#!/usr/bin/python -tt
#
# Copyright (c) 2009, 2010, 2011 Intel, Inc.
#
# 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; version 2 of the License
#
# 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.

from __future__ import with_statement
import os
import sys
import tempfile
import shutil
import subprocess
import rpm
from mic import msger
from mic.utils import errors, proxy, misc
from mic.utils.rpmmisc import readRpmHeader, RPMInstallCallback
from mic.chroot import cleanup_mounts, setup_chrootenv, cleanup_chrootenv

PATH_BOOTSTRAP = "/usr/sbin:/usr/bin:/sbin:/bin"

RPMTRANS_FLAGS = [
                   rpm.RPMTRANS_FLAG_ALLFILES,
                   rpm.RPMTRANS_FLAG_NOSCRIPTS,
                   rpm.RPMTRANS_FLAG_NOTRIGGERS,
                 ]

RPMVSF_FLAGS = [
                 rpm._RPMVSF_NOSIGNATURES,
                 rpm._RPMVSF_NODIGESTS
               ]

RPMPROB_FLAGS = [
                  rpm.RPMPROB_FILTER_OLDPACKAGE,
                  rpm.RPMPROB_FILTER_REPLACEPKG,
                  rpm.RPMPROB_FILTER_IGNOREARCH
                ]

class MiniBackend(object):
    def __init__(self, rootdir, arch=None, repomd=None):
        self._ts = None
        self.rootdir = os.path.abspath(rootdir)
        self.arch = arch
        self.repomd = repomd
        self.dlpkgs = []
        self.localpkgs = {}
        self.optionals = []
        self.preins = {}
        self.postins = {}
        self.scriptlets = False

    def __del__(self):
        try:
            del self.ts
        except:
            pass

    def get_ts(self):
        if not self._ts:
            self._ts = rpm.TransactionSet(self.rootdir)
            self._ts.setFlags(reduce(lambda x, y: x|y, RPMTRANS_FLAGS))
            self._ts.setVSFlags(reduce(lambda x, y: x|y, RPMVSF_FLAGS))
            self._ts.setProbFilter(reduce(lambda x, y: x|y, RPMPROB_FLAGS))

        return self._ts

    def del_ts(self):
        if self._ts:
            self._ts.closeDB()
            self._ts = None

    ts = property(fget = lambda self: self.get_ts(),
                  fdel = lambda self: self.del_ts(),
                  doc="TransactionSet object")

    def selectPackage(self, pkg):
        if not pkg in self.dlpkgs:
            self.dlpkgs.append(pkg)

    def runInstall(self):
        # FIXME: check space
        self.downloadPkgs()
        self.installPkgs()

        if not self.scriptlets:
            return

        for pkg in self.preins.keys():
            prog, script = self.preins[pkg]
            self.run_pkg_script(pkg, prog, script, '0')
        for pkg in self.postins.keys():
            prog, script = self.postins[pkg]
            self.run_pkg_script(pkg, prog, script, '1')

    def downloadPkgs(self):
        nonexist = []
        for pkg in self.dlpkgs:
            localpth = misc.get_package(pkg, self.repomd, self.arch)
            if localpth:
                self.localpkgs[pkg] = localpth
            elif pkg in self.optionals:
                # skip optional rpm
                continue
            else:
                # mark nonexist rpm
                nonexist.append(pkg)

        if nonexist:
            raise errors.BootstrapError("Can't get rpm binary: %s" %
                                        ','.join(nonexist))

    def installPkgs(self):
        for pkg in self.localpkgs.keys():
            rpmpath = self.localpkgs[pkg]

            hdr = readRpmHeader(self.ts, rpmpath)

            # save prein and postin scripts
            self.preins[pkg] = (hdr['PREINPROG'], hdr['PREIN'])
            self.postins[pkg] = (hdr['POSTINPROG'], hdr['POSTIN'])

            # mark pkg as install
            self.ts.addInstall(hdr, rpmpath, 'u')

        # run transaction
        self.ts.order()
        cb = RPMInstallCallback(self.ts)
        errs = self.ts.run(cb.callback, '')

        # ts.run() exit codes are, hmm, "creative": None means all ok, empty 
        # list means some errors happened in the transaction and non-empty 
        # list that there were errors preventing the ts from starting...
        if errs is not None:
             raise errors.BootstrapError("Transaction couldn't start: %s" % '\n'.join(errs))

    def run_pkg_script(self, pkg, prog, script, arg):
        mychroot = lambda: os.chroot(self.rootdir)

        if not script:
            return

        if prog == "<lua>":
            prog = "/usr/bin/lua"

        tmpdir = os.path.join(self.rootdir, "tmp")
        if not os.path.exists(tmpdir):
            os.makedirs(tmpdir)
        tmpfd, tmpfp = tempfile.mkstemp(dir=tmpdir, prefix="%s.pre-" % pkg)
        script = script.replace('\r', '')
        os.write(tmpfd, script)
        os.close(tmpfd)
        os.chmod(tmpfp, 0700)

        try:
            script_fp = os.path.join('/tmp', os.path.basename(tmpfp))
            subprocess.call([prog, script_fp, arg], preexec_fn=mychroot)
        except (OSError, IOError), err:
            msger.warning(str(err))
        finally:
            os.unlink(tmpfp)

class Bootstrap(object):
    def __init__(self, rootdir, distro, arch=None):
        self.rootdir = misc.mkdtemp(dir=rootdir, prefix=distro)
        self.distro = distro
        self.arch = arch
        self.logfile = None
        self.pkgslist = []
        self.repomd = None

    def __del__(self):
        self.cleanup()

    def get_rootdir(self):
        if os.path.exists(self.rootdir):
            shutil.rmtree(self.rootdir, ignore_errors=True)
        os.makedirs(self.rootdir)
        return self.rootdir

    def dirsetup(self, rootdir=None):
        _path = lambda pth: os.path.join(rootdir, pth.lstrip('/'))

        if not rootdir:
            rootdir = self.rootdir

        try:
            # make /tmp and /etc path
            tmpdir = _path('/tmp')
            if not os.path.exists(tmpdir):
                os.makedirs(tmpdir)
            etcdir = _path('/etc')
            if not os.path.exists(etcdir):
                os.makedirs(etcdir)

            # touch distro file
            tzdist = _path('/etc/%s-release' % self.distro)
            if not os.path.exists(tzdist):
                with open(tzdist, 'w') as wf:
                    wf.write("bootstrap")
        except:
            pass

    def create(self, repomd, pkglist, optlist=()):
        try:
            pkgmgr = MiniBackend(self.get_rootdir())
            pkgmgr.arch = self.arch
            pkgmgr.repomd = repomd
            pkgmgr.optionals = list(optlist)
            map(pkgmgr.selectPackage, pkglist + list(optlist))
            pkgmgr.runInstall()
        except (OSError, IOError, errors.CreatorError), err:
            raise errors.BootstrapError("%s" % err)

    def run(self, cmd, chdir, rootdir=None, bindmounts=None):
        def mychroot():
            os.chroot(rootdir)
            os.chdir(chdir)

        def sync_timesetting(rootdir):
            try:
                # sync time and zone info to bootstrap
                if os.path.exists(rootdir + "/etc/localtime"):
