############################################################################
# Copyright 2009 Benjamin Kellermann                                       #
#                                                                          #
# This file is part of dudle.                                              #
#                                                                          #
# Dudle is free software: you can redistribute it and/or modify it under   #
# the terms of the GNU Affero General Public License as published by       #
# the Free Software Foundation, either version 3 of the License, or        #
# (at your option) any later version.                                      #
#                                                                          #
# Dudle is distributed in the hope that it will be useful, but WITHOUT ANY #
# WARRANTY; without even the implied warranty of MERCHANTABILITY or        #
# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public     #
# License for more details.                                                #
#                                                                          #
# You should have received a copy of the GNU Affero General Public License #
# along with dudle.  If not, see <http://www.gnu.org/licenses/>.           #
############################################################################

require "time"

class LogEntry
	attr_accessor :rev, :timestamp, :comment
	def initialize(rev,timestamp,comment)
		@rev = rev
		@timestamp = timestamp
		@comment = comment
	end
	def to_html(link = true)
		ret = "<tr><td>"
		ret += "<a href='?revision=#{@rev}' >" if link
		ret += "#{@rev}"
		ret += "</a>" if link
		ret += "</td>"
		ret += "<td>#{@timestamp.strftime('%d.%m, %H:%M')}</td>"
		ret += "<td class='historycomment'>#{CGI.escapeHTML(@comment)}</td>"
		ret += "</tr>"
		ret
	end
end

class Log
	def initialize(a = [])
		@log = a
	end
	def min
		ret = @log[0]
		@log.each{|l|
			ret.rev = l if l.rev < ret.rev
		}
		ret
	end
	def max
		ret = @log[-1]
		@log.each{|l|
			ret.rev = l if l.rev > ret.rev
		}
		ret
	end
	def revisions
		@log.collect{|e| e.rev }
	end
	def [](revision)
		i = revisions.index(revision)
		if i
			return @log[i]
		else # no revision found, search the nearest
			dist = revisions.collect{|e| (e - revision).abs }.sort[0]
			i = revisions.index(revision + dist) || revisions.index(revision - dist)
			return @log[i]
		end
	end
	def around_rev(rev,number)
		ret = [self[rev]]
		midindex = @log.index(ret[0])
		counter = 1
		while ret.size < number && counter < @log.size
			ret << @log[midindex + counter]
			counter *= -1 if counter <= midindex
			if counter > 0
				counter += 1
			end
			ret.compact!
		end
		ret.sort!{|a,b| a.rev <=> b.rev}
		Log.new(ret)
	end
	def add(revision,timestamp,comment)
		@log << LogEntry.new(revision,timestamp,comment)
		@log.sort!{|a,b| a.rev <=> b.rev}
	end
	def to_html(notlinkrevision)
		ret = "<table><tr><th>Version</th><th>Date</th><th>Comment</th></tr>"
		self.each do |l|
			ret += l.to_html(notlinkrevision != l.rev)
		end
		ret += "</table>"
		ret
	end
	def each
		@log.each{|e| yield(e)}
	end
	def collect
		@log.collect{|e| yield(e)}
	end
	def comment_matches(regex)
		Log.new(@log.collect{|e| e if e.comment =~ regex}.compact)
	end
	def flatten
		h = []
		minrev = min.rev
		rev = max.rev
		while rev > minrev
			elem = self[rev]
			prevrev = elem.comment.scan(/^Reverted Poll to version (\d*)$/).flatten[0]
			if prevrev
				rev = prevrev.to_i	
			else
				h << elem
				rev += -1
			end
		end
		h.sort!{|a,b| a.rev <=> b.rev}
		a = []
		begin 
			a << h.pop
		end while a.last.comment =~ /^Column .*$/
		a.pop	
		a.sort!{|a1,b1| a1.rev <=> b1.rev}
		Log.new(a)
	end
end

if __FILE__ == $0
require "test/unit"
  class Log_test < Test::Unit::TestCase
    def test_indexes

			l = Log.new
			l.add(10,Time.now,"baz 10")
			20.times{|i|
				l.add(i,Time.now,"foo #{i}") unless i == 10
			}

			assert_equal(0,l.min.rev)
			assert_equal(19,l.max.rev)
      assert_equal("baz 10",l[10].comment)

      assert_equal([10],l.comment_matches(/^baz \d*$/).revisions)

			[42,23].each{|i|
				l.add(i,Time.now,"foo #{i}")
			}
			assert_equal(l[42],l[37])

			assert_equal([16,17,18,19,23,42],l.around_rev(23,6).revisions)
			assert_equal([0,1,2,3,4,5,6,7,8,9,10,11],l.around_rev(2,12).revisions)
			assert_equal(l.revisions,l.around_rev(0,99).revisions)

    end
  end 
end