;;;;  -*- Mode: LISP; Syntax: Common-Lisp; Base: 10; Pkg: umlisp -*-
;; SQL/UMLS database Layer over database backend
;; Copyright (c) 2001 Kevin M. Rosenberg, M.D.
;; $Id: sql.lisp,v 1.1 2002/10/05 20:17:14 kevin Exp $

(in-package :umlisp)

(declaim (optimize (speed 1) (safety 3)))

(defvar *umls-sql-dsn* "KUMLS2002AC")
(defun umls-sql-dsn ()
  *umls-sql-dsn*)
(defun umls-sql-dsn! (dbname)
  (sql-disconnect-pooled)
  (setq *umls-sql-dsn* dbname))

(defvar *umls-sql-user* "webumls")
(defun umls-sql-user ()
  *umls-sql-user*)
(defun umls-sql-user! (u)
  (sql-disconnect-pooled)
  (setq *umls-sql-user* u))

(defvar *umls-sql-passwd* "webumls")
(defun umls-sql-passwd ()
  *umls-sql-passwd*)
(defun umls-sql-passwd! (p)
  (sql-disconnect-pooled)
  (setq *umls-sql-passwd* p))

(defvar *umls-sql-host* "localhost")
(defun umls-sql-host ()
  *umls-sql-host*)
(defun umls-sql-host! (h)
  (sql-disconnect-pooled)
  (setq *umls-sql-host* h))

(defvar *umls-sql-type* :mysql)
(defun umls-sql-type ()
  *umls-sql-type*)
(defun umls-sql-type! (h)
  (sql-disconnect-pooled)
  (setq *umls-sql-type* h))

(defun sql-connect ()
  "Connect to UMLS database, automatically used pooled connections"
  (clsql:connect `(,(umls-sql-host) ,(umls-sql-dsn) ,(umls-sql-user) ,(umls-sql-passwd)) 
		 :database-type *umls-sql-type* :pool t))

(defun sql-disconnect (conn)
  "Disconnect from UMLS database, but put connection back into pool"
  (clsql:disconnect :database conn))

(defun sql-disconnect-pooled ()
  (clsql:disconnect-pooled))

(defmacro with-sql-connection ((conn) &body body)
  `(let ((,conn (sql-connect)))
     (unwind-protect
	 (progn ,@body)
       (when ,conn (clsql:disconnect :database ,conn)))))

(defun sql (stmt conn)
  (if (string-equal "SELECT" (subseq stmt 0 6))
      (sql-query stmt conn)
    (sql-execute stmt conn)))

(defun sql-query (cmd conn &key (types :auto))
  (clsql:query cmd :database conn :types types))

(defun sql-execute (cmd conn)
  (clsql:execute-command cmd :database conn))

(defun umls-sql (stmt)
  (check-type stmt string)
  (with-sql-connection (conn)
    (sql stmt conn)))

;;; Pool of open connections

(defmacro with-mutex-sql ((conn) &body body)
  `(let ((,conn (sql-connect)))
     (unwind-protect
	 (progn ,@body)
       (when ,conn (sql-disconnect ,conn)))))

(defun mutex-sql-execute (cmd)
  (with-mutex-sql (conn)
    (sql-execute cmd conn)))

(defun mutex-sql-query (cmd &key (types :auto))
  (with-mutex-sql (conn)
    (sql-query cmd conn :types types)))