;;;; -*- Mode: LISP; Syntax: ANSI-Common-Lisp; Base: 10 -*-
;;;; *************************************************************************
;;;; FILE IDENTIFICATION
;;;;
;;;; Name:     conditions.lisp
;;;; Purpose:  Error conditions for CLSQL
;;;;
;;;; $Id$
;;;;
;;;; This file, part of CLSQL, is Copyright (c) 2002-2004 by Kevin M. Rosenberg
;;;;
;;;; CLSQL users are granted the rights to distribute and use this software
;;;; as governed by the terms of the Lisp Lesser GNU Public License
;;;; (http://opensource.franz.com/preamble.html), also known as the LLGPL.
;;;; *************************************************************************

(in-package #:clsql-sys)

(defvar *backend-warning-behavior* :warn
  "Action to perform on warning messages from backend. Default is to :warn. May also be
set to :error to signal an error or :ignore/nil to silently ignore the warning.")

;;; CommonSQL-compatible conditions
 
(define-condition sql-condition ()
  ())

(define-condition sql-error (simple-error)
  ())

(define-condition sql-database-error (sql-error)
  ((error-id :initarg :error-id 
	     :initform nil
	     :reader sql-error-error-id)
   (secondary-error-id :initarg :secondary-error-id
		       :initform nil
		       :reader sql-error-secondary-error-id)
   (database-message :initarg :message
		     :initform nil
		     :reader sql-error-database-message)
   (database :initarg :database
		     :initform nil
		     :reader sql-error-database))
  (:report (lambda (c stream)
	     (format stream "A database error occurred~A: ~A / ~A~%  ~A"
		     (if (sql-error-database c)
			 (format nil " on database ~A" (sql-error-database c))
			 "")
		     (sql-error-error-id c)
		     (sql-error-secondary-error-id c)
		     (sql-error-database-message c))))
  (:documentation "Used to signal an error in a CLSQL database interface."))

(define-condition sql-connection-error (sql-database-error)
  ((database-type :initarg :database-type :initform nil
		  :reader sql-error-database-type)
   (connection-spec :initarg :connection-spec :initform nil
		  :reader sql-error-connection-spec))
  (:report (lambda (c stream)
	     (format stream "While trying to connect to database ~A~%  using database-type ~A:~%  Error ~D / ~A~%  has occurred."
		     (database-name-from-spec
		      (sql-error-connection-spec c)
		      (sql-error-database-type c))
		     (sql-error-database-type c)
		     (sql-error-error-id c)
		     (sql-error-database-message c))))
  (:documentation "Used to signal an error in connecting to a database."))

(define-condition sql-database-data-error (sql-database-error)
  ((expression :initarg :expression :initarg nil 
	       :reader sql-error-expression))
  (:report (lambda (c stream)
	     (format stream "While accessing database ~A~%  with expression ~S:~%  Error ~D / ~A~%  has occurred."
		     (sql-error-database c)
		     (sql-error-expression c)
		     (sql-error-error-id c)
		     (sql-error-database-message c))))
  (:documentation "Used to signal an error with the SQL data
  passed to a database."))

(define-condition sql-temporary-error (sql-database-error)
  ()
  (:documentation "Used to signal an error when the database
cannot currently process a valid interaction because, for
example, it is still executing another command possibly issued by
another user."))

(define-condition sql-timeout-error (sql-connection-error)
  ()
  (:documentation "Used to signal an error when the database
times out while processing some operation."))

(define-condition sql-fatal-error (sql-connection-error)
  ()
  (:documentation "Used to signal an error when the database
connection is no longer usable."))

(define-condition sql-user-error (sql-error)
  ((message :initarg :message
	    :initform "Unspecified error"
	    :reader sql-user-error-message))
  (:report (lambda (c stream)
	     (format stream "A CLSQL lisp code error occurred: ~A "
		     (sql-user-error-message c))))
  (:documentation  "Used to signal lisp errors inside CLSQL."))



;; Signal conditions

(defun signal-closed-database-error (database)
  (error 'sql-fatal-error
	 :database database
	 :message "Database is closed."))

(defun signal-no-database-error (database)
  (error 'sql-database-error
	 :database database
	 :message (format nil "~A is not a database." database)))


;;; CLSQL Extensions

(define-condition sql-warning (warning sql-condition)
  ((message :initarg :message :reader sql-warning-message))
  (:report (lambda (c stream)
	     (format stream (sql-warning-message c)))))

(define-condition sql-database-warning (sql-warning)
  ((database :initarg :database :reader sql-warning-database))
  (:report (lambda (c stream)
	     (format stream 
		     "While accessing database ~A~%  Warning: ~A~%  has occurred."
		     (sql-warning-database c)
		     (sql-warning-message c)))))