c-relay/src/config.c

#include "config.h"
#include "default_config_event.h"
#include "../nostr_core_lib/nostr_core/nostr_core.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <unistd.h>
#include <dirent.h>
#include <sys/stat.h>
#include <errno.h>

// External database connection (from main.c)
extern sqlite3* g_db;

// Global configuration manager instance
config_manager_t g_config_manager = {0};
char g_database_path[512] = {0};

// Logging functions (defined in main.c)
extern void log_info(const char* message);
extern void log_success(const char* message);
extern void log_warning(const char* message);
extern void log_error(const char* message);

// Current configuration cache
static cJSON* g_current_config = NULL;

// Cache for initial configuration event (before database is initialized)
static cJSON* g_pending_config_event = NULL;

// ================================
// UTILITY FUNCTIONS
// ================================

char** find_existing_nrdb_files(void) {
    DIR *dir;
    struct dirent *entry;
    char **files = NULL;
    int count = 0;
    
    dir = opendir(".");
    if (dir == NULL) {
        return NULL;
    }
    
    // Count .nrdb files
    while ((entry = readdir(dir)) != NULL) {
        if (strstr(entry->d_name, ".nrdb") != NULL) {
            count++;
        }
    }
    rewinddir(dir);
    
    if (count == 0) {
        closedir(dir);
        return NULL;
    }
    
    // Allocate array for filenames
    files = malloc((count + 1) * sizeof(char*));
    if (!files) {
        closedir(dir);
        return NULL;
    }
    
    // Store filenames
    int i = 0;
    while ((entry = readdir(dir)) != NULL && i < count) {
        if (strstr(entry->d_name, ".nrdb") != NULL) {
            files[i] = malloc(strlen(entry->d_name) + 1);
            if (files[i]) {
                strcpy(files[i], entry->d_name);
                i++;
            }
        }
    }
    files[i] = NULL;  // Null terminate
    
    closedir(dir);
    return files;
}

char* extract_pubkey_from_filename(const char* filename) {
    if (!filename) return NULL;
    
    // Find .nrdb extension
    const char* dot = strstr(filename, ".nrdb");
    if (!dot) return NULL;
    
    // Calculate pubkey length
    size_t pubkey_len = dot - filename;
    if (pubkey_len != 64) return NULL;  // Invalid pubkey length
    
    // Allocate and copy pubkey
    char* pubkey = malloc(pubkey_len + 1);
    if (!pubkey) return NULL;
    
    strncpy(pubkey, filename, pubkey_len);
    pubkey[pubkey_len] = '\0';
    
    return pubkey;
}

char* get_database_name_from_relay_pubkey(const char* relay_pubkey) {
    if (!relay_pubkey || strlen(relay_pubkey) != 64) {
        return NULL;
    }
    
    char* db_name = malloc(strlen(relay_pubkey) + 6);  // +6 for ".nrdb\0"
    if (!db_name) return NULL;
    
    sprintf(db_name, "%s.nrdb", relay_pubkey);
    return db_name;
}

// ================================
// DATABASE FUNCTIONS
// ================================

int create_database_with_relay_pubkey(const char* relay_pubkey) {
    char* db_name = get_database_name_from_relay_pubkey(relay_pubkey);
    if (!db_name) {
        log_error("Failed to generate database name");
        return -1;
    }
    
    strncpy(g_database_path, db_name, sizeof(g_database_path) - 1);
    g_database_path[sizeof(g_database_path) - 1] = '\0';
    
    log_info("Creating database with relay pubkey");
    printf("  Database: %s\n", db_name);
    
    free(db_name);
    return 0;
}

// ================================
// CONFIGURATION EVENT FUNCTIONS
// ================================

int store_config_event_in_database(const cJSON* event) {
    if (!event || !g_db) {
        return -1;
    }
    
