#!/usr/bin/env ruby

#$DBG = true

require '/Users/john/build/cvs/nitro/nitro-0.40-own/glycerin'

# a specific facets version
require_gem 'facets', '= 1.4.5'
require 'facets'
require 'facets/core/string/camelize'

require 'og'

$psql = Og.run(
  :destroy => false,
  :evolve_schema => :add,
  :store => :postgresql,
  :name => 'oxyliquit',
  :user => 'john',
  :password => nil,
  :classes => [Class.new]
)

module RevOg

  ###################################################################
  # PostgreSQL side
  ###################################################################

  def get_og_tables
    tables = $psql.conn.query("
      SELECT c.oid, n.nspname, c.relname
        FROM pg_catalog.pg_class c
        LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
        WHERE c.relkind = 'r' AND
          n.nspname NOT IN ('pg_catalog', 'pg_toast') AND
          pg_catalog.pg_table_is_visible(c.oid)
        ORDER BY 2, 3;
    ")

    ogtables = []
    ogreltables = []

    tables.each_row do |t, i|
      case t[tables.fields.index('relname')]
      when /^#{Og.table_prefix}j_/
        ogreltables << t
      when /^#{Og.table_prefix}/
        ogtables << t
      end
    end

    return th(tables, ogtables)
  end

  def get_klass_fields(oid)
    fields = $psql.conn.query %{
      SELECT a.attname AS column,
        pg_catalog.format_type(a.atttypid, a.atttypmod) AS type,
        (SELECT substring(pg_catalog.pg_get_expr(d.adbin, d.adrelid) for 128)
          FROM pg_catalog.pg_attrdef d
            WHERE d.adrelid = a.attrelid AND d.adnum = a.attnum
                  AND a.atthasdef) AS extrainfo,
        a.attnotnull, a.attnum
      FROM pg_catalog.pg_attribute a
        WHERE a.attrelid = '#{oid}' AND a.attnum > 0 AND NOT a.attisdropped
      ORDER BY a.attnum;}

    return th(fields)
  end

  ###################################################################
  # Ruby side
  ###################################################################

  def create_og_attribute(info)
    name = info['column']
    type = case info['type']
      when /timestamp/: Time
      when 'text': String
      when 'integer': Fixnum
      when 'boolean': TrueClass
      else Object
      end

    att = "attr_accessor :#{name}, #{type}"

    #att << ', :null => false' if info['attnotnull'] = 't'
    if info['extrainfo'] =~ /#{info['column']}_seq/
      att << ', :primary_key => true'
    end

    return att
  end

  ###################################################################
  # Aggregation
  ###################################################################

  def create_og_klasses
    klasses = []

    t = get_og_tables

    t.each do |info|
      klasses << create_og_klass(info)
    end

    return klasses
  end

  def create_og_klass(info)
    klass_name = info['relname'].scan(/^#{Og.table_prefix}(.*)/).to_s.camelize
    klass_flds = get_klass_fields(info['oid'])

    attrs = klass_flds.map {|info| create_og_attribute(info) }

    %{
class #{klass_name}
#{attrs.map{|x|"    #{x}"}.join("\n")}
end
    }
  end

private
  def th(res, array = nil)
    unless array
      array = []
      res.each_row {|x,i| array << x }
    end

    out = []

    array.each do |row|
      rowh = {}
      row.each_with_index do |field,i|
        rowh[res.fields[i]] = field
      end
      out << rowh
    end

    return out
  end
end


if $0 == __FILE__
  include RevOg

  puts create_og_klasses
end