require 'fileutils'

class Database
	def initialize(file)
		@file = file
		File.open(@file, 'w').write unless File.exist? @file
		lines = File.readlines(@file) if File.exist? @file
		FileUtils.touch(@file) unless File.exist? @file
		lines.count = 0 unless File.exist? @file
		@start = 0
		@end = lines.count
	end

	def message(msg)
		puts "#{@file}: #{msg}"
	end

	def get(key)
		lines= File.readlines(@file)
		eval('[' + lines.join() + ']').map { |hash|
			hash[key]
		}
	end

	def prepend(key, val)
		lines = File.readlines(@file)
		lines.insert(@start, "{:key => '#{key}', :value => '#{val}'},\n")
		File.write(@file, lines.join)
	end

	def append(key, val)
		message "added #{key} => #{val}"
		lines = File.readlines(@file)
		lines.insert(@end, "{:key => '#{key}', :value => '#{val}'},\n")
		File.write(@file, lines.join)
	end

	def <<(hash)
		lines = File.readlines(@file)
		lines.insert(@end, "{:key => '#{hash[:key]}', :value => '#{hash[:value]}'},\n")
		File.write(@file, lines.join)
	end

	def [](i)
		lines = File.readlines(@file)
		return eval('[' + lines.join() + ']')[i]
		#return eval lines[i]
	end

	def []=(i, hash)
		lines = File.readlines(@file)
		lines.insert(i, "{:key => '#{hash[:key]}', :value => '#{hash[:value]}'},\n")
		File.write(@file, lines.join)
	end
end