#!/usr/bin/env ruby
# encoding: utf-8

# architecture
#
# master <-> dev
# master -> client
# clien -> clientA | clientB
#
# merge using two of these branches should be 
#   restricted to these rules
# merge to one of these branch and an unknown one should
#   raise a warning, and may the option to add this new branch
#   to the hierarchy

$architecture={ 
    :master => [ :dev, :client ],
    :dev => [ :master ],
    :client => [ :clientA, :clientB ] }

def get_current_branch()
    (`git branch --no-color | awk '$1 == "*" {print $2}'`).chop.intern
end

if ARGV.length == 0
    puts %{usage: $0:t [git_command or local_command]
    
local commands:
    allmerges: merge from top to down}
    exit 0
end

require 'set'
$known_branches=Set.new
$architecture.each do |k,v| 
    $known_branches.add(k)
    v.each { |b| $known_branches.add(b) }
end

def rec_merge(branch)
    if $architecture[branch].nil?
        return
    end
    $architecture[branch].each do |b|
        if $flag.has_key?(b.to_s + branch.to_s)
            next
        end
        flagname=branch.to_s + b.to_s
        if $flag.has_key?(flagname)
            next
        end
        if system %{eng checkout #{b}}
            if get_current_branch != b
                puts "Can't checkout to #{b}"
                exit 2
            end
            if system %{eng merge #{branch}}
                $flag[flagname]=true
                rec_merge(b)
            else
                exit 1
            end
        else
            exit 1
        end
    end
end

def do_all_merges
    puts 'Will merge from father to sons'
    current_branch=get_current_branch
    $flag={}
    rec_merge(:master)
    system %{git co #{current_branch}}
end

def do_merge
    current_branch=get_current_branch
    src_branch=ARGV[1].intern
    puts %{do_merge: #{src_branch} => #{current_branch}}
    if $known_branches.include?(current_branch)
        if $known_branches.include?(src_branch)
            if $architecture.has_key?(src_branch) and 
                $architecture[src_branch].include?(current_branch)
                system %{git merge #{src_branch}}
            else
                puts %{Forbidden merge: #{src_branch} => #{current_branch}}
            end
        else
            puts %{Warning! #{src_branch} not mentionned in rb configuration}
            sleep 2
            system %{git merge #{src_branch}}
            puts %{Warning! #{src_branch} not mentionned in rb configuration}
        end
    end
end

case ARGV[0] 
    when 'allmerges' then do_all_merges
    when 'merge' then do_merge
    else system %{git #{ARGV.join(' ')}}
end