#! /usr/bin/env python
# -*- coding: utf-8 -*-
#
# Copyright (C) 2007-2010 Siegfried-A. Gevatter <rainct@ubuntu.com>
# With some changes by Iain Lane <iain@orangesquash.org.uk>,
#                      Stefano Rivera <stefanor@ubuntu.com>
# Based upon pbuilder-dist-simple by Jamin Collins and Jordan Mantha.
#
# ##################################################################
#
# 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.
#
# See file /usr/share/common-licenses/GPL-2 for more details.
#
# ##################################################################
#
# This script is a wrapper to be able to easily use pbuilder/cowbuilder for
# different distributions (eg, Gutsy, Hardy, Debian unstable, etc).
#
# You can create symlinks to a pbuilder-dist executable to get different
# configurations. For example, a symlink called pbuilder-hardy will assume
# that the target distribution is always meant to be Ubuntu Hardy.

import os
import subprocess
from sys import exit, argv, stderr

import ubuntutools.misc

debian_distros = ['etch', 'lenny', 'squeeze', 'sid', 'stable', 'testing',
                  'unstable', 'experimental']

class pbuilder_dist:
    def __init__(self, builder):
        # Base directory where pbuilder will put all the files it creates.
        self.base = None

        # Name of the operation which pbuilder should perform.
        self.operation = None

        # Wheter additional components should be used or not. That is,
        # 'universe' and 'multiverse' for Ubuntu chroots and 'contrib'
        # and 'non-free' for Debian.
        self.extra_components = True

        # File where the log of the last operation will be saved.
        self.logfile = None

        # System architecture
        self.system_architecture = None

        # Build architecture
        self.build_architecture = None

        # System's distribution
        self.system_distro = None

        # Target distribution
        self.target_distro = None

        # This is an identificative string which will either take the form
        # 'distribution' or 'distribution-architecture'.
        self.chroot_string = None

        # Authentication method
        self.auth = 'sudo'

        # Builder
        self.builder = builder

        # Ensure that the used builder is installed
        paths = set(os.environ['PATH'].split(':'))
        paths |= set(('/sbin', '/usr/sbin', '/usr/local/sbin'))
        if not any(os.path.exists(os.path.join(p, builder)) for p in paths):
            print >> stderr, 'Error: Could not find "%s".' % builder
            exit(1)

        ##############################################################

        self.base = os.path.expanduser(os.environ.get('PBUILDFOLDER',
                                                      '~/pbuilder/'))

        if not os.path.isdir(self.base):
            try:
                os.makedirs(self.base)
            except os.OSError:
                print >> stderr, ('Error: Cannot create base directory "%s"'
                                  % self.base)
                exit(1)

        if 'PBUILDAUTH' in os.environ:
            self.auth = os.environ['PBUILDAUTH']

        self.system_architecture = ubuntutools.misc.host_architecture()
        self.system_distro = ubuntutools.misc.system_distribution()
        if not self.system_architecture or not self.system_distro:
            exit(1)

        self.target_distro = self.system_distro

    def set_target_distro(self, distro):
        """ pbuilder_dist.set_target_distro(distro) -> None

        Check if the given target distribution name is correct, if it
        isn't know to the system ask the user for confirmation before
        proceeding, and finally either save the value into the appropiate
        variable or finalize pbuilder-dist's execution.
        """
        if not distro.isalpha():
            print >> stderr, ('Error: "%s" is an invalid distribution codename.'
                              % distro)
            exit(1)

        if not os.path.isfile(os.path.join('/usr/share/debootstrap/scripts/',
                                           distro)):
            if os.path.isdir('/usr/share/debootstrap/scripts/'):
                # Debian experimental doesn't have a debootstrap file but
                # should work nevertheless.
                if distro not in debian_distros:
                    answer = ask(('Warning: Unknown distribution "%s". Do you '
                                  'want to continue [y/N]? ') % distro)
                    if answer not in ('y', 'Y'):
                        exit(0)
            else:
                print >> stderr, 'Please install package "debootstrap".'
                exit(1)

        self.target_distro = distro

    def set_operation(self, operation):
        """ pbuilder_dist.set_operation -> None

