package router

import (
	"fmt"
	"net/http"
	"path/filepath"
	"regexp"
	"strings"
	"time"

	"github.com/gin-contrib/cors"
	"github.com/gin-gonic/gin"
	"github.com/gotify/location"
	"github.com/gotify/server/v2/api"
	"github.com/gotify/server/v2/api/stream"
	"github.com/gotify/server/v2/auth"
	"github.com/gotify/server/v2/config"
	"github.com/gotify/server/v2/database"
	"github.com/gotify/server/v2/docs"
	gerror "github.com/gotify/server/v2/error"
	"github.com/gotify/server/v2/model"
	"github.com/gotify/server/v2/plugin"
	"github.com/gotify/server/v2/ui"
)

// Create creates the gin engine with all routes.
func Create(db *database.GormDatabase, vInfo *model.VersionInfo, conf *config.Configuration) (*gin.Engine, func()) {
	g := gin.New()

	g.RemoteIPHeaders = []string{"X-Forwarded-For"}
	g.SetTrustedProxies(conf.Server.TrustedProxies)
	g.ForwardedByClientIP = true

	g.Use(func(ctx *gin.Context) {
		// Map sockets "@" to 127.0.0.1, because gin-gonic can only trust IPs.
		if ctx.Request.RemoteAddr == "@" {
			ctx.Request.RemoteAddr = "127.0.0.1:65535"
		}
	})

	g.Use(gin.LoggerWithFormatter(logFormatter), gin.Recovery(), gerror.Handler(), location.Default())
	g.NoRoute(gerror.NotFound())

	if conf.Server.SSL.Enabled != nil && conf.Server.SSL.RedirectToHTTPS != nil && *conf.Server.SSL.Enabled && *conf.Server.SSL.RedirectToHTTPS {
		g.Use(func(ctx *gin.Context) {
			if ctx.Request.TLS != nil {
				ctx.Next()
				return
			}
			if ctx.Request.Method != http.MethodGet && ctx.Request.Method != http.MethodHead {
				ctx.Data(http.StatusBadRequest, "text/plain; charset=utf-8", []byte("Use HTTPS"))
				ctx.Abort()
				return
			}
			host := ctx.Request.Host
			if idx := strings.LastIndex(host, ":"); idx != -1 {
				host = host[:idx]
			}
			if conf.Server.SSL.Port != 443 {
				host = fmt.Sprintf("%s:%d", host, conf.Server.SSL.Port)
			}
			ctx.Redirect(http.StatusFound, fmt.Sprintf("https://%s%s", host, ctx.Request.RequestURI))
			ctx.Abort()
		})
	}
	streamHandler := stream.New(
		time.Duration(conf.Server.Stream.PingPeriodSeconds)*time.Second, 15*time.Second, conf.Server.Stream.AllowedOrigins)
	go func() {
		ticker := time.NewTicker(5 * time.Minute)
		for range ticker.C {
			connectedTokens := streamHandler.CollectConnectedClientTokens()
			now := time.Now()
			db.UpdateClientTokensLastUsed(connectedTokens, &now)
		}
	}()
	authentication := auth.Auth{DB: db}
	messageHandler := api.MessageAPI{Notifier: streamHandler, DB: db}
	healthHandler := api.HealthAPI{DB: db}
	clientHandler := api.ClientAPI{
		DB:            db,
		ImageDir:      conf.UploadedImagesDir,
		NotifyDeleted: streamHandler.NotifyDeletedClient,
	}
	applicationHandler := api.ApplicationAPI{
		DB:       db,
		ImageDir: conf.UploadedImagesDir,
	}
	userChangeNotifier := new(api.UserChangeNotifier)
	userHandler := api.UserAPI{DB: db, PasswordStrength: conf.PassStrength, UserChangeNotifier: userChangeNotifier, Registration: conf.Registration}

	pluginManager, err := plugin.NewManager(db, conf.PluginsDir, g.Group("/plugin/:id/custom/"), streamHandler)
	if err != nil {
		panic(err)
	}
	pluginHandler := api.PluginAPI{
		Manager:  pluginManager,
		Notifier: streamHandler,
		DB:       db,
	}

	userChangeNotifier.OnUserDeleted(streamHandler.NotifyDeletedUser)
	userChangeNotifier.OnUserDeleted(pluginManager.RemoveUser)
	userChangeNotifier.OnUserAdded(pluginManager.InitializeForUserID)

	ui.Register(g, *vInfo, conf.Registration)

	g.GET("/health", healthHandler.Health)
	g.GET("/swagger", docs.Serve)
	g.StaticFS("/image", &onlyImageFS{inner: gin.Dir(conf.UploadedImagesDir, false)})

	g.GET("/docs", docs.UI)

	g.Use(func(ctx *gin.Context) {
		ctx.Header("Content-Type", "application/json")
		for header, value := range conf.Server.ResponseHeaders {
			ctx.Header(header, value)
		}
	})
	g.Use(cors.New(auth.CorsConfig(conf)))