    // Get event fields
    cJSON* id_obj = cJSON_GetObjectItem(event, "id");
    cJSON* pubkey_obj = cJSON_GetObjectItem(event, "pubkey");
    cJSON* created_at_obj = cJSON_GetObjectItem(event, "created_at");
    cJSON* kind_obj = cJSON_GetObjectItem(event, "kind");
    cJSON* content_obj = cJSON_GetObjectItem(event, "content");
    cJSON* sig_obj = cJSON_GetObjectItem(event, "sig");
    cJSON* tags_obj = cJSON_GetObjectItem(event, "tags");
    
    if (!id_obj || !pubkey_obj || !created_at_obj || !kind_obj || !content_obj || !sig_obj || !tags_obj) {
        return -1;
    }
    
    // Convert tags to JSON string
    char* tags_str = cJSON_Print(tags_obj);
    if (!tags_str) {
        return -1;
    }
    
    // Insert or replace the configuration event (kind 33334 is replaceable)
    const char* sql = "INSERT OR REPLACE INTO events (id, pubkey, created_at, kind, event_type, content, sig, tags) VALUES (?, ?, ?, ?, ?, ?, ?, ?)";
    sqlite3_stmt* stmt;
    
    int rc = sqlite3_prepare_v2(g_db, sql, -1, &stmt, NULL);
    if (rc != SQLITE_OK) {
        log_error("Failed to prepare configuration event insert");
        free(tags_str);
        return -1;
    }
    
    sqlite3_bind_text(stmt, 1, cJSON_GetStringValue(id_obj), -1, SQLITE_STATIC);
    sqlite3_bind_text(stmt, 2, cJSON_GetStringValue(pubkey_obj), -1, SQLITE_STATIC);
    sqlite3_bind_int64(stmt, 3, (sqlite3_int64)cJSON_GetNumberValue(created_at_obj));
    sqlite3_bind_int(stmt, 4, (int)cJSON_GetNumberValue(kind_obj));
    sqlite3_bind_text(stmt, 5, "addressable", -1, SQLITE_STATIC);  // kind 33334 is addressable
    sqlite3_bind_text(stmt, 6, cJSON_GetStringValue(content_obj), -1, SQLITE_STATIC);
    sqlite3_bind_text(stmt, 7, cJSON_GetStringValue(sig_obj), -1, SQLITE_STATIC);
    sqlite3_bind_text(stmt, 8, tags_str, -1, SQLITE_TRANSIENT);
    
    rc = sqlite3_step(stmt);
    sqlite3_finalize(stmt);
    free(tags_str);
    
    if (rc == SQLITE_DONE) {
        log_success("Configuration event stored in database");
        return 0;
    } else {
        log_error("Failed to store configuration event");
        return -1;
    }
}

cJSON* load_config_event_from_database(const char* relay_pubkey) {
    if (!g_db || !relay_pubkey) {
        return NULL;
    }
    
    const char* sql;
    sqlite3_stmt* stmt;
    int rc;
    
    // If we have admin pubkey, query by it; otherwise find the most recent kind 33334 event
    if (strlen(g_config_manager.admin_pubkey) > 0) {
        sql = "SELECT id, pubkey, created_at, kind, content, sig, tags FROM events WHERE kind = 33334 AND pubkey = ? ORDER BY created_at DESC LIMIT 1";
        rc = sqlite3_prepare_v2(g_db, sql, -1, &stmt, NULL);
        if (rc != SQLITE_OK) {
            log_error("Failed to prepare configuration event query");
            return NULL;
        }
        sqlite3_bind_text(stmt, 1, g_config_manager.admin_pubkey, -1, SQLITE_STATIC);
    } else {
        // During existing relay startup, we don't know the admin pubkey yet
        // Look for any kind 33334 configuration event (should only be one per relay)
        sql = "SELECT id, pubkey, created_at, kind, content, sig, tags FROM events WHERE kind = 33334 ORDER BY created_at DESC LIMIT 1";
        rc = sqlite3_prepare_v2(g_db, sql, -1, &stmt, NULL);
        if (rc != SQLITE_OK) {
            log_error("Failed to prepare configuration event query");
            return NULL;
        }
    }
    
