package main

import (
	"context"
	"encoding/json"
	"fmt"
	"net"
	"net/http"
	_ "net/http/pprof"
	"os"
	"path/filepath"
	"strings"
	"time"

	"github.com/google/uuid"
	"github.com/gorilla/mux"
	"github.com/urfave/cli/v2"
	"go.opencensus.io/stats"
	"go.opencensus.io/tag"
	"golang.org/x/xerrors"

	"github.com/filecoin-project/go-jsonrpc/auth"
	"github.com/filecoin-project/lotus/api"
	"github.com/filecoin-project/lotus/build"
	lcli "github.com/filecoin-project/lotus/cli"
	"github.com/filecoin-project/lotus/lib/harmony/harmonydb"
	"github.com/filecoin-project/lotus/lib/ulimit"
	"github.com/filecoin-project/lotus/metrics"
	"github.com/filecoin-project/lotus/node"
	"github.com/filecoin-project/lotus/node/config"
	"github.com/filecoin-project/lotus/node/modules/dtypes"
	"github.com/filecoin-project/lotus/node/repo"
	"github.com/filecoin-project/lotus/storage/paths"
	"github.com/filecoin-project/lotus/storage/sealer/storiface"
)

var runCmd = &cli.Command{
	Name:  "run",
	Usage: "Start a lotus provider process",
	Flags: []cli.Flag{
		&cli.StringFlag{
			Name:  "provider-api",
			Usage: "2345",
		},
		&cli.BoolFlag{
			Name:  "enable-gpu-proving",
			Usage: "enable use of GPU for mining operations",
			Value: true,
		},
		&cli.BoolFlag{
			Name:  "nosync",
			Usage: "don't check full-node sync status",
		},
		&cli.BoolFlag{
			Name:  "manage-fdlimit",
			Usage: "manage open file limit",
			Value: true,
		},
		&cli.StringFlag{
			Name:    "db_host",
			EnvVars: []string{"LOTUS_DB_HOST"},
			Usage:   "Command separated list of hostnames for yugabyte cluster",
			Value:   "yugabyte",
		},
		&cli.StringFlag{
			Name:    "db_name",
			EnvVars: []string{"LOTUS_DB_NAME"},
			Value:   "yugabyte",
		},
		&cli.StringFlag{
			Name:    "db_user",
			EnvVars: []string{"LOTUS_DB_USER"},
			Value:   "yugabyte",
		},
		&cli.StringFlag{
			Name:    "db_password",
			EnvVars: []string{"LOTUS_DB_PASSWORD"},
			Value:   "yugabyte",
		},
		&cli.StringFlag{
			Name:    "db_port",
			EnvVars: []string{"LOTUS_DB_PORT"},
			Hidden:  true,
			Value:   "5433",
		},
	},
	Action: func(cctx *cli.Context) error {
		if !cctx.Bool("enable-gpu-proving") {
			err := os.Setenv("BELLMAN_NO_GPU", "true")
			if err != nil {
				return err
			}
		}

		ctx, _ := tag.New(lcli.DaemonContext(cctx),
			tag.Insert(metrics.Version, build.BuildVersion),
			tag.Insert(metrics.Commit, build.CurrentCommit),
			tag.Insert(metrics.NodeType, "provider"),
		)
		// Register all metric views
		/*
			if err := view.Register(
				metrics.MinerNodeViews...,
			); err != nil {
				log.Fatalf("Cannot register the view: %v", err)
			}
		*/
		// Set the metric to one so it is published to the exporter
		stats.Record(ctx, metrics.LotusInfo.M(1))

		if cctx.Bool("manage-fdlimit") {
			if _, _, err := ulimit.ManageFdLimit(); err != nil {
				log.Errorf("setting file descriptor limit: %s", err)
			}
		}

