;; -*- scheme -*-

;; Optional arguments to chicken-install (requires Chicken 4.5.1):
;; -D sql-de-lite-internal-lib: Force linking with included SQLite library.
;; -D sql-de-lite-external-lib: Force linking with system SQLite library.

;; Use CSC_OPTIONS="-I<incdir> -L<libdir>" chicken-install
;; if you want to look for an external SQLite3 library in a non-standard location.

(define extension-version "0.6.4")

;; Minimum SQLite version to accept when choosing whether to use external library.
;; There's also a minimum legal version that we can even use, but we just let the
;; linker error out if too old.
(define +min-sqlite3-libversion+ 3007011)   ;; 3007011 is included with egg

(define sqlite3-options
  '(-C -DSQLITE_ENABLE_FTS3
    -C -DSQLITE_ENABLE_FTS3_PARENTHESIS
    -C -DSQLITE_THREADSAFE=0                ;; otherwise, pthreads required
    ))

;; Options are pulled from (extra-features), i.e. the -D option to chicken-install.
;; (extra-features) requires Chicken 4.5.1; otherwise, options are set to empty.
(define sql-de-lite-options
  (handle-exceptions exn '() (extra-features)))
(define force-internal-lib?
  (memq 'sql-de-lite-internal-lib sql-de-lite-options))
(define force-external-lib?
  (memq 'sql-de-lite-external-lib sql-de-lite-options))
(when (and force-internal-lib?
           force-external-lib?)
  (error 'sql-de-lite "cannot force both external and internal SQLite lib"))

(define-syntax compile/error
  ;; Required for Chicken < 4.6, which calls (reset) on (compile) error.
  (syntax-rules ()
    ((compile/error args ...)
     (let ((old-reset (reset-handler)))
       (parameterize ((reset-handler
                       (lambda ()
                         (parameterize ((reset-handler old-reset))
                           (error 'compile "compilation error")))))
         (compile args ...))))))

;; Returns sqlite3 libversion number (e.g. 3006021) or #f if unable to obtain.
(define (get-sqlite3-libversion)
  (let ((exe (cond-expand (windows ".\\version-check.exe")  ;; stupid, but make-pathname can't do \ anymore
                          (else "./version-check"))))
    (and (handle-exceptions e #f
           (compile/error -o ,exe version-check.scm -lsqlite3))
         (and (let ((version (with-input-from-pipe exe read))) ;; never errors
                (and (number? version) version))))))

(define (build/internal)
  (print "\n+++ SQLite3 version >= " +min-sqlite3-libversion+ " not found, using bundled version\n")
  (compile -s -O2 -d2 -inline -local sql-de-lite.scm -j sql-de-lite
           -Isqlite3 sqlite3/sqlite3.c
           ,@sqlite3-options)
  ;; Using Chicken to compile the shell may link to extraneous libraries,
  ;; but it's easier than figuring out the compilation process ourselves.
  (compile -O2 -o chicken-sqlite3 -Isqlite3
           sqlite3/shell.c sqlite3/sqlite3.c
           ,@sqlite3-options
           -C -DSQLITE_THREADSAFE=0      ;; Shell is single-threaded.
           )
  (install-library)
  (install-shell))

(define (build/external ver)
  (when ver
    (print "\n+++ SQLite3 version " ver " found\n"))
  (compile -s -O2 -d2 -inline -local sql-de-lite.scm -j sql-de-lite -lsqlite3)
  (install-library))

(define (install-library)
  (compile -s -O2 -d0 sql-de-lite.import.scm)
  (install-extension
   'sql-de-lite
   `("sql-de-lite.so" "sql-de-lite.import.so")
   `((version ,extension-version))))

(define (install-shell)
  (install-program
   'sql-de-lite-shell
   `("chicken-sqlite3")
   `((version ,extension-version))))

;;; Main logic

(cond (force-internal-lib?
       (build/internal))
      (force-external-lib?
       (build/external #f))
      (else
       (let ((ver (get-sqlite3-libversion)))
         (if (and ver (>= ver +min-sqlite3-libversion+))
             (build/external ver)
             (build/internal)))))