module Csvsql

# File lib/csvsql.rb, line 32
def self.clear_cache!
  FileUtils.rm_f(Dir.glob(File.join(CACHE_DIR, '*')))
end

# File lib/csvsql.rb, line 20
def execute(sql, csv_data, opts = {})
  csvdb = init_data(csv_data, opts)
  pst = Csvsql::Tracker.commit(:execute_query_sql) do
    csvdb.prepare(sql)
  end
  Csvsql::Tracker.commit(:output_format)
  CSV.generate do |csv|
    csv << pst.columns.zip(pst.types).map { |c| c.compact.join(':') }
    pst.each { |line| csv << line }
  end.tap { Csvsql::Tracker.commit(:output_format) }
end

# File lib/csvsql.rb, line 68
def get_db_cache_path(csv_path)
  csv_path = csv_path || ''
  return unless File.exist?(csv_path)

  stat = File.stat(csv_path)
  filename = Digest::SHA2.hexdigest(File.absolute_path(csv_path)) + '.cache'
  file_stat = [File.absolute_path(csv_path), stat.size, stat.ctime].join("\n")
  stat_path = File.join(CACHE_DIR, filename.gsub(/\.cache$/, '.stat'))
  cache_path = File.join(CACHE_DIR, filename)

  if File.exist?(stat_path)
    if File.read(stat_path) == file_stat
      cache_path
    else
      if update_cb
        update_cb.call
      else
        FileUtils.rm(cache_path)
      end
      File.write(stat_path, file_stat)
      cache_path
    end
  else
    File.write(stat_path, file_stat)
    cache_path
  end
end

# File lib/csvsql.rb, line 38
def init_data(csv_data, opts)
  encoding = opts.delete(:encoding)
  use_cache = opts.delete(:use_cache)
  csvdb = Csvsql::Db.new(opts)

  unless use_cache
    csvdb.import(csv_data, encoding: encoding)
    return csvdb
  end

  case csv_data
  when StringIO, IO
    # nothing
  when Hash
    dbs = []
    csv_data.each do |dbname, csv_path|
      dbs << [dbname, csvdb.init_db(get_db_cache_path(csv_path) || '')]
      csvdb.import(csv_path, encoding: encoding)
    end
    dbs.each do |dbname, db|
      csvdb.execute("ATTACH DATABASE '#{db.filename}' AS #{dbname};")
    end
  else
    csvdb.init_db(get_db_cache_path(csv_data) || '')
    csvdb.import(csv_data, encoding: encoding)
  end

  csvdb
end