package api

import (
	"context"
	"crypto/sha256"
	"encoding/hex"
	"encoding/json"
	"log"
	"net"
	"net/http"
	"strings"
	"time"

	"halcyon/store"
)

// clientIP is the address a request really came from. Behind our own reverse
// proxy (a loopback or private peer) the proxy's X-Forwarded-For names it;
// otherwise the header is untrusted and ignored.
func clientIP(r *http.Request) string {
	host, _, err := net.SplitHostPort(r.RemoteAddr)
	if err != nil {
		host = r.RemoteAddr
	}
	if ip := net.ParseIP(host); ip != nil && (ip.IsLoopback() || ip.IsPrivate()) {
		if xff := r.Header.Get("X-Forwarded-For"); xff != "" {
			first := strings.TrimSpace(strings.Split(xff, ",")[0])
			if net.ParseIP(first) != nil {
				return first
			}
		}
	}
	return host
}

func sha256Hex(b []byte) string {
	h := sha256.Sum256(b)
	return hex.EncodeToString(h[:])
}

// audit records something a player did. It is best effort: a failure to write
// the log is reported but never fails the player's request.
func (s *Server) audit(r *http.Request, player int64, action string, ship int64, slot int, detail map[string]any) {
	if detail == nil {
		detail = map[string]any{}
	}
	b, _ := json.Marshal(detail)
	err := s.st.AddAudit(context.WithoutCancel(r.Context()), store.AuditEntry{
		At: time.Now().Unix(), PlayerID: player, Action: action, Ship: ship, Slot: slot,
		Detail: string(b), IP: clientIP(r),
	})
	if err != nil {
		log.Printf("audit: could not record %s for player %d: %v", action, player, err)
	}
}