// mautrix-gmessages - A Matrix-Google Messages puppeting bridge.
// Copyright (C) 2023 Tulir Asokan
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program 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 Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

package main

import (
	"encoding/json"
	"fmt"
	"strings"

	"github.com/skip2/go-qrcode"
	"maunium.net/go/mautrix"
	"maunium.net/go/mautrix/bridge/commands"
	"maunium.net/go/mautrix/bridge/status"
	"maunium.net/go/mautrix/event"
	"maunium.net/go/mautrix/id"

	"go.mau.fi/mautrix-gmessages/libgm/gmproto"
)

type WrappedCommandEvent struct {
	*commands.Event
	Bridge *GMBridge
	User   *User
	Portal *Portal
}

func (br *GMBridge) RegisterCommands() {
	proc := br.CommandProcessor.(*commands.Processor)
	proc.AddHandlers(
		cmdLoginQR,
		cmdLoginGoogle,
		cmdDeleteSession,
		cmdLogout,
		cmdReconnect,
		cmdDisconnect,
		cmdSetActive,
		cmdPing,
		cmdPM,
		cmdDeletePortal,
		cmdDeleteAllPortals,
	)
}

func wrapCommand(handler func(*WrappedCommandEvent)) func(*commands.Event) {
	return func(ce *commands.Event) {
		user := ce.User.(*User)
		var portal *Portal
		if ce.Portal != nil {
			portal = ce.Portal.(*Portal)
		}
		br := ce.Bridge.Child.(*GMBridge)
		handler(&WrappedCommandEvent{ce, br, user, portal})
	}
}

var (
	HelpSectionConnectionManagement = commands.HelpSection{Name: "Connection management", Order: 11}
	HelpSectionPortalManagement     = commands.HelpSection{Name: "Portal management", Order: 20}
)

var cmdLoginQR = &commands.FullHandler{
	Func:    wrapCommand(fnLoginQR),
	Name:    "login-qr",
	Aliases: []string{"login"},
	Help: commands.HelpMeta{
		Section:     commands.HelpSectionAuth,
		Description: "Link the bridge to Google Messages on your Android phone by scanning a QR code.",
	},
}

func fnLoginQR(ce *WrappedCommandEvent) {
	if ce.User.Session != nil {
		if ce.User.IsConnected() {
			ce.Reply("You're already logged in")
		} else {
			ce.Reply("You're already logged in. Perhaps you wanted to `reconnect`?")
		}
		return
	} else if ce.User.pairSuccessChan != nil {
		ce.Reply("You already have a login in progress")
		return
	}

	ch, err := ce.User.Login(6)
	if err != nil {
		ce.ZLog.Err(err).Msg("Failed to start login")
		ce.Reply("Failed to start login: %v", err)
		return
	}
	var prevEvent id.EventID
	for item := range ch {
		switch {
		case item.qr != "":
			ce.ZLog.Debug().Msg("Got code in QR channel")
			prevEvent = ce.User.sendQR(ce, item.qr, prevEvent)
		case item.err != nil:
			ce.ZLog.Err(err).Msg("Error in QR channel")
			prevEvent = ce.User.sendQREdit(ce, &event.MessageEventContent{
				MsgType: event.MsgNotice,
				Body:    fmt.Sprintf("Failed to log in: %v", err),
			}, prevEvent)
		case item.success:
			ce.ZLog.Debug().Msg("Got pair success in QR channel")
			prevEvent = ce.User.sendQREdit(ce, &event.MessageEventContent{
				MsgType: event.MsgNotice,
				Body:    "Successfully logged in",
			}, prevEvent)
		default:
			ce.ZLog.Error().Any("item_data", item).Msg("Unknown item in QR channel")
		}
	}
	ce.ZLog.Trace().Msg("Login command finished")
}

var cmdLoginGoogle = &commands.FullHandler{
	Func:    wrapCommand(fnLoginGoogle),
	Name:    "login-google",
	Aliases: []string{"login"},
	Help: commands.HelpMeta{
		Section:     commands.HelpSectionAuth,
		Description: "Link the bridge to Google Messages on your Android phone by logging in with your Google account.",
	},
}

