package server

import (
	metrics "com.navi.medici.janus/instrumentation"
	"com.navi.medici.janus/lib"
	"com.navi.medici.janus/utils"
	"compress/gzip"
	"encoding/json"
	"io"
	"io/ioutil"
	"net/http"
	"time"
	"fmt"
	"strings"
)

var (
	healthyBool bool = true
)

const (
	JSON    = "json"
	SUCCESS = "success"
	ERROR   = "error"
)

type NewSchemaRequest struct {
	Topic      string `json:"topic"`
	Schema     string `json:"schema"`
	SchemaType string `json:"schema_type"`
}

type CustomResponse struct {
	Code    int    `json:"code"`
	Message string `json:"message"`
}

func eventsHandlerJson(w http.ResponseWriter, r *http.Request) {
	eventHandlerStartTime := utils.NanosToMillis(time.Now().UnixNano())
	
	headerName := "X-Correlation-Id"
 	substring := "abcdabcd-1234"
	headerValue, ok := r.Header[headerName]
	if ok {
		if strings.HasPrefix(headerValue[0], substring) {
			w.Header().Set("Content-Type", "application/json")
			var rsp = CustomResponse{Code: 200, Message: "OK"}
			json.NewEncoder(w).Encode(rsp)
			fmt.Println("Dropped blacklisted request")
			return
	  	}
	}
	
	var reader io.Reader
	// check if body is gzip compressed
	if r.Header.Get("Content-Encoding") == "gzip" {
		var err error
		reader, err = gzip.NewReader(r.Body)
		if err != nil {
			// log.Printf(err)
			w.Header().Set("Content-Type", "application/json")
			http.Error(w, "Error while decompressing GZIP payload", http.StatusBadRequest)
			metrics.EventHandlerTimeHist.WithLabelValues(JSON, ERROR).Observe(float64(utils.NanosToMillis(time.Now().UnixNano()) - eventHandlerStartTime))
			return
		}
	} else {
		reader = r.Body
	}

	body, err := ioutil.ReadAll(reader)
	if err != nil {
		// log.Printf(err)
		w.Header().Set("Content-Type", "application/json")
		http.Error(w, "Request body invalid", http.StatusBadRequest)
		metrics.EventHandlerTimeHist.WithLabelValues(JSON, ERROR).Observe(float64(utils.NanosToMillis(time.Now().UnixNano()) - eventHandlerStartTime))
		return
	}
	
	w.Header().Set("Content-Type", "application/json")
	lib.JsonRequestChannel <- &lib.RequestObject{Body: body, Header: r.Header}
	var rsp = CustomResponse{Code: 200, Message: "OK"}
	json.NewEncoder(w).Encode(rsp)
	metrics.EventHandlerTimeHist.WithLabelValues(JSON, SUCCESS).Observe(float64(utils.NanosToMillis(time.Now().UnixNano()) - eventHandlerStartTime))
}

func healthHandler(w http.ResponseWriter, r *http.Request) {
	if healthyBool {
		w.Header().Set("Content-Type", "application/json")
		io.WriteString(w, "true")
	} else {
		http.Error(w, "server unhealthy", http.StatusServiceUnavailable)
		return
	}
}