;;; ob-sql.el --- Babel Functions for SQL            -*- lexical-binding: t; -*-

;; Copyright (C) 2009-2020 Free Software Foundation, Inc.

;; Author: Eric Schulte
;; Keywords: literate programming, reproducible research
;; Homepage: https://orgmode.org

;; This file is part of GNU Emacs.

;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.

;;; Commentary:

;; Org-Babel support for evaluating sql source code.
;; (see also ob-sqlite.el)
;;
;; SQL is somewhat unique in that there are many different engines for
;; the evaluation of sql (Mysql, PostgreSQL, etc...), so much of this
;; file will have to be implemented engine by engine.
;;
;; Also SQL evaluation generally takes place inside of a database.
;;
;; Header args used:
;; - engine
;; - cmdline
;; - dbhost
;; - dbport
;; - dbuser
;; - dbpassword
;; - dbconnection (to reference connections in sql-connection-alist)
;; - database
;; - colnames (default, nil, means "yes")
;; - result-params
;; - out-file
;;
;; The following are used but not really implemented for SQL:
;; - colname-names
;; - rownames
;; - rowname-names
;;
;; Engines supported:
;; - mysql
;; - dbi
;; - mssql
;; - sqsh
;; - postgresql
;; - oracle
;; - vertica
;;
;; TODO:
;;
;; - support for sessions
;; - support for more engines
;; - what's a reasonable way to drop table data into SQL?
;;

;;; Code:
(require 'ob)

(declare-function org-table-import "org-table" (file arg))
(declare-function orgtbl-to-csv "org-table" (table params))
(declare-function org-table-to-lisp "org-table" (&optional txt))
(declare-function cygwin-convert-file-name-to-windows "cygw32.c" (file &optional absolute-p))

(defvar sql-connection-alist)
(defvar org-babel-default-header-args:sql '())

(defconst org-babel-header-args:sql
  '((engine	       . :any)
    (out-file	       . :any)
    (dbhost	       . :any)
    (dbport	       . :any)
    (dbuser	       . :any)
    (dbpassword	       . :any)
    (database	       . :any))
  "SQL-specific header arguments.")

(defun org-babel-expand-body:sql (body params)
  "Expand BODY according to the values of PARAMS."
  (org-babel-sql-expand-vars
   body (org-babel--get-vars params)))

(defun org-babel-sql-dbstring-mysql (host port user password database)
  "Make MySQL cmd line args for database connection.  Pass nil to omit that arg."
  (combine-and-quote-strings
   (delq nil
	 (list (when host     (concat "-h" host))
	       (when port     (format "-P%d" port))
	       (when user     (concat "-u" user))
	       (when password (concat "-p" password))
	       (when database (concat "-D" database))))))

(defun org-babel-sql-dbstring-postgresql (host port user database)
  "Make PostgreSQL command line args for database connection.
Pass nil to omit that arg."
  (combine-and-quote-strings
   (delq nil
	 (list (when host (concat "-h" host))
	       (when port (format "-p%d" port))
	       (when user (concat "-U" user))
	       (when database (concat "-d" database))))))

(defun org-babel-sql-dbstring-oracle (host port user password database)
  "Make Oracle command line arguments for database connection.

If HOST and PORT are nil then don't pass them.  This allows you
to use names defined in your \"TNSNAMES\" file.  So you can
connect with

  <user>/<password>@<host>:<port>/<database>

or

  <user>/<password>@<database>

using its alias."
  (cond ((and user password database host port)
	 (format "%s/%s@%s:%s/%s" user password host port database))
	((and user password database)
	 (format "%s/%s@%s" user password database))
	(t (user-error "Missing information to connect to database"))))

(defun org-babel-sql-dbstring-mssql (host user password database)
  "Make sqlcmd command line args for database connection.
`sqlcmd' is the preferred command line tool to access Microsoft
SQL Server on Windows and Linux platform."
  (mapconcat #'identity
	     (delq nil
		   (list (when host (format "-S \"%s\"" host))
			 (when user (format "-U \"%s\"" user))
			 (when password (format "-P \"%s\"" password))
			 (when database (format "-d \"%s\"" database))))
	     " "))

(defun org-babel-sql-dbstring-sqsh (host user password database)
  "Make sqsh command line args for database connection.
\"sqsh\" is one method to access Sybase or MS SQL via Linux platform"
  (mapconcat #'identity
             (delq nil
                   (list  (when host     (format "-S \"%s\"" host))
                          (when user     (format "-U \"%s\"" user))
                          (when password (format "-P \"%s\"" password))
                          (when database (format "-D \"%s\"" database))))
             " "))

