cproof/src/ai/ai_client.h

#ifndef AI_CLIENT_H
#define AI_CLIENT_H

#include <glib.h>

/**
 * @brief AI message structure for conversation history.
 */
typedef struct ai_message_t
{
    gchar* role;    /* "user" or "assistant" */
    gchar* content; /* Message content */
} AIMessage;

/**
 * @brief AI provider configuration.
 */
typedef struct ai_provider_t
{
    gchar* name;           /* Provider name (e.g., "openai", "perplexity") */
    gchar* api_url;        /* API endpoint URL */
    gchar* project_id;     /* Optional project ID (for some providers) */
    gchar* default_model;  /* Default model for this provider */
    GHashTable* settings;  /* Extensible per-provider settings (e.g., tools=enabled, search=disabled) */
    GList* models;         /* Cached models (gchar*) */
    gboolean models_fresh; /* Whether models cache is current */
    gint32 ref_count;      /* Reference count (atomic) */
} AIProvider;

/**
 * @brief AI chat session structure.
 */
typedef struct ai_session_t
{
    pthread_mutex_t lock; /* Protects all session fields below */
    gchar* provider_name; /* Provider name */
    AIProvider* provider; /* Provider configuration */
    gchar* model;         /* Model identifier (e.g., "gpt-4", "sonar") */
    gchar* api_key;       /* API key for this session */
    GList* history;       /* Conversation history (GList of AIMessage*) */
    gint32 ref_count;     /* Reference count (atomic) */
} AISession;

/* ========================================================================
 * Provider Management
 * ======================================================================== */

/**
 * Initialize the AI client and load default providers.
 */
void ai_client_init(void);

/**
 * Shutdown the AI client and free resources.
 */
void ai_client_shutdown(void);

/**
 * Get a provider by name.
 * @param name The provider name (e.g., "openai", "perplexity")
 * @return AIProvider*, or NULL if not found
 */
AIProvider* ai_get_provider(const gchar* name);

/**
 * Add or update a provider configuration.
 * @param name The provider name
 * @param api_url The API endpoint URL
 * @return New AIProvider* (caller must unref when done)
 */
AIProvider* ai_add_provider(const gchar* name, const gchar* api_url);

/**
 * Remove a provider by name.
 * @param name The provider name
 * @return TRUE if provider was removed, FALSE if not found
 */
gboolean ai_remove_provider(const gchar* name);

/**
 * Increment the reference count of a provider.
 * @param provider The provider to reference
 * @return The same provider pointer
 */
AIProvider* ai_provider_ref(AIProvider* provider);

/**
 * Decrement the reference count of a provider.
 * @param provider The provider to unreference
 */
void ai_provider_unref(AIProvider* provider);

/**
 * List all configured providers.
 * @return GList of AIProvider* (caller must not free the list or providers,
 *         and must not unref the returned providers)
 */
GList* ai_list_providers(void);

/**
 * Find a provider name for autocomplete.
 * @param search_str The search string
 * @param previous Whether to go to previous match
 * @param context Unused
 * @return Provider name, or NULL if not found
 */
gchar* ai_providers_find(const char* const search_str, gboolean previous, void* context);

/**
 * Reset the provider autocomplete state.
 * Called from cmd_ac_reset() to clear autocomplete state.
 */
void ai_providers_reset_ac(void);

/**
 * Get the API key for a provider.
 * @param provider_name The provider name
 * @return The API key, or NULL if not set (caller must free)
 */
gchar* ai_get_provider_key(const gchar* provider_name);

/**
 * Set the API key for a provider.
 * @param provider_name The provider name
 * @param api_key The API key to set
 */
void ai_set_provider_key(const gchar* provider_name, const gchar* api_key);

/**
 * Set the default model for a provider.
 * @param provider_name The provider name
 * @param model The default model name
 */
void ai_set_provider_default_model(const gchar* provider_name, const gchar* model);

/**
 * Get the default model for a provider.
 * @param provider_name The provider name
 * @return The default model name (caller must not free), or NULL if not set
 */
const gchar* ai_get_provider_default_model(const gchar* provider_name);

/**
 * Set a custom setting for a provider.
 * @param provider_name The provider name
 * @param setting The setting key (e.g., "tools", "search")
 * @param value The setting value
 */
void ai_set_provider_setting(const gchar* provider_name, const gchar* setting, const gchar* value);

