package app

import (
	"context"
	"encoding/json"
	"fmt"
	"io/ioutil"
	"net"
	"net/http"
	"os"
	"path/filepath"
	"strings"

	"forge.cadoles.com/arcad/edge/pkg/app"
	"forge.cadoles.com/arcad/edge/pkg/bus"
	"forge.cadoles.com/arcad/edge/pkg/bus/memory"
	appHTTP "forge.cadoles.com/arcad/edge/pkg/http"
	"forge.cadoles.com/arcad/edge/pkg/module"
	appModule "forge.cadoles.com/arcad/edge/pkg/module/app"
	appModuleMemory "forge.cadoles.com/arcad/edge/pkg/module/app/memory"
	"forge.cadoles.com/arcad/edge/pkg/module/auth"
	authHTTP "forge.cadoles.com/arcad/edge/pkg/module/auth/http"
	"forge.cadoles.com/arcad/edge/pkg/module/blob"
	"forge.cadoles.com/arcad/edge/pkg/module/cast"
	"forge.cadoles.com/arcad/edge/pkg/module/fetch"
	netModule "forge.cadoles.com/arcad/edge/pkg/module/net"
	"forge.cadoles.com/arcad/edge/pkg/storage"
	"forge.cadoles.com/arcad/edge/pkg/storage/sqlite"
	"gitlab.com/wpetit/goweb/logger"

	"forge.cadoles.com/arcad/edge/pkg/bundle"
	"github.com/dop251/goja"
	"github.com/go-chi/chi/v5"
	"github.com/go-chi/chi/v5/middleware"
	"github.com/lestrrat-go/jwx/v2/jwa"
	"github.com/lestrrat-go/jwx/v2/jwk"
	"github.com/pkg/errors"
	"github.com/urfave/cli/v2"

	_ "embed"

	_ "forge.cadoles.com/arcad/edge/pkg/module/auth/http/passwd/argon2id"
	_ "forge.cadoles.com/arcad/edge/pkg/module/auth/http/passwd/plain"
)

func RunCommand() *cli.Command {
	return &cli.Command{
		Name:  "run",
		Usage: "Run the specified app bundle",
		Flags: []cli.Flag{
			&cli.StringFlag{
				Name:    "path",
				Usage:   "use `PATH` as app bundle (zipped bundle or directory)",
				Aliases: []string{"p"},
				Value:   ".",
			},
			&cli.StringFlag{
				Name:    "address",
				Usage:   "use `ADDRESS` as http server listening address",
				Aliases: []string{"a"},
				Value:   ":8080",
			},
			&cli.StringFlag{
				Name:  "log-format",
				Usage: "use `LOG-FORMAT` ('json' or 'human')",
				Value: "human",
			},
			&cli.IntFlag{
				Name:  "log-level",
				Usage: "use `LOG-LEVEL` (0: debug -> 5: fatal)",
				Value: 0,
			},
			&cli.StringFlag{
				Name:  "storage-file",
				Usage: "use `FILE` for SQLite storage database",
				Value: ".edge/%APPID%/data.sqlite?_pragma=foreign_keys(1)&_pragma=busy_timeout=60000",
			},
			&cli.StringFlag{
				Name:  "accounts-file",
				Usage: "use `FILE` as local accounts",
				Value: ".edge/%APPID%/accounts.json",
			},
		},
		Action: func(ctx *cli.Context) error {
			address := ctx.String("address")
			path := ctx.String("path")

			logFormat := ctx.String("log-format")
			logLevel := ctx.Int("log-level")

			logger.SetFormat(logger.Format(logFormat))
			logger.SetLevel(logger.Level(logLevel))

			cmdCtx := ctx.Context

			absPath, err := filepath.Abs(path)
			if err != nil {
				return errors.Wrapf(err, "could not resolve path '%s'", path)
			}

			logger.Info(cmdCtx, "opening app bundle", logger.F("path", absPath))

			bundle, err := bundle.FromPath(path)
			if err != nil {
				return errors.Wrapf(err, "could not open path '%s' as an app bundle", path)
			}

			manifest, err := app.LoadManifest(bundle)
			if err != nil {
				return errors.Wrap(err, "could not load manifest from app bundle")
			}

			storageFile := injectAppID(ctx.String("storage-file"), manifest.ID)

			if err := ensureDir(storageFile); err != nil {
				return errors.WithStack(err)
			}

			db, err := sqlite.Open(storageFile)
			if err != nil {
				return errors.WithStack(err)
			}

			ds := sqlite.NewDocumentStoreWithDB(db)
			bs := sqlite.NewBlobStoreWithDB(db)
			bus := memory.NewBus()

			handler := appHTTP.NewHandler(
				appHTTP.WithBus(bus),
				appHTTP.WithServerModules(getServerModules(bus, ds, bs, manifest, address)...),
			)
			if err := handler.Load(bundle); err != nil {
				return errors.Wrap(err, "could not load app bundle")
			}

			router := chi.NewRouter()
			router.Use(middleware.Logger)

			accountsFile := injectAppID(ctx.String("accounts-file"), manifest.ID)

			accounts, err := loadLocalAccounts(accountsFile)
			if err != nil {
				return errors.Wrap(err, "could not load local accounts")
			}

