;; 
;; Author: David Krentzlin
;; 
;; Created: So Nov 14 14:35:46 2010 (CET)
;; Last-Updated: Do Mär 29 12:19:31 2012 (CEST)
;;           By:


(module nomads-postgresql
  ()
  (import chicken scheme)
  (require-library postgresql nomads)
  (import nomads postgresql)
  (import (only extras sprintf))


  (db-with-connection
   (lambda (connection-spec proc)
     (let ((connection (connect connection-spec)))
       (handle-exceptions exn
                          (begin (when (connection? connection)
                                   (disconnect connection))
                                 (signal exn))
                          (proc connection)
                          (disconnect connection)))))

  (db-with-transaction with-transaction)

  (db-schema-information-exists?
   (lambda (con table)
     (not (zero? (row-count (query con "SELECT tablename FROM pg_tables WHERE schemaname='public' AND tablename=$1" table))))))
  
  (db-initialize-schema-information
   (lambda (con table)
     (query con (sprintf "DROP TABLE \"~A\" IF EXISTS " table))
     (query con
            (sprintf "CREATE TABLE \"~A\" (version character varying(255) NOT NULL)" table))))


  (db-version-list
   (lambda (con table)
     (let ((result (query con (sprintf "SELECT version FROM \"~A\" " table))))
       (if (zero? (row-count result)) '() (row-values result)))))

   (db-add-version
    (lambda (con version table)
      (query con (sprintf "INSERT INTO \"~A\" (version) VALUES($1) " table) version)))

  (db-remove-version
   (lambda (con version table)
     (query con (sprintf "DELETE FROM \"~A\" WHERE version=$1 " table) version)))

  (db-execute-sql
   (lambda (con expr)
     (row-map values (query con expr))))

  (db-error? (condition-predicate 'postgresql))

  (db-message-from-error (condition-property-accessor 'postgresql 'message-detail))

  )