// Copyright (c) 2023 Proton AG
//
// This file is part of Proton Mail Bridge.
//
// Proton Mail Bridge is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Proton Mail Bridge is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Proton Mail Bridge.  If not, see <https://www.gnu.org/licenses/>.

package bridge_test

import (
	"context"
	"fmt"
	"net"
	"net/http"
	"net/mail"
	"strings"
	"sync/atomic"
	"testing"
	"time"

	"github.com/ProtonMail/gluon/rfc822"
	"github.com/ProtonMail/go-proton-api"
	"github.com/ProtonMail/go-proton-api/server"
	"github.com/ProtonMail/proton-bridge/v3/internal/bridge"
	"github.com/ProtonMail/proton-bridge/v3/internal/constants"
	"github.com/ProtonMail/proton-bridge/v3/internal/events"
	"github.com/ProtonMail/proton-bridge/v3/internal/user"
	"github.com/bradenaw/juniper/stream"
	"github.com/bradenaw/juniper/xslices"
	"github.com/emersion/go-imap"
	"github.com/emersion/go-imap/client"
	"github.com/golang/mock/gomock"
	"github.com/google/uuid"
	"github.com/stretchr/testify/require"
)

func TestBridge_User_BadMessage_BadEvent(t *testing.T) {
	withEnv(t, func(ctx context.Context, s *server.Server, netCtl *proton.NetCtl, locator bridge.Locator, storeKey []byte) {
		// Create a user.
		userID, addrID, err := s.CreateUser("user", password)
		require.NoError(t, err)

		labelID, err := s.CreateLabel(userID, "folder", "", proton.LabelTypeFolder)
		require.NoError(t, err)

		// Create 10 messages for the user.
		withClient(ctx, t, s, "user", password, func(ctx context.Context, c *proton.Client) {
			createNumMessages(ctx, t, c, addrID, labelID, 10)
		})

		withBridge(ctx, t, s.GetHostURL(), netCtl, locator, storeKey, func(bridge *bridge.Bridge, mocks *bridge.Mocks) {
			userLoginAndSync(ctx, t, bridge, "user", password)

			var messageIDs []string

			// Create 10 more messages for the user, generating events.
			withClient(ctx, t, s, "user", password, func(ctx context.Context, c *proton.Client) {
				messageIDs = createNumMessages(ctx, t, c, addrID, labelID, 10)
			})

			// If bridge attempts to sync the new messages, it should get a BadRequest error.
			doBadRequest := true
			s.AddStatusHook(func(req *http.Request) (int, bool) {
				if !doBadRequest {
					return 0, false
				}

				if xslices.Index(xslices.Map(messageIDs, func(messageID string) string {
					return "/mail/v4/messages/" + messageID
				}), req.URL.Path) < 0 {
					return 0, false
				}

				return http.StatusBadRequest, true
			})

			userReceiveBadErrorAndLogout(t, bridge, mocks)

			// Remove messages
			withClient(ctx, t, s, "user", password, func(ctx context.Context, c *proton.Client) {
				require.NoError(t, c.DeleteMessage(ctx, messageIDs...))
			})
			doBadRequest = false

			// Login again
			_, err := bridge.LoginFull(ctx, "user", password, nil, nil)
			require.NoError(t, err)

			userContinueEventProcess(ctx, t, s, bridge)
		})
	})
}

func TestBridge_User_BadMessage_NoBadEvent(t *testing.T) {
	withEnv(t, func(ctx context.Context, s *server.Server, netCtl *proton.NetCtl, locator bridge.Locator, storeKey []byte) {
		// Create a user.
		_, addrID, err := s.CreateUser("user", password)
		require.NoError(t, err)