func fnLoginGoogle(ce *WrappedCommandEvent) {
	if ce.User.Session != nil {
		if ce.User.IsConnected() {
			ce.Reply("You're already logged in")
		} else {
			ce.Reply("You're already logged in. Perhaps you wanted to `reconnect`?")
		}
		return
	} else if ce.User.pairSuccessChan != nil {
		ce.Reply("You already have a login in progress")
		return
	}
	ce.User.CommandState = &commands.CommandState{
		Next:   commands.MinimalHandlerFunc(wrapCommand(fnLoginGoogleCookies)),
		Action: "Login",
	}
	ce.Reply("Send your Google cookies here, formatted as a key-value JSON object (see <https://docs.mau.fi/bridges/go/gmessages/authentication.html> for details)")
}

func fnLoginGoogleCookies(ce *WrappedCommandEvent) {
	ce.User.CommandState = nil
	if ce.User.Session != nil {
		if ce.User.IsConnected() {
			ce.Reply("You're already logged in")
		} else {
			ce.Reply("You're already logged in. Perhaps you wanted to `reconnect`?")
		}
		return
	} else if ce.User.pairSuccessChan != nil {
		ce.Reply("You already have a login in progress")
		return
	}
	var cookies map[string]string
	err := json.Unmarshal([]byte(ce.RawArgs), &cookies)
	if err != nil {
		ce.Reply("Failed to parse cookies: %v", err)
		return
	}
	err = ce.User.LoginGoogle(cookies, func(emoji string) {
		ce.Reply(emoji)
	})
	if err != nil {
		ce.Reply("Login failed: %v", err)
	} else {
		ce.Reply("Login successful")
	}
}

func (user *User) sendQREdit(ce *WrappedCommandEvent, content *event.MessageEventContent, prevEvent id.EventID) id.EventID {
	if len(prevEvent) != 0 {
		content.SetEdit(prevEvent)
	}
	resp, err := ce.Bot.SendMessageEvent(ce.RoomID, event.EventMessage, &content)
	if err != nil {
		ce.ZLog.Err(err).Msg("Failed to send edited QR code")
	} else if len(prevEvent) == 0 {
		prevEvent = resp.EventID
	}
	return prevEvent
}

func (user *User) sendQR(ce *WrappedCommandEvent, code string, prevEvent id.EventID) id.EventID {
	var content event.MessageEventContent
	url, err := user.uploadQR(code)
	if err != nil {
		ce.ZLog.Err(err).Msg("Failed to upload QR code")
		content = event.MessageEventContent{
			MsgType: event.MsgNotice,
			Body:    fmt.Sprintf("Failed to upload QR code: %v", err),
		}
	} else {
		content = event.MessageEventContent{
			MsgType: event.MsgImage,
			Body:    code,
			URL:     url.CUString(),
		}
	}
	return user.sendQREdit(ce, &content, prevEvent)
}

func (user *User) uploadQR(code string) (id.ContentURI, error) {
	qrCode, err := qrcode.Encode(code, qrcode.Low, 256)
	if err != nil {
		return id.ContentURI{}, err
	}
	resp, err := user.bridge.Bot.UploadBytes(qrCode, "image/png")
	if err != nil {
		return id.ContentURI{}, err
	}
	return resp.ContentURI, nil
}

var cmdLogout = &commands.FullHandler{
	Func: wrapCommand(fnLogout),
	Name: "logout",
	Help: commands.HelpMeta{
		Section:     commands.HelpSectionAuth,
		Description: "Unpair the bridge and delete session information.",
	},
}

func fnLogout(ce *WrappedCommandEvent) {
	if ce.User.Session == nil && ce.User.Client == nil {
		ce.Reply("You're not logged in")
		return
	}
	logoutOK := ce.User.Logout(status.BridgeState{StateEvent: status.StateLoggedOut}, true)
	if logoutOK {
		ce.Reply("Successfully logged out")
	} else {
		ce.Reply("Session information removed, but unpairing may not have succeeded")
	}
}

var cmdDeleteSession = &commands.FullHandler{
	Func: wrapCommand(fnDeleteSession),
	Name: "delete-session",
	Help: commands.HelpMeta{
		Section:     commands.HelpSectionAuth,
		Description: "Delete session information and disconnect from Google Messages without sending a logout request.",
	},
}

func fnDeleteSession(ce *WrappedCommandEvent) {
	if ce.User.Session == nil && ce.User.Client == nil {
		ce.Reply("Nothing to purge: no session information stored and no active connection.")
		return
	}
	ce.User.Logout(status.BridgeState{StateEvent: status.StateLoggedOut}, false)
	ce.Reply("Session information purged")
}

