package api

import (
	"embed"
	"net"
	"net/http"

	"github.com/gin-contrib/cors"
	"github.com/gin-gonic/gin"
	"github.com/go-gost/core/auth"
	"github.com/go-gost/core/service"
)

var (
	//go:embed swagger.yaml
	swaggerDoc embed.FS
)

type Response struct {
	Code int    `json:"code,omitempty"`
	Msg  string `json:"msg,omitempty"`
}

type options struct {
	accessLog  bool
	pathPrefix string
	auther     auth.Authenticator
}

type Option func(*options)

func PathPrefixOption(pathPrefix string) Option {
	return func(o *options) {
		o.pathPrefix = pathPrefix
	}
}

func AccessLogOption(enable bool) Option {
	return func(o *options) {
		o.accessLog = enable
	}
}

func AutherOption(auther auth.Authenticator) Option {
	return func(o *options) {
		o.auther = auther
	}
}

type server struct {
	s      *http.Server
	ln     net.Listener
	cclose chan struct{}
}

func NewService(addr string, opts ...Option) (service.Service, error) {
	ln, err := net.Listen("tcp", addr)
	if err != nil {
		return nil, err
	}

	var options options
	for _, opt := range opts {
		opt(&options)
	}

	gin.SetMode(gin.ReleaseMode)

	r := gin.New()
	r.Use(
		cors.New((cors.Config{
			AllowAllOrigins:     true,
			AllowMethods:        []string{"GET", "POST", "PUT", "DELETE", "OPTIONS"},
			AllowHeaders:        []string{"*"},
			AllowPrivateNetwork: true,
		})),
		gin.Recovery(),
	)
	if options.accessLog {
		r.Use(mwLogger())
	}

	router := r.Group("")
	if options.pathPrefix != "" {
		router = router.Group(options.pathPrefix)
	}

	router.StaticFS("/docs", http.FS(swaggerDoc))

	config := router.Group("/config")
	config.Use(mwBasicAuth(options.auther))
	registerConfig(config)

	return &server{
		s: &http.Server{
			Handler: r,
		},
		ln:     ln,
		cclose: make(chan struct{}),
	}, nil
}

func (s *server) Serve() error {
	return s.s.Serve(s.ln)
}

func (s *server) Addr() net.Addr {
	return s.ln.Addr()
}

func (s *server) Close() error {
	return s.s.Close()
}

func (s *server) IsClosed() bool {
	select {
	case <-s.cclose:
		return true
	default:
		return false
	}
}

func registerConfig(config *gin.RouterGroup) {
	config.GET("", getConfig)
	config.POST("", saveConfig)

	config.POST("/services", createService)
	config.PUT("/services/:service", updateService)
	config.DELETE("/services/:service", deleteService)

	config.POST("/chains", createChain)
	config.PUT("/chains/:chain", updateChain)
	config.DELETE("/chains/:chain", deleteChain)

	config.POST("/hops", createHop)
	config.PUT("/hops/:hop", updateHop)
	config.DELETE("/hops/:hop", deleteHop)

	config.POST("/authers", createAuther)
	config.PUT("/authers/:auther", updateAuther)
	config.DELETE("/authers/:auther", deleteAuther)

	config.POST("/admissions", createAdmission)
	config.PUT("/admissions/:admission", updateAdmission)
	config.DELETE("/admissions/:admission", deleteAdmission)

	config.POST("/bypasses", createBypass)
	config.PUT("/bypasses/:bypass", updateBypass)
	config.DELETE("/bypasses/:bypass", deleteBypass)

	config.POST("/resolvers", createResolver)
	config.PUT("/resolvers/:resolver", updateResolver)
	config.DELETE("/resolvers/:resolver", deleteResolver)

	config.POST("/hosts", createHosts)
	config.PUT("/hosts/:hosts", updateHosts)
	config.DELETE("/hosts/:hosts", deleteHosts)

	config.POST("/ingresses", createIngress)
	config.PUT("/ingresses/:ingress", updateIngress)
	config.DELETE("/ingresses/:ingress", deleteIngress)

	config.POST("/routers", createRouter)
	config.PUT("/routers/:router", updateRouter)
	config.DELETE("/routers/:router", deleteRouter)

	config.POST("/observers", createObserver)
	config.PUT("/observers/:observer", updateObserver)
	config.DELETE("/observers/:observer", deleteObserver)

	config.POST("/recorders", createRecorder)
	config.PUT("/recorders/:recorder", updateRecorder)
	config.DELETE("/recorders/:recorder", deleteRecorder)

	config.POST("/sds", createSD)
	config.PUT("/sds/:sd", updateSD)
	config.DELETE("/sds/:sd", deleteSD)

	config.POST("/limiters", createLimiter)
	config.PUT("/limiters/:limiter", updateLimiter)
	config.DELETE("/limiters/:limiter", deleteLimiter)

	config.POST("/climiters", createConnLimiter)
	config.PUT("/climiters/:limiter", updateConnLimiter)
	config.DELETE("/climiters/:limiter", deleteConnLimiter)

	config.POST("/rlimiters", createRateLimiter)
	config.PUT("/rlimiters/:limiter", updateRateLimiter)
	config.DELETE("/rlimiters/:limiter", deleteRateLimiter)
}