    cJSON* event = NULL;
    if (sqlite3_step(stmt) == SQLITE_ROW) {
        // Reconstruct the event JSON from database columns
        event = cJSON_CreateObject();
        if (event) {
            const char* event_pubkey = (const char*)sqlite3_column_text(stmt, 1);
            
            cJSON_AddStringToObject(event, "id", (const char*)sqlite3_column_text(stmt, 0));
            cJSON_AddStringToObject(event, "pubkey", event_pubkey);
            cJSON_AddNumberToObject(event, "created_at", sqlite3_column_int64(stmt, 2));
            cJSON_AddNumberToObject(event, "kind", sqlite3_column_int(stmt, 3));
            cJSON_AddStringToObject(event, "content", (const char*)sqlite3_column_text(stmt, 4));
            cJSON_AddStringToObject(event, "sig", (const char*)sqlite3_column_text(stmt, 5));
            
            // If we didn't have admin pubkey, store it now
            if (strlen(g_config_manager.admin_pubkey) == 0) {
                strncpy(g_config_manager.admin_pubkey, event_pubkey, sizeof(g_config_manager.admin_pubkey) - 1);
                g_config_manager.admin_pubkey[sizeof(g_config_manager.admin_pubkey) - 1] = '\0';
            }
            
            // Parse tags JSON
            const char* tags_str = (const char*)sqlite3_column_text(stmt, 6);
            if (tags_str) {
                cJSON* tags = cJSON_Parse(tags_str);
                if (tags) {
                    cJSON_AddItemToObject(event, "tags", tags);
                } else {
                    cJSON_AddItemToObject(event, "tags", cJSON_CreateArray());
                }
            } else {
                cJSON_AddItemToObject(event, "tags", cJSON_CreateArray());
            }
        }
    }
    
    sqlite3_finalize(stmt);
    return event;
}

// ================================
// CONFIGURATION ACCESS FUNCTIONS
// ================================

const char* get_config_value(const char* key) {
    static char buffer[CONFIG_VALUE_MAX_LENGTH];
    
    if (!key || !g_current_config) {
        return NULL;
    }
    
    // Look for key in current configuration tags
    cJSON* tags = cJSON_GetObjectItem(g_current_config, "tags");
    if (!tags || !cJSON_IsArray(tags)) {
        return NULL;
    }
    
    cJSON* tag = NULL;
    cJSON_ArrayForEach(tag, tags) {
        if (cJSON_IsArray(tag) && cJSON_GetArraySize(tag) >= 2) {
            cJSON* tag_key = cJSON_GetArrayItem(tag, 0);
            cJSON* tag_value = cJSON_GetArrayItem(tag, 1);
            
            if (tag_key && tag_value && 
                cJSON_IsString(tag_key) && cJSON_IsString(tag_value)) {
                
                if (strcmp(cJSON_GetStringValue(tag_key), key) == 0) {
                    strncpy(buffer, cJSON_GetStringValue(tag_value), sizeof(buffer) - 1);
                    buffer[sizeof(buffer) - 1] = '\0';
                    return buffer;
                }
            }
        }
    }
    
    return NULL;
}

int get_config_int(const char* key, int default_value) {
    const char* str_value = get_config_value(key);
    if (!str_value) {
        return default_value;
    }
    
    char* endptr;
    long val = strtol(str_value, &endptr, 10);
    
    if (endptr == str_value || *endptr != '\0') {
        return default_value;
    }
    
    return (int)val;
}

int get_config_bool(const char* key, int default_value) {
    const char* str_value = get_config_value(key);
    if (!str_value) {
        return default_value;
    }
    
    if (strcasecmp(str_value, "true") == 0 || 
        strcasecmp(str_value, "yes") == 0 || 
        strcasecmp(str_value, "1") == 0) {
        return 1;
    } else if (strcasecmp(str_value, "false") == 0 || 
               strcasecmp(str_value, "no") == 0 || 
               strcasecmp(str_value, "0") == 0) {
        return 0;
    }
    
    return default_value;
}

// ================================
// FIRST-TIME STARTUP FUNCTIONS
// ================================

int is_first_time_startup(void) {
    char** existing_files = find_existing_nrdb_files();
    if (existing_files) {
        // Free the array
        for (int i = 0; existing_files[i]; i++) {
            free(existing_files[i]);
        }
        free(existing_files);
        return 0;  // Not first time
    }
    return 1;  // First time
}

