// NIP-11 Relay Information Document module
#define _GNU_SOURCE
#include <stdio.h>
#include "debug.h"
#include <stdlib.h>
#include <string.h>
#include <pthread.h>
#include <libwebsockets.h>
#include "../nostr_core_lib/cjson/cJSON.h"
#include "config.h"


// Forward declarations for configuration functions
const char* get_config_value(const char* key);
int get_config_int(const char* key, int default_value);
int get_config_bool(const char* key, int default_value);

// NIP-11 relay information is now managed directly from config table

// Forward declarations for constants (defined in config.h and other headers)
#define HTTP_STATUS_OK 200
#define HTTP_STATUS_NOT_ACCEPTABLE 406
#define HTTP_STATUS_INTERNAL_SERVER_ERROR 500


/////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////////////
//             NIP-11 RELAY INFORMATION DOCUMENT
/////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////////////

// Helper function to parse comma-separated string into cJSON array
cJSON* parse_comma_separated_array(const char* csv_string) {
    if (!csv_string || strlen(csv_string) == 0) {
        return cJSON_CreateArray();
    }

    cJSON* array = cJSON_CreateArray();
    if (!array) {
        return NULL;
    }

    char* csv_copy = strdup(csv_string);
    if (!csv_copy) {
        cJSON_Delete(array);
        return NULL;
    }

    char* token = strtok(csv_copy, ",");
    while (token) {
        // Trim whitespace
        while (*token == ' ') token++;
        char* end = token + strlen(token) - 1;
        while (end > token && *end == ' ') *end-- = '\0';

        if (strlen(token) > 0) {
            // Try to parse as number first (for supported_nips)
            char* endptr;
            long num = strtol(token, &endptr, 10);
            if (*endptr == '\0') {
                // It's a number
                cJSON_AddItemToArray(array, cJSON_CreateNumber(num));
            } else {
                // It's a string
                cJSON_AddItemToArray(array, cJSON_CreateString(token));
            }
        }
        token = strtok(NULL, ",");
    }

    free(csv_copy);
    return array;
}

// Initialize relay information using configuration system
void init_relay_info() {
    // NIP-11 relay information is now generated dynamically from config table
    // No initialization needed - data is fetched directly from database when requested
}

// Clean up relay information JSON objects
void cleanup_relay_info() {
    // NIP-11 relay information is now generated dynamically from config table
    // No cleanup needed - data is fetched directly from database when requested
}

// Generate NIP-11 compliant JSON document
cJSON* generate_relay_info_json() {
    cJSON* info = cJSON_CreateObject();
    if (!info) {
        DEBUG_ERROR("Failed to create relay info JSON object");
        return NULL;
    }

    // Get all config values directly from database
    const char* relay_name = get_config_value("relay_name");
    const char* relay_description = get_config_value("relay_description");
    const char* relay_banner = get_config_value("relay_banner");
    const char* relay_icon = get_config_value("relay_icon");
    const char* relay_pubkey = get_config_value("relay_pubkey");
    const char* relay_contact = get_config_value("relay_contact");
    const char* supported_nips_csv = get_config_value("supported_nips");
    const char* relay_software = get_config_value("relay_software");
    const char* relay_version = get_config_value("relay_version");
    const char* privacy_policy = get_config_value("privacy_policy");
    const char* terms_of_service = get_config_value("terms_of_service");
    const char* posting_policy = get_config_value("posting_policy");
    const char* language_tags_csv = get_config_value("language_tags");
    const char* relay_countries_csv = get_config_value("relay_countries");
    const char* payments_url = get_config_value("payments_url");

    // Get config values for limitations
    int max_message_length = get_config_int("max_message_length", 16384);
    int max_subscriptions_per_client = get_config_int("max_subscriptions_per_client", 20);
    int max_limit = get_config_int("max_limit", 5000);
    int max_event_tags = get_config_int("max_event_tags", 100);
    int max_content_length = get_config_int("max_content_length", 8196);
    int default_limit = get_config_int("default_limit", 500);
    int min_pow_difficulty = get_config_int("pow_min_difficulty", 0);
    int admin_enabled = get_config_bool("admin_enabled", 0);

