package main

import (
	"context"
	"encoding/json"
	"fmt"
	"net"
	"net/http"
	"os"
	"strings"

	"github.com/gorilla/mux"
	log "github.com/sirupsen/logrus"

	"git.deuxfleurs.fr/Deuxfleurs/easybridge/connector"
	"git.deuxfleurs.fr/Deuxfleurs/easybridge/mxlib"
)

var mx *mxlib.Client

func StartAppService(errch chan error, ctx context.Context) (*http.Server, error) {
	mx = mxlib.NewClient(config.Server, registration.AsToken)

	err := InitDb()
	if err != nil {
		return nil, err
	}

	if dbKvGet("ezbr_initialized") != "yes" {
		err = mx.RegisterUser(registration.SenderLocalpart)
		if mxe, ok := err.(*mxlib.MxError); !ok || mxe.ErrCode != "M_USER_IN_USE" {
			return nil, err
		}

		_, st := os.Stat(config.AvatarFile)
		if !os.IsNotExist(st) {
			err = mx.ProfileAvatar(ezbrMxId(), &connector.FileMediaObject{
				Path: config.AvatarFile,
			})
			if err != nil {
				return nil, err
			}
		}

		err = mx.ProfileDisplayname(ezbrMxId(), fmt.Sprintf("Easybridge (%s)", EASYBRIDGE_SYSTEM_PROTOCOL))
		if err != nil {
			return nil, err
		}

		dbKvPut("ezbr_initialized", "yes")
	}

	router := mux.NewRouter()
	router.HandleFunc("/_matrix/app/v1/transactions/{txnId}", handleTxn)
	router.HandleFunc("/transactions/{txnId}", handleTxn)

	log.Printf("Starting HTTP server on %s", config.ASBindAddr)
	http_server := &http.Server{
		Addr:    config.ASBindAddr,
		Handler: checkTokenAndLog(router),
		BaseContext: func(net.Listener) context.Context {
			return ctx
		},
	}
	go func() {
		err := http_server.ListenAndServe()
		if err != nil {
			errch <- err
		}
	}()

	// Notify users that Easybridge has restarted
	go func() {
		var users []DbAccountConfig
		db.Model(&DbAccountConfig{}).Select("mx_user_id").Group("mx_user_id").Find(&users)
		for _, u := range users {
			ezbrSystemSendf(u.MxUserID,
				"Easybridge has restarted, please visit %s or open configuration widget to reconnect to your accounts.",
				config.WebURL)
		}
	}()

	return http_server, nil
}

func checkTokenAndLog(handler http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		r.ParseForm()
		if strings.Join(r.Form["access_token"], "") != registration.HsToken {
			http.Error(w, "Wrong or no token provided", http.StatusUnauthorized)
			return
		}

		log.Printf("%s %s %s\n", r.RemoteAddr, r.Method, strings.Split(r.URL.String(), "?")[0])
		handler.ServeHTTP(w, r)
	})
}

func handleTxn(w http.ResponseWriter, r *http.Request) {
	if r.Method == "PUT" {
		var txn mxlib.Transaction
		err := json.NewDecoder(r.Body).Decode(&txn)
		if err != nil {
			http.Error(w, err.Error(), http.StatusBadRequest)
			log.Warnf("JSON decode error: %s\n", err)
			return
		}

		log.Debugf("Processing transaction %s (%d events)", mux.Vars(r)["txnId"], len(txn.Events))
		log.Tracef("Transaction content: %#v\n", txn)

		for i := range txn.Events {
			ev := &txn.Events[i]
			if isBridgedIdentifier(ev.Sender) {
				// Don't do anything with ezbr events that come back to us
				continue
			}
			err = handleTxnEvent(ev)
			if err != nil {
				ezbrSystemSend(ev.Sender, fmt.Sprintf("Could not process %s (from %s): %s", ev.Type, ev.Sender, err))
			}
		}

		fmt.Fprintf(w, "{}\n")
	} else {
		http.Error(w, "Expected PUT request", http.StatusBadRequest)
	}
}

func handleTxnEvent(e *mxlib.Event) error {
	if e.Type == "m.room.message" {
		e_body, ok := e.Content["body"].(string)
		if !ok {
			return fmt.Errorf("Invalid m.room.message event, body is not defined: %#v", e)
		}
		typ, ok := e.Content["msgtype"].(string)
		if !ok {
			return fmt.Errorf("Invalid m.room.message event, msgtype is not defined: %#v", e)
		}