// ================================
// COMPATIBILITY FUNCTIONS
// ================================

int init_configuration_system(const char* config_dir_override, const char* config_file_override) {
    // Suppress unused parameter warnings for compatibility function
    (void)config_dir_override;
    (void)config_file_override;
    
    log_info("Initializing event-based configuration system...");
    
    // Clear configuration manager state
    memset(&g_config_manager, 0, sizeof(config_manager_t));
    g_config_manager.db = g_db;
    
    // For now, set empty paths for compatibility
    g_config_manager.config_file_path[0] = '\0';
    
    log_success("Event-based configuration system initialized");
    return 0;
}

void cleanup_configuration_system(void) {
    log_info("Cleaning up configuration system...");
    
    if (g_current_config) {
        cJSON_Delete(g_current_config);
        g_current_config = NULL;
    }
    
    if (g_pending_config_event) {
        cJSON_Delete(g_pending_config_event);
        g_pending_config_event = NULL;
    }
    
    memset(&g_config_manager, 0, sizeof(config_manager_t));
    log_success("Configuration system cleaned up");
}

int set_database_config(const char* key, const char* value, const char* changed_by) {
    // Suppress unused parameter warnings for compatibility function
    (void)key;
    (void)value;
    (void)changed_by;
    
    // Temporary compatibility function - does nothing for now
    // In the new system, configuration is only updated via events
    log_warning("set_database_config called - not supported in event-based config");
    return 0;
}

// ================================
// KEY GENERATION FUNCTIONS
// ================================

// Helper function to generate random private key
int generate_random_private_key_bytes(unsigned char* privkey_bytes) {
    if (!privkey_bytes) {
        return -1;
    }
    
    FILE* urandom = fopen("/dev/urandom", "rb");
    if (!urandom) {
        log_error("Failed to open /dev/urandom for key generation");
        return -1;
    }
    
    if (fread(privkey_bytes, 1, 32, urandom) != 32) {
        log_error("Failed to read random bytes for private key");
        fclose(urandom);
        return -1;
    }
    fclose(urandom);
    
    // Verify the private key is valid using nostr_core_lib
    if (nostr_ec_private_key_verify(privkey_bytes) != NOSTR_SUCCESS) {
        log_error("Generated private key failed validation");
        return -1;
    }
    
    return 0;
}

// ================================
// DEFAULT CONFIG EVENT CREATION
// ================================

cJSON* create_default_config_event(const unsigned char* admin_privkey_bytes,
                                   const char* relay_privkey_hex,
                                   const char* relay_pubkey_hex) {
    if (!admin_privkey_bytes || !relay_privkey_hex || !relay_pubkey_hex) {
        log_error("Invalid parameters for creating default config event");
        return NULL;
    }
    
    log_info("Creating default configuration event...");
    
    // Create tags array with default configuration values
    cJSON* tags = cJSON_CreateArray();
    if (!tags) {
        log_error("Failed to create tags array");
        return NULL;
    }
    
    // Add d tag with relay pubkey
    cJSON* d_tag = cJSON_CreateArray();
    cJSON_AddItemToArray(d_tag, cJSON_CreateString("d"));
    cJSON_AddItemToArray(d_tag, cJSON_CreateString(relay_pubkey_hex));
    cJSON_AddItemToArray(tags, d_tag);
    
