package fiber

import (
	"html/template"
	"log"
	"strconv"
	"strings"
	"time"

	"github.com/dmitriygnatenko/internal/interfaces"
	"github.com/dmitriygnatenko/internal/services/handler"
	adminHandler "github.com/dmitriygnatenko/internal/services/handler/admin"
	"github.com/gofiber/fiber/v2"
	"github.com/gofiber/fiber/v2/middleware/basicauth"
	"github.com/gofiber/fiber/v2/middleware/cors"
	"github.com/gofiber/fiber/v2/middleware/monitor"
	"github.com/gofiber/fiber/v2/middleware/recover"
	jwt "github.com/gofiber/jwt/v3"
	"github.com/gofiber/template/html"
)

const (
	appName       = "dmitriygnatenko"
	templatesPath = "./../../internal/templates"
	staticPath    = "../../web"
	metricsURI    = "/metrics"
)

func Init(sp interfaces.ServiceProvider) (*fiber.App, error) {
	fiberApp := fiber.New(getConfig(sp))

	// Configure web root
	fiberApp.Static("/", staticPath)

	// Configure CORS middleware
	fiberApp.Use(cors.New(getCORSConfig(sp)))

	// Configure recover middleware
	fiberApp.Use(recover.New())

	// Configure JWT middleware
	fiberApp.Use(jwt.New(getJWTConfig(sp)))

	// Configure Basic auth
	basicAuth := basicauth.New(basicauth.Config{
		Users: map[string]string{
			sp.GetEnvService().GetBasicAuthUser(): sp.GetEnvService().GetBasicAuthPassword(),
		},
	})

	// Metrics
	fiberApp.Get(metricsURI, basicAuth, monitor.New(getMetricsConfig()))

	// Public handlers
	fiberApp.Get("/", handler.MainPageHandler(sp))
	fiberApp.Get("/tag/:tag", handler.TagHandler(sp))
	fiberApp.Get("/article/:article", handler.ArticleHandler(sp))

	// Protected handlers
	admin := fiberApp.Group("/admin", basicAuth)
	admin.Get("/", adminHandler.ArticleHandler(sp))
	admin.All("/article/add", adminHandler.AddArticleHandler(sp))
	admin.All("/article/edit/:id<int>", adminHandler.EditArticleHandler(sp))
	admin.All("/article/delete/:id<int>", adminHandler.DeleteArticleHandler(sp))
	admin.Get("/tag", adminHandler.TagHandler(sp))
	admin.All("/tag/add", adminHandler.AddTagHandler(sp))
	admin.All("/tag/edit/:id<int>", adminHandler.EditTagHandler(sp))
	admin.All("/tag/delete/:id<int>", adminHandler.DeleteTagHandler(sp))

	return fiberApp, nil
}

func getConfig(sp interfaces.ServiceProvider) fiber.Config {
	return fiber.Config{
		AppName:               appName,
		DisableStartupMessage: true,
		Views:                 getViewsEngine(sp.GetEnvService()),
		ErrorHandler:          getErrorHandler(sp),
	}
}

// nolint
func getJWTConfig(sp interfaces.ServiceProvider) jwt.Config {
	return jwt.Config{
		SigningKey: []byte(sp.GetEnvService().GetJWTSecretKey()),
		ErrorHandler: func(fctx *fiber.Ctx, err error) error {
			return fiber.NewError(fiber.StatusForbidden, err.Error())
		},
		Filter: func(fctx *fiber.Ctx) bool {
			method := fctx.Method()
			path := fctx.Path()

			if method != fiber.MethodGet && method != fiber.MethodPost &&
				method != fiber.MethodPut && method != fiber.MethodDelete {
				return true
			}

			if strings.HasPrefix(path, "/api/") && path != "/api/v1/auth/login" {
				return false
			}

			return true
		},
	}
}

func getMetricsConfig() monitor.Config {
	return monitor.Config{
		Title: "dmitriygnatenko.ru metrics",
	}
}

func getCORSConfig(sp interfaces.ServiceProvider) cors.Config {
	return cors.Config{
		AllowOrigins: sp.GetEnvService().GetCORSAllowOrigins(),
		AllowMethods: sp.GetEnvService().GetCORSAllowMethods(),
	}
}

func getViewsEngine(env interfaces.Env) *html.Engine {
	engine := html.New(templatesPath, ".html")

	// nolint:gocritic
	engine.AddFunc("now", func() time.Time {
		return time.Now()
	})

	// nolint:gosec
	engine.AddFunc("noescape", func(str string) template.HTML {
		return template.HTML(str)
	})

	engine.AddFunc("gridsep", func(i, l int) bool {
		i++
		return i%3 == 0 && i != l
	})

	engine.AddFunc("version", func() string {
		return strconv.Itoa(env.GetStaticVersion())
	})

	engine.AddFunc("ga", func() string {
		return env.GetGAKey()
	})

	return engine
}

func getErrorHandler(sp interfaces.ServiceProvider) fiber.ErrorHandler {
	return func(fctx *fiber.Ctx, err error) error {
		errCode := fiber.StatusInternalServerError
		if e, ok := err.(*fiber.Error); ok {
			errCode = e.Code
		}

		if err.Error() != "" {
			errorsEmail := sp.GetEnvService().GetErrorsEmail()
			if errCode == fiber.StatusInternalServerError && errorsEmail != "" {
				log.Println(err)
				// nolint
				sp.GetMailerService().Send(
					errorsEmail,
					"AUTO - dmitriygnatenko.ru error",
					err.Error(),
				)
			}
		}

		var renderData fiber.Map

		if errCode == fiber.StatusNotFound {
			renderData = fiber.Map{
				"pageTitle": "Страница не найдена",
				"code":      fiber.StatusNotFound,
				"text":      "Запрашиваемая вами страница не найдена",
			}
		} else {
			renderData = fiber.Map{
				"pageTitle": "Внутренняя ошибка",
				"code":      fiber.StatusInternalServerError,
				"text":      "Внутренняя ошибка сервера, идем исправлять...",
			}
		}

		renderData["headTitle"] = "От слона к суслику - статьи про PHP, Go, алгоритмы"

		return fctx.Render("error", renderData, "_layout")
	}
}