package rpc

import (
	"context"
	"fmt"
	"log"
	"net/http"
	"time"

	"forge.cadoles.com/Pyxis/orion/emlid"
	"forge.cadoles.com/Pyxis/orion/emlid/updater"
	"forge.cadoles.com/Pyxis/orion/openwrt"
	"github.com/gorilla/rpc"
	"github.com/gorilla/rpc/json"
	"github.com/pkg/errors"
)

// OrionService is the JSON-RPC API
type OrionService struct {
	UCI *openwrt.UCI
}

// NewOrionService create a new OrionService !
func NewOrionService() *OrionService {
	uci := openwrt.NewUCI()
	return &OrionService{
		UCI: uci,
	}
}

// UCIArgs argument structure for exported method OwrtListWifiDevices
type UCIArgs struct{}

// UCIResponse is the response structure for exposed method OwrtListWifiDevices
type UCIResponse struct {
	Devices []map[string]string
}

// OwrtListWifiDevices offers an RPC Method to list Wifi nics in a OpenWRT device.
func (o *OrionService) OwrtListWifiDevices(r *http.Request, args *UCIArgs, reply *UCIResponse) error {
	o.UCI.LoadWirelessConf()
	devs := o.UCI.GetWifiDevices()
	reply.Devices = devs
	return nil
}

// ListIfaceArgs argument structure for exported method OwrtListWifiDevices
type ListIfaceArgs struct{}

// ListIfaceResponse is the response structure for exposed method OwrtListWifiDevices
type ListIfaceResponse struct {
	Interfaces []*openwrt.UCIWirelessInterface
}

// OwrtListWifiInterfaces offers an RPC Method to list wifi interfaces in a OpenWRT device.
func (o *OrionService) OwrtListWifiInterfaces(r *http.Request, args *ListIfaceArgs, reply *ListIfaceResponse) error {
	o.UCI.LoadWirelessConf()
	reply.Interfaces = o.UCI.GetWifiIfaces()
	return nil
}

// CreateIfaceArgs argument structure for exported method OwrtCreateWifiInterface
type CreateIfaceArgs struct {
	Iface   *openwrt.UCIWirelessInterface
	Cleanup bool
}

// CreateIfaceResponse argument structure for exported method OwrtCreateWifiInterface
type CreateIfaceResponse struct {
	Iface  *openwrt.UCIWirelessInterface
	Errors []*openwrt.Action
}

// OwrtCreateWifiInterface Create a WifiInterface in openwrt
func (o *OrionService) OwrtCreateWifiInterface(r *http.Request,
	args *CreateIfaceArgs,
	reply *CreateIfaceResponse) error {
	reply.Iface = nil

	if args.Cleanup {
		o.UCI.LoadWirelessConf()
		w := o.UCI.GetWifiIfaces()
		for _, iface := range w {
			iface.Delete(o.UCI)
		}
		o.UCI.Commit()
		o.UCI.Reload()
		time.Sleep(3 * time.Second)
	}

	o.UCI.LoadWirelessConf()
	create := args.Iface.Create(o.UCI)
	if create.ReturnCode != 0 {
		reply.Errors = append(reply.Errors, create)
		return nil
	}
	create = args.Iface.SysAdd(o.UCI)
	if create.ReturnCode == 233 {
		delete := args.Iface.SysDel(o.UCI)
		if delete.ReturnCode != 0 {
			reply.Errors = append(reply.Errors, delete)
			return nil
		}
		create = args.Iface.SysAdd(o.UCI)
		if create.ReturnCode != 0 {
			reply.Errors = append(reply.Errors, create)
			return nil
		}
	}
	create = args.Iface.Up(o.UCI)
	if create.ReturnCode != 0 {
		reply.Errors = append(reply.Errors, create)
		return nil
	}
	create = args.Iface.Save(o.UCI)
	if create.ReturnCode != 0 {
		reply.Errors = append(reply.Errors, create)
		return nil
	}
	reply.Iface = args.Iface
	return nil
}