    // Add relay keys
    cJSON* relay_pubkey_tag = cJSON_CreateArray();
    cJSON_AddItemToArray(relay_pubkey_tag, cJSON_CreateString("relay_pubkey"));
    cJSON_AddItemToArray(relay_pubkey_tag, cJSON_CreateString(relay_pubkey_hex));
    cJSON_AddItemToArray(tags, relay_pubkey_tag);
    
    cJSON* relay_privkey_tag = cJSON_CreateArray();
    cJSON_AddItemToArray(relay_privkey_tag, cJSON_CreateString("relay_privkey"));
    cJSON_AddItemToArray(relay_privkey_tag, cJSON_CreateString(relay_privkey_hex));
    cJSON_AddItemToArray(tags, relay_privkey_tag);
    
    // Add all default configuration values
    for (size_t i = 0; i < DEFAULT_CONFIG_COUNT; i++) {
        cJSON* tag = cJSON_CreateArray();
        cJSON_AddItemToArray(tag, cJSON_CreateString(DEFAULT_CONFIG_VALUES[i].key));
        cJSON_AddItemToArray(tag, cJSON_CreateString(DEFAULT_CONFIG_VALUES[i].value));
        cJSON_AddItemToArray(tags, tag);
    }
    
    // Create and sign event using nostr_core_lib
    cJSON* event = nostr_create_and_sign_event(
        33334,                                          // kind
        "C Nostr Relay Configuration",                  // content
        tags,                                           // tags
        admin_privkey_bytes,                           // private key bytes for signing
        time(NULL)                                      // created_at timestamp
    );
    
    cJSON_Delete(tags); // Clean up tags as they were duplicated in nostr_create_and_sign_event
    
    if (!event) {
        log_error("Failed to create and sign configuration event");
        return NULL;
    }
    
    // Log success information
    cJSON* id_obj = cJSON_GetObjectItem(event, "id");
    cJSON* pubkey_obj = cJSON_GetObjectItem(event, "pubkey");
    
    if (id_obj && pubkey_obj) {
        log_success("Default configuration event created successfully");
        printf("  Event ID: %s\n", cJSON_GetStringValue(id_obj));
        printf("  Admin Public Key: %s\n", cJSON_GetStringValue(pubkey_obj));
    }
    
    return event;
}

// ================================
// IMPLEMENTED FUNCTIONS
// ================================

int first_time_startup_sequence(void) {
    log_info("Starting first-time startup sequence...");
    
    // 1. Generate admin keypair using /dev/urandom + nostr_core_lib
    unsigned char admin_privkey_bytes[32];
    char admin_privkey[65], admin_pubkey[65];
    
    if (generate_random_private_key_bytes(admin_privkey_bytes) != 0) {
        log_error("Failed to generate admin private key");
        return -1;
    }
    nostr_bytes_to_hex(admin_privkey_bytes, 32, admin_privkey);
    
    unsigned char admin_pubkey_bytes[32];
    if (nostr_ec_public_key_from_private_key(admin_privkey_bytes, admin_pubkey_bytes) != NOSTR_SUCCESS) {
        log_error("Failed to derive admin public key");
        return -1;
    }
    nostr_bytes_to_hex(admin_pubkey_bytes, 32, admin_pubkey);
    
    // 2. Generate relay keypair using /dev/urandom + nostr_core_lib
    unsigned char relay_privkey_bytes[32];
    char relay_privkey[65], relay_pubkey[65];
    
    if (generate_random_private_key_bytes(relay_privkey_bytes) != 0) {
        log_error("Failed to generate relay private key");
        return -1;
    }
    nostr_bytes_to_hex(relay_privkey_bytes, 32, relay_privkey);
    
    unsigned char relay_pubkey_bytes[32];
    if (nostr_ec_public_key_from_private_key(relay_privkey_bytes, relay_pubkey_bytes) != NOSTR_SUCCESS) {
        log_error("Failed to derive relay public key");
        return -1;
    }
    nostr_bytes_to_hex(relay_pubkey_bytes, 32, relay_pubkey);
    