var cmdReconnect = &commands.FullHandler{
	Func: wrapCommand(fnReconnect),
	Name: "reconnect",
	Help: commands.HelpMeta{
		Section:     HelpSectionConnectionManagement,
		Description: "Reconnect to Google Messages.",
	},
}

func fnReconnect(ce *WrappedCommandEvent) {
	if ce.User.Client == nil {
		if ce.User.Session == nil {
			ce.Reply("You're not logged into Google Messages. Please log in first.")
		} else {
			ce.User.Connect()
			ce.Reply("Started connecting to Google Messages")
		}
	} else {
		ce.User.DeleteConnection()
		ce.User.BridgeState.Send(status.BridgeState{StateEvent: status.StateTransientDisconnect, Error: GMNotConnected})
		ce.User.Connect()
		ce.Reply("Restarted connection to Google Messages")
	}
}

var cmdDisconnect = &commands.FullHandler{
	Func: wrapCommand(fnDisconnect),
	Name: "disconnect",
	Help: commands.HelpMeta{
		Section:     HelpSectionConnectionManagement,
		Description: "Disconnect from Google Messages (without logging out).",
	},
}

func fnDisconnect(ce *WrappedCommandEvent) {
	if ce.User.Client == nil {
		ce.Reply("You don't have a Google Messages connection.")
		return
	}
	ce.User.DeleteConnection()
	ce.Reply("Successfully disconnected. Use the `reconnect` command to reconnect.")
	ce.User.BridgeState.Send(status.BridgeState{StateEvent: status.StateBadCredentials, Error: GMNotConnected})
}

var cmdSetActive = &commands.FullHandler{
	Func: wrapCommand(fnSetActive),
	Name: "set-active",
	Help: commands.HelpMeta{
		Section:     HelpSectionConnectionManagement,
		Description: "Set the bridge as the active browser (if you opened Google Messages in a real browser)",
	},
}

func fnSetActive(ce *WrappedCommandEvent) {
	if ce.User.Client == nil {
		ce.Reply("You don't have a Google Messages connection.")
		return
	}
	err := ce.User.Client.SetActiveSession()
	if err != nil {
		ce.Reply("Failed to set active session: %v", err)
	} else {
		ce.Reply("Set bridge as active session")
	}
}

var cmdPing = &commands.FullHandler{
	Func: wrapCommand(fnPing),
	Name: "ping",
	Help: commands.HelpMeta{
		Section:     HelpSectionConnectionManagement,
		Description: "Check your connection to Google Messages.",
	},
}

func fnPing(ce *WrappedCommandEvent) {
	if ce.User.Session == nil {
		if ce.User.Client != nil {
			ce.Reply("Connected to Google Messages, but not logged in.")
		} else {
			ce.Reply("You're not logged into Google Messages.")
		}
	} else if ce.User.Client == nil || !ce.User.Client.IsConnected() {
		ce.Reply("Linked to %s, but not connected to Google Messages.", ce.User.PhoneID)
	} else if ce.User.longPollingError != nil {
		ce.Reply("Linked to %s, but long polling is erroring (%v)", ce.User.PhoneID, ce.User.longPollingError)
	} else if ce.User.browserInactiveType != "" {
		ce.Reply("Linked to %s, but not active, use `set-active` to reconnect", ce.User.PhoneID)
	} else {
		modifiers := make([]string, 0, 3)
		if ce.User.batteryLow {
			modifiers = append(modifiers, "battery low")
		}
		if ce.User.mobileData {
			modifiers = append(modifiers, "using mobile data")
		}
		if !ce.User.phoneResponding {
			modifiers = append(modifiers, "phone not responding")
		}
		var modifierStr string
		if len(modifiers) > 0 {
			modifierStr = fmt.Sprintf(" (warnings: %s)", strings.Join(modifiers, ", "))
		}
		ce.Reply("Linked to %s and active as primary browser%s", ce.User.PhoneID, modifierStr)
	}
}

var cmdPM = &commands.FullHandler{
	Func: wrapCommand(fnPM),
	Name: "pm",
	Help: commands.HelpMeta{
		Section:     HelpSectionPortalManagement,
		Description: "Create a chat on Google Messages",
		Args:        "<phone numbers...>",
	},
	RequiresLogin: true,
}

