#! /usr/bin/ruby
module RbLocate
	class Indexer
		attr_accessor :mutex
		def initialize(path)
			puts "Setting up indexer for #{path}"
			@path = path
			@backend = Backend::SqLite.new
		end


		def walk
			require "find"
			Find.find(@path) do |file|
				mutex.synchronize do
					puts "Adding #{file}"
					@backend.put(file)
				end
			end
		end
	end


	class IndexThreadFactory
		def initialize(path)
			@backend = Backend::SqLite.new
			@threads = []
			@path = path
		end

		def populate_threads
			require "thread"
			mutex = Mutex.new
			Dir.open(@path).each do |item|
				item = @path+item
				if File.ftype(item) == "directory" and not item.match(/^\/\.+/)
					@threads.push( Thread.new {
						indexer = Indexer.new(item)
						indexer.mutex = mutex
						indexer.walk
						puts "Thread for #{item} ready"
					})
				else
					puts "File: #{item}"
					@backend.put(item) unless item.match(/^\/\.+$/)
				end
			end
		end

		def wait
			@threads.each do |t|
				t.join
			end
		end
	end




	class Search
		def initialize
			@backend = Backend::SqLite.new
		end

		def search(string)
			@backend.search(string) do |file|
				puts file
			end
		end
	end




	module Backend
		module Generic
			def self.is_uid?(path, uid)
				return true if uid == 0
				File::Stat.new(path).uid == uid
			end

			def self.is_gid?(path, gid)
				return true if gid == 0
				File::Stat.new(path).gid == gid
			end

		end


		class SqLite

			def initialize
				require "sqlite3"
				@database = SQLite3::Database.new("files.db")
			end

			def put(path)
				retry_counter = 0
				begin
					@database.execute("INSERT INTO files VALUES (NULL, ?)", path)
				rescue SQLite3::SQLException => error
					puts "Error: #{error.to_s}"
				rescue SQLite3::BusyException => error
					if retry_counter <= 1000
						puts "Database is locked. Waiting ..."
						sleep 0.1
						retry
					else
						puts "Tried too often. Giving up"
					end
				end
			end


			def search(string, &block)
				string = quote string
				begin
					@database.execute("SELECT id, path FROM files WHERE path LIKE '%#{string}%'") do |id,path|
						unless File.exists?(path)
							delete_by_id id
							next
						end
						yield path if Generic.is_uid?(path, Process.euid) and Generic.is_gid?(path, Process.gid)
					end
				rescue SQLite3::BusyException => error
					retry
				end
			end

			def delete_by_id(id)
				@database.execute("DELETE FROM files WHERE id = ?", id)
			end



			def quote(string)
				string.gsub(/'/, "''")
			end
		end
	end
end

case ARGV[0]
	when "--search"
		search = RbLocate::Search.new
		search.search(ARGV[1])
	when "--index"
		factory = RbLocate::IndexThreadFactory.new(ARGV[1])
		factory.populate_threads
		factory.wait
	else
		puts "Invalid option"
end