package api

import (
	"context"
	"log/slog"
	"net"
	"net/http"
	"net/url"
	"time"

	"git.yetaga.in/alazyreader/going-further/storage"
)

type LinkProvider interface {
	Link(key string) *url.URL
	List() []string
	Details(key string) storage.Link
}

type SessionProvider interface {
	Login(username string, password string) (string, bool) // session token, valid
	Valid(token string) bool
	User(token string) string // token -> username
}

type UserProvider interface {
	List() []string // usernames
	Add(username string, password string) error
	Update(username string, password string) error
	Remove(username string) error
}

type shutdown struct {
	wait    int
	timeout int
}

type Server struct {
	host    string
	port    string
	version string

	users    UserProvider
	sessions SessionProvider
	links    LinkProvider

	http  *http.Server
	waits shutdown

	log *slog.Logger
}

func NewServer(logger *slog.Logger, port string, version string) *Server {
	return &Server{
		log:     logger,
		port:    port,
		version: version,
		waits: shutdown{
			wait:    10,
			timeout: 10,
		},
	}
}

// Setup returns start and stop functions for the http service
func (s *Server) Setup() (func(), func()) {
	mux := http.NewServeMux()
	mux.HandleFunc("GET /version", versionHandleFunc(s.log, s.version))

	mux.HandleFunc("GET /login", getLoginHandleFunc(s.sessions, s.log))
	mux.HandleFunc("POST /login", postLoginHandleFunc(s.sessions, s.log))

	mux.HandleFunc("GET /manage", getManageHandleFunc(s.log))

	mux.HandleFunc("GET /manage/links", getLinkListHandleFunc(s.links, s.log))
	mux.HandleFunc("GET /manage/links/{name}", getLinkHandleFunc(s.links, s.log))
	mux.HandleFunc("POST /manage/links", postLinkHandleFunc(s.links, s.log))
	mux.HandleFunc("PUT /manage/links/{name}", putLinkHandleFunc(s.links, s.log))
	mux.HandleFunc("DELETE /manage/links/{name}", deleteLinkHandleFunc(s.links, s.log))

	mux.HandleFunc("GET /manage/users", getUserListHandleFunc(s.users, s.log))
	mux.HandleFunc("GET /manage/users/{name}", getUserHandleFunc(s.users, s.log))
	mux.HandleFunc("POST /manage/users", postUserHandleFunc(s.users, s.log))
	mux.HandleFunc("PUT /manage/users/{name}", putUserHandleFunc(s.users, s.log))
	mux.HandleFunc("DELETE /manage/users/{name}", deleteUserHandleFunc(s.users, s.log))

	mux.HandleFunc("GET /static/", staticHandleFunc())

	mux.HandleFunc("GET /", linkHandleFunc(s.links, s.log))

	s.http = &http.Server{
		Addr:    net.JoinHostPort(s.host, s.port),
		Handler: mux,
	}

	return s.start(), s.stop()
}

func (s *Server) start() func() {
	return func() {
		s.log.Info("server startup", slog.String("addr", s.http.Addr))
		if err := s.http.ListenAndServe(); err != nil && err != http.ErrServerClosed {
			s.log.Error("error listening and serving", slog.String("error", err.Error()))
		}
	}
}
func (s *Server) stop() func() {
	return func() {
		s.log.Info("server shutdown")
		time.Sleep(time.Duration(s.waits.wait) * time.Second)
		shutdownCtx, cancel := context.WithTimeout(context.Background(), time.Duration(s.waits.timeout)*time.Second)
		defer cancel()
		if err := s.http.Shutdown(shutdownCtx); err != nil {
			s.log.Error("error shutting down http server", slog.String("error", err.Error()))
		}
	}
}