grain/config/Blacklist.go

package config

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

	"github.com/gorilla/websocket"
	"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"
        }
    }

    // Check mutelist blacklist
    if len(blacklistConfig.MuteListAuthors) > 0 {
        cfg := GetConfig()
        if cfg == nil {
            log.Println("Server configuration is not loaded")
            return true, "Internal server error: server configuration is missing"
        }

        localRelayURL := fmt.Sprintf("ws://localhost%s", cfg.Server.Port)
        mutelistedPubkeys, err := FetchPubkeysFromLocalMuteList(localRelayURL, blacklistConfig.MuteListAuthors)
        if err != nil {
            log.Printf("Error fetching pubkeys from mutelist: %v", err)
            return true, "Error fetching pubkeys from mutelist"
        }

        for _, mutelistedPubkey := range mutelistedPubkeys {
            if pubkey == mutelistedPubkey {
                log.Printf("Pubkey %s is in the mutelist", pubkey)
                return true, "not allowed: pubkey is in mutelist"
            }
        }
    } else {
        log.Println("No mutelist event IDs specified in the blacklist configuration")
    }

    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
}

// FetchPubkeysFromLocalMuteList sends a REQ to the local relay for mute list events.
func FetchPubkeysFromLocalMuteList(localRelayURL string, muteListAuthors []string) ([]string, error) {
    var wg sync.WaitGroup
    var mu sync.Mutex
    var allPubkeys []string
    results := make(chan []string, 1)

    wg.Add(1)
    go func() {
        defer wg.Done()

        conn, _, err := websocket.DefaultDialer.Dial(localRelayURL, nil)
        if err != nil {
            log.Printf("Failed to connect to local relay %s: %v", localRelayURL, err)
            return
        }
        defer conn.Close()

        subscriptionID := "mutelist-fetch"

        // Create the REQ message to fetch the mute list events by IDs.
        req := []interface{}{"REQ", subscriptionID, map[string]interface{}{
            "authors": muteListAuthors,
            "kinds": []int{10000}, // Mute list events kind.
        }}

        reqJSON, err := json.Marshal(req)
        if err != nil {
            log.Printf("Failed to marshal request: %v", err)
            return
        }

        err = conn.WriteMessage(websocket.TextMessage, reqJSON)
        if err != nil {
            log.Printf("Failed to send request to local relay %s: %v", localRelayURL, err)
            return
        }

        // Listen for messages from the local relay.
        for {
            _, message, err := conn.ReadMessage()
            if err != nil {
                log.Printf("Error reading message from local relay %s: %v", localRelayURL, err)
                break
            }

            // Log the raw message for debugging.
            log.Printf("Received raw message: %s", message)

            var response []interface{}
            err = json.Unmarshal(message, &response)
            if err != nil || len(response) < 2 {
                log.Printf("Invalid message format or failed to unmarshal: %v", err)
                continue
            }

            // Check for "EVENT" type messages.
            eventType, ok := response[0].(string)
            if !ok {
                log.Printf("Unexpected event type: %v", response[0])
                continue
            }

            if eventType == "EOSE" {
                // End of subscription events; send a "CLOSE" message to the relay.
                closeReq := []interface{}{"CLOSE", subscriptionID}
                closeReqJSON, err := json.Marshal(closeReq)
                if err != nil {
                    log.Printf("Failed to marshal close request: %v", err)
                } else {
                    if err = conn.WriteMessage(websocket.TextMessage, closeReqJSON); err != nil {
                        log.Printf("Failed to send close request to relay %s: %v", localRelayURL, err)
                    } else {
                        log.Println("Sent CLOSE request to end subscription.")
                        
                        // Wait for a potential response or timeout
                        conn.SetReadDeadline(time.Now().Add(500 * time.Millisecond))
                        _, _, err = conn.ReadMessage()
                        if err != nil {
                            if err == io.EOF {
                                log.Println("Connection closed by the server after CLOSE request (EOF)")
                            } else if websocket.IsCloseError(err, websocket.CloseNormalClosure, websocket.CloseGoingAway) {
                                log.Println("WebSocket closed normally after CLOSE request")
                            } else {
                                log.Printf("Unexpected error after CLOSE request: %v", err)
                            }
                        }
                    }
                }
                
                // Ensure we break the loop after handling EOSE
                break
            }

            if eventType == "EVENT" {
                // Safely cast the event data from the third element.
                if len(response) < 3 {
                    log.Printf("Unexpected event format with insufficient data: %v", response)
                    continue
                }

                eventData, ok := response[2].(map[string]interface{})
                if !ok {
                    log.Printf("Expected event data to be a map, got: %T", response[2])
                    continue
                }

                // Log event data for debugging.
                log.Printf("Event data received: %+v", eventData)

                pubkeys := extractPubkeysFromMuteListEvent(eventData)
                results <- pubkeys
            }
        }
    }()

    go func() {
        wg.Wait()
        close(results)
    }()

    // Collect results from the relay.
    for pubkeys := range results {
        mu.Lock()
        allPubkeys = append(allPubkeys, pubkeys...)
        mu.Unlock()
    }

    return allPubkeys, nil
}

// extractPubkeysFromMuteListEvent extracts pubkeys from a mute list event.
func extractPubkeysFromMuteListEvent(eventData map[string]interface{}) []string {
    var pubkeys []string

    tags, ok := eventData["tags"].([]interface{})
    if !ok {
        log.Println("Tags field is missing or not an array")
        return pubkeys
    }

    for _, tag := range tags {
        tagArray, ok := tag.([]interface{})
        if ok && len(tagArray) > 1 && tagArray[0] == "p" {
            pubkey, ok := tagArray[1].(string)
            if ok {
                pubkeys = append(pubkeys, pubkey)
            }
        }
    }

    log.Printf("Extracted pubkeys: %v", pubkeys)
    return pubkeys
}