// ConnectIfaceArgs argument structure for exported method OwrtCreateWifiInterface
type ConnectIfaceArgs struct {
	Iface *openwrt.UCIWirelessInterface
	SSID  string
	Key   string
}

// ConnectIfaceResponse argument structure for exported method OwrtCreateWifiInterface
type ConnectIfaceResponse struct {
	status int
	Errors []string
}

// OwrtConnectWifiInterface connects a given Wifi Interface to a given SSID
func (o *OrionService) OwrtConnectWifiInterface(r *http.Request,
	args *ConnectIfaceArgs,
	reply *ConnectIfaceResponse) error {
	o.UCI.LoadWirelessConf()
	iface := o.UCI.GetWifiIface(args.Iface.Index)
	cells := iface.Scan()

	for _, cell := range cells {
		if cell.Ssid == args.SSID {
			cn := iface.Connect(o.UCI, cell, args.Key)
			if cn.ReturnCode != 0 {
				reply.status = cn.ReturnCode
				reply.Errors = append(reply.Errors, cn.Stdout, cn.Stderr, cn.Command)
			}
			reply.status = 0
			return nil
		}
	}
	reply.status = 1
	msg := fmt.Sprintf("Wifi Cell with SSID %s is not available !", args.SSID)
	reply.Errors = append(reply.Errors, msg)
	return nil
}

// OrionBox describe an fresh Orion box (base or rover)
type OrionBox struct {
	Address    string
	NewAddress string
	SSID       string
	Security   string
	WifiKey    string
}

// OrionServer describe the Orion master server
type OrionServer struct {
	Address     string
	SSID        string
	Security    string
	WifiKey     string
	ClientIface *openwrt.UCIWirelessInterface
}

// UpdateOrionBoxArgs argument structure for exported method OwrtCreateWifiInterface
type UpdateOrionBoxArgs struct {
	Box    *OrionBox
	Server *OrionServer
}

// UpdateOrionBoxResponse argument structure for exported method OwrtCreateWifiInterface
type UpdateOrionBoxResponse struct {
	IP      string
	Netmask string
	Synced  bool
	Version string
	Status  *updater.UpdateStatus
	Results *updater.TestResults
}

// Connect wifi interface to a Orion box wifi hotspot!
func (o *OrionService) connectBox(box *OrionBox, server *OrionServer) error {
	o.UCI.LoadWirelessConf()
	if server == nil {
		return fmt.Errorf("Server definition is empty")
	}

	if box == nil {
		return fmt.Errorf("Box definitioni is emtpy")
	}
	iface := server.ClientIface
	cells := iface.Scan()
	for _, cell := range cells {
		if cell.Ssid == box.SSID {
			cn := iface.Connect(o.UCI, cell, box.WifiKey)
			if cn.ReturnCode != 0 {
				return fmt.Errorf("%s\n%s", cn.Stdout, cn.Stderr)
			}
			dhcli := openwrt.NewDhcpClient(iface.SysDevName)
			dhres := dhcli.AskForIP()
			if dhres.CmdRes.ReturnCode != 0 {
				return fmt.Errorf("%s\n%s", cn.Stdout, cn.Stderr)
			}
			re := o.UCI.Reload()
			if re.ReturnCode != 0 {
				return fmt.Errorf("%s\n%s", re.Stdout, re.Stderr)
			}
			return nil
		}
	}
	return fmt.Errorf("Wifi cell with SSID %s is not available", box.SSID)
}

func (o *OrionService) discoverService() ([]emlid.Service, error) {
	return emlid.Discover(20 * time.Second)
}