		ev := &connector.Event{
			Type: connector.EVENT_MESSAGE,
			Text: e_body,
			Id:   e.EventId,
		}

		if typ == "m.emote" {
			ev.Type = connector.EVENT_MESSAGE
		} else if typ == "m.file" || typ == "m.image" {
			ev.Text = ""
			ev.Attachments = []connector.SMediaObject{
				connector.SMediaObject{mx.ParseMediaInfo(e.Content)},
			}
		}

		if pm_room := dbIsPmRoom(e.RoomId); pm_room != nil {
			if pm_room.Protocol == EASYBRIDGE_SYSTEM_PROTOCOL {
				handleSystemMessage(e.Sender, e_body)
				return nil
			}
			// If this is a private message room
			acct := FindAccount(pm_room.MxUserID, pm_room.AccountName)
			if acct == nil {
				return fmt.Errorf("Not connected to %s", pm_room.AccountName)
			} else if e.Sender == pm_room.MxUserID {
				ev.Author = acct.Conn.User()
				ev.Recipient = pm_room.UserID
				_, err := acct.Conn.Send(ev)
				return err
			}
		} else if room := dbIsPublicRoom(e.RoomId); room != nil {
			// If this is a regular room
			acct := FindJoinedAccount(e.Sender, room.Protocol, room.RoomID)
			if acct == nil {
				mx.RoomKick(e.RoomId, e.Sender, fmt.Sprintf("Not present in %s on %s, please talk with Easybridge to rejoin", room.RoomID, room.Protocol))
				return fmt.Errorf("not joined %s on %s", room.RoomID, room.Protocol)
			} else {
				ev.Author = acct.Conn.User()
				ev.Room = room.RoomID

				// use room id as lock slot key, see account.go in eventInternal
				dbLockSlot(e.RoomId)
				defer dbUnlockSlot(e.RoomId)

				created_ev_id, err := acct.Conn.Send(ev)
				if err == nil && created_ev_id != "" {
					cache_key := fmt.Sprintf("%s/event_seen/%s/%s",
						room.Protocol, e.RoomId, created_ev_id)
					dbKvPutLocked(cache_key, "yes")
				}
				return err
			}
		} else {
			return fmt.Errorf("Room not bridged")
		}
	} else if e.Type == "m.room.member" {
		ms, ok := e.Content["membership"].(string)
		if !ok {
			return fmt.Errorf("Invalid m.room.member event, membership is not defined: %#v", e)
		}

		if ms == "leave" {
			if pm_room := dbIsPmRoom(e.RoomId); pm_room != nil {
				// If user leaves a PM room, we must drop it
				dbDeletePmRoom(pm_room)
				them_mx, err := dbGetMxUser(pm_room.Protocol, pm_room.UserID)
				if err != nil {
					return err
				}
				mx.RoomLeaveAs(e.RoomId, them_mx)
				return nil
			} else if room := dbIsPublicRoom(e.RoomId); room != nil {
				// If leaving a public room, leave from server as well
				acct := FindJoinedAccount(e.Sender, room.Protocol, room.RoomID)
				if acct != nil {
					acct.Conn.Leave(room.RoomID)
					acct.delAutojoin(room.RoomID)
					return nil
				} else {
					mx.RoomKick(e.RoomId, e.Sender, fmt.Sprintf("Not present in %s on %s, please talk with Easybridge to rejoin", room.RoomID, room.Protocol))
					return fmt.Errorf("not joined %s on %s", room.RoomID, room.Protocol)
				}
			} else {
				return fmt.Errorf("Room not bridged")
			}
		}
	} else if e.Type == "m.room.topic" {
		e_topic, ok := e.Content["topic"].(string)
		if !ok {
			return fmt.Errorf("Invalid m.room.topic event, topic is not defined: %#v", e)
		}

		if room := dbIsPublicRoom(e.RoomId); room != nil {
			acct := FindJoinedAccount(e.Sender, room.Protocol, room.RoomID)
			if acct != nil {
				return acct.Conn.SetRoomInfo(room.RoomID, &connector.RoomInfo{
					Topic: e_topic,
				})
			} else {
				return fmt.Errorf("Could not find room account for %s %s %s", e.Sender, room.Protocol, room.RoomID)
			}
		}
	}
	return nil
}