		// Create 10 messages for the user.
		withClient(ctx, t, s, "user", password, func(ctx context.Context, c *proton.Client) {
			createNumMessages(ctx, t, c, addrID, proton.InboxLabel, 10)
		})

		withBridge(ctx, t, s.GetHostURL(), netCtl, locator, storeKey, func(bridge *bridge.Bridge, mocks *bridge.Mocks) {
			userLoginAndSync(ctx, t, bridge, "user", password)

			var messageIDs []string

			// Create 10 more messages for the user, generating events.
			withClient(ctx, t, s, "user", password, func(ctx context.Context, c *proton.Client) {
				messageIDs = createNumMessages(ctx, t, c, addrID, proton.InboxLabel, 10)
			})

			// If bridge attempts to sync the new messages, it should get a BadRequest error.
			s.AddStatusHook(func(req *http.Request) (int, bool) {
				if strings.Contains(req.URL.Path, "/mail/v4/messages/"+messageIDs[2]) {
					return http.StatusUnprocessableEntity, true
				}

				return 0, false
			})

			// Remove messages
			withClient(ctx, t, s, "user", password, func(ctx context.Context, c *proton.Client) {
				require.NoError(t, c.DeleteMessage(ctx, messageIDs...))
			})

			userContinueEventProcess(ctx, t, s, bridge)
		})
	})
}

func TestBridge_User_SameMessageLabelCreated_NoBadEvent(t *testing.T) {
	withEnv(t, func(ctx context.Context, s *server.Server, netCtl *proton.NetCtl, locator bridge.Locator, storeKey []byte) {
		// Create a user.
		userID, addrID, err := s.CreateUser("user", password)
		require.NoError(t, err)

		var messageIDs []string

		// Create 10 messages for the user.
		withClient(ctx, t, s, "user", password, func(ctx context.Context, c *proton.Client) {
			messageIDs = createNumMessages(ctx, t, c, addrID, proton.InboxLabel, 10)
		})

		withBridge(ctx, t, s.GetHostURL(), netCtl, locator, storeKey, func(bridge *bridge.Bridge, _ *bridge.Mocks) {
			userLoginAndSync(ctx, t, bridge, "user", password)

			labelID, err := s.CreateLabel(userID, "folder", "", proton.LabelTypeFolder)
			require.NoError(t, err)

			// Add NOOP events
			require.NoError(t, s.AddLabelCreatedEvent(userID, labelID))
			require.NoError(t, s.AddMessageCreatedEvent(userID, messageIDs[9]))

			userContinueEventProcess(ctx, t, s, bridge)
		})
	})
}

func TestBridge_User_MessageLabelDeleted_NoBadEvent(t *testing.T) {
	withEnv(t, func(ctx context.Context, s *server.Server, netCtl *proton.NetCtl, locator bridge.Locator, storeKey []byte) {
		// Create a user.
		userID, addrID, err := s.CreateUser("user", password)
		require.NoError(t, err)

		labelID, err := s.CreateLabel(userID, "folder", "", proton.LabelTypeFolder)
		require.NoError(t, err)

		// Create 10 messages for the user.
		withClient(ctx, t, s, "user", password, func(ctx context.Context, c *proton.Client) {
			createNumMessages(ctx, t, c, addrID, labelID, 10)
		})

		withBridge(ctx, t, s.GetHostURL(), netCtl, locator, storeKey, func(bridge *bridge.Bridge, _ *bridge.Mocks) {
			userLoginAndSync(ctx, t, bridge, "user", password)

			// Create and delete 10 more messages for the user, generating delete events.
			withClient(ctx, t, s, "user", password, func(ctx context.Context, c *proton.Client) {
				messageIDs := createNumMessages(ctx, t, c, addrID, labelID, 10)
				require.NoError(t, c.DeleteMessage(ctx, messageIDs...))
			})

			// Create and delete 10 labels for the user, generating delete events.
			withClient(ctx, t, s, "user", password, func(ctx context.Context, c *proton.Client) {
				for i := 0; i < 10; i++ {
					label, err := c.CreateLabel(ctx, proton.CreateLabelReq{
						Name:  uuid.NewString(),
						Color: "#f66",
						Type:  proton.LabelTypeLabel,
					})
					require.NoError(t, err)

					require.NoError(t, c.DeleteLabel(ctx, label.ID))
				}
			})

			userContinueEventProcess(ctx, t, s, bridge)
		})
	})
}

func TestBridge_User_AddressEvents_NoBadEvent(t *testing.T) {
	withEnv(t, func(ctx context.Context, s *server.Server, netCtl *proton.NetCtl, locator bridge.Locator, storeKey []byte) {
		// Create a user.
		userID, addrID, err := s.CreateUser("user", password)
		require.NoError(t, err)