/**
 * Get a custom setting for a provider.
 * @param provider_name The provider name
 * @param setting The setting key
 * @return The setting value (caller must free), or NULL if not set
 */
gchar* ai_get_provider_setting(const gchar* provider_name, const gchar* setting);

/**
 * Fetch available models from a provider's API.
 * @param provider_name The provider name
 * @param user_data User data (ProfAiWin* for UI display)
 * @return TRUE if the request was successfully queued, FALSE otherwise
 */
gboolean ai_fetch_models(const gchar* provider_name, gpointer user_data);

/**
 * Check if models cache is fresh for a provider.
 * @param provider_name The provider name
 * @return TRUE if models are fresh, FALSE otherwise
 */
gboolean ai_models_are_fresh(const gchar* provider_name);

/* ========================================================================
 * Parsing helpers (exposed for testing)
 * ======================================================================== */

/**
 * Parse model IDs from an OpenAI-compatible API response.
 * Expected format: {"object":"list","data":[{"id":"model1",...},...]}
 * @param provider The provider to add models to
 * @param json The JSON response from the API
 */
void ai_parse_models_from_json(AIProvider* provider, const gchar* json);

/**
 * Extract assistant content from an LLM response body. Tries Perplexity
 * /v1/responses "text" first, falls back to OpenAI "content". Decodes
 * the \" and \n escape sequences only.
 * @param response_json The JSON body from the provider
 * @return Newly allocated content string, or NULL if not found (caller frees)
 */
gchar* ai_parse_response(const gchar* response_json);

/**
 * Extract human-readable error message from an API error envelope.
 * Expected format: {"error":{"message":"...","type":"...","code":...}}
 * Decodes \" \n \\ \t escapes.
 * @param error_json The JSON body of the error response
 * @return Newly allocated error message, or NULL if not parseable (caller frees)
 */
gchar* ai_parse_error_message(const gchar* error_json);

/* ========================================================================
 * Session Management
 * ======================================================================== */

/**
 * Create a new AI session with the specified provider and model.
 * @param provider_name The provider name (e.g., "openai")
 * @param model The model identifier (e.g., "gpt-4")
 * @return New AISession*, or NULL on failure
 */
AISession* ai_session_create(const gchar* provider_name, const gchar* model);

/**
 * Increment the reference count of an AI session.
 * @param session The session to reference
 * @return The same session pointer
 */
AISession* ai_session_ref(AISession* session);

/**
 * Decrement the reference count and free the session when it reaches zero.
 * @param session The session to unreference
 */
void ai_session_unref(AISession* session);

/**
 * Add a message to the session history.
 * @param session The session
 * @param role The message role ("user" or "assistant")
 * @param content The message content
 */
void ai_session_add_message(AISession* session, const gchar* role, const gchar* content);

/**
 * Clear the conversation history.
 * @param session The session
 */
void ai_session_clear_history(AISession* session);

/**
 * Get the current model for a session.
 * @param session The session
 * @return The model name (caller must not free)
 */
const gchar* ai_session_get_model(AISession* session);

/**
 * Set the model for a session.
 * @param session The session
 * @param model The model name
 */
void ai_session_set_model(AISession* session, const gchar* model);

/**
 * Atomically switch session provider, model, and API key.
 * All mutations happen under the session lock to prevent races with
 * _ai_request_thread() which snapshots session state before making requests.
 *
 * @param session The session
 * @param provider_name New provider name
 * @param model New model identifier
 * @param api_key New API key (caller must free after calling this)
 */
void ai_session_switch(AISession* session, const gchar* provider_name,
                       const gchar* model, gchar* api_key);

/* ========================================================================
 * Request Handling
 * ======================================================================== */

/**
 * Send a prompt to the AI provider asynchronously.
 * @param session The AI session containing provider and model
 * @param prompt The prompt to send
 * @param user_data User data (ProfAiWin* for UI display)
 * @return TRUE if the request was successfully queued, FALSE otherwise
 */
gboolean ai_send_prompt(AISession* session, const gchar* prompt,
                        gpointer user_data);

/**
 * Escape a string for JSON embedding.
 * @param str The string to escape
 * @return Newly allocated escaped string (caller must free)
 */
gchar* ai_json_escape(const gchar* str);

#endif /* AI_CLIENT_H */