package server

import (
	"log"
	"time"

	"git.phc.dm.unipi.it/phc/website/config"
	"git.phc.dm.unipi.it/phc/website/handler"
	"git.phc.dm.unipi.it/phc/website/model"
	"github.com/gofiber/fiber/v2"
	"github.com/gofiber/fiber/v2/middleware/etag"
	"github.com/gofiber/fiber/v2/middleware/logger"
	"github.com/gofiber/fiber/v2/middleware/recover"
	"github.com/gofiber/redirect/v2"
)

func UserMiddleware(h handler.Service) fiber.Handler {
	return func(c *fiber.Ctx) error {
		token := c.Cookies("session-token")
		user := h.HandleUser(token)
		c.Locals("user", user)
		return c.Next()
	}
}

func CreateContext(ctx *fiber.Ctx) handler.Context {
	// the "_" here is required because Go cannot cast <nil> of type interface{} to *model.User, in other words <nil> of type *model.User and <nil> of type interface{} are different type. In this case the "_" returns a boolean that tells whether the cast succeeded or not, if it is false the user variable gets assigned its default zero value that is <nil> of type *model.User
	user, _ := ctx.Locals("user").(*model.User)

	context := handler.Context{}
	handler.SetContextValue(context, handler.UserKey, user)

	return context
}

func NewFiberServer(h handler.Service) *fiber.App {
	app := fiber.New()
	routes(h, app)
	return app
}

// routes defines routes under "/"
func routes(h handler.Service, r fiber.Router) {
	//
	// Initial setup
	//

	r.Use(logger.New())
	r.Use(recover.New())

	// Remove trailing slash from URLs
	r.Use(redirect.New(redirect.Config{
		Rules: map[string]string{
			"/*/": "/$1",
		},
	}))

	// Better static file serving setup
	r.Route("/public", func(r fiber.Router) {
		// Cache client side files based on checksum
		r.Use(etag.New())

		staticConfig := fiber.Static{}
		if config.Mode == "development" {
			log.Printf("Disabling Cache-Control in development mode")

			// if no "Cache-Control" is present the browser will cache heuristically (and we don't want that)
			r.Use(func(c *fiber.Ctx) error {
				c.Set("Cache-Control", "no-cache")
				return c.Next()
			})

			staticConfig.CacheDuration = 1 * time.Millisecond
		}

		r.Static("/", "./_frontend/out", staticConfig)
		r.Static("/", "./_public", staticConfig)
	})

	// Serve generated css and js files and the static "./_public" folder

	// Process all request and add user to the request context if there is a session cookie
	r.Use(UserMiddleware(h))

	//
	// Pages
	//

	r.Get("/", func(c *fiber.Ctx) error {
		c.Type("html")
		return h.HandleStaticPage(c, "home.html", CreateContext(c))
	})

	r.Get("/link", func(c *fiber.Ctx) error {
		c.Type("html")
		return h.HandleStaticPage(c, "link.html", CreateContext(c))
	})

	r.Get("/login", func(c *fiber.Ctx) error {
		c.Type("html")
		return h.HandleStaticPage(c, "login.html", CreateContext(c))
	})

	r.Get("/utenti", func(c *fiber.Ctx) error {
		c.Type("html")
		return h.HandleStaticPage(c, "utenti.html", CreateContext(c))
	})

	r.Get("/storia", func(c *fiber.Ctx) error {
		c.Type("html")
		return h.HandleStoriaPage(c, CreateContext(c))
	})

	r.Get("/appunti", func(c *fiber.Ctx) error {
		query := c.Query("q", "")

		c.Type("html")
		return h.HandleQueryAppunti(c, query, CreateContext(c))
	})

	r.Get("/appunti/condivisi", func(c *fiber.Ctx) error {
		c.Type("html")
		return h.HandleAppuntiCondivisiPage(c, CreateContext(c))
	})

	r.Get("/news", func(c *fiber.Ctx) error {
		c.Type("html")
		return h.HandleNewsPage(c, CreateContext(c))
	})

	r.Get("/guide", func(c *fiber.Ctx) error {
		c.Type("html")
		return h.HandleGuidePage(c, CreateContext(c))
	})

	r.Get("/news/rss", func(c *fiber.Ctx) error {
		c.Type("xml")
		return h.HandleNewsFeedPage(c)
	})

	r.Get("/guide/rss", func(c *fiber.Ctx) error {
		c.Type("xml")
		return h.HandleGuideFeedPage(c)
	})

	r.Post("/login", func(c *fiber.Ctx) error {
		var loginForm struct {
			Provider string `form:"provider"`
			Username string `form:"username"`
			Password string `form:"password"`
		}

		if err := c.BodyParser(&loginForm); err != nil {
			return err
		}

		session, err := h.HandleLogin(loginForm.Username, loginForm.Password)
		if err != nil {
			return err
		}

		inThreeDays := time.Now().Add(3 * 24 * time.Hour)
		c.Cookie(&fiber.Cookie{
			Name:    "session-token",
			Path:    "/",
			Value:   session.Token,
			Expires: inThreeDays,
		})

		return c.Redirect("/profilo")
	})

	r.Get("/profilo", func(c *fiber.Ctx) error {
		c.Type("html")
		return h.HandleProfilePage(c, CreateContext(c))
	})

	r.Get("/logout", func(c *fiber.Ctx) error {
		c.Cookie(&fiber.Cookie{
			Name:    "session-token",
			Path:    "/",
			Value:   "",
			Expires: time.Now(),
		})

		return c.Redirect("/")
	})

	r.Get("/news/:article", func(c *fiber.Ctx) error {
		articleID := c.Params("article")

		c.Type("html")
		return h.HandleNewsArticlePage(c, articleID, CreateContext(c))
	})

	r.Get("/guide/:article", func(c *fiber.Ctx) error {
		articleID := c.Params("article")

		c.Type("html")
		return h.HandleGuideArticlePage(c, articleID, CreateContext(c))
	})

	routesApi(h, r.Group("/api"))
}

// routesApi defines routes under "/api"
func routesApi(h handler.Service, r fiber.Router) {
	r.Get("/utenti", func(c *fiber.Ctx) error {
		utenti, err := h.HandleListaUtenti()
		if err != nil {
			return err
		}

		return c.JSON(utenti)
	})

	r.Get("/profilo", func(c *fiber.Ctx) error {
		user, err := h.HandleRequiredUser(CreateContext(c))
		if err != nil {
			return err
		}

		return c.JSON(user)
	})
}