		// Create 10 messages for the user.
		withClient(ctx, t, s, "user", password, func(ctx context.Context, c *proton.Client) {
			createNumMessages(ctx, t, c, addrID, proton.InboxLabel, 10)
		})

		withBridge(ctx, t, s.GetHostURL(), netCtl, locator, storeKey, func(bridge *bridge.Bridge, _ *bridge.Mocks) {
			userLoginAndSync(ctx, t, bridge, "user", password)

			addrID, err = s.CreateAddress(userID, "other@pm.me", password)
			require.NoError(t, err)
			userContinueEventProcess(ctx, t, s, bridge)

			require.NoError(t, s.AddAddressCreatedEvent(userID, addrID))
			userContinueEventProcess(ctx, t, s, bridge)
		})

		otherID, err := s.CreateAddress(userID, "another@pm.me", password)
		require.NoError(t, err)
		require.NoError(t, s.RemoveAddress(userID, otherID))

		withBridge(ctx, t, s.GetHostURL(), netCtl, locator, storeKey, func(bridge *bridge.Bridge, _ *bridge.Mocks) {
			userContinueEventProcess(ctx, t, s, bridge)

			require.NoError(t, s.CreateAddressKey(userID, addrID, password))
			userContinueEventProcess(ctx, t, s, bridge)

			require.NoError(t, s.RemoveAddress(userID, addrID))
			userContinueEventProcess(ctx, t, s, bridge)
		})
	})
}

func TestBridge_User_Network_NoBadEvents(t *testing.T) {
	withEnv(t, func(ctx context.Context, s *server.Server, netCtl *proton.NetCtl, locator bridge.Locator, storeKey []byte) {
		retVal := int32(0)

		setResponseAndWait := func(status int32) {
			atomic.StoreInt32(&retVal, status)
			time.Sleep(user.EventPeriod)
		}

		s.AddStatusHook(func(req *http.Request) (int, bool) {
			status := atomic.LoadInt32(&retVal)
			if strings.Contains(req.URL.Path, "/core/v4/events/") {
				return int(status), status != 0
			}

			return 0, false
		})

		// Create a user.
		_, addrID, err := s.CreateUser("user", password)
		require.NoError(t, err)

		withBridge(ctx, t, s.GetHostURL(), netCtl, locator, storeKey, func(bridge *bridge.Bridge, mocks *bridge.Mocks) {
			userLoginAndSync(ctx, t, bridge, "user", password)

			// Create 10 more messages for the user, generating events.
			withClient(ctx, t, s, "user", password, func(ctx context.Context, c *proton.Client) {
				createNumMessages(ctx, t, c, addrID, proton.InboxLabel, 10)

				setResponseAndWait(http.StatusInternalServerError)
				setResponseAndWait(http.StatusServiceUnavailable)
				setResponseAndWait(http.StatusPaymentRequired)
				setResponseAndWait(http.StatusForbidden)
				setResponseAndWait(http.StatusBadRequest)
				setResponseAndWait(http.StatusUnprocessableEntity)
				setResponseAndWait(http.StatusTooManyRequests)
				time.Sleep(10 * time.Second) // needs minimum of 10 seconds to retry
			})

			setResponseAndWait(0)
			time.Sleep(10 * time.Second) // needs up to 20 seconds to retry
			userContinueEventProcess(ctx, t, s, bridge)
		})
	})
}

func TestBridge_User_DropConn_NoBadEvent(t *testing.T) {
	l, err := net.Listen("tcp", "127.0.0.1:0")
	require.NoError(t, err)

	dropListener := proton.NewListener(l, proton.NewDropConn)
	defer func() { _ = dropListener.Close() }()

	withEnv(t, func(ctx context.Context, s *server.Server, netCtl *proton.NetCtl, locator bridge.Locator, storeKey []byte) {
		// Create a user.
		_, addrID, err := s.CreateUser("user", password)
		require.NoError(t, err)

