package main

import (
	"encoding/json"
	"fmt"
	"log"
	"net/http"
	"os"
	"time"
)

// MockWallarm is a test server that simulates a Wallarm node.
// Usage: go run mock_wallarm.go [--mode=allow|block|slow|flaky]
//
// Modes:
//   allow  — always return "allow" verdict
//   block  — always return "block" verdict
//   slow   — delay 5s then allow (tests timeout)
//   flaky  — succeed 3 times, then fail 3 times (tests circuit breaker)

type Verdict struct {
	Verdict string `json:"verdict"`
	Reason  string `json:"reason,omitempty"`
	Score   int    `json:"score,omitempty"`
}

var (
	requestCount int
	mode         string
)

func main() {
	mode = "allow"
	if len(os.Args) > 1 {
		mode = os.Args[1]
	}
	// Also support --mode=block style
	if len(mode) > 7 && mode[:7] == "--mode=" {
		mode = mode[7:]
	}

	http.HandleFunc("/inspect", handleInspect)
	http.HandleFunc("/health", handleHealth)

	port := "8085"
	if p := os.Getenv("PORT"); p != "" {
		port = p
	}

	log.Printf("Mock Wallarm node starting on :%s (mode=%s)", port, mode)
	if err := http.ListenAndServe(":"+port, nil); err != nil {
		log.Fatal(err)
	}
}

func handleInspect(w http.ResponseWriter, r *http.Request) {
	requestCount++

	switch mode {
	case "block":
		writeVerdict(w, "block", "SQL injection detected", 95)

	case "slow":
		time.Sleep(5 * time.Second)
		writeVerdict(w, "allow", "clean", 0)

	case "flaky":
		if requestCount <= 3 {
			writeVerdict(w, "allow", "clean", 0)
		} else {
			// Simulate failure — return 500
			http.Error(w, "internal error", 500)
		}
		if requestCount >= 6 {
			requestCount = 0 // reset cycle
		}

	default: // allow
		writeVerdict(w, "allow", fmt.Sprintf("clean (request #%d)", requestCount), 0)
	}
}

func handleHealth(w http.ResponseWriter, r *http.Request) {
	writeJSON(w, http.StatusOK, map[string]string{"status": "ok"})
}

func writeVerdict(w http.ResponseWriter, verdict, reason string, score int) {
	writeJSON(w, http.StatusOK, Verdict{Verdict: verdict, Reason: reason, Score: score})
}

func writeJSON(w http.ResponseWriter, status int, v interface{}) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(status)
	json.NewEncoder(w).Encode(v)
}