    // Add basic relay information
    if (relay_name && strlen(relay_name) > 0) {
        cJSON_AddStringToObject(info, "name", relay_name);
        free((char*)relay_name);
    } else {
        cJSON_AddStringToObject(info, "name", "C Nostr Relay");
    }

    if (relay_description && strlen(relay_description) > 0) {
        cJSON_AddStringToObject(info, "description", relay_description);
        free((char*)relay_description);
    } else {
        cJSON_AddStringToObject(info, "description", "A high-performance Nostr relay implemented in C with SQLite storage");
    }

    if (relay_banner && strlen(relay_banner) > 0) {
        cJSON_AddStringToObject(info, "banner", relay_banner);
        free((char*)relay_banner);
    }

    if (relay_icon && strlen(relay_icon) > 0) {
        cJSON_AddStringToObject(info, "icon", relay_icon);
        free((char*)relay_icon);
    }

    if (relay_pubkey && strlen(relay_pubkey) > 0) {
        cJSON_AddStringToObject(info, "pubkey", relay_pubkey);
        free((char*)relay_pubkey);
    }

    if (relay_contact && strlen(relay_contact) > 0) {
        cJSON_AddStringToObject(info, "contact", relay_contact);
        free((char*)relay_contact);
    }

    // Add supported NIPs
    if (supported_nips_csv && strlen(supported_nips_csv) > 0) {
        cJSON* supported_nips = parse_comma_separated_array(supported_nips_csv);
        if (supported_nips) {
            cJSON_AddItemToObject(info, "supported_nips", supported_nips);
        }
        free((char*)supported_nips_csv);
    } else {
        // Default supported NIPs
        cJSON* supported_nips = cJSON_CreateArray();
        if (supported_nips) {
            cJSON_AddItemToArray(supported_nips, cJSON_CreateNumber(1));   // NIP-01: Basic protocol
            cJSON_AddItemToArray(supported_nips, cJSON_CreateNumber(9));   // NIP-09: Event deletion
            cJSON_AddItemToArray(supported_nips, cJSON_CreateNumber(11));  // NIP-11: Relay information
            cJSON_AddItemToArray(supported_nips, cJSON_CreateNumber(13));  // NIP-13: Proof of Work
            cJSON_AddItemToArray(supported_nips, cJSON_CreateNumber(15));  // NIP-15: EOSE
            cJSON_AddItemToArray(supported_nips, cJSON_CreateNumber(20));  // NIP-20: Command results
            cJSON_AddItemToArray(supported_nips, cJSON_CreateNumber(40));  // NIP-40: Expiration Timestamp
            cJSON_AddItemToArray(supported_nips, cJSON_CreateNumber(42));  // NIP-42: Authentication
            cJSON_AddItemToObject(info, "supported_nips", supported_nips);
        }
    }

    // Add software information
    if (relay_software && strlen(relay_software) > 0) {
        cJSON_AddStringToObject(info, "software", relay_software);
        free((char*)relay_software);
    } else {
        cJSON_AddStringToObject(info, "software", "https://git.laantungir.net/laantungir/c-relay.git");
    }

    if (relay_version && strlen(relay_version) > 0) {
        cJSON_AddStringToObject(info, "version", relay_version);
        free((char*)relay_version);
    } else {
        cJSON_AddStringToObject(info, "version", "0.2.0");
    }

    // Add policies
    if (privacy_policy && strlen(privacy_policy) > 0) {
        cJSON_AddStringToObject(info, "privacy_policy", privacy_policy);
        free((char*)privacy_policy);
    }

    if (terms_of_service && strlen(terms_of_service) > 0) {
        cJSON_AddStringToObject(info, "terms_of_service", terms_of_service);
        free((char*)terms_of_service);
    }

    if (posting_policy && strlen(posting_policy) > 0) {
        cJSON_AddStringToObject(info, "posting_policy", posting_policy);
        free((char*)posting_policy);
    }

    // Add server limitations
    cJSON* limitation = cJSON_CreateObject();
    if (limitation) {
        cJSON_AddNumberToObject(limitation, "max_message_length", max_message_length);
        cJSON_AddNumberToObject(limitation, "max_subscriptions", max_subscriptions_per_client);
        cJSON_AddNumberToObject(limitation, "max_limit", max_limit);
        cJSON_AddNumberToObject(limitation, "max_subid_length", SUBSCRIPTION_ID_MAX_LENGTH);
        cJSON_AddNumberToObject(limitation, "max_event_tags", max_event_tags);
        cJSON_AddNumberToObject(limitation, "max_content_length", max_content_length);
        cJSON_AddNumberToObject(limitation, "min_pow_difficulty", min_pow_difficulty);
        cJSON_AddBoolToObject(limitation, "auth_required", admin_enabled ? cJSON_True : cJSON_False);
        cJSON_AddBoolToObject(limitation, "payment_required", cJSON_False);
        cJSON_AddBoolToObject(limitation, "restricted_writes", cJSON_False);
        cJSON_AddNumberToObject(limitation, "created_at_lower_limit", 0);
        cJSON_AddNumberToObject(limitation, "created_at_upper_limit", 2147483647);
        cJSON_AddNumberToObject(limitation, "default_limit", default_limit);
        cJSON_AddItemToObject(info, "limitation", limitation);
    }

