package appservice

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

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

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

type Config struct {
	HttpBindAddr string
	Server       string
	DbType       string
	DbPath       string
	MatrixDomain string
}

var registration *mxlib.Registration
var config *Config

var mx *mxlib.Client

func Start(r *mxlib.Registration, c *Config) (chan error, error) {
	registration = r
	config = c

	mx = mxlib.NewClient(c.Server, r.AsToken)

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

	err = mx.RegisterUser(registration.SenderLocalpart)
	if mxe, ok := err.(*mxlib.MxError); !ok || mxe.ErrCode != "M_USER_IN_USE" {
		return nil, err
	}
	err = mx.ProfileDisplayname(ezbrMxId(), fmt.Sprintf("Easybridge (%s)", EASYBRIDGE_SYSTEM_PROTOCOL))
	if err != nil {
		return nil, err
	}

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

	errch := make(chan error)
	go func() {
		log.Printf("Starting HTTP server on %s", config.HttpBindAddr)
		err := http.ListenAndServe(config.HttpBindAddr, checkTokenAndLog(router))
		if err != nil {
			errch <- err
		}
	}()

	return errch, 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, r.URL)
		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("Got transaction %#v\n", txn)

		for i := range txn.Events {
			ev := &txn.Events[i]
			if strings.HasPrefix(ev.Sender, "@"+registration.SenderLocalpart) {
				// 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 (%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" {
		ev := &connector.Event{
			Type: connector.EVENT_MESSAGE,
			Text: e.Content["body"].(string),
		}
		typ := e.Content["msgtype"].(string)
		if typ == "m.emote" {
			ev.Type = connector.EVENT_MESSAGE
		}

		if pm_room := dbIsPmRoom(e.RoomId); pm_room != nil {
			if pm_room.Protocol == EASYBRIDGE_SYSTEM_PROTOCOL {
				handleSystemMessage(e.Sender, e.Content["body"].(string))
				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
				return acct.Conn.Send(ev)
			}
		} 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 {
				ev.Author = acct.Conn.User()
				ev.Room = room.RoomID
				return acct.Conn.Send(ev)
			} 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.member" {
		ms := e.Content["membership"].(string)
		if ms == "leave" {
			if pm_room := dbIsPmRoom(e.RoomId); pm_room != nil {
				// If leaving a PM room, we must delete it
				them_mx := userMxId(pm_room.Protocol, pm_room.UserID)
				mx.RoomLeaveAs(e.RoomId, them_mx)
				db.Delete(pm_room)
				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)
					return nil
					// TODO: manage autojoin list, remove this room
				} 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" {
		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.Content["topic"].(string),
				})
			} 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)
	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, "- query <protocol or account> <user id>: open private buffer to contact")
	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":
		var account *Account
		if accts, ok := registeredAccounts[mxid]; ok {
			for name, acct := range accts {
				if name == cmd[1] || acct.Protocol == cmd[1] {
					account = acct
					break
				}
			}
		}
		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":
		var account *Account
		if accts, ok := registeredAccounts[mxid]; ok {
			for name, acct := range accts {
				if name == cmd[1] || acct.Protocol == cmd[1] {
					account = acct
					break
				}
			}
		}
		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])
		}
	default:
		ezbrSystemSend(mxid, "Unrecognized command. Type `help` if you need some help!")
	}
}