    // 3. Store keys in global config manager
    strncpy(g_config_manager.admin_pubkey, admin_pubkey, sizeof(g_config_manager.admin_pubkey) - 1);
    g_config_manager.admin_pubkey[sizeof(g_config_manager.admin_pubkey) - 1] = '\0';
    strncpy(g_config_manager.relay_pubkey, relay_pubkey, sizeof(g_config_manager.relay_pubkey) - 1);
    g_config_manager.relay_pubkey[sizeof(g_config_manager.relay_pubkey) - 1] = '\0';
    
    // 4. Create database with relay pubkey name
    if (create_database_with_relay_pubkey(relay_pubkey) != 0) {
        log_error("Failed to create database with relay pubkey");
        return -1;
    }
    
    // 5. Create initial configuration event using defaults
    cJSON* config_event = create_default_config_event(admin_privkey_bytes, relay_privkey, relay_pubkey);
    if (!config_event) {
        log_error("Failed to create default configuration event");
        return -1;
    }
    
    // 6. Try to store configuration event in database, but cache it if database isn't ready
    if (store_config_event_in_database(config_event) == 0) {
        log_success("Initial configuration event stored successfully");
    } else {
        log_warning("Failed to store initial configuration event - will retry after database init");
        // Cache the event for later storage
        if (g_pending_config_event) {
            cJSON_Delete(g_pending_config_event);
        }
        g_pending_config_event = cJSON_Duplicate(config_event, 1);
    }
    
    // 7. Cache the current config
    if (g_current_config) {
        cJSON_Delete(g_current_config);
    }
    g_current_config = cJSON_Duplicate(config_event, 1);
    
    // 8. Clean up
    cJSON_Delete(config_event);
    
    // 9. Print admin private key for user to save
    printf("\n");
    printf("=================================================================\n");
    printf("IMPORTANT: SAVE THIS ADMIN PRIVATE KEY SECURELY!\n");
    printf("=================================================================\n");
    printf("Admin Private Key: %s\n", admin_privkey);
    printf("Admin Public Key:  %s\n", admin_pubkey);
    printf("\nRelay Private Key: %s\n", relay_privkey);
    printf("Relay Public Key:  %s\n", relay_pubkey);
    printf("\nDatabase: %s\n", g_database_path);
    printf("\nThis admin private key is needed to update configuration!\n");
    printf("Store it safely - it will not be displayed again.\n");
    printf("=================================================================\n");
    printf("\n");
    
    log_success("First-time startup sequence completed");
    return 0;
}

int startup_existing_relay(const char* relay_pubkey) {
    if (!relay_pubkey) {
        log_error("Invalid relay pubkey for existing relay startup");
        return -1;
    }
    
    log_info("Starting existing relay...");
    printf("  Relay pubkey: %s\n", relay_pubkey);
    
    // Store relay pubkey in global config manager
    strncpy(g_config_manager.relay_pubkey, relay_pubkey, sizeof(g_config_manager.relay_pubkey) - 1);
    
    // Set database path
    char* db_name = get_database_name_from_relay_pubkey(relay_pubkey);
    if (!db_name) {
        log_error("Failed to generate database name");
        return -1;
    }
    
    strncpy(g_database_path, db_name, sizeof(g_database_path) - 1);
    g_database_path[sizeof(g_database_path) - 1] = '\0';
    free(db_name);
    
    // Load configuration event from database (after database is initialized)
    // This will be done in apply_configuration_from_database()
    
    log_success("Existing relay startup prepared");
    return 0;
}

int process_configuration_event(const cJSON* event) {
    if (!event) {
        log_error("Invalid configuration event");
        return -1;
    }
    
    log_info("Processing configuration event...");
    
    // Validate event structure
    cJSON* kind_obj = cJSON_GetObjectItem(event, "kind");
    cJSON* pubkey_obj = cJSON_GetObjectItem(event, "pubkey");
    
    if (!kind_obj || cJSON_GetNumberValue(kind_obj) != 33334) {
        log_error("Invalid event kind for configuration");
        return -1;
    }
    
    if (!pubkey_obj) {
        log_error("Missing pubkey in configuration event");
        return -1;
    }
    
