/*
Copyright 2017-2022 CAcert Inc.
SPDX-License-Identifier: Apache-2.0

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package u

import (
	"context"
	"fmt"
	"io/fs"
	"log"
	"net/http"
	"strconv"

	"github.com/alexedwards/scs/v2"
	"github.com/go-chi/chi/v5"
	"github.com/go-chi/chi/v5/middleware"
	"github.com/go-playground/form/v4"
	"github.com/jmoiron/sqlx"
	"github.com/vearutop/statigz"
	"github.com/vearutop/statigz/brotli"

	"git.cacert.org/cacert-boardvoting/internal/handlers"
	"git.cacert.org/cacert-boardvoting/internal/jobs"
	"git.cacert.org/cacert-boardvoting/internal/models"
	"git.cacert.org/cacert-boardvoting/internal/notifications"
	"git.cacert.org/cacert-boardvoting/ui"
)

type Application struct {
	errorLog, infoLog *log.Logger
	users             *models.UserModel
	motions           *models.MotionModel
	jobScheduler      *jobs.JobScheduler
	mailNotifier      *notifications.MailNotifier
	mailConfig        *notifications.MailConfig
	templateCache     *handlers.TemplateCache
	sessionManager    *scs.SessionManager
	formDecoder       *form.Decoder
}

func New(
	errorLog, infoLog *log.Logger,
	db *sqlx.DB,
	mailConfig *notifications.MailConfig,
	sessionManager *scs.SessionManager,
) (*Application, error) {
	app := &Application{
		errorLog:       errorLog,
		infoLog:        infoLog,
		mailConfig:     mailConfig,
		motions:        &models.MotionModel{DB: db},
		users:          &models.UserModel{DB: db},
		sessionManager: sessionManager,
	}

	var err error

	app.templateCache, err = handlers.NewTemplateCache()
	if err != nil {
		return nil, fmt.Errorf("could not initialize template cache: %w", err)
	}

	app.setupFormDecoder()

	app.mailNotifier = notifications.NewMailNotifier(
		app.mailConfig,
		notifications.NotifierLog(app.infoLog, app.errorLog),
	)

	go app.mailNotifier.Start()

	app.jobScheduler = jobs.NewJobScheduler(jobs.SchedulerLog(app.infoLog, app.errorLog))

	app.jobScheduler.AddJob(jobs.NewCloseDecisionsJob(
		app.motions,
		app.mailNotifier,
		jobs.CloseDecisionsLog(app.infoLog, app.errorLog),
	))

	app.jobScheduler.AddJob(jobs.NewRemindVoters(
		app.users, app.motions, app.mailNotifier,
		jobs.RemindVotersLog(app.infoLog, app.errorLog),
	))

	go app.jobScheduler.Schedule()

	return app, nil
}

func (app *Application) Close() error {
	app.jobScheduler.Quit()
	app.mailNotifier.Quit()

	return nil
}

func (app *Application) setupFormDecoder() {
	decoder := form.NewDecoder()

	decoder.RegisterCustomTypeFunc(func(values []string) (interface{}, error) {
		v, err := models.VoteTypeFromString(values[0])
		if err != nil {
			return nil, fmt.Errorf("could not convert value %s: %w", values[0], err)
		}

		return v, nil
	}, new(models.VoteType))
	decoder.RegisterCustomTypeFunc(func(values []string) (interface{}, error) {
		v, err := models.VoteChoiceFromString(values[0])
		if err != nil {
			return nil, fmt.Errorf("could not convert value %s: %w", values[0], err)
		}

		return v, nil
	}, new(models.VoteChoice))
	decoder.RegisterCustomTypeFunc(func(values []string) (interface{}, error) {
		userID, err := strconv.Atoi(values[0])
		if err != nil {
			return nil, fmt.Errorf("could not convert value %s to user ID: %w", values[0], err)
		}

		u, err := app.users.ByID(context.Background(), int64(userID))
		if err != nil {
			return nil, fmt.Errorf("could not convert value %s to user: %w", values[0], err)
		}

		return u, nil
	}, new(models.User))

	app.formDecoder = decoder
}

func (app *Application) Routes() http.Handler {
	staticDir, _ := fs.Sub(ui.Files, "static")