		// Create 10 messages for the user.
		withClient(ctx, t, s, "user", password, func(ctx context.Context, c *proton.Client) {
			createNumMessages(ctx, t, c, addrID, proton.InboxLabel, 10)
		})

		withBridge(ctx, t, s.GetHostURL(), netCtl, locator, storeKey, func(bridge *bridge.Bridge, mocks *bridge.Mocks) {
			userLoginAndSync(ctx, t, bridge, "user", password)

			mocks.Reporter.EXPECT().ReportMessageWithContext(gomock.Any(), gomock.Any()).AnyTimes()

			// Create 10 more messages for the user, generating events.
			withClient(ctx, t, s, "user", password, func(ctx context.Context, c *proton.Client) {
				createNumMessages(ctx, t, c, addrID, proton.InboxLabel, 10)
			})

			var count int

			// The first 10 times bridge attempts to sync any of the messages, drop the connection.
			s.AddStatusHook(func(req *http.Request) (int, bool) {
				if strings.Contains(req.URL.Path, "/mail/v4/messages") {
					if count++; count < 10 {
						dropListener.DropAll()
					}
				}

				return 0, false
			})

			info, err := bridge.QueryUserInfo("user")
			require.NoError(t, err)

			client, err := client.Dial(fmt.Sprintf("%v:%v", constants.Host, bridge.GetIMAPPort()))
			require.NoError(t, err)
			require.NoError(t, client.Login(info.Addresses[0], string(info.BridgePass)))
			defer func() { _ = client.Logout() }()

			// The IMAP client will eventually see 20 messages.
			require.Eventually(t, func() bool {
				status, err := client.Status("INBOX", []imap.StatusItem{imap.StatusMessages})
				return err == nil && status.Messages == 20
			}, 10*time.Second, 100*time.Millisecond)
		})
	}, server.WithListener(dropListener))
}

func TestBridge_User_UpdateDraftAndCreateOtherMessage(t *testing.T) {
	withEnv(t, func(ctx context.Context, s *server.Server, netCtl *proton.NetCtl, locator bridge.Locator, storeKey []byte) {
		// Create a bridge user.
		_, _, err := s.CreateUser("user", password)
		require.NoError(t, err)

		// Initially sync the user.
		withBridge(ctx, t, s.GetHostURL(), netCtl, locator, storeKey, func(bridge *bridge.Bridge, mocks *bridge.Mocks) {
			userLoginAndSync(ctx, t, bridge, "user", password)
		})

		withClient(ctx, t, s, "user", password, func(ctx context.Context, c *proton.Client) {
			user, err := c.GetUser(ctx)
			require.NoError(t, err)

			addrs, err := c.GetAddresses(ctx)
			require.NoError(t, err)

			salts, err := c.GetSalts(ctx)
			require.NoError(t, err)

			keyPass, err := salts.SaltForKey(password, user.Keys.Primary().ID)
			require.NoError(t, err)

			_, addrKRs, err := proton.Unlock(user, addrs, keyPass)
			require.NoError(t, err)

			// Create a draft (generating a "create draft message" event).
			draft, err := c.CreateDraft(ctx, addrKRs[addrs[0].ID], proton.CreateDraftReq{
				Message: proton.DraftTemplate{
					Subject:  "subject",
					Sender:   &mail.Address{Name: "sender", Address: addrs[0].Email},
					Body:     "body",
					MIMEType: rfc822.TextPlain,
				},
			})
			require.NoError(t, err)

			// Process those events
			withBridge(ctx, t, s.GetHostURL(), netCtl, locator, storeKey, func(bridge *bridge.Bridge, mocks *bridge.Mocks) {
				userContinueEventProcess(ctx, t, s, bridge)
			})