	{
		g.GET("/plugin", authentication.RequireClient(), pluginHandler.GetPlugins)
		pluginRoute := g.Group("/plugin/", authentication.RequireClient())
		{
			pluginRoute.GET("/:id/config", pluginHandler.GetConfig)
			pluginRoute.POST("/:id/config", pluginHandler.UpdateConfig)
			pluginRoute.GET("/:id/display", pluginHandler.GetDisplay)
			pluginRoute.POST("/:id/enable", pluginHandler.EnablePlugin)
			pluginRoute.POST("/:id/disable", pluginHandler.DisablePlugin)
		}
	}

	g.Group("/user").Use(authentication.Optional()).POST("", userHandler.CreateUser)

	g.OPTIONS("/*any")

	// swagger:operation GET /version version getVersion
	//
	// Get version information.
	//
	// ---
	// produces: [application/json]
	// responses:
	//   200:
	//     description: Ok
	//     schema:
	//         $ref: "#/definitions/VersionInfo"
	g.GET("version", func(ctx *gin.Context) {
		ctx.JSON(200, vInfo)
	})

	g.Group("/").Use(authentication.RequireApplicationToken()).POST("/message", messageHandler.CreateMessage)

	clientAuth := g.Group("")
	{
		clientAuth.Use(authentication.RequireClient())
		app := clientAuth.Group("/application")
		{
			app.GET("", applicationHandler.GetApplications)

			app.POST("", applicationHandler.CreateApplication)

			app.POST("/:id/image", applicationHandler.UploadApplicationImage)

			app.DELETE("/:id/image", applicationHandler.RemoveApplicationImage)

			app.PUT("/:id", applicationHandler.UpdateApplication)

			app.DELETE("/:id", applicationHandler.DeleteApplication)

			tokenMessage := app.Group("/:id/message")
			{
				tokenMessage.GET("", messageHandler.GetMessagesWithApplication)

				tokenMessage.DELETE("", messageHandler.DeleteMessageWithApplication)
			}
		}

		client := clientAuth.Group("/client")
		{
			client.GET("", clientHandler.GetClients)

			client.POST("", clientHandler.CreateClient)

			client.DELETE("/:id", clientHandler.DeleteClient)

			client.PUT("/:id", clientHandler.UpdateClient)
		}

		message := clientAuth.Group("/message")
		{
			message.GET("", messageHandler.GetMessages)

			message.DELETE("", messageHandler.DeleteMessages)

			message.DELETE("/:id", messageHandler.DeleteMessage)
		}

		clientAuth.GET("/stream", streamHandler.Handle)

		clientAuth.GET("current/user", userHandler.GetCurrentUser)

		clientAuth.POST("current/user/password", userHandler.ChangePassword)
	}

	authAdmin := g.Group("/user")
	{
		authAdmin.Use(authentication.RequireAdmin())

		authAdmin.GET("", userHandler.GetUsers)

		authAdmin.DELETE("/:id", userHandler.DeleteUserByID)

		authAdmin.GET("/:id", userHandler.GetUserByID)

		authAdmin.POST("/:id", userHandler.UpdateUserByID)
	}
	return g, streamHandler.Close
}

var tokenRegexp = regexp.MustCompile("token=[^&]+")

func logFormatter(param gin.LogFormatterParams) string {
	if (param.ClientIP == "127.0.0.1" || param.ClientIP == "::1") && param.Path == "/health" {
		return ""
	}

	var statusColor, methodColor, resetColor string
	if param.IsOutputColor() {
		statusColor = param.StatusCodeColor()
		methodColor = param.MethodColor()
		resetColor = param.ResetColor()
	}

	if param.Latency > time.Minute {
		param.Latency = param.Latency - param.Latency%time.Second
	}
	path := tokenRegexp.ReplaceAllString(param.Path, "token=[masked]")
	return fmt.Sprintf("%v |%s %3d %s| %13v | %15s |%s %-7s %s %#v\n%s",
		param.TimeStamp.Format(time.RFC3339),
		statusColor, param.StatusCode, resetColor,
		param.Latency,
		param.ClientIP,
		methodColor, param.Method, resetColor,
		path,
		param.ErrorMessage,
	)
}

type onlyImageFS struct {
	inner http.FileSystem
}

func (fs *onlyImageFS) Open(name string) (http.File, error) {
	ext := filepath.Ext(name)
	if !api.ValidApplicationImageExt(ext) {
		return nil, fmt.Errorf("invalid file")
	}
	return fs.inner.Open(name)
}