(ns my.util.sql
  (:use clojure.contrib.condition)
  (:require
    [clojure.contrib.sql :as sql]
    [clj-record.core     :as rec]
    [my.util.error       :as err]))

(def *transaction-error* nil) ; While a transaction-wrapper is running, bound to the last error message set by rollback-with-raise

(defn rollback-with-raise
  "Call within a transaction body to rollback the transaction and raise a condition
   with the related error-code"
  [error-code]
  (println "ROLLING BACK: " error-code)
  (set! *transaction-error* error-code)
  (sql/set-rollback-only))

(defmacro transaction
  "Execute body in a clj-record transaction. rollback-with-raise may be called in body and will
   rollback the transaction and raise a condition with the specified error-code"
  [db-spec & body]
  `(binding [my.util.sql/*transaction-error*  nil]
     (try
       (let [tx-result# (rec/transaction ~db-spec ~@body)]
         (if-not (nil? *transaction-error*)
           (err/raise-with-message *transaction-error*))
         tx-result#)
       (catch Exception e#
         (println "CAUGHT: " e#)
         (if-not (nil? *transaction-error*)
           (err/raise-with-message *transaction-error*)
           (err/raise-with-message :transaction-wrapper-error e#))))))