			// Update the draft (generating an "update draft message" event).
			require.NoError(t, getErr(c.UpdateDraft(ctx, draft.ID, addrKRs[addrs[0].ID], proton.UpdateDraftReq{
				Message: proton.DraftTemplate{
					Subject:  "subject 2",
					Sender:   &mail.Address{Name: "sender", Address: addrs[0].Email},
					Body:     "body 2",
					MIMEType: rfc822.TextPlain,
				},
			})))

			// Import a message (generating a "create message" event).
			str, err := c.ImportMessages(ctx, addrKRs[addrs[0].ID], 1, 1, proton.ImportReq{
				Metadata: proton.ImportMetadata{
					AddressID: addrs[0].ID,
					Flags:     proton.MessageFlagReceived,
				},
				Message: []byte("From: someone@example.com\r\nTo: blabla@example.com\r\n\r\nhello"),
			})
			require.NoError(t, err)

			res, err := stream.Collect(ctx, str)
			require.NoError(t, err)

			// Process those events.
			withBridge(ctx, t, s.GetHostURL(), netCtl, locator, storeKey, func(bridge *bridge.Bridge, mocks *bridge.Mocks) {
				userContinueEventProcess(ctx, t, s, bridge)
			})

			// Update the imported message (generating an "update message" event).
			require.NoError(t, c.MarkMessagesUnread(ctx, res[0].MessageID))

			// Process those events.
			withBridge(ctx, t, s.GetHostURL(), netCtl, locator, storeKey, func(bridge *bridge.Bridge, mocks *bridge.Mocks) {
				userContinueEventProcess(ctx, t, s, bridge)
			})
		})
	})
}

// userLoginAndSync logs in user and waits until user is fully synced.
func userLoginAndSync(
	ctx context.Context,
	t *testing.T,
	bridge *bridge.Bridge,
	username string, password []byte, //nolint:unparam
) {
	syncCh, done := chToType[events.Event, events.SyncFinished](bridge.GetEvents(events.SyncFinished{}))
	defer done()

	userID, err := bridge.LoginFull(ctx, username, password, nil, nil)
	require.NoError(t, err)

	require.Equal(t, userID, (<-syncCh).UserID)
}

func userReceiveBadErrorAndLogout(
	t *testing.T,
	bridge *bridge.Bridge,
	mocks *bridge.Mocks,
) {
	// The user will continue to process events and will receive bad request errors.
	mocks.Reporter.EXPECT().ReportMessageWithContext(gomock.Any(), gomock.Any()).MinTimes(1)

	// The user will eventually be logged out due to the bad request errors.
	require.Eventually(t, func() bool {
		return len(bridge.GetUserIDs()) == 1 && len(getConnectedUserIDs(t, bridge)) == 0
	}, 100*user.EventPeriod, user.EventPeriod)
}

// userContinueEventProcess checks that user will continue to process events and will not receive any bad request errors.
func userContinueEventProcess(
	ctx context.Context,
	t *testing.T,
	s *server.Server,
	bridge *bridge.Bridge,
) {
	info, err := bridge.QueryUserInfo("user")
	require.NoError(t, err)

	client, err := client.Dial(fmt.Sprintf("%v:%v", constants.Host, bridge.GetIMAPPort()))
	require.NoError(t, err)
	require.NoError(t, client.Login(info.Addresses[0], string(info.BridgePass)))
	defer func() { _ = client.Logout() }()

	randomLabel := uuid.NewString()

	// Create a new label.
	withClient(ctx, t, s, "user", password, func(ctx context.Context, c *proton.Client) {
		require.NoError(t, getErr(c.CreateLabel(ctx, proton.CreateLabelReq{
			Name:  randomLabel,
			Color: "#f66",
			Type:  proton.LabelTypeLabel,
		})))
	})

	// Wait for the label to be created.
	require.Eventually(t, func() bool {
		return xslices.IndexFunc(clientList(client), func(mailbox *imap.MailboxInfo) bool {
			return mailbox.Name == "Labels/"+randomLabel
		}) >= 0
	}, 100*user.EventPeriod, user.EventPeriod)
}