package hls

import (
	_ "embed"
	"errors"
	"fmt"
	"net"
	"net/http"
	gopath "path"
	"strings"
	"time"

	"github.com/gin-gonic/gin"

	"github.com/bluenviron/mediamtx/internal/conf"
	"github.com/bluenviron/mediamtx/internal/defs"
	"github.com/bluenviron/mediamtx/internal/logger"
	"github.com/bluenviron/mediamtx/internal/protocols/httpserv"
	"github.com/bluenviron/mediamtx/internal/restrictnetwork"
)

const (
	hlsPauseAfterAuthError = 2 * time.Second
)

//go:embed index.html
var hlsIndex []byte

//go:embed hls.min.js
var hlsMinJS []byte

type httpServer struct {
	address        string
	encryption     bool
	serverKey      string
	serverCert     string
	allowOrigin    string
	trustedProxies conf.IPsOrCIDRs
	readTimeout    conf.StringDuration
	pathManager    defs.PathManager
	parent         *Server

	inner *httpserv.WrappedServer
}

func (s *httpServer) initialize() error {
	if s.encryption {
		if s.serverCert == "" {
			return fmt.Errorf("server cert is missing")
		}
	} else {
		s.serverKey = ""
		s.serverCert = ""
	}

	router := gin.New()
	router.SetTrustedProxies(s.trustedProxies.ToTrustedProxies()) //nolint:errcheck

	router.NoRoute(s.onRequest)

	network, address := restrictnetwork.Restrict("tcp", s.address)

	var err error
	s.inner, err = httpserv.NewWrappedServer(
		network,
		address,
		time.Duration(s.readTimeout),
		s.serverCert,
		s.serverKey,
		router,
		s,
	)
	if err != nil {
		return err
	}

	return nil
}

// Log implements logger.Writer.
func (s *httpServer) Log(level logger.Level, format string, args ...interface{}) {
	s.parent.Log(level, format, args...)
}

func (s *httpServer) close() {
	s.inner.Close()
}

func (s *httpServer) onRequest(ctx *gin.Context) {
	ctx.Writer.Header().Set("Access-Control-Allow-Origin", s.allowOrigin)
	ctx.Writer.Header().Set("Access-Control-Allow-Credentials", "true")

	switch ctx.Request.Method {
	case http.MethodOptions:
		ctx.Writer.Header().Set("Access-Control-Allow-Methods", "OPTIONS, GET")
		ctx.Writer.Header().Set("Access-Control-Allow-Headers", "Authorization, Range")
		ctx.Writer.WriteHeader(http.StatusNoContent)
		return

	case http.MethodGet:

	default:
		return
	}

	// remove leading prefix
	pa := ctx.Request.URL.Path[1:]

	var dir string
	var fname string

	switch {
	case strings.HasSuffix(pa, "/hls.min.js"):
		ctx.Writer.Header().Set("Cache-Control", "max-age=3600")
		ctx.Writer.Header().Set("Content-Type", "application/javascript")
		ctx.Writer.WriteHeader(http.StatusOK)
		ctx.Writer.Write(hlsMinJS)
		return

	case pa == "", pa == "favicon.ico", strings.HasSuffix(pa, "/hls.min.js.map"):
		return

	case strings.HasSuffix(pa, ".m3u8") ||
		strings.HasSuffix(pa, ".ts") ||
		strings.HasSuffix(pa, ".mp4") ||
		strings.HasSuffix(pa, ".mp"):
		dir, fname = gopath.Dir(pa), gopath.Base(pa)

		if strings.HasSuffix(fname, ".mp") {
			fname += "4"
		}

	default:
		dir, fname = pa, ""

		if !strings.HasSuffix(dir, "/") {
			ctx.Writer.Header().Set("Location", httpserv.LocationWithTrailingSlash(ctx.Request.URL))
			ctx.Writer.WriteHeader(http.StatusMovedPermanently)
			return
		}
	}

	dir = strings.TrimSuffix(dir, "/")
	if dir == "" {
		return
	}

	user, pass, hasCredentials := ctx.Request.BasicAuth()

	res := s.pathManager.GetConfForPath(defs.PathGetConfForPathReq{
		AccessRequest: defs.PathAccessRequest{
			Name:    dir,
			Query:   ctx.Request.URL.RawQuery,
			Publish: false,
			IP:      net.ParseIP(ctx.ClientIP()),
			User:    user,
			Pass:    pass,
			Proto:   defs.AuthProtocolHLS,
		},
	})
	if res.Err != nil {
		var terr defs.AuthenticationError
		if errors.As(res.Err, &terr) {
			if !hasCredentials {
				ctx.Header("WWW-Authenticate", `Basic realm="mediamtx"`)
				ctx.Writer.WriteHeader(http.StatusUnauthorized)
				return
			}

			ip := ctx.ClientIP()
			_, port, _ := net.SplitHostPort(ctx.Request.RemoteAddr)
			remoteAddr := net.JoinHostPort(ip, port)

			s.Log(logger.Info, "connection %v failed to authenticate: %v", remoteAddr, terr.Message)

			// wait some seconds to stop brute force attacks
			<-time.After(hlsPauseAfterAuthError)

			ctx.Writer.WriteHeader(http.StatusUnauthorized)
			return
		}

		ctx.Writer.WriteHeader(http.StatusNotFound)
		return
	}

	switch fname {
	case "":
		ctx.Writer.Header().Set("Cache-Control", "max-age=3600")
		ctx.Writer.Header().Set("Content-Type", "text/html")
		ctx.Writer.WriteHeader(http.StatusOK)
		ctx.Writer.Write(hlsIndex)

	default:
		s.parent.handleRequest(muxerHandleRequestReq{
			path: dir,
			file: fname,
			ctx:  ctx,
		})
	}
}