		// Open repo

		repoPath := cctx.String(FlagProviderRepo)
		r, err := repo.NewFS(repoPath)
		if err != nil {
			return err
		}

		ok, err := r.Exists()
		if err != nil {
			return err
		}
		if !ok {
			if err := r.Init(repo.Provider); err != nil {
				return err
			}

			lr, err := r.Lock(repo.Provider)
			if err != nil {
				return err
			}

			var localPaths []storiface.LocalPath

			if !cctx.Bool("no-local-storage") {
				b, err := json.MarshalIndent(&storiface.LocalStorageMeta{
					ID:       storiface.ID(uuid.New().String()),
					Weight:   10,
					CanSeal:  true,
					CanStore: false,
				}, "", "  ")
				if err != nil {
					return xerrors.Errorf("marshaling storage config: %w", err)
				}

				if err := os.WriteFile(filepath.Join(lr.Path(), "sectorstore.json"), b, 0644); err != nil {
					return xerrors.Errorf("persisting storage metadata (%s): %w", filepath.Join(lr.Path(), "sectorstore.json"), err)
				}

				localPaths = append(localPaths, storiface.LocalPath{
					Path: lr.Path(),
				})
			}

			if err := lr.SetStorage(func(sc *storiface.StorageConfig) {
				sc.StoragePaths = append(sc.StoragePaths, localPaths...)
			}); err != nil {
				return xerrors.Errorf("set storage config: %w", err)
			}

			{
				// init datastore for r.Exists
				_, err := lr.Datastore(context.Background(), "/metadata")
				if err != nil {
					return err
				}
			}
			if err := lr.Close(); err != nil {
				return xerrors.Errorf("close repo: %w", err)
			}
		}

		lr, err := r.Lock(repo.Provider)
		if err != nil {
			return err
		}
		defer func() {
			if err := lr.Close(); err != nil {
				log.Error("closing repo", err)
			}
		}()

		db, err := harmonydb.NewFromConfig(config.HarmonyDB{
			Username: cctx.String("db_user"),
			Password: cctx.String("db_password"),
			Hosts:    strings.Split(cctx.String("db_host"), ","),
			Database: cctx.String("db_name"),
			Port:     cctx.String("db_port"),
		})
		if err != nil {
			return err
		}
		// TODO add harmonytask
		_ = db

		shutdownChan := make(chan struct{})

		stop, err := node.New(ctx,
			node.Override(new(dtypes.ShutdownChan), shutdownChan),
			node.Provider(r),
		)
		if err != nil {
			return xerrors.Errorf("creating node: %w", err)
		}

		const unspecifiedAddress = "0.0.0.0"
		address := cctx.String("listen")
		addressSlice := strings.Split(address, ":")
		if ip := net.ParseIP(addressSlice[0]); ip != nil {
			if ip.String() == unspecifiedAddress {
				timeout, err := time.ParseDuration(cctx.String("timeout"))
				if err != nil {
					return err
				}
				rip, err := extractRoutableIP(timeout)
				if err != nil {
					return err
				}
				address = rip + ":" + addressSlice[1]
			}
		}
		localStore, err := paths.NewLocal(ctx, lr, nil, []string{"http://" + address + "/remote"})
		if err != nil {
			return err
		}

		handler := mux.NewRouter()
		fh := &paths.FetchHandler{Local: localStore, PfHandler: &paths.DefaultPartialFileHandler{}}
		handler.NotFoundHandler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			if !auth.HasPerm(r.Context(), nil, api.PermAdmin) {
				w.WriteHeader(401)
				_ = json.NewEncoder(w).Encode(struct{ Error string }{"unauthorized: missing admin permission"})
				return
			}

			fh.ServeHTTP(w, r)
		})
		// local APIs
		{
			m := mux.NewRouter()
			// debugging
			m.Handle("/debug/metrics", metrics.Exporter())
			m.PathPrefix("/").Handler(http.DefaultServeMux) // pprof

			var hnd http.Handler = m

			handler.PathPrefix("/").Handler(hnd)
		}

		// Serve the RPC.
		endpoint, err := r.APIEndpoint()
		if err != nil {
			return xerrors.Errorf("getting API endpoint: %w", err)
		}
		rpcStopper, err := node.ServeRPC(handler, "lotus-provider", endpoint)
		if err != nil {
			return fmt.Errorf("failed to start json-rpc endpoint: %s", err)
		}

		// Monitor for shutdown.
		finishCh := node.MonitorShutdown(shutdownChan,
			node.ShutdownHandler{Component: "rpc server", StopFunc: rpcStopper},
			node.ShutdownHandler{Component: "provider", StopFunc: stop},
		)

		<-finishCh
		return nil
	},
}

func extractRoutableIP(timeout time.Duration) (string, error) {
	conn, err := net.DialTimeout("udp", "8.8.8.8:80", timeout)
	if err != nil {
		return "", err
	}
	defer conn.Close()
	return conn.LocalAddr().(*net.UDPAddr).IP.String(), nil
}