    // Verify it's from the admin
    const char* event_pubkey = cJSON_GetStringValue(pubkey_obj);
    if (strlen(g_config_manager.admin_pubkey) > 0) {
        if (strcmp(event_pubkey, g_config_manager.admin_pubkey) != 0) {
            log_error("Configuration event not from authorized admin");
            return -1;
        }
    }
    
    // Comprehensive event validation using nostr_core_lib
    log_info("Validating configuration event structure and signature...");
    
    // First validate the event structure (fields, format, etc.)
    if (nostr_validate_event_structure((cJSON*)event) != NOSTR_SUCCESS) {
        log_error("Configuration event has invalid structure");
        return -1;
    }
    
    // Then validate the cryptographic signature
    if (nostr_verify_event_signature((cJSON*)event) != NOSTR_SUCCESS) {
        log_error("Configuration event has invalid signature");
        return -1;
    }
    
    log_success("Configuration event structure and signature validated successfully");
    
    // Store in database
    if (store_config_event_in_database(event) != 0) {
        log_error("Failed to store configuration event");
        return -1;
    }
    
    // Apply configuration
    if (apply_configuration_from_event(event) != 0) {
        log_error("Failed to apply configuration from event");
        return -1;
    }
    
    log_success("Configuration event processed successfully");
    return 0;
}

// ================================
// RUNTIME CONFIGURATION HANDLERS
// ================================

// External functions and globals from main.c that need to be updated
extern void update_subscription_manager_config(void);
extern void init_pow_config(void);
extern void init_expiration_config(void);
extern void init_relay_info(void);

// Compare configuration values between old and new config
static const char* get_config_value_from_event(const cJSON* event, const char* key) {
    if (!event || !key) return NULL;
    
    cJSON* tags = cJSON_GetObjectItem(event, "tags");
    if (!tags || !cJSON_IsArray(tags)) return NULL;
    
    cJSON* tag = NULL;
    cJSON_ArrayForEach(tag, tags) {
        if (cJSON_IsArray(tag) && cJSON_GetArraySize(tag) >= 2) {
            cJSON* tag_key = cJSON_GetArrayItem(tag, 0);
            cJSON* tag_value = cJSON_GetArrayItem(tag, 1);
            
            if (tag_key && tag_value &&
                cJSON_IsString(tag_key) && cJSON_IsString(tag_value)) {
                if (strcmp(cJSON_GetStringValue(tag_key), key) == 0) {
                    return cJSON_GetStringValue(tag_value);
                }
            }
        }
    }
    return NULL;
}

// Check if a configuration value has changed
static int config_value_changed(const cJSON* old_config, const cJSON* new_config, const char* key) {
    const char* old_value = get_config_value_from_event(old_config, key);
    const char* new_value = get_config_value_from_event(new_config, key);
    
    // Both NULL - no change
    if (!old_value && !new_value) return 0;
    
    // One is NULL, other isn't - changed
    if (!old_value || !new_value) return 1;
    
    // Compare string values
    return strcmp(old_value, new_value) != 0;
}

// Apply runtime configuration changes by calling appropriate handlers
int apply_runtime_config_handlers(const cJSON* old_config, const cJSON* new_config) {
    if (!new_config) return 0;
    
    int handlers_applied = 0;
    
    log_info("Checking for runtime configuration changes...");
    
    // Subscription Manager Configuration
    if (config_value_changed(old_config, new_config, "max_subscriptions_per_client") ||
        config_value_changed(old_config, new_config, "max_total_subscriptions")) {
        log_info("Subscription limits changed - updating subscription manager");
        update_subscription_manager_config();
        handlers_applied++;
    }
    
    // NIP-13 Proof of Work Configuration
    if (config_value_changed(old_config, new_config, "pow_min_difficulty") ||
        config_value_changed(old_config, new_config, "pow_mode")) {
        log_info("PoW configuration changed - reinitializing PoW system");
        init_pow_config();
        handlers_applied++;
    }
    