func handleSystemMessage(mxid string, msg string) {
	cmd := strings.Fields(msg)
	if len(cmd) == 0 {
		return
	}

	switch cmd[0] {
	case "help":
		ezbrSystemSend(mxid, "Welcome to Easybridge! Here is a list of available commands:")
		ezbrSystemSend(mxid, "- help: request help")
		ezbrSystemSend(mxid, "- list: list accounts")
		ezbrSystemSend(mxid, "- accounts: list accounts")
		ezbrSystemSend(mxid, "- join <protocol or account> <room id>: join public chat room")
		ezbrSystemSend(mxid, "- talk <protocol or account> <user id>: open private conversation to contact")
		ezbrSystemSend(mxid, "- search <protocol or account> <name>: search for users by name")
		ezbrSystemSend(mxid, "- cmd <protocol or account> <command>: send special command to account")
	case "list", "account", "accounts":
		one := false
		if accts, ok := registeredAccounts[mxid]; ok {
			for name, acct := range accts {
				one = true
				ezbrSystemSendf(mxid, "- %s (%s)", name, acct.Protocol)
			}
		}
		if !one {
			ezbrSystemSendf(mxid, "No account currently configured")
		}
	case "join":
		if len(cmd) != 3 {
			ezbrSystemSendf(mxid, "Usage: %s <protocol or account> <room id>", cmd[0])
			return
		}

		account := findAccount(mxid, cmd[1])
		if account != nil {
			err := account.Conn.Join(connector.RoomID(cmd[2]))
			if err != nil {
				ezbrSystemSendf(mxid, "%s", err)
			}
		} else {
			ezbrSystemSendf(mxid, "No account with name or using protocol %s", cmd[1])
		}
	case "query", "talk":
		if len(cmd) != 3 {
			ezbrSystemSendf(mxid, "Usage: %s <protocol or account> <user id>", cmd[0])
			return
		}

		account := findAccount(mxid, cmd[1])
		if account != nil {
			quser := connector.UserID(cmd[2])
			err := account.Conn.Invite(quser, connector.RoomID(""))
			if err != nil {
				ezbrSystemSendf(mxid, "%s", err)
				return
			}

			quser_mxid, err := dbGetMxUser(account.Protocol, quser)
			if err != nil {
				ezbrSystemSendf(mxid, "%s", err)
				return
			}
			_, err = dbGetMxPmRoom(account.Protocol, quser, quser_mxid, mxid, account.AccountName)
			if err != nil {
				ezbrSystemSendf(mxid, "%s", err)
			}
		} else {
			ezbrSystemSendf(mxid, "No account with name or using protocol %s", cmd[1])
		}
	case "search":
		if len(cmd) < 3 {
			ezbrSystemSendf(mxid, "Usage: %s <protocol or account> <name>", cmd[0])
			return
		}

		account := findAccount(mxid, cmd[1])
		if account != nil {
			rep, err := account.Conn.SearchForUsers(strings.Join(cmd[2:], " "))
			if err != nil {
				ezbrSystemSendf(mxid, "Search error: %s", err)
			} else {
				ezbrSystemSendf(mxid, "%d users found", len(rep))
				for _, user := range rep {
					ezbrSystemSendf(mxid, "- %s (%s)", user.DisplayName, user.ID)
				}
			}
		} else {
			ezbrSystemSendf(mxid, "No account with name or using protocol %s", cmd[1])
		}
	case "cmd":
		if len(cmd) < 3 {
			ezbrSystemSendf(mxid, "Usage: %s <protocol or account> <name>", cmd[0])
			return
		}

		account := findAccount(mxid, cmd[1])
		if account != nil {
			account.Conn.UserCommand(strings.Join(cmd[2:], " "))
		} else {
			ezbrSystemSendf(mxid, "No account with name or using protocol %s", cmd[1])
		}
	default:
		ezbrSystemSend(mxid, "Unrecognized command. Type `help` if you need some help!")
	}
}

func findAccount(mxid string, q string) *Account {
	if accts, ok := registeredAccounts[mxid]; ok {
		for name, acct := range accts {
			if strings.EqualFold(name, q) || strings.EqualFold(acct.Protocol, q) {
				return acct
			}
		}
	}
	return nil
}