/*
 * Ginxsom Blossom Server Header
 *
 * This header contains all function declarations and type definitions
 * organized by BUD (Blossom Unified Draft) sections.
 */

#ifndef GINXSOM_H
#define GINXSOM_H
// Version information (auto-updated by build system)
#define VERSION_MAJOR 0
#define VERSION_MINOR 1
#define VERSION_PATCH 18
#define VERSION "v0.1.18"

#include <stddef.h>
#include <stdint.h>
#include <time.h>
#include <fcgi_stdio.h>
#include <sqlite3.h>
#include "../nostr_core_lib/cjson/cJSON.h"

#ifdef __cplusplus
extern "C" {
#endif

/////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////////////
//             BUD 01 - Basic Protocol Flow
/////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////////////

// Database connection management
extern sqlite3* db;
int init_database(void);
void close_database(void);

// Global configuration variables (defined in main.c)
extern char g_db_path[4096];
extern char g_storage_dir[4096];

// SHA-256 extraction and validation
const char* extract_sha256_from_uri(const char* uri);

// HEAD request handling
void handle_head_request(const char* uri);

/////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////////////
//             BUD 02 - Upload & Authentication
/////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////////////

// Request validation system - implemented in request_validator.c
// Functions implemented in src/request_validator.c

// NOSTR result constants
#define NOSTR_SUCCESS 0
#define NOSTR_ERROR_INVALID_JSON -1
#define NOSTR_ERROR_MISSING_FIELD -2
#define NOSTR_ERROR_INVALID_SIGNATURE -3
#define NOSTR_ERROR_INVALID_PUBKEY -4
#define NOSTR_ERROR_DATABASE -10
#define NOSTR_ERROR_UNAUTHORIZED -11
#define NOSTR_ERROR_MEMORY -12

// NIP-42 modes
typedef enum {
    NIP42_MODE_DISABLED = 0,
    NIP42_MODE_OPTIONAL = 1,
    NIP42_MODE_REQUIRED = 2
} nip42_mode_t;

// Request validation types and enums (matching ginxsom usage)
typedef struct {
    const char* operation;        // Operation type ("upload", "delete", "list", "publish", "admin")
    const char* auth_header;      // Raw authorization header (optional)
    cJSON* event;                 // Parsed NOSTR event for validation (optional)
    const char* resource_hash;    // Resource hash (SHA-256, optional)
    const char* mime_type;        // MIME type (optional)
    long file_size;               // File size (optional)
    const char* relay_url;        // Relay URL for NIP-42 validation (optional)
    const char* challenge_id;     // Challenge ID for NIP-42 verification (optional)
    int nip42_mode;               // NIP-42 mode: 0=disabled, 1=optional, 2=required
    const char* client_ip;        // Client IP address (optional)
    void* app_context;            // Application context (unused, for compatibility)
} nostr_request_t;

// Extended request structure for unified API
typedef struct {
    const char* operation;        // Operation type ("upload", "delete", "list", "publish", "admin")
    const char* auth_header;      // Raw authorization header (optional)
    cJSON* event;                 // Parsed NOSTR event for validation (optional)
    const char* resource_hash;    // Resource hash (SHA-256, optional)
    const char* mime_type;        // MIME type (optional)
    long file_size;               // File size (optional)
    const char* request_url;      // Request URL for NIP-42 relay URL validation (optional)
    const char* challenge_id;     // Challenge ID for NIP-42 verification (optional)
    int nip42_enabled;            // Whether NIP-42 authentication is enabled
    const char* client_ip;        // Client IP address (optional)
    void* app_context;            // Application context (unused, for compatibility)
} nostr_unified_request_t;

typedef struct {
    int valid;                    // 0 = invalid/denied, 1 = valid/allowed
    int error_code;               // NOSTR_SUCCESS or specific error code
    char reason[256];             // Human-readable reason for denial/acceptance
    char pubkey[65];              // Extracted pubkey from validated event (if available)
    
    // NEW: File data for upload operations (Option 1 implementation)
    unsigned char *file_data;     // File content buffer (malloc'd by validator)
    size_t file_size;             // Size of file data in bytes
    char expected_hash[65];       // Expected SHA-256 hash from Blossom event
    int owns_file_data;           // 1 if validator owns memory, 0 if not
} nostr_request_result_t;

// Challenge structure for NIP-42
typedef struct {
    char challenge_id[65];
    time_t expires_at;
} nostr_nip42_challenge_t;

// Function declarations for nostr_core_lib functions used by ginxsom
int nostr_validate_event(cJSON* event);
int nostr_validate_event_structure(cJSON* event);
int nostr_verify_event_signature(cJSON* event);
int nostr_sha256(const unsigned char* data, size_t len, unsigned char* hash);
void nostr_bytes_to_hex(const unsigned char* bytes, size_t len, char* hex_out);
int nostr_crypto_init(void);

// Unified API function (main entry point)
int nostr_validate_unified_request(const nostr_unified_request_t* request, nostr_request_result_t* result);
int ginxsom_request_validator_init(const char* db_path, const char* app_name);
int nostr_auth_rules_enabled(void);
void ginxsom_request_validator_cleanup(void);
void nostr_request_validator_force_cache_refresh(void);
int nostr_request_validator_generate_nip42_challenge(void* challenge_struct, const char* client_ip);