			// Add auth handler
			key, err := dummyKey()
			if err != nil {
				return errors.WithStack(err)
			}
			router.Handle("/auth/*", authHTTP.NewLocalHandler(
				jwa.HS256, key,
				authHTTP.WithRoutePrefix("/auth"),
				authHTTP.WithAccounts(accounts...),
			))

			// Add app handler
			router.Handle("/*", handler)

			logger.Info(cmdCtx, "listening", logger.F("address", address))

			if err := http.ListenAndServe(address, router); err != nil {
				return errors.WithStack(err)
			}

			return nil
		},
	}
}

func getServerModules(bus bus.Bus, ds storage.DocumentStore, bs storage.BlobStore, manifest *app.Manifest, address string) []app.ServerModuleFactory {
	return []app.ServerModuleFactory{
		module.ContextModuleFactory(),
		module.ConsoleModuleFactory(),
		cast.CastModuleFactory(),
		module.LifecycleModuleFactory(),
		netModule.ModuleFactory(bus),
		module.RPCModuleFactory(bus),
		module.StoreModuleFactory(ds),
		blob.ModuleFactory(bus, bs),
		module.Extends(
			auth.ModuleFactory(
				auth.WithJWT(dummyKeySet),
			),
			func(o *goja.Object) {
				if err := o.Set("CLAIM_TENANT", "arcad_tenant"); err != nil {
					panic(errors.New("could not set 'CLAIM_TENANT' property"))
				}

				if err := o.Set("CLAIM_ENTRYPOINT", "arcad_entrypoint"); err != nil {
					panic(errors.New("could not set 'CLAIM_ENTRYPOINT' property"))
				}

				if err := o.Set("CLAIM_ROLE", "arcad_role"); err != nil {
					panic(errors.New("could not set 'CLAIM_ROLE' property"))
				}

				if err := o.Set("CLAIM_PREFERRED_USERNAME", "preferred_username"); err != nil {
					panic(errors.New("could not set 'CLAIM_PREFERRED_USERNAME' property"))
				}
			},
		),
		appModule.ModuleFactory(appModuleMemory.NewRepository(
			func(ctx context.Context, id app.ID, from string) (string, error) {
				addr := address
				if strings.HasPrefix(addr, ":") {
					addr = "0.0.0.0" + addr
				}

				host, port, err := net.SplitHostPort(addr)
				if err != nil {
					return "", errors.WithStack(err)
				}

				addr, err = findMatchingDeviceAddress(ctx, from, host)
				if err != nil {
					return "", errors.WithStack(err)
				}

				return fmt.Sprintf("http://%s:%s", addr, port), nil
			},
			manifest,
		)),
		fetch.ModuleFactory(bus),
	}
}

var dummySecret = []byte("not_so_secret")

func dummyKey() (jwk.Key, error) {
	key, err := jwk.FromRaw(dummySecret)
	if err != nil {
		return nil, errors.WithStack(err)
	}

	return key, nil
}

func dummyKeySet() (jwk.Set, error) {
	key, err := dummyKey()
	if err != nil {
		return nil, errors.WithStack(err)
	}

	if err := key.Set(jwk.AlgorithmKey, jwa.HS256); err != nil {
		return nil, errors.WithStack(err)
	}

	set := jwk.NewSet()

	if err := set.AddKey(key); err != nil {
		return nil, errors.WithStack(err)
	}

	return set, nil
}

func ensureDir(path string) error {
	if err := os.MkdirAll(filepath.Dir(path), os.ModePerm); err != nil {
		return errors.WithStack(err)
	}

	return nil
}

func injectAppID(str string, appID app.ID) string {
	return strings.ReplaceAll(str, "%APPID%", string(appID))
}

//go:embed default-accounts.json
var defaultAccounts []byte

func loadLocalAccounts(path string) ([]authHTTP.LocalAccount, error) {
	if err := ensureDir(path); err != nil {
		return nil, errors.WithStack(err)
	}

	data, err := ioutil.ReadFile(path)
	if err != nil {
		if errors.Is(err, os.ErrNotExist) {
			if err := ioutil.WriteFile(path, defaultAccounts, 0o640); err != nil {
				return nil, errors.WithStack(err)
			}

			data = defaultAccounts
		} else {
			return nil, errors.WithStack(err)
		}
	}

	var accounts []authHTTP.LocalAccount

	if err := json.Unmarshal(data, &accounts); err != nil {
		return nil, errors.WithStack(err)
	}

	return accounts, nil
}

func findMatchingDeviceAddress(ctx context.Context, from string, defaultAddr string) (string, error) {
	if from == "" {
		return defaultAddr, nil
	}

	fromIP := net.ParseIP(from)

	if fromIP == nil {
		return defaultAddr, nil
	}

	ifaces, err := net.Interfaces()
	if err != nil {
		return "", errors.WithStack(err)
	}

	for _, ifa := range ifaces {
		addrs, err := ifa.Addrs()
		if err != nil {
			logger.Error(
				ctx, "could not retrieve iface adresses",
				logger.E(errors.WithStack(err)), logger.F("iface", ifa.Name),
			)

			continue
		}

		for _, addr := range addrs {
			ip, network, err := net.ParseCIDR(addr.String())
			if err != nil {
				logger.Error(
					ctx, "could not parse address",
					logger.E(errors.WithStack(err)), logger.F("address", addr.String()),
				)

				continue
			}

			if !network.Contains(fromIP) {
				continue
			}

			return ip.String(), nil
		}
	}

	return defaultAddr, nil
}