package standard

import (
	"net/http"
	"sync"

	"github.com/labstack/echo"
	"github.com/labstack/echo/engine"
	"github.com/labstack/gommon/log"
)

type (
	Server struct {
		*http.Server
		config  *engine.Config
		handler engine.HandlerFunc
		pool    *Pool
		logger  *log.Logger
	}

	Pool struct {
		request  sync.Pool
		response sync.Pool
		header   sync.Pool
		url      sync.Pool
	}
)

func New(addr string) *Server {
	c := &engine.Config{Address: addr}
	return NewConfig(c)
}

func NewTLS(addr, certfile, keyfile string) *Server {
	c := &engine.Config{
		Address:     addr,
		TLSCertfile: certfile,
		TLSKeyfile:  keyfile,
	}
	return NewConfig(c)
}

func NewConfig(c *engine.Config) (s *Server) {
	s = &Server{
		Server: new(http.Server),
		config: c,
		pool: &Pool{
			request: sync.Pool{
				New: func() interface{} {
					return &Request{}
				},
			},
			response: sync.Pool{
				New: func() interface{} {
					return &Response{logger: s.logger}
				},
			},
			header: sync.Pool{
				New: func() interface{} {
					return &Header{}
				},
			},
			url: sync.Pool{
				New: func() interface{} {
					return &URL{}
				},
			},
		},
		handler: func(req engine.Request, res engine.Response) {
			s.logger.Fatal("handler not set")
		},
		logger: log.New("echo"),
	}
	return
}

func (s *Server) SetHandler(h engine.HandlerFunc) {
	s.handler = h
}

func (s *Server) SetLogger(l *log.Logger) {
	s.logger = l
}

func (s *Server) Start() {
	s.Addr = s.config.Address
	s.Handler = s
	certfile := s.config.TLSCertfile
	keyfile := s.config.TLSKeyfile
	if certfile != "" && keyfile != "" {
		s.logger.Fatal(s.ListenAndServeTLS(certfile, keyfile))
	} else {
		s.logger.Fatal(s.ListenAndServe())
	}
}

func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	// Request
	req := s.pool.request.Get().(*Request)
	reqHdr := s.pool.header.Get().(*Header)
	reqURL := s.pool.url.Get().(*URL)
	reqHdr.reset(r.Header)
	reqURL.reset(r.URL)
	req.reset(r, reqHdr, reqURL)

	// Response
	res := s.pool.response.Get().(*Response)
	resHdr := s.pool.header.Get().(*Header)
	resHdr.reset(w.Header())
	res.reset(w, resHdr)

	s.handler(req, res)

	s.pool.request.Put(req)
	s.pool.header.Put(reqHdr)
	s.pool.url.Put(reqURL)
	s.pool.response.Put(res)
	s.pool.header.Put(resHdr)
}

// WrapHandler wraps `http.Handler` into `echo.HandlerFunc`.
func WrapHandler(h http.Handler) echo.HandlerFunc {
	return func(c echo.Context) error {
		w := c.Response().Object().(http.ResponseWriter)
		r := c.Request().Object().(*http.Request)
		h.ServeHTTP(w, r)
		return nil
	}
}

// WrapMiddleware wraps `http.Handler` into `echo.MiddlewareFunc`
func WrapMiddleware(h http.Handler) echo.MiddlewareFunc {
	return func(next echo.Handler) echo.Handler {
		return echo.HandlerFunc(func(c echo.Context) error {
			w := c.Response().Object().(http.ResponseWriter)
			r := c.Request().Object().(*http.Request)
			if !c.Response().Committed() {
				h.ServeHTTP(w, r)
			}
			return next.Handle(c)
		})
	}
}