(defun org-babel-sql-dbstring-vertica (host port user password database)
  "Make Vertica command line args for database connection. Pass nil to omit that arg."
  (mapconcat #'identity
	      (delq nil
		    (list (when host     (format "-h %s" host))
			  (when port     (format "-p %d" port))
			  (when user     (format "-U %s" user))
			  (when password (format "-w %s" (shell-quote-argument password) ))
			  (when database (format "-d %s" database))))
	      " "))

(defun org-babel-sql-convert-standard-filename (file)
  "Convert FILE to OS standard file name.
If in Cygwin environment, uses Cygwin specific function to
convert the file name.  In a Windows-NT environment, do nothing.
Otherwise, use Emacs' standard conversion function."
  (cond ((fboundp 'cygwin-convert-file-name-to-windows)
	 (format "%S" (cygwin-convert-file-name-to-windows file)))
	((string= "windows-nt" system-type) file)
	(t (format "%S" (convert-standard-filename file)))))

(defun org-babel-find-db-connection-param (params name)
  "Return database connection parameter NAME.
Given a parameter NAME, if :dbconnection is defined in PARAMS
then look for the parameter into the corresponding connection
defined in `sql-connection-alist`, otherwise look into PARAMS.
Look `sql-connection-alist` (part of SQL mode) for how to define
database connections."
  (if (assq :dbconnection params)
      (let* ((dbconnection (cdr (assq :dbconnection params)))
             (name-mapping '((:dbhost . sql-server)
                             (:dbport . sql-port)
                             (:dbuser . sql-user)
                             (:dbpassword . sql-password)
                             (:database . sql-database)))
             (mapped-name (cdr (assq name name-mapping))))
        (cadr (assq mapped-name
                    (cdr (assoc dbconnection sql-connection-alist)))))
    (cdr (assq name params))))

(defun org-babel-execute:sql (body params)
  "Execute a block of Sql code with Babel.
This function is called by `org-babel-execute-src-block'."
  (let* ((result-params (cdr (assq :result-params params)))
         (cmdline (cdr (assq :cmdline params)))
         (dbhost (org-babel-find-db-connection-param params :dbhost))
         (dbport (org-babel-find-db-connection-param params :dbport))
         (dbuser (org-babel-find-db-connection-param params :dbuser))
         (dbpassword (org-babel-find-db-connection-param params :dbpassword))
         (database (org-babel-find-db-connection-param params :database))
         (engine (cdr (assq :engine params)))
         (colnames-p (not (equal "no" (cdr (assq :colnames params)))))
         (in-file (org-babel-temp-file "sql-in-"))
         (out-file (or (cdr (assq :out-file params))
                       (org-babel-temp-file "sql-out-")))
	 (header-delim "")
         (command (pcase (intern engine)
                    (`dbi (format "dbish --batch %s < %s | sed '%s' > %s"
				  (or cmdline "")
				  (org-babel-process-file-name in-file)
				  "/^+/d;s/^|//;s/(NULL)/ /g;$d"
				  (org-babel-process-file-name out-file)))
                    (`monetdb (format "mclient -f tab %s < %s > %s"
				      (or cmdline "")
				      (org-babel-process-file-name in-file)
				      (org-babel-process-file-name out-file)))
		    (`mssql (format "sqlcmd %s -s \"\t\" %s -i %s -o %s"
				    (or cmdline "")
				    (org-babel-sql-dbstring-mssql
				     dbhost dbuser dbpassword database)
				    (org-babel-sql-convert-standard-filename
				     (org-babel-process-file-name in-file))
				    (org-babel-sql-convert-standard-filename
				     (org-babel-process-file-name out-file))))
                    (`mysql (format "mysql %s %s %s < %s > %s"
				    (org-babel-sql-dbstring-mysql
				     dbhost dbport dbuser dbpassword database)
				    (if colnames-p "" "-N")
				    (or cmdline "")
				    (org-babel-process-file-name in-file)
				    (org-babel-process-file-name out-file)))
		    (`postgresql (format
				  "%s%s --set=\"ON_ERROR_STOP=1\" %s -A -P \
footer=off -F \"\t\"  %s -f %s -o %s %s"
				  (if dbpassword
				      (format "PGPASSWORD=%s " dbpassword)
				    "")
				  (or sql-postgres-program "psql") ;; default is psql
				  (if colnames-p "" "-t")
				  (org-babel-sql-dbstring-postgresql
				   dbhost dbport dbuser database)
				  (org-babel-process-file-name in-file)
				  (org-babel-process-file-name out-file)
				  (or cmdline "")))
		    (`sqsh (format "sqsh %s %s -i %s -o %s -m csv"
				   (or cmdline "")
				   (org-babel-sql-dbstring-sqsh
				    dbhost dbuser dbpassword database)
				   (org-babel-sql-convert-standard-filename
				    (org-babel-process-file-name in-file))
				   (org-babel-sql-convert-standard-filename
				    (org-babel-process-file-name out-file))))
		    (`vertica (format "vsql %s -f %s -o %s %s"
				    (org-babel-sql-dbstring-vertica
				     dbhost dbport dbuser dbpassword database)
				    (org-babel-process-file-name in-file)
				    (org-babel-process-file-name out-file)
				    (or cmdline "")))
                    (`oracle (format
			      "sqlplus -s %s < %s > %s"
			      (org-babel-sql-dbstring-oracle
			       dbhost dbport dbuser dbpassword database)
			      (org-babel-process-file-name in-file)
			      (org-babel-process-file-name out-file)))
                    (_ (error "No support for the %s SQL engine" engine)))))
    (with-temp-file in-file
      (insert
       (pcase (intern engine)
	 (`dbi "/format partbox\n")
         (`oracle "SET PAGESIZE 50000
SET NEWPAGE 0
SET TAB OFF
SET SPACE 0
SET LINESIZE 9999
SET TRIMOUT ON TRIMSPOOL ON
SET ECHO OFF
SET FEEDBACK OFF
SET VERIFY OFF
SET HEADING ON
SET MARKUP HTML OFF SPOOL OFF
SET COLSEP '|'

