Add full-text search (FTS) tools to MCP query server

include/MCP_Thread.h

@@ -57,6 +57,7 @@ class MCP_Threads_Handler
 		char* mcp_mysql_password;               ///< MySQL password for tool connections
 		char* mcp_mysql_schema;                 ///< Default schema/database
 		char* mcp_catalog_path;                 ///< Path to catalog SQLite database
+		char* mcp_fts_path;                     ///< Path to FTS SQLite database
 	} variables;
 
 	/**

include/MySQL_FTS.h

@@ -0,0 +1,192 @@
+#ifndef CLASS_MYSQL_FTS_H
+#define CLASS_MYSQL_FTS_H
+
+#include "sqlite3db.h"
+#include <string>
+#include <vector>
+#include <memory>
+
+// Forward declaration
+class MySQL_Tool_Handler;
+
+/**
+ * @brief MySQL Full Text Search (FTS) for Fast Data Discovery
+ *
+ * This class manages a dedicated SQLite database that provides:
+ * - Full-text search indexes for MySQL tables
+ * - Fast data discovery before querying the actual MySQL database
+ * - Cross-table search capabilities
+ * - BM25 ranking with FTS5
+ *
+ * The FTS system serves as a fast local cache for AI agents to quickly
+ * find relevant data before making targeted queries to MySQL backend.
+ */
+class MySQL_FTS {
+private:
+	SQLite3DB* db;
+	std::string db_path;
+
+	/**
+	 * @brief Initialize FTS schema
+	 * @return 0 on success, -1 on error
+	 */
+	int init_schema();
+
+	/**
+	 * @brief Create FTS metadata tables
+	 * @return 0 on success, -1 on error
+	 */
+	int create_tables();
+
+	/**
+	 * @brief Create per-index tables (data and FTS5 virtual table)
+	 * @param schema Schema name
+	 * @param table Table name
+	 * @return 0 on success, -1 on error
+	 */
+	int create_index_tables(const std::string& schema, const std::string& table);
+
+	/**
+	 * @brief Get sanitized data table name for a schema.table
+	 * @param schema Schema name
+	 * @param table Table name
+	 * @return Sanitized table name
+	 */
+	std::string get_data_table_name(const std::string& schema, const std::string& table);
+
+	/**
+	 * @brief Get FTS search table name for a schema.table
+	 * @param schema Schema name
+	 * @param table Table name
+	 * @return Sanitized FTS table name
+	 */
+	std::string get_fts_table_name(const std::string& schema, const std::string& table);
+
+	/**
+	 * @brief Sanitize a name for use as SQLite table name
+	 * @param name Name to sanitize
+	 * @return Sanitized name
+	 */
+	std::string sanitize_name(const std::string& name);
+
+	/**
+	 * @brief Escape single quotes for SQL
+	 * @param str String to escape
+	 * @return Escaped string
+	 */
+	std::string escape_sql(const std::string& str);
+
+public:
+	/**
+	 * @brief Constructor
+	 * @param path Path to the FTS database file
+	 */
+	MySQL_FTS(const std::string& path);
+
+	/**
+	 * @brief Destructor
+	 */
+	~MySQL_FTS();
+
+	/**
+	 * @brief Initialize the FTS database
+	 * @return 0 on success, -1 on error
+	 */
+	int init();
+
+	/**
+	 * @brief Close the FTS database
+	 */
+	void close();
+
+	/**
+	 * @brief Check if an index exists for a schema.table
+	 * @param schema Schema name
+	 * @param table Table name
+	 * @return true if exists, false otherwise
+	 */
+	bool index_exists(const std::string& schema, const std::string& table);
+
+	/**
+	 * @brief Create and populate an FTS index for a MySQL table
+	 *
+	 * @param schema Schema name
+	 * @param table Table name
+	 * @param columns JSON array of column names to index
+	 * @param primary_key Primary key column name
+	 * @param where_clause Optional WHERE clause for filtering
+	 * @param mysql_handler Pointer to MySQL_Tool_Handler for executing queries
+	 * @return JSON result with success status and metadata
+	 */
+	std::string index_table(
+		const std::string& schema,
+		const std::string& table,
+		const std::string& columns,
+		const std::string& primary_key,
+		const std::string& where_clause,
+		MySQL_Tool_Handler* mysql_handler
+	);
+
+	/**
+	 * @brief Search indexed data using FTS5
+	 *
+	 * @param query FTS5 search query
+	 * @param schema Optional schema filter
+	 * @param table Optional table filter
+	 * @param limit Max results (default 100)
+	 * @param offset Pagination offset (default 0)
+	 * @return JSON result with matches and snippets
+	 */
+	std::string search(
+		const std::string& query,
+		const std::string& schema = "",
+		const std::string& table = "",
+		int limit = 100,
+		int offset = 0
+	);
+
+	/**
+	 * @brief List all FTS indexes with metadata
+	 * @return JSON array of indexes
+	 */
+	std::string list_indexes();
+
+	/**
+	 * @brief Remove an FTS index
+	 *
+	 * @param schema Schema name
+	 * @param table Table name
+	 * @return JSON result
+	 */
+	std::string delete_index(const std::string& schema, const std::string& table);
+
+	/**
+	 * @brief Refresh an index with fresh data (full rebuild)
+	 *
+	 * @param schema Schema name
+	 * @param table Table name
+	 * @param mysql_handler Pointer to MySQL_Tool_Handler for executing queries
+	 * @return JSON result
+	 */
+	std::string reindex(
+		const std::string& schema,
+		const std::string& table,
+		MySQL_Tool_Handler* mysql_handler
+	);
+
+	/**
+	 * @brief Rebuild ALL FTS indexes with fresh data
+	 *
+	 * @param mysql_handler Pointer to MySQL_Tool_Handler for executing queries
+	 * @return JSON result with summary
+	 */
+	std::string rebuild_all(MySQL_Tool_Handler* mysql_handler);
+
+	/**
+	 * @brief Get database handle for direct access
+	 * @return SQLite3DB pointer
+	 */
+	SQLite3DB* get_db() { return db; }
+};
+
+#endif /* CLASS_MYSQL_FTS_H */