        Check if the given string is a valid pbuilder operation and
        depending on this either save it into the appropiate variable
        or finalize pbuilder-dist's execution.
        """
        arguments = ('create', 'update', 'build', 'clean', 'login', 'execute')

        if operation not in arguments:
            if operation.endswith('.dsc'):
                if os.path.isfile(operation):
                    self.operation = 'build'
                    return [operation]
                else:
                    print >> stderr, ('Error: Could not find file "%s".'
                                      % operation)
                    exit(1)
            else:
                print >> stderr, (
                        'Error: "%s" is not a recognized argument.\n'
                        'Please use one of these: %s.'
                    ) % (operation, ', '.join(arguments))
                exit(1)
        else:
            self.operation = operation
            return []

    def get_command(self, remaining_arguments = None):
        """ pbuilder_dist.get_command -> string

        Generate the pbuilder command which matches the given configuration
        and return it as a string.
        """
        if not self.build_architecture:
            self.chroot_string = self.target_distro
            self.build_architecture = self.system_architecture
        else:
            self.chroot_string = (self.target_distro + '-'
                                  + self.build_architecture)

        prefix = os.path.join(self.base, self.chroot_string)
        result = '%s_result/' % prefix

        if not self.logfile and self.operation != 'login':
            self.logfile = os.path.normpath('%s/last_operation.log' % result)

        if not os.path.isdir(result):
            try:
                os.makedirs(result)
            except os.OSError:
                print >> stderr, ('Error: Cannot create results directory "%s"'
                                  % result)
                exit(1)

        if self.builder == 'pbuilder':
            base = '--basetgz "%s-base.tgz"' % prefix
        elif self.builder == 'cowbuilder':
            base = '--basepath "%s-base.cow"' % prefix
        else:
            print >> stderr, 'Error: Unrecognized builder "%s".' % self.builder
            exit(1)

        arguments = [
            '--%s' % self.operation,
            base,
            '--distribution', self.target_distro,
            '--buildresult', result,
            '--aptcache', '/var/cache/apt/archives/',
            '--override-config',
        ]

        if self.logfile:
            arguments += ['--logfile', self.logfile]

        if os.path.exists('/var/cache/archive/'):
            arguments += ['--bindmounts', '/var/cache/archive/']

        localrepo = '/var/cache/archive/' + self.target_distro
        if os.path.exists(localrepo):
            arguments += [
                    '--othermirror ',
                    'deb file:///var/cache/archive/ %s/' % self.target_distro,
            ]

        if self.target_distro in debian_distros:
            arguments += ['--mirror', 'http://ftp.debian.org/debian']
            # work around bug #599695
            arguments += [
                    '--debootstrapopts',
                    '--keyring=/usr/share/keyrings/debian-archive-keyring.gpg',
            ]
            components = 'main'
            if self.extra_components:
                components += ' contrib non-free'
        else:
            if self.build_architecture in ('amd64', 'i386'):
                arguments += ['--mirror', 'http://archive.ubuntu.com/ubuntu/']
            elif (self.build_architecture == 'powerpc'
                    and self.target_distro == 'dapper'):
                arguments += ['--mirror', 'http://archive.ubuntu.com/ubuntu/']
            else:
                arguments += ['--mirror',
                              'http://ports.ubuntu.com/ubuntu-ports/']
            components = 'main restricted'
            if self.extra_components:
                components += ' universe multiverse'

        arguments += ['--components', components]

        if self.build_architecture != self.system_architecture:
            arguments += ['--debootstrapopts',
                          '--arch=' + self.build_architecture]

        apt_conf_dir = os.path.join(self.base,
                                    'etc/%s/apt.conf' % self.target_distro)
        if os.path.exists(apt_conf_dir):
            arguments += ['--aptconfdir', apt_conf_dir]

