require 'formula'

class SqliteFunctions < Formula
  url 'http://www.sqlite.org/contrib/download/extension-functions.c?get=25', :using  => NoUnzipCurlDownloadStrategy
  md5 '3a32bfeace0d718505af571861724a43'
  version '2010-01-06'
end

class Sqlite < Formula
  homepage 'http://sqlite.org/'
  url 'http://www.sqlite.org/sqlite-autoconf-3070701.tar.gz'
  md5 '554026fe7fac47b1cf61c18d5fe43419'
  version '3.7.7.1'

  def options
  [
    ["--with-rtree", "Enables the R*Tree index module"],
    ["--with-fts", "Enables the FTS Module"],
    ["--universal", "Build a universal binary."],
    ["--with-functions", "Enables more math and string functions for SQL queries."]
  ]
  end

  def install
    # O2 and O3 leads to corrupt/invalid rtree indexes
    # http://groups.google.com/group/spatialite-users/browse_thread/thread/8e1cfa79f2d02a00#
    ENV.Os
    ENV.append "CFLAGS", "-DSQLITE_ENABLE_RTREE=1" if ARGV.include? "--with-rtree"
    ENV.append "CPPFLAGS","-DSQLITE_ENABLE_FTS3 -DSQLITE_ENABLE_FTS3_PARENTHESIS" if ARGV.include? "--with-fts"
    ENV.universal_binary if ARGV.build_universal?

    system "./configure", "--prefix=#{prefix}", "--disable-dependency-tracking",
                          (ARGV.include? "--with-functions") ? "--enable-dynamic-extensions" : ""
    system "make install"

    if ARGV.include? "--with-functions"
      d=Pathname.getwd
      SqliteFunctions.new.brew { mv 'extension-functions.c?get=25', d + 'extension-functions.c' }
      system ENV.cc, "-fno-common", "-dynamiclib", "extension-functions.c", "-o", "libsqlitefunctions.dylib", *ENV.cflags.split
      lib.install "libsqlitefunctions.dylib"
    end
  end

  if ARGV.include? "--with-functions"
    def caveats
      <<-EOS.undent
        Usage instructions for applications calling the sqlite3 API functions:

          In your application, call sqlite3_enable_load_extension(db,1) to
          allow loading external libraries.  Then load the library libsqlitefunctions
          using sqlite3_load_extension; the third argument should be 0.
          See http://www.sqlite.org/cvstrac/wiki?p=LoadableExtensions.
          Select statements may now use these functions, as in
          SELECT cos(radians(inclination)) FROM satsum WHERE satnum = 25544;

        Usage instructions for the sqlite3 program:

          If the program is built so that loading extensions is permitted,
          the following will work:
           sqlite> SELECT load_extension('#{lib}/libsqlitefunctions.dylib');
           sqlite> select cos(radians(45));
           0.707106781186548
      EOS
    end
  end
end