")
	 ((or `mssql `sqsh) "SET NOCOUNT ON

")
	 (`vertica "\\a\n")
	 (_ ""))
       (org-babel-expand-body:sql body params)
       ;; "sqsh" requires "go" inserted at EOF.
       (if (string= engine "sqsh") "\ngo" "")))
    (org-babel-eval command "")
    (org-babel-result-cond result-params
      (with-temp-buffer
	(progn (insert-file-contents-literally out-file) (buffer-string)))
      (with-temp-buffer
	(cond
	 ((memq (intern engine) '(dbi mysql postgresql sqsh vertica))
	  ;; Add header row delimiter after column-names header in first line
	  (cond
	   (colnames-p
	    (with-temp-buffer
	      (insert-file-contents out-file)
	      (goto-char (point-min))
	      (forward-line 1)
	      (insert "-\n")
	      (setq header-delim "-")
	      (write-file out-file)))))
	 (t
	  ;; Need to figure out the delimiter for the header row
	  (with-temp-buffer
	    (insert-file-contents out-file)
	    (goto-char (point-min))
	    (when (re-search-forward "^\\(-+\\)[^-]" nil t)
	      (setq header-delim (match-string-no-properties 1)))
	    (goto-char (point-max))
	    (forward-char -1)
	    (while (looking-at "\n")
	      (delete-char 1)
	      (goto-char (point-max))
	      (forward-char -1))
	    (write-file out-file))))
	(org-table-import out-file (if (string= engine "sqsh") '(4) '(16)))
	(org-babel-reassemble-table
	 (mapcar (lambda (x)
		   (if (string= (car x) header-delim)
		       'hline
		     x))
		 (org-table-to-lisp))
	 (org-babel-pick-name (cdr (assq :colname-names params))
			      (cdr (assq :colnames params)))
	 (org-babel-pick-name (cdr (assq :rowname-names params))
			      (cdr (assq :rownames params))))))))

(defun org-babel-sql-expand-vars (body vars)
  "Expand the variables held in VARS in BODY."
  (mapc
   (lambda (pair)
     (setq body
	   (replace-regexp-in-string
	    (format "$%s" (car pair))
	    (let ((val (cdr pair)))
              (if (listp val)
                  (let ((data-file (org-babel-temp-file "sql-data-")))
                    (with-temp-file data-file
                      (insert (orgtbl-to-csv
                               val '(:fmt (lambda (el) (if (stringp el)
                                                      el
                                                    (format "%S" el)))))))
                    data-file)
                (if (stringp val) val (format "%S" val))))
	    body)))
   vars)
  body)

(defun org-babel-prep-session:sql (_session _params)
  "Raise an error because Sql sessions aren't implemented."
  (error "SQL sessions not yet implemented"))

(provide 'ob-sql)



;;; ob-sql.el ends here