    // Add retention policies (empty array for now)
    cJSON* retention = cJSON_CreateArray();
    if (retention) {
        cJSON_AddItemToObject(info, "retention", retention);
    }

    // Add geographical and language information
    if (relay_countries_csv && strlen(relay_countries_csv) > 0) {
        cJSON* relay_countries = parse_comma_separated_array(relay_countries_csv);
        if (relay_countries) {
            cJSON_AddItemToObject(info, "relay_countries", relay_countries);
        }
        free((char*)relay_countries_csv);
    } else {
        cJSON* relay_countries = cJSON_CreateArray();
        if (relay_countries) {
            cJSON_AddItemToArray(relay_countries, cJSON_CreateString("*"));
            cJSON_AddItemToObject(info, "relay_countries", relay_countries);
        }
    }

    if (language_tags_csv && strlen(language_tags_csv) > 0) {
        cJSON* language_tags = parse_comma_separated_array(language_tags_csv);
        if (language_tags) {
            cJSON_AddItemToObject(info, "language_tags", language_tags);
        }
        free((char*)language_tags_csv);
    } else {
        cJSON* language_tags = cJSON_CreateArray();
        if (language_tags) {
            cJSON_AddItemToArray(language_tags, cJSON_CreateString("*"));
            cJSON_AddItemToObject(info, "language_tags", language_tags);
        }
    }

    // Add content tags (empty array)
    cJSON* tags = cJSON_CreateArray();
    if (tags) {
        cJSON_AddItemToObject(info, "tags", tags);
    }

    // Add payment information if configured
    if (payments_url && strlen(payments_url) > 0) {
        cJSON_AddStringToObject(info, "payments_url", payments_url);
        free((char*)payments_url);
    }

    // Add fees (empty object - no payment required by default)
    cJSON* fees = cJSON_CreateObject();
    if (fees) {
        cJSON_AddItemToObject(info, "fees", fees);
    }

    return info;
}

// NIP-11 HTTP session data structure for managing buffer lifetime
struct nip11_session_data {
    int type; // 0 for NIP-11
    char* json_buffer;
    size_t json_length;
    int headers_sent;
    int body_sent;
};

// Handle NIP-11 HTTP request with proper asynchronous buffer management
int handle_nip11_http_request(struct lws* wsi, const char* accept_header) {
    
    // Check if client accepts application/nostr+json
    int accepts_nostr_json = 0;
    if (accept_header) {
        if (strstr(accept_header, "application/nostr+json") != NULL) {
            accepts_nostr_json = 1;
        }
    }
    
    if (!accepts_nostr_json) {
        DEBUG_WARN("HTTP request without proper Accept header for NIP-11");
        // Return 406 Not Acceptable
        unsigned char buf[LWS_PRE + 256];
        unsigned char *p = &buf[LWS_PRE];
        unsigned char *start = p;
        unsigned char *end = &buf[sizeof(buf) - 1];

        if (lws_add_http_header_status(wsi, HTTP_STATUS_NOT_ACCEPTABLE, &p, end)) {
            return -1;
        }
        if (lws_add_http_header_by_token(wsi, WSI_TOKEN_HTTP_CONTENT_TYPE, (unsigned char*)"text/plain", 10, &p, end)) {
            return -1;
        }
        if (lws_add_http_header_content_length(wsi, 0, &p, end)) {
            return -1;
        }
        if (lws_finalize_http_header(wsi, &p, end)) {
            return -1;
        }
        lws_write(wsi, start, p - start, LWS_WRITE_HTTP_HEADERS);
        return -1; // Close connection
    }
    
    // Generate relay information JSON
    cJSON* info_json = generate_relay_info_json();
    if (!info_json) {
        DEBUG_ERROR("Failed to generate relay info JSON");
        unsigned char buf[LWS_PRE + 256];
        unsigned char *p = &buf[LWS_PRE];
        unsigned char *start = p;
        unsigned char *end = &buf[sizeof(buf) - 1];

        if (lws_add_http_header_status(wsi, HTTP_STATUS_INTERNAL_SERVER_ERROR, &p, end)) {
            return -1;
        }
        if (lws_add_http_header_by_token(wsi, WSI_TOKEN_HTTP_CONTENT_TYPE, (unsigned char*)"text/plain", 10, &p, end)) {
            return -1;
        }
        if (lws_add_http_header_content_length(wsi, 0, &p, end)) {
            return -1;
        }
        if (lws_finalize_http_header(wsi, &p, end)) {
            return -1;
        }
        lws_write(wsi, start, p - start, LWS_WRITE_HTTP_HEADERS);
        return -1;
    }
    