func fnPM(ce *WrappedCommandEvent) {
	var reqData gmproto.GetOrCreateConversationRequest
	reqData.Numbers = make([]*gmproto.ContactNumber, 0, len(ce.Args))
	for _, number := range ce.Args {
		number = strings.TrimSpace(number)
		if number == "" {
			continue
		}
		reqData.Numbers = append(reqData.Numbers, &gmproto.ContactNumber{
			// This should maybe sometimes be 7
			MysteriousInt: 2,
			Number:        number,
			Number2:       number,
		})
	}
	resp, err := ce.User.Client.GetOrCreateConversation(&reqData)
	if err != nil {
		ce.ZLog.Err(err).Msg("Failed to start chat")
		ce.Reply("Failed to start chat: request failed")
	} else if len(reqData.Numbers) > 1 && resp.GetStatus() == gmproto.GetOrCreateConversationResponse_CREATE_RCS {
		ce.Reply("All recipients are on RCS, but creating RCS groups via this command is not yet supported.")
	} else if resp.GetConversation() == nil {
		ce.ZLog.Warn().
			Int("req_number_count", len(reqData.Numbers)).
			Str("status", resp.GetStatus().String()).
			Msg("No conversation in chat create response")
		ce.Reply("Failed to start chat: no conversation in response")
	} else if portal := ce.User.GetPortalByID(resp.Conversation.ConversationID); portal.MXID != "" {
		ce.Reply("Chat already exists at [%s](https://matrix.to/#/%s)", portal.MXID, portal.MXID)
	} else if err = portal.CreateMatrixRoom(ce.User, resp.Conversation, false); err != nil {
		ce.ZLog.Err(err).Msg("Failed to create matrix room")
		ce.Reply("Failed to create portal room for conversation")
	} else {
		ce.Reply("Chat created: [%s](https://matrix.to/#/%s)", portal.MXID, portal.MXID)
	}
}

var cmdDeletePortal = &commands.FullHandler{
	Func: wrapCommand(fnDeletePortal),
	Name: "delete-portal",
	Help: commands.HelpMeta{
		Section:     HelpSectionPortalManagement,
		Description: "Delete the current portal. If the portal is used by other people, this is limited to bridge admins.",
	},
	RequiresPortal: true,
}

func fnDeletePortal(ce *WrappedCommandEvent) {
	if !ce.User.Admin && ce.Portal.Receiver != ce.User.RowID {
		ce.Reply("Only bridge admins can delete other users' portals")
		return
	}

	ce.ZLog.Info().Str("conversation_id", ce.Portal.ID).Msg("Deleting portal from command")
	ce.Portal.Delete()
	ce.Portal.Cleanup()
}

var cmdDeleteAllPortals = &commands.FullHandler{
	Func: wrapCommand(fnDeleteAllPortals),
	Name: "delete-all-portals",
	Help: commands.HelpMeta{
		Section:     HelpSectionPortalManagement,
		Description: "Delete all portals.",
	},
}

func fnDeleteAllPortals(ce *WrappedCommandEvent) {
	portals := ce.Bridge.GetAllPortalsForUser(ce.User.RowID)
	if len(portals) == 0 {
		ce.Reply("Didn't find any portals to delete")
		return
	}

	leave := func(portal *Portal) {
		if len(portal.MXID) > 0 {
			_, _ = portal.MainIntent().KickUser(portal.MXID, &mautrix.ReqKickUser{
				Reason: "Deleting portal",
				UserID: ce.User.MXID,
			})
		}
	}
	intent := ce.User.DoublePuppetIntent
	if intent != nil {
		leave = func(portal *Portal) {
			if len(portal.MXID) > 0 {
				_, _ = intent.LeaveRoom(portal.MXID)
				_, _ = intent.ForgetRoom(portal.MXID)
			}
		}
	}
	roomYeeting := ce.Bridge.SpecVersions.Supports(mautrix.BeeperFeatureRoomYeeting)
	if roomYeeting {
		leave = func(portal *Portal) {
			portal.Cleanup()
		}
	}
	ce.Reply("Found %d portals, deleting...", len(portals))
	for _, portal := range portals {
		portal.Delete()
		leave(portal)
	}
	if !roomYeeting {
		ce.Reply("Finished deleting portal info. Now cleaning up rooms in background.")
		go func() {
			for _, portal := range portals {
				portal.Cleanup()
			}
			ce.Reply("Finished background cleanup of deleted portal rooms.")
		}()
	} else {
		ce.Reply("Finished deleting portals.")
	}
}