        # Append remaining arguments
        if remaining_arguments:
            arguments.extend(remaining_arguments)

        # Export the distribution and architecture information to the
        # environment so that it is accessible to ~/.pbuilderrc (LP: #628933).
        return [
            self.auth,
            'ARCH=' + self.build_architecture,
            'DIST=' + self.target_distro,
            self.builder,
        ] + arguments


def ask(question):
    """ ask(question) -> string

    Ask the given question and return the answer. Also catch
    KeyboardInterrupt (Ctrl+C) and EOFError (Ctrl+D) exceptions and
    immediately return None if one of those is found.
    """
    try:
        answer = raw_input(question)
    except (KeyboardInterrupt, EOFError):
        print
        answer = None

    return answer

def help(exit_code = 0):
    """ help() -> None

    Print a help message for pbuilder-dist, and exit with the given code.
    """
    print 'See  man pbuilder-dist  for more information.'

    exit(exit_code)

def main():
    """ main() -> None

    This is pbuilder-dist's main function. It creates a pbuilder_dist
    object, modifies all necessary settings taking data from the
    executable's name and command line options and finally either ends
    the script and runs pbuilder itself or exists with an error message.
    """
    script_name = os.path.basename(argv[0])
    parts = script_name.split('-')

    # Copy arguments into another list for save manipulation
    args = argv[1:]

    if ('-' in script_name and parts[0] not in ('pbuilder', 'cowbuilder')
            or len(parts) > 3):
        print >> stderr, ('Error: "%s" is not a valid name for a '
                          '"pbuilder-dist" executable.') % script_name
        exit(1)

    if len(args) < 1:
        print >> stderr, 'Insufficient number of arguments.'
        help(1)

    if args[0] in ('-h', '--help', 'help'):
        help(0)

    app = pbuilder_dist(parts[0])

    if len(parts) > 1 and parts[1] != 'dist' and '.' not in parts[1]:
        app.set_target_distro(parts[1])
    else:
        app.set_target_distro(args.pop(0))

    if len(parts) > 2:
        requested_arch = parts[2]
    elif len(args) > 0 and args[0] in (
            'alpha', 'amd64', 'arm', 'armeb', 'armel', 'i386', 'lpia', 'm68k',
            'mips', 'mipsel', 'powerpc', 'ppc64', 'sh4', 'sh4eb', 'sparc',
            'sparc64'):
        requested_arch = args.pop(0)
    else:
        requested_arch = None

    if requested_arch:
        app.build_architecture = requested_arch
        # For some foreign architectures we need to use qemu
        if (requested_arch != app.system_architecture
                and (app.system_architecture, requested_arch) not in [
                    ('amd64', 'i386'), ('amd64', 'lpia'), ('arm', 'armel'),
                    ('armel', 'arm'), ('i386', 'lpia'), ('lpia', 'i386'),
                    ('powerpc', 'ppc64'), ('ppc64', 'powerpc'),
                    ('sparc', 'sparc64'), ('sparc64', 'sparc')]):
            args.append('--debootstrap qemu-debootstrap')

    if 'mainonly' in argv or '--main-only' in argv:
        app.extra_components = False
        if 'mainonly' in argv:
            args.remove('mainonly')
        else:
            args.remove('--main-only')

    if len(args) < 1:
        print >> stderr, 'Insufficient number of arguments.'
        help(1)

    # Parse the operation
    args = app.set_operation(args.pop(0)) + args

    if app.operation == 'build' and '.dsc' not in ' '.join(args):
        print >> stderr, ('Error: You have to specify a .dsc file if you want '
                          'to build.')
        exit(1)

    # Execute the pbuilder command
    if not '--debug-echo' in args:
        exit(subprocess.call(app.get_command(args)))
    else:
        print app.get_command([arg for arg in args if arg != '--debug-echo'])

if __name__ == '__main__':
    try:
        main()
    except KeyboardInterrupt:
        print >> stderr, 'Manually aborted.'
        exit(1)