// setupMasterWifi connects to the box, add wifi network and join it !
func (o *OrionService) setupMasterWifi(rqContext context.Context, box *OrionBox, server *OrionServer) error {
	if err := o.connectBox(box, server); err != nil {
		return errors.Wrap(err, "Connect to box failed")
	}

	if server.Security == "" {
		server.Security = string(updater.SecurityWPAPSK)
	}

	var boxCli *updater.Client
	service, err := o.discoverService()
	if len(service) == 0 {
		boxCli = updater.NewClient(
			emlid.WithEndpoint(box.Address, 80),
		)
	} else if err != nil {
		boxCli = updater.NewClient(
			emlid.WithService(service[0]),
		)
	} else {
		return err
	}

	if err := boxCli.Connect(); err != nil {
		return errors.Wrap(err, "Connecting to Box failed")
	}
	defer boxCli.Close()

	ctx, testResultsCancel := context.WithTimeout(rqContext, 55*time.Second)
	defer testResultsCancel()
	_, err = boxCli.TestResults(ctx)
	if err != nil {
		return errors.Wrap(err, "Minimal test failed")
	}

	ctx, addWifiCancel := context.WithTimeout(rqContext, 55*time.Second)
	defer addWifiCancel()

	done, err := boxCli.AddWifiNetwork(ctx, server.SSID, updater.WifiSecurity(server.Security), server.WifiKey)
	if err != nil {
		return errors.Wrap(err, "AddWifiNetworkFailed")
	}

	if !done {
		return fmt.Errorf("Impossible to add wifi network")
	}

	ctx, joinWifiCancel := context.WithTimeout(ctx, 55*time.Second)
	defer joinWifiCancel()

	if err := boxCli.JoinWifiNetwork(ctx, server.SSID, true); err != nil {
		return errors.Wrap(err, "Time sync failed")
	}
	return nil
}

// updateAndReboot connects to the box with the New adress and run basic tests on version dans updates
func (o *OrionService) updateAndReboot(rqContext context.Context, box *OrionBox, server *OrionServer, reply *UpdateOrionBoxResponse) error {
	var boxCli *updater.Client
	service, err := o.discoverService()
	if err != nil {
		boxCli = updater.NewClient(
			emlid.WithService(service[0]),
		)
	} else {
		boxCli = updater.NewClient(
			emlid.WithEndpoint(box.NewAddress, 80),
		)
	}

	if err := boxCli.Connect(); err != nil {
		if err := boxCli.Connect(); err != nil {
			return errors.Wrap(err, "Connecting to Box on master wifi network failed")
		}
	}
	defer boxCli.Close()

	ctx, timeSyncedCancel := context.WithTimeout(rqContext, 55*time.Second)
	defer timeSyncedCancel()
	synced, err := boxCli.TimeSynced(ctx)
	if err != nil {
		return errors.Wrap(err, "Time sync failed")
	}
	reply.Synced = synced

	ctx, reachviewVersionCancel := context.WithTimeout(rqContext, 55*time.Second)
	defer reachviewVersionCancel()
	version, err := boxCli.ReachViewVersion(ctx)
	if err != nil {
		return err
	}
	reply.Version = version

	ctx, updateCancel := context.WithTimeout(rqContext, 55*time.Second)
	defer updateCancel()
	status, err := boxCli.Update(ctx)
	if err != nil {
		return errors.Wrap(err, "System update failed")
	}
	reply.Status = status

	if err := boxCli.SkipUpdate(); err != nil {
		log.Fatalf("error while skipping update: %s", err)
	}

	ctx, rebootCancel := context.WithTimeout(rqContext, 55*time.Second)
	defer rebootCancel()
	return boxCli.RebootNow(ctx, true)

}

// UpdateOrionBox starts provisionning process for an Orion box (base or rover)
func (o *OrionService) UpdateOrionBox(r *http.Request,
	args *UpdateOrionBoxArgs,
	reply *UpdateOrionBoxResponse) error {

	if err := o.setupMasterWifi(r.Context(), args.Box, args.Server); err != nil {
		return err
	}

	return o.updateAndReboot(r.Context(), args.Box, args.Server, reply)
}

// NewServer returns a new configured JSON-RPC server
func NewServer() *rpc.Server {
	server := rpc.NewServer()
	server.RegisterCodec(json.NewCodec(), "application/json")
	if err := server.RegisterService(NewOrionService(), "Orion"); err != nil {
		panic(err)
	}
	return server
}