;;; postgresql.setup -*- Scheme -*-

(use files utils)

(define pkg-config-available?
  (handle-exceptions exn
    (begin
      (print "pkg-config is NOT available. Will use pg_config.")
      #f)
    (print "Checking if pkg-config is available...")
    (system* "pkg-config --version")
    (print "pkg-config is available.")
    #t))

(define libpq-flags
  (if pkg-config-available?
      '("`pkg-config --cflags libpq`" "`pkg-config --libs libpq`")
      '(-C -I -C "\"`pg_config --includedir`\""
           "-L\"`pg_config --libdir`\""
           -rpath "`pg_config --libdir`" -lpq)))

(define PQescapeIdentifier-presence-checker #<<EOF
  #include <libpq-fe.h>
  int main(void)
  {
     PGconn *conn = NULL; /* Bork */
     return PQescapeIdentifier(conn, "test", 4) != NULL;
  }
EOF
)

(define PQconnectdbParams-presence-checker #<<EOF
  #include <libpq-fe.h>
  int main(void)
  {
     const char *kw[] = {"a", NULL};
     const char *val[] = {"b", NULL};
     return PQconnectdbParams(kw, val, 0) != NULL;
  }
EOF
)

(define PG_DIAG_INTERNAL_QUERY+POSITION-checker #<<EOF
  #include <libpq-fe.h>
  int main(void)
  {
     int foo = PG_DIAG_INTERNAL_QUERY;
     int bar = PG_DIAG_INTERNAL_POSITION;
     return foo + bar;
  }
EOF
)

(define PG_DIAG_SCHEMA_INFO-checker #<<EOF
  #include <libpq-fe.h>
  int main(void)
  {
     int s = PG_DIAG_SCHEMA_NAME;
     int t = PG_DIAG_TABLE_NAME;
     int col = PG_DIAG_COLUMN_NAME;
     int d = PG_DIAG_DATATYPE_NAME;
     int con = PG_DIAG_CONSTRAINT_NAME;
     return s + t + col + d + con;
  }
EOF
)

(define feature-checks
  `((has-PQescapeIdentifier . ,PQescapeIdentifier-presence-checker)
    (has-PQconnectdbParams . ,PQconnectdbParams-presence-checker)
    (has-PG_DIAG_INTERNAL_QUERY+POSITION . ,PG_DIAG_INTERNAL_QUERY+POSITION-checker)
    (has-PG_DIAG_SCHEMA_INFO . ,PG_DIAG_SCHEMA_INFO-checker)))

(define-syntax try-compile-pgsql-prog
  (syntax-rules ()
    ((_ str)
     (begin
      (with-output-to-file "attempt.c" (lambda () (display str) (newline)))
      (let ((result (handle-exceptions ex #f (compile "attempt.c" ,@libpq-flags))))
        (delete-file* "attempt.c")
        (delete-file* "attempt.o")
        (delete-file* "attempt")
        result)))))

(define (check-features)
  (fold (lambda (feature/test features)
          (if (try-compile-pgsql-prog (cdr feature/test))
              (append! `(-feature ,(car feature/test)) features)
              features))
        '()
        feature-checks))

(compile -s -O2 -d0 postgresql.scm -j postgresql ,@(check-features) ,@libpq-flags)

(compile postgresql.import.scm -s -O2 -d0)

(install-extension
 'postgresql
 '("postgresql.so" "postgresql.import.so")
 '((version "3.9.3")
   (documentation "postgresql.html")))