package main

import (
	"context"
	"github.com/dgraph-io/ristretto"
	"github.com/docker/docker/api/types"
	"github.com/docker/docker/client"
	"github.com/eko/gocache/cache"
	"github.com/eko/gocache/store"
	"github.com/gin-gonic/gin"
	"github.com/go-co-op/gocron"
	"go.uber.org/zap"
	"go.uber.org/zap/zapcore"
	"io/ioutil"
	"net/http"
	"os"
	"serverctl/pkg/db"
	"serverctl/pkg/db/postgres"
	"serverctl/pkg/users"
	"time"
)

func setupLogger() *zap.Logger {
	highPriority := zap.LevelEnablerFunc(func(lvl zapcore.Level) bool {
		return lvl >= zapcore.ErrorLevel
	})
	lowPriority := zap.LevelEnablerFunc(func(lvl zapcore.Level) bool {
		return lvl < zapcore.ErrorLevel
	})
	fileDebugging := zapcore.AddSync(ioutil.Discard)
	fileErrors := zapcore.AddSync(ioutil.Discard)

	consoleDebugging := zapcore.Lock(os.Stdout)
	consoleErrors := zapcore.Lock(os.Stderr)

	fileEncoder := zapcore.NewJSONEncoder(zap.NewProductionEncoderConfig())
	consoleEncoder := zapcore.NewConsoleEncoder(zap.NewDevelopmentEncoderConfig())

	core := zapcore.NewTee(
		zapcore.NewCore(fileEncoder, fileErrors, highPriority),
		zapcore.NewCore(consoleEncoder, consoleErrors, highPriority),
		zapcore.NewCore(fileEncoder, fileDebugging, lowPriority),
		zapcore.NewCore(consoleEncoder, consoleDebugging, lowPriority),
	)

	logger := zap.New(core)
	defer logger.Sync()
	return logger
}
func BasicAuthMiddleware(l *zap.Logger, us *users.Service) gin.HandlerFunc {
	return func(c *gin.Context) {
		username, password, hasAuth := c.Request.BasicAuth()
		if !hasAuth {
			l.Info("user could not be authenticated",
				zap.String("username", username))
			c.Header("WWW-Authenticate", "Basic realm=serverctl")
			c.Abort()
			c.JSON(http.StatusUnauthorized, gin.H{"message": "credentials were invalid (authorization header missing)"})
			return
		}

		user, err := us.Authenticate(c.Request.Context(), username, password)
		if err != nil {
			l.Info("user could not be authenticated",
				zap.String("username", username))
			c.Abort()
			c.Header("WWW-Authenticate", "Basic realm=serverctl")
			c.JSON(http.StatusUnauthorized, gin.H{"message": "credentials were invalid (credentials didn't match)"})
			return
		}

		l.Debug("user has been authenticated",
			zap.Int("userId", user.Id),
			zap.String("email", user.Email))
		c.Set("userId", user.Id)
		c.Next()
	}
}
func setupApi(l *zap.Logger, cc *cache.Cache, us *users.Service) {
	l.Info("Setting up serverctl setupApi (using gin)")

	r := gin.Default()

	r.POST("/auth/register", func(c *gin.Context) {
		type RegisterUser struct {
			Email    string `json:"email" binding:"required"`
			Password string `json:"password" binding:"required"`
		}
		var registerUser RegisterUser
		if err := c.BindJSON(&registerUser); err != nil {
			return
		}

		createUser, err := us.Create(registerUser.Email, registerUser.Password)
		if err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"message": "you have provided invalid input"})
			return
		}

		c.JSON(http.StatusCreated, gin.H{"message": "user has been registered", "userId": createUser})
	})

	containers := r.Group("/containers", BasicAuthMiddleware(l, us))
	containers.GET("/", func(c *gin.Context) {
		type container struct {
			Name string `json:"name"`
		}
		var msg struct {
			Containers []container `json:"containers"`
		}

		get, err := cc.Get("docker-containers")
		if err != nil {
			c.JSON(http.StatusInternalServerError, gin.H{"message": "could not get containers from container runtime"})
			return
		}

		msg.Containers = []container{}
		for _, cont := range get.([]types.Container) {
			msg.Containers = append(msg.Containers, container{
				Name: cont.Names[0],
			})
		}

		c.JSON(http.StatusOK, msg)
	})

	r.Run(":8080")

}
func setupDocker(l *zap.Logger) *client.Client {
	l.Info("Setting up Docker")
	cli, err := client.NewClientWithOpts(client.FromEnv, client.WithAPIVersionNegotiation())
	if err != nil {
		panic(err)
	}

	return cli
}
func setupCache(l *zap.Logger) *cache.Cache {
	l.Info("Setting up cache")
	ristrettoCache, err := ristretto.NewCache(&ristretto.Config{
		NumCounters: 1000,
		MaxCost:     100,
		BufferItems: 64,
	})
	if err != nil {
		panic(err)
	}
	ristrettoStore := store.NewRistretto(ristrettoCache, nil)
	cacheManager := cache.New(ristrettoStore)

	return cacheManager
}
func setupCron(l *zap.Logger, cm *cache.Cache, cc *client.Client) {
	l.Info("Setting up job scheduler (cron)")

	s := gocron.NewScheduler(time.UTC)

	s.Every(10).Second().Do(func() {
		l.Debug("getting container list")
		list, err := cc.ContainerList(context.Background(), types.ContainerListOptions{})
		if err != nil {
			l.Warn(err.Error())
			return
		}

		err = cm.Set("docker-containers", list, &store.Options{
			Cost: 2,
		})
		if err != nil {
			l.Warn(err.Error())
			return
		}
	})

	s.StartAsync()
}

func main() {
	logger := setupLogger()
	logger.Info("Starting serverctl")

	cacheM := setupCache(logger)
	containerClient := setupDocker(logger)
	setupCron(logger, cacheM, containerClient)

	database := db.NewClient(logger)
	usersRepository := postgres.NewUsersRepository(database)
	usersService := users.NewService(logger, usersRepository, cacheM)

	setupApi(logger, cacheM, usersService)
}