include/MySQL_Tool_Handler.h

@@ -2,6 +2,7 @@
 #define CLASS_MYSQL_TOOL_HANDLER_H
 
 #include "MySQL_Catalog.h"
+#include "MySQL_FTS.h"
 #include "cpp.h"
 #include <string>
 #include <memory>
@@ -51,6 +52,10 @@ class MySQL_Tool_Handler {
 	// Catalog for LLM memory
 	MySQL_Catalog* catalog;                     ///< SQLite catalog for LLM discoveries
 
+	// FTS for fast data discovery
+	MySQL_FTS* fts;                             ///< SQLite FTS for full-text search
+	pthread_mutex_t fts_lock;                  ///< Mutex protecting FTS lifecycle/usage
+
 	// Query guardrails
 	int max_rows;                               ///< Maximum rows to return (default 200)
 	int timeout_ms;                             ///< Query timeout in milliseconds (default 2000)
@@ -74,13 +79,6 @@ class MySQL_Tool_Handler {
 	 */
 	void return_connection(MYSQL* mysql);
 
-	/**
-	 * @brief Execute a query and return results as JSON
-	 * @param query SQL query to execute
-	 * @return JSON with results or error
-	 */
-	std::string execute_query(const std::string& query);
-
 	/**
 	 * @brief Validate SQL is read-only
 	 * @param query SQL to validate
@@ -111,16 +109,25 @@ class MySQL_Tool_Handler {
 	 * @param password MySQL password
 	 * @param schema Default schema/database
 	 * @param catalog_path Path to catalog database
+	 * @param fts_path Path to FTS database
 	 */
 	MySQL_Tool_Handler(
 		const std::string& hosts,
 		const std::string& ports,
 		const std::string& user,
 		const std::string& password,
 		const std::string& schema,
-		const std::string& catalog_path
+		const std::string& catalog_path,
+		const std::string& fts_path = ""
 	);
 
+	/**
+	 * @brief Reset FTS database path at runtime
+	 * @param path New SQLite FTS database path
+	 * @return true on success, false on error
+	 */
+	bool reset_fts_path(const std::string& path);
+
 	/**
 	 * @brief Destructor
 	 */
@@ -137,6 +144,13 @@ class MySQL_Tool_Handler {
 	 */
 	void close();
 
+	/**
+	 * @brief Execute a query and return results as JSON
+	 * @param query SQL query to execute
+	 * @return JSON with results or error
+	 */
+	std::string execute_query(const std::string& query);
+
 	// ========== Inventory Tools ==========
 
 	/**
@@ -389,6 +403,77 @@ class MySQL_Tool_Handler {
 	 * @return JSON result
 	 */
 	std::string catalog_delete(const std::string& kind, const std::string& key);
+
+	// ========== FTS Tools (Full Text Search) ==========
+
+	/**
+	 * @brief Create and populate an FTS index for a MySQL table
+	 * @param schema Schema name
+	 * @param table Table name
+	 * @param columns JSON array of column names to index
+	 * @param primary_key Primary key column name
+	 * @param where_clause Optional WHERE clause for filtering
+	 * @return JSON result with success status and metadata
+	 */
+	std::string fts_index_table(
+		const std::string& schema,
+		const std::string& table,
+		const std::string& columns,
+		const std::string& primary_key,
+		const std::string& where_clause = ""
+	);
+
+	/**
+	 * @brief Search indexed data using FTS5
+	 * @param query FTS5 search query
+	 * @param schema Optional schema filter
+	 * @param table Optional table filter
+	 * @param limit Max results (default 100)
+	 * @param offset Pagination offset (default 0)
+	 * @return JSON result with matches and snippets
+	 */
+	std::string fts_search(
+		const std::string& query,
+		const std::string& schema = "",
+		const std::string& table = "",
+		int limit = 100,
+		int offset = 0
+	);
+
+	/**
+	 * @brief List all FTS indexes with metadata
+	 * @return JSON array of indexes
+	 */
+	std::string fts_list_indexes();
+
+	/**
+	 * @brief Remove an FTS index
+	 * @param schema Schema name
+	 * @param table Table name
+	 * @return JSON result
+	 */
+	std::string fts_delete_index(const std::string& schema, const std::string& table);
+
+	/**
+	 * @brief Refresh an index with fresh data (full rebuild)
+	 * @param schema Schema name
+	 * @param table Table name
+	 * @return JSON result
+	 */
+	std::string fts_reindex(const std::string& schema, const std::string& table);
+
+	/**
+	 * @brief Rebuild ALL FTS indexes with fresh data
+	 * @return JSON result with summary
+	 */
+	std::string fts_rebuild_all();
+
+	/**
+	 * @brief Reinitialize FTS handler with a new database path
+	 * @param fts_path New path to FTS database
+	 * @return 0 on success, -1 on error
+	 */
+	int reinit_fts(const std::string& fts_path);
 };
 
 #endif /* CLASS_MYSQL_TOOL_HANDLER_H */