    // NIP-40 Expiration Configuration
    if (config_value_changed(old_config, new_config, "nip40_expiration_enabled") ||
        config_value_changed(old_config, new_config, "nip40_expiration_strict") ||
        config_value_changed(old_config, new_config, "nip40_expiration_filter") ||
        config_value_changed(old_config, new_config, "nip40_expiration_grace_period")) {
        log_info("Expiration configuration changed - reinitializing expiration system");
        init_expiration_config();
        handlers_applied++;
    }
    
    // NIP-11 Relay Information
    if (config_value_changed(old_config, new_config, "relay_description") ||
        config_value_changed(old_config, new_config, "relay_contact") ||
        config_value_changed(old_config, new_config, "relay_software") ||
        config_value_changed(old_config, new_config, "relay_version") ||
        config_value_changed(old_config, new_config, "max_message_length") ||
        config_value_changed(old_config, new_config, "max_event_tags") ||
        config_value_changed(old_config, new_config, "max_content_length")) {
        log_info("Relay information changed - reinitializing relay info");
        init_relay_info();
        handlers_applied++;
    }
    
    // Log configuration changes for audit
    if (handlers_applied > 0) {
        char audit_msg[512];
        snprintf(audit_msg, sizeof(audit_msg),
                "Configuration updated via kind 33334 event - %d system components reinitialized",
                handlers_applied);
        log_success(audit_msg);
    } else {
        log_info("No runtime configuration changes detected");
    }
    
    return handlers_applied;
}

int apply_configuration_from_event(const cJSON* event) {
    if (!event) {
        log_error("Invalid event for configuration application");
        return -1;
    }
    
    log_info("Applying configuration from event...");
    
    // Store previous config for comparison
    cJSON* old_config = g_current_config;
    
    // Update cached configuration
    g_current_config = cJSON_Duplicate(event, 1);
    
    // Extract admin pubkey if not already set
    cJSON* pubkey_obj = cJSON_GetObjectItem(event, "pubkey");
    if (pubkey_obj && strlen(g_config_manager.admin_pubkey) == 0) {
        strncpy(g_config_manager.admin_pubkey, cJSON_GetStringValue(pubkey_obj),
                sizeof(g_config_manager.admin_pubkey) - 1);
    }
    
    // Apply runtime configuration changes
    int handlers_applied = apply_runtime_config_handlers(old_config, g_current_config);
    
    // Clean up old config
    if (old_config) {
        cJSON_Delete(old_config);
    }
    
    char success_msg[256];
    snprintf(success_msg, sizeof(success_msg),
             "Configuration applied from event (%d handlers executed)", handlers_applied);
    log_success(success_msg);
    return 0;
}

// ================================
// REAL-TIME EVENT HANDLER (called from main.c)
// ================================

// Handle kind 33334 configuration events received via WebSocket
int handle_configuration_event(cJSON* event, char* error_message, size_t error_size) {
    if (!event) {
        snprintf(error_message, error_size, "invalid: null configuration event");
        return -1;
    }

    log_info("Handling configuration event from WebSocket");

    // Use existing process_configuration_event function
    if (process_configuration_event(event) == 0) {
        // Success
        error_message[0] = '\0';  // Empty error message indicates success
        return 0;
    } else {
        // Failed to process
        snprintf(error_message, error_size, "error: failed to process configuration event");
        return -1;
    }
}

// ================================
// RETRY INITIAL CONFIG EVENT STORAGE
// ================================

int retry_store_initial_config_event(void) {
    if (!g_pending_config_event) {
        // No pending event to store
        return 0;
    }
    
    log_info("Retrying storage of initial configuration event...");
    
    // Try to store the cached configuration event
    if (store_config_event_in_database(g_pending_config_event) == 0) {
        log_success("Initial configuration event stored successfully on retry");
        
        // Clean up the pending event
        cJSON_Delete(g_pending_config_event);
        g_pending_config_event = NULL;
        return 0;
    } else {
        log_error("Failed to store initial configuration event on retry");
        return -1;
    }
}