// New NIP-42 challenge management functions
int nostr_generate_nip42_challenge(char* challenge_out, size_t challenge_size, const char* client_ip);
const char* nostr_request_validator_get_last_violation_type(void);
void nostr_request_validator_clear_violation(void);

// File data cleanup function
void nostr_request_result_free_file_data(nostr_request_result_t* result);

// Upload handling
void handle_upload_request(void);
void handle_upload_request_with_validation(nostr_request_result_t* validation_result);

// Blob metadata structure
typedef struct {
    char sha256[65];
    long size;
    char type[128];
    long uploaded_at;
    char filename[256];
    int found;
} blob_metadata_t;

// Blob metadata database operations
int insert_blob_metadata(const char* sha256, long size, const char* type,
                         long uploaded_at, const char* uploader_pubkey,
                         const char* filename);
int get_blob_metadata(const char* sha256, blob_metadata_t* metadata);

/////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////////////
//             BUD 04 - Mirroring
/////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////////////

// Mirror request handling
void handle_mirror_request(void);

// URL validation for mirroring
int validate_mirror_url(const char* url);

// Content type detection for mirrored blobs
const char* determine_blob_content_type(const char* url, const char* header_content_type,
                                       const unsigned char* data, size_t size);

/////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////////////
//             BUD 06 - Upload Requirements
/////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////////////

// Upload policy management (for future implementation)
void handle_upload_requirements_request(void);

// BUD-06 specific functions
void handle_head_upload_request(void);
int validate_upload_headers(const char** sha256, const char** content_type,
                           long* content_length, char* error_reason, size_t reason_size);
void send_upload_error_response(int status_code, const char* error_type,
                               const char* message, const char* x_reason);
void send_upload_success_response(const char* sha256, const char* content_type, long content_length);
int validate_content_length(const char* content_length_str, long* parsed_length);
int check_blob_exists(const char* sha256);

/////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////////////
//             BUD 09 - Blob Report (NIP-56 Report Events)
/////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////////////

// Report event validation
int validate_report_event_structure(cJSON* event);
int extract_blob_hashes_from_report(cJSON* event, char blob_hashes[][65], int max_hashes);
int validate_report_types(cJSON* event);

// Report storage and handling
int store_blob_report(const char* event_json, const char* reporter_pubkey);
void handle_report_request(void);

/////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////////////
//             BUD 08 - NIP-94 File Metadata Tags
/////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////////////

// NIP-94 configuration and control
int nip94_is_enabled(void);
int nip94_get_origin(char* out, size_t out_size);

// MIME type and file extension handling
const char* mime_to_extension(const char* mime_type);
void nip94_build_blob_url(const char* origin, const char* sha256, const char* mime_type, char* out, size_t out_size);

// Image dimension parsing
int parse_png_dimensions(const unsigned char* data, size_t size, int* width, int* height);
int parse_jpeg_dimensions(const unsigned char* data, size_t size, int* width, int* height);
int parse_webp_dimensions(const unsigned char* data, size_t size, int* width, int* height);
int nip94_get_dimensions(const unsigned char* data, size_t size, const char* mime_type, int* width, int* height);

// NIP-94 metadata emission
void nip94_emit_field(const char* url, const char* mime, const char* sha256, long size, int width, int height);

/////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////////////
//             UTILITY FUNCTIONS
/////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////////////

// HTTP response helpers
void send_error_response(int status_code, const char* error_type, const char* message, const char* details);
void send_json_response(int status_code, const char* json_content);

// Logging utilities
void log_request(const char* method, const char* uri, const char* auth_status, int status_code);

// Centralized application logging (writes to logs/app/app.log)
typedef enum {
    LOG_DEBUG = 0,
    LOG_INFO = 1,
    LOG_WARN = 2,
    LOG_ERROR = 3
} log_level_t;

void app_log(log_level_t level, const char* format, ...);

// SHA-256 validation helper (used by multiple BUDs)
int validate_sha256_format(const char* sha256);

/////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////////////
//             ADMIN API ENDPOINTS
/////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////////////

// Admin API request handler
void handle_admin_api_request(const char* method, const char* uri, const char* validated_pubkey, int is_authenticated);

// Admin event handler (Kind 23458/23459)
void handle_admin_event_request(void);

// Admin interface handler (serves embedded web UI)
void handle_admin_interface_request(const char* path);

// Individual endpoint handlers
void handle_stats_api(void);
void handle_config_get_api(void);
void handle_config_put_api(void);
void handle_config_key_put_api(const char* key);
void handle_files_api(void);
void handle_health_api(void);

// Admin authentication functions
int authenticate_admin_request(const char* auth_header);
int is_admin_enabled(void);
int verify_admin_pubkey(const char* event_pubkey);

// Admin API utility functions
void send_json_response(int status, const char* json_content);
void send_json_error(int status, const char* error, const char* message);
int parse_query_params(const char* query_string, char params[][256], int max_params);

#ifdef __cplusplus
}
#endif

#endif // GINXSOM_H