package main

import (
	"embed"
	"log"
	"net/http"
	"strconv"

	"jxs.me/todogo/database"
	"jxs.me/todogo/views"
)

//go:embed public/*
var publicFS embed.FS

type server struct {
	views  *views.Views
	router *http.ServeMux
	db     *database.DB
}

func newServer() *server {

	srv := &server{
		views:  views.New(),
		router: http.NewServeMux(),
		db:     database.New(),
	}
	srv.routes()

	return srv
}

func (s *server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	s.router.ServeHTTP(w, r)
}

func (s *server) HandleList() http.HandlerFunc {
	type viewModel struct {
		Todos      []database.Todo
		Only       string
		Incomplete int
	}

	list := s.views.Renderer("list.html")

	return func(w http.ResponseWriter, r *http.Request) {
		q := r.URL.Query()
		only := q.Get("only")

		var dbTodos []database.Todo
		var err error
		switch only {
		case "active":
			dbTodos, err = s.db.GetTodosByCompleted(false)
		case "completed":
			dbTodos, err = s.db.GetTodosByCompleted(true)
		default:
			dbTodos, err = s.db.GetAllTodos()
		}

		if err != nil {
			http.Error(w, "Failed to fetch todos", http.StatusInternalServerError)
			return
		}

		incomplete := s.db.GetIncompleteTodosCount()

		vm := viewModel{
			Todos:      dbTodos,
			Only:       only,
			Incomplete: incomplete,
		}
		list(w, r, vm)
	}
}

func (s *server) HandleCreate() http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		title := r.Form.Get("title")

		if err := s.db.InsertTodo(title); err != nil {
			http.Error(w, "failed to insert", http.StatusInternalServerError)
			return
		}

		http.Redirect(w, r, "/", http.StatusSeeOther)
	}
}

func (s *server) HandleToggle() http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		rawId := r.Form.Get("id")
		id, err := strconv.Atoi(rawId)

		if err != nil {
			http.Error(w, "Bad id", http.StatusBadRequest)
			return
		}
		err = s.db.ToggleTodo(id)

		if err != nil {
			http.Error(w, "failed to toggle", http.StatusInternalServerError)
			return
		}

		http.Redirect(w, r, "/", http.StatusSeeOther)
	}
}

func (s *server) HandleDestroy() http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		rawId := r.Form.Get("id")
		id, err := strconv.Atoi(rawId)
		if err != nil {
			http.Error(w, "Bad id", http.StatusBadRequest)
			return
		}
		err = s.db.DeleteTodo(id)

		if err != nil {
			http.Error(w, "failed to toggle", http.StatusInternalServerError)
			return
		}

		http.Redirect(w, r, "/", http.StatusSeeOther)
	}
}

func (s *server) HandleClear() http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		err := s.db.DeleteCompletedTodos()
		if err != nil {
			http.Error(w, "failed to clear", http.StatusInternalServerError)
			return
		}

		http.Redirect(w, r, "/", http.StatusSeeOther)
	}
}

func (s *server) routes() {
	s.router.Handle("/public/", http.FileServer(http.FS(publicFS)))
	s.router.HandleFunc("/", WithMethod("GET", s.HandleList()))
	s.router.HandleFunc("/todo", WithForm(WithMethod("POST", s.HandleCreate())))
	s.router.HandleFunc("/toggle", WithForm(WithMethod("POST", s.HandleToggle())))
	s.router.HandleFunc("/destroy", WithForm(WithMethod("POST", s.HandleDestroy())))
	s.router.HandleFunc("/clear", WithMethod("POST", s.HandleClear()))
}

func run() error {
	srv := newServer()

	log.Print("Running on 8080")
	return http.ListenAndServe(":8080", srv)
}

func main() {
	log.Fatal(run())
}