require "rexml/document"

=begin
structure = [
  {
    "tablename" => "table1",
    "colums" => [
      {
        "name" => "col1",
        "datatype" => "text",
        "null" => "0",
        "autoincrement" => "1",
        "relation" => nil,
        "comment" => "com",
      },
      {
        "name" => "item_id",
        "datatype" => "string",
        "null" => "0",
        "autoincrement" => "1",
        "relation" => {"table" => "items", "column" => "id"},
        "comment" => "has_many",
      },
      {
        "name" => "col3",
        "datatype" => "integer",
        "null" => "0",
        "autoincrement" => "1",
        "relation" => nil,
        "comment" => "",
      },
    ],
    "comment" => "user has many actions"
  },

]
=end

class Sqld4r_parser
  @@trans_map = {
    "INTEGER" => "integer",
    "DECIMAL" => "integer",
    "FLOAT" => "float",
    "DOUBLE" => "float",
    "CHAR" => "string",
    "VARCHAR" => "string",
    "MEDIUMTEXT" => "text",
    "BINARY" => "binary",
    "VARBINARY" => "binary",
    "BLOB" => "binary",
    "DATE" => "date",
    "TIME" => "time",
    "DATETIME" => "datetime",
    "YEAR" => "date",
    "TIMESTAMP" => "timestamp",
    "ENUM" => "string",
    "SET" => "boolean",
  }
  
  def initialize
    super()
    @structure = []
    self
  end
  
  def parse(filepath)
    doc = REXML::Document.new File.new(filepath)
    doc.elements.each("sql/table") do |table|
      #puts table.attributes["name"]
      @structure << table_hash(table)
    end
    @structure
  end
  
  def table_hash(table_elem)
    buffer_hash = {}
    buffer_hash["tablename"] = table_elem.attributes["name"]
    begin
      buffer_hash["comment"] = table_elem.elements["comment"].text
    rescue
      buffer_hash["comment"] = ""
    end
    buffer_hash["colums"] = []
    table_elem.elements.each("row") do |row|
      buffer_hash["colums"] << colums_hash(row)
    end
    return buffer_hash
  end

=begin
    <row name="user_id" null="0" autoincrement="0">
      <datatype>INTEGER</datatype>
      <relation table="users" row="id" />
    </row>

      {
        "name" => "col2",
        "datatype" => "integer",
        "null" => "0",
        "autoincrement" => "1",
        "relation" => {"table" => "users", "column" => "id"},
        "comment" => "has_many",
      },
=end
  
  def colums_hash(row)
    rowbuffer_hash = {}
    rowbuffer_hash["name"] = row.attributes["name"]
    rowbuffer_hash["null"] = row.attributes["null"]
    rowbuffer_hash["autoincrement"] = row.attributes["autoincrement"]
    rowbuffer_hash["datatype"] = @@trans_map[row.elements["datatype"].text]
    begin
      rowbuffer_hash["relation"] = {"table" => row.elements["relation"].attributes["table"], "column" => row.elements["relation"].attributes["row"]}
    rescue
      rowbuffer_hash["relation"] = nil
    end
    begin
      rowbuffer_hash["comment"] = row.elements["comment"].text
    rescue
      rowbuffer_hash["comment"] = ""
    end
    return rowbuffer_hash
  end
end