grain/config/Blacklist.go

package config

import (
	"fmt"
	types "grain/config/types"
	"grain/server/utils"
	"log"
	"os"
	"strings"
	"sync"
	"time"

	"gopkg.in/yaml.v2"
)

// CheckBlacklist checks if a pubkey is in the blacklist based on event content
func CheckBlacklist(pubkey, eventContent string) (bool, string) {
    blacklistConfig := GetBlacklistConfig()
    if blacklistConfig == nil || !blacklistConfig.Enabled {
        return false, ""
    }

    log.Printf("Checking blacklist for pubkey: %s", pubkey)

    // Check for permanent blacklist by pubkey or npub.
    if isPubKeyPermanentlyBlacklisted(pubkey, blacklistConfig) {
        log.Printf("Pubkey %s is permanently blacklisted", pubkey)
        return true, fmt.Sprintf("pubkey %s is permanently blacklisted", pubkey)
    }

    // Check for temporary ban.
    if isPubKeyTemporarilyBlacklisted(pubkey) {
        log.Printf("Pubkey %s is temporarily blacklisted", pubkey)
        return true, fmt.Sprintf("pubkey %s is temporarily blacklisted", pubkey)
    }

    // Check for permanent ban based on wordlist.
    for _, word := range blacklistConfig.PermanentBanWords {
        if strings.Contains(eventContent, word) {
            err := AddToPermanentBlacklist(pubkey)
            if err != nil {
                return true, fmt.Sprintf("pubkey %s is permanently banned and failed to save: %v", pubkey, err)
            }
            return true, "blocked: pubkey is permanently banned"
        }
    }

    // Check for temporary ban based on wordlist.
    for _, word := range blacklistConfig.TempBanWords {
        if strings.Contains(eventContent, word) {
            err := AddToTemporaryBlacklist(pubkey, *blacklistConfig)
            if err != nil {
                return true, fmt.Sprintf("pubkey %s is temporarily banned and failed to save: %v", pubkey, err)
            }
            return true, "blocked: pubkey is temporarily banned"
        }
    }

    return false, ""
}


// Checks if a pubkey is temporarily blacklisted
func isPubKeyTemporarilyBlacklisted(pubkey string) bool {
	mu.Lock()
	defer mu.Unlock()

	entry, exists := tempBannedPubkeys[pubkey]
	if !exists {
		log.Printf("Pubkey %s not found in temporary blacklist", pubkey)
		return false
	}

	now := time.Now()
	if now.After(entry.unbanTime) {
		log.Printf("Temporary ban for pubkey %s has expired. Count: %d", pubkey, entry.count)
		return false
	}

	log.Printf("Pubkey %s is currently temporarily blacklisted. Count: %d, Unban time: %s", pubkey, entry.count, entry.unbanTime)
	return true
}

func ClearTemporaryBans() {
	mu.Lock()
	defer mu.Unlock()
	tempBannedPubkeys = make(map[string]*tempBanEntry)
}

var (
	tempBannedPubkeys = make(map[string]*tempBanEntry)
	mu                sync.Mutex
)

type tempBanEntry struct {
	count     int
	unbanTime time.Time
}

// Adds a pubkey to the temporary blacklist
func AddToTemporaryBlacklist(pubkey string, blacklistConfig types.BlacklistConfig) error {
	mu.Lock()
	defer mu.Unlock()

	entry, exists := tempBannedPubkeys[pubkey]
	if !exists {
		log.Printf("Creating new temporary ban entry for pubkey %s", pubkey)
		entry = &tempBanEntry{
			count:     0,
			unbanTime: time.Now(),
		}
		tempBannedPubkeys[pubkey] = entry
	} else {
		log.Printf("Updating existing temporary ban entry for pubkey %s. Current count: %d", pubkey, entry.count)
		if time.Now().After(entry.unbanTime) {
			log.Printf("Previous ban for pubkey %s has expired. Keeping count at %d", pubkey, entry.count)
		}
	}

	// Increment the count
	entry.count++
	entry.unbanTime = time.Now().Add(time.Duration(blacklistConfig.TempBanDuration) * time.Second)

	log.Printf("Pubkey %s temporary ban count updated to: %d, MaxTempBans: %d, New unban time: %s", pubkey, entry.count, blacklistConfig.MaxTempBans, entry.unbanTime)

	if entry.count > blacklistConfig.MaxTempBans {
		log.Printf("Attempting to move pubkey %s to permanent blacklist", pubkey)
		delete(tempBannedPubkeys, pubkey)

		// Release the lock before calling AddToPermanentBlacklist
		mu.Unlock()
		err := AddToPermanentBlacklist(pubkey)
		mu.Lock() // Re-acquire the lock

		if err != nil {
			log.Printf("Error adding pubkey %s to permanent blacklist: %v", pubkey, err)
			return err
		}
		log.Printf("Successfully added pubkey %s to permanent blacklist", pubkey)
	}

	return nil
}

func isPubKeyPermanentlyBlacklisted(pubKey string, blacklistConfig *types.BlacklistConfig) bool {
    if blacklistConfig == nil || !blacklistConfig.Enabled {
        return false
    }

    // Check pubkeys.
    for _, blacklistedKey := range blacklistConfig.PermanentBlacklistPubkeys {
        if pubKey == blacklistedKey {
            return true
        }
    }

    // Check npubs.
    for _, npub := range blacklistConfig.PermanentBlacklistNpubs {
        decodedPubKey, err := utils.DecodeNpub(npub)
        if err != nil {
            fmt.Println("Error decoding npub:", err)
            continue
        }
        if pubKey == decodedPubKey {
            return true
        }
    }

    return false
}

func AddToPermanentBlacklist(pubkey string) error {
    blacklistConfig := GetBlacklistConfig()
    if blacklistConfig == nil {
        return fmt.Errorf("blacklist configuration is not loaded")
    }

    // Check if already blacklisted.
    if isPubKeyPermanentlyBlacklisted(pubkey, blacklistConfig) {
        return fmt.Errorf("pubkey %s is already in the permanent blacklist", pubkey)
    }

    // Add pubkey to the permanent blacklist.
    blacklistConfig.PermanentBlacklistPubkeys = append(blacklistConfig.PermanentBlacklistPubkeys, pubkey)

    // Persist changes to blacklist.yml.
    return saveBlacklistConfig(*blacklistConfig)
}

func saveBlacklistConfig(blacklistConfig types.BlacklistConfig) error {
    data, err := yaml.Marshal(blacklistConfig)
    if err != nil {
        return fmt.Errorf("failed to marshal blacklist config: %v", err)
    }

    err = os.WriteFile("blacklist.yml", data, 0644)
    if err != nil {
        return fmt.Errorf("failed to write config to file: %v", err)
    }

    return nil
}