#!/usr/bin/env python
#
# pkgdepcheck.py
#
# Script to find missing dependencies in current based on stable


#+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++#
#                                                                             #
# pkgdepcheck - a script to find subdependencies                              #
#                                                                             #
# Copyright Tim Beech <tim~beech~at~gmail~dot~com>.                      #
#                                                                             #
# This program is free software; you can redistribute it and/or               #
# modify it under the terms of the GNU General Public License                 #
# as published by the Free Software Foundation; either version 2              #
# of the License, or (at your option) any later version.                      #
#                                                                             #
# This program 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 General Public License for more details.                                #
#                                                                             #
# You should have received a copy of the GNU General Public License           #
# along with this program; if not, write to the Free Software                 #
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA. #
#                                                                             #
#+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++#


def main():
    #open the package data (CSV format)
    #for each repo, find out whether it is present
    #and get the dependency list
    #if appropriate, print its deps
    #then send it to a function to recursively check
    #it and its deps
    #some output to cover other cases
   
    while True:
        package = raw_input("Please enter name of package:    ")
        salixCurrent = 'salix32-current.csv'
        salixStable = 'salix32-13.37.csv'
        slackCurrent = 'slack32-current.csv'
        slackStable = 'slack32-13.37.csv'
        
        presentSalixStable, depSalixStable = checkRepo(package, salixStable)
        presentSalixCurrent, depSalixCurrent = checkRepo(package, salixCurrent)
        presentSlackStable, depSlackStable = checkRepo(package, slackStable)
        presentSlackCurrent, depSlackCurrent = checkRepo(package, slackCurrent)
        if presentSalixStable and not presentSalixCurrent:
            print "The package ", package, "is present in stable but has not been packaged for current yet."
            print
            if presentSlackCurrent:
                print "Aha! present in Slackware current."
                if presentSlackStable:
                    print "It was present in Salix stable too, so a Salix package is probably still needed."
                print
            print "Its dependencies are ",
            print
            for i in depSalixStable.split(","):
                print i,
            print
            print "We will now check whether any of these deps remain unpackaged in current."
            print "The following packages are missing:"

            checkDeps(package)
                       
        if presentSalixCurrent:
            print "The package ", package, "has already been packaged for current."
        elif not presentSalixStable:
            if presentSlackStable or presentSlackCurrent:
                print "The package ", package, " is a Slackware package."
                if presentSalixCurrent:
                        print "However, it was packaged in Salix stable, so \
                        probably will be this time too."
            else:
                print "The package ", package, "is not present in stable."
    
def checkRepo(package, repo):
    #for each row in the package data for one repo,
    #get the package name and the deps field
    #if it is the requested package, return true and the deps
    #if not, return False and an empty string
    import csv
    repoReader = csv.reader(open(repo))
    pkgnameCell, depCell = 0,5
    
    for row in repoReader:
        rawText = ','.join(row)
        name = getEntry(rawText, pkgnameCell)
        dep = getEntry(rawText, depCell)
        if package == name:
            return True, dep
    return False, ""

def checkDeps(package):
    #a recursive function
    #if the package is present return
    #if it isn't, print its name
    #if it has no deps return
    #if it has them, recurse for each one
    
    salixStable = 'salix32-13.37.csv'
    salixCurrent = 'salix32-current.csv'
    slackStable = 'slack32-13.37.csv'
    slackCurrent = 'slack32-current.csv'

    #maybe not all these are necessary ...
    
    package = checkVel(package)
    

    presentSalixStable, depSalixStable = checkRepo(package, salixStable)
    presentSalixCurrent, depSalixCurrent = checkRepo(package, salixCurrent)
    presentSlackStable, depSlackStable = checkRepo(package, slackStable)
    presentSlackCurrent, depSlackCurrent = checkRepo(package, slackCurrent)

    
    if presentSalixCurrent:
        return
    elif presentSlackCurrent and not presentSalixStable:
        #If it was packaged in Salix stable, it probably needs to be again now.
        return
    
    else:
        print package
        if depSalixStable == "":
            return

        for dep in depSalixStable.split(","):

            checkDeps(dep)


def checkVel(package):
    #deal with depX|depY items
    #this recursive function should cope with more than two
    #if it finds | it sends the remainder for checking
    #during which it will be called again
    #
    #however this doesn't entirely solve it
    #it requires *both* (or all) options to be present
    firstHalf, otherHalf, count = "", "", 0
    for char in package:
        count = count + 1
        if char == "|":
            otherHalf = checkVel(package[count:])
            break                           
        else:
            firstHalf = firstHalf + char

    if otherHalf != "":
        checkDeps(otherHalf)
    return firstHalf
    
            
def getEntry(rawText,cell):
    #from a row of CSV data, extract the nth cell
    #delimited by semicolons
    count = 0
    for i in rawText.split(";"):
        if count == cell:
            return stripQuotes(i)
        count = count + 1


def stripQuotes(text):
    # remove leading or trailing quotation marks
    if text[0] == '"':
        text = text[1:]
    if text[-1] == '"':
        text = text[:-1]
    return text



main()