	staticData, ok := staticDir.(fs.ReadDirFS)
	if !ok {
		app.errorLog.Fatal("could not use uiStaticDir as fs.ReadDirFS")
	}

	fileServer := statigz.FileServer(staticData, brotli.AddEncoding, statigz.EncodeOnInit)

	router := chi.NewRouter()

	router.Use(middleware.RealIP)
	router.Use(middleware.RequestLogger(&middleware.DefaultLogFormatter{Logger: app.infoLog}))
	router.Use(middleware.Recoverer)
	router.Use(handlers.SecureHeaders)

	router.NotFound(func(w http.ResponseWriter, _ *http.Request) { handlers.NotFound(w) })

	router.Get(
		"/",
		http.RedirectHandler("/motions/", http.StatusMovedPermanently).ServeHTTP,
	)
	router.Get(
		"/favicon.ico",
		http.RedirectHandler("/static/images/favicon.ico", http.StatusMovedPermanently).ServeHTTP,
	)
	router.Get("/static/*", http.StripPrefix("/static", fileServer).ServeHTTP)

	userMiddleware := handlers.NewUserMiddleware(app.users, app.errorLog)

	flashes := handlers.NewFlashes(app.sessionManager)

	handlerParams := handlers.CommonParams{
		Flashes:       flashes,
		TemplateCache: app.templateCache,
		FormDecoder:   app.formDecoder,
	}

	motionHandler := handlers.NewMotionHandler(app.motions, app.mailNotifier, app.jobScheduler, handlerParams)
	voteHandler := handlers.NewVoteHandler(app.motions, app.users, app.mailNotifier, handlerParams)
	userHandler := handlers.NewUserHandler(app.users, handlerParams)

	router.Group(func(r chi.Router) {
		r.Use(app.sessionManager.LoadAndSave, userMiddleware.TryAuthenticate)

		r.Get("/motions/", motionHandler.List)
		r.Get("/motions/{tag}", motionHandler.Details)

		r.Group(func(r chi.Router) {
			r.Use(userMiddleware.UserCanEditVote, handlers.NoSurf)

			r.Get("/newmotion/", motionHandler.NewForm)
			r.Post("/newmotion/", motionHandler.New)

			r.Route("/motions/{tag}", func(r chi.Router) {
				r.Get("/edit", motionHandler.EditForm)
				r.Post("/edit", motionHandler.Edit)
				r.Get("/withdraw", motionHandler.WithdrawForm)
				r.Post("/withdraw", motionHandler.Withdraw)
			})
		})

		r.Group(func(r chi.Router) {
			r.Use(userMiddleware.UserCanVote, handlers.NoSurf)

			r.Get("/vote/{tag}/{choice}", voteHandler.VoteForm)
			r.Post("/vote/{tag}/{choice}", voteHandler.Vote)
			r.Get("/proxy/{tag}", voteHandler.ProxyVoteForm)
			r.Post("/proxy/{tag}", voteHandler.ProxyVote)
		})

		r.Group(func(r chi.Router) {
			r.Use(userMiddleware.CanManageUsers, handlers.NoSurf)

			r.Get("/users/", userHandler.List)
			r.Get("/new-user/", userHandler.CreateForm)
			r.Post("/new-user/", userHandler.Create)

			r.Route("/users/{id}", func(r chi.Router) {
				r.Get("/", userHandler.EditForm)
				r.Post("/", userHandler.Edit)
				r.Get("/add-mail", userHandler.AddEmailForm)
				r.Post("/add-mail", userHandler.AddEmail)
				r.Get("/mail/{address}/delete", userHandler.DeleteEmailForm)
				r.Post("/mail/{address}/delete", userHandler.DeleteEmail)
				r.Get("/delete", userHandler.DeleteForm)
				r.Post("/delete", userHandler.Delete)
			})

			r.Get("/voters/", userHandler.ChangeVotersForm)
			r.Post("/voters/", userHandler.ChangeVoters)
		})
	})

	router.Method(http.MethodGet, "/health", handlers.NewHealthCheck(app.mailNotifier, app.motions))

	return router
}