;;;; database.lisp
;;;;
;;;; Copyright (c) 2016 Samuel W. Flint <swflint@flintfam.org>

(in-package #:collect)

;;; "collect" goes here.

(defun format-column (column-definition)
  (if (not (listp column-definition))
      (string-downcase (format nil "~a" column-definition))
      (if (eq 'as (first column-definition))
          (format nil "~a AS ~a"
                  (format-column (second column-definition))
                  (format-column (third column-definition)))
          (string-downcase (format nil "~a.~a"
                                   (first column-definition)
                                   (format-table-name (second column-definition)))))))

(defun format-table-name (table-name)
  (string-downcase (format nil "~a" table-name)))

(defun format-where-clause (where &aux (where-clause (if (listp where) where (list where))))
  (let* ((operator (first where-clause))
         (lhs (second where-clause))
         (rhs (third where-clause)))
    (case operator
      (<
       (format nil "(~a < ~a)" (format-where-clause lhs) (format-where-clause rhs)))
      (>
       (format nil "(~a > ~a)" (format-where-clause lhs) (format-where-clause rhs)))
      (=
       (format nil "(~a = ~a)" (format-where-clause lhs) (format-where-clause rhs)))
      (or
       (format nil "(~a OR ~a)" (format-where-clause lhs) (format-where-clause rhs)))
      (and
       (format nil "(~a AND ~a)" (format-where-clause lhs) (format-where-clause rhs)))
      (t
       (if (numberp operator)
           operator
           (format-table-name where))))))

(defun query-maker (query)
  (destructuring-bind (nil columns &key from where group order limit) query
    ;; (list columns from where group order limit)
    (let ((column-format (map 'list #'format-column columns))
          (tables (map 'list #'format-table-name from))
          (where (format-where-clause where)))
      (format nil "SELECT ~{~a~^, ~} FROM ~{~a~^, ~}~@[ WHERE ~a~]~@[ GROUP BY ~a~]~@[ ORDER BY ~a~]~@[ LIMIT ~a~];"
              column-format
              tables
              where
              group
              order
              limit))))

(defun open-database ())

(defun get-all-forms ())

(defun get-all-queries ())

;;; End collect