    char* json_string = cJSON_Print(info_json);
    cJSON_Delete(info_json);

    if (!json_string) {
        DEBUG_ERROR("Failed to serialize relay info JSON");
        unsigned char buf[LWS_PRE + 256];
        unsigned char *p = &buf[LWS_PRE];
        unsigned char *start = p;
        unsigned char *end = &buf[sizeof(buf) - 1];

        if (lws_add_http_header_status(wsi, HTTP_STATUS_INTERNAL_SERVER_ERROR, &p, end)) {
            return -1;
        }
        if (lws_add_http_header_by_token(wsi, WSI_TOKEN_HTTP_CONTENT_TYPE, (unsigned char*)"text/plain", 10, &p, end)) {
            return -1;
        }
        if (lws_add_http_header_content_length(wsi, 0, &p, end)) {
            return -1;
        }
        if (lws_finalize_http_header(wsi, &p, end)) {
            return -1;
        }
        lws_write(wsi, start, p - start, LWS_WRITE_HTTP_HEADERS);
        return -1;
    }

    size_t json_len = strlen(json_string);
    
    // Allocate session data to manage buffer lifetime across callbacks
    struct nip11_session_data* session_data = malloc(sizeof(struct nip11_session_data));
    if (!session_data) {
        DEBUG_ERROR("Failed to allocate NIP-11 session data");
        free(json_string);
        return -1;
    }
    
    // Store JSON buffer in session data for asynchronous handling
    session_data->type = 0; // NIP-11
    session_data->json_buffer = json_string;
    session_data->json_length = json_len;
    session_data->headers_sent = 0;
    session_data->body_sent = 0;
    
    // Store session data in WSI user data for callback access
    lws_set_wsi_user(wsi, session_data);
    
    // Prepare HTTP response with CORS headers
    unsigned char buf[LWS_PRE + 1024];
    unsigned char *p = &buf[LWS_PRE];
    unsigned char *start = p;
    unsigned char *end = &buf[sizeof(buf) - 1];
    
    // Add status
    if (lws_add_http_header_status(wsi, HTTP_STATUS_OK, &p, end)) {
        free(session_data->json_buffer);
        free(session_data);
        return -1;
    }
    
    // Add content type
    if (lws_add_http_header_by_token(wsi, WSI_TOKEN_HTTP_CONTENT_TYPE,
                                     (unsigned char*)"application/nostr+json", 22, &p, end)) {
        free(session_data->json_buffer);
        free(session_data);
        return -1;
    }
    
    // Add content length
    if (lws_add_http_header_content_length(wsi, json_len, &p, end)) {
        free(session_data->json_buffer);
        free(session_data);
        return -1;
    }
    
    // Add CORS headers as required by NIP-11
    if (lws_add_http_header_by_name(wsi, (unsigned char*)"access-control-allow-origin:",
                                    (unsigned char*)"*", 1, &p, end)) {
        free(session_data->json_buffer);
        free(session_data);
        return -1;
    }
    if (lws_add_http_header_by_name(wsi, (unsigned char*)"access-control-allow-headers:",
                                    (unsigned char*)"content-type, accept", 20, &p, end)) {
        free(session_data->json_buffer);
        free(session_data);
        return -1;
    }
    if (lws_add_http_header_by_name(wsi, (unsigned char*)"access-control-allow-methods:",
                                    (unsigned char*)"GET, OPTIONS", 12, &p, end)) {
        free(session_data->json_buffer);
        free(session_data);
        return -1;
    }

    // Add Connection: close to ensure connection closes after response
    if (lws_add_http_header_by_name(wsi, (unsigned char*)"connection:", (unsigned char*)"close", 5, &p, end)) {
        free(session_data->json_buffer);
        free(session_data);
        return -1;
    }
    
    // Finalize headers
    if (lws_finalize_http_header(wsi, &p, end)) {
        free(session_data->json_buffer);
        free(session_data);
        return -1;
    }
    
    // Write headers
    if (lws_write(wsi, start, p - start, LWS_WRITE_HTTP_HEADERS) < 0) {
        free(session_data->json_buffer);
        free(session_data);
        return -1;
    }
    
    session_data->headers_sent = 1;
    
    // Request callback for body transmission
    lws_callback_on_writable(wsi);

    return 0;
}