to create a comment. If the comment is not detected after 10 seconds the test fails.
			t.Run("IMAP", func(t *testing.T) {
				defer tests.PrintCurrentTest(t)()

				payload, err := incoming_payload.CreateReferencePayload(issue)
				assert.NoError(t, err)
				token, err := token_service.CreateToken(token_service.ReplyHandlerType, user, payload)
				assert.NoError(t, err)

				msg := sender_service.NewMessageFrom(
					strings.Replace(setting.IncomingEmail.ReplyToAddress, setting.IncomingEmail.TokenPlaceholder, token, 1),
					"",
					user.Email,
					"",
					token,
				)

				err = sender_service.Send(&smtpTestSender{}, msg)
				assert.NoError(t, err)

				assert.Eventually(t, func() bool {
					comments, err := issues_model.FindComments(t.Context(), &issues_model.FindCommentsOptions{
						IssueID: issue.ID,
						Type:    issues_model.CommentTypeComment,
					})
					assert.NoError(t, err)
					assert.NotEmpty(t, comments)

					comment := comments[len(comments)-1]

					return comment.PosterID == user.ID && comment.Content == token
				}, 10*time.Second, 1*time.Second)
			})
		}
	})
}

// A simple SMTP mail sender used for integration tests.
type smtpTestSender struct{}

func (s *smtpTestSender) Send(from string, to []string, msg io.WriterTo) error {
	conn, err := net.Dial("tcp", net.JoinHostPort(setting.IncomingEmail.Host, "25"))
	if err != nil {
		return err
	}
	defer conn.Close()

	client, err := smtp.NewClient(conn, setting.IncomingEmail.Host)
	if err != nil {
		return err
	}

	if err = client.Mail(from); err != nil {
		return err
	}

	for _, rec := range to {
		if err = client.Rcpt(rec); err != nil {
			return err
		}
	}

	w, err := client.Data()
	if err != nil {
		return err
	}
	if _, err := msg.WriteTo(w); err != nil {
		return err
	}
	if err := w.Close(); err != nil {
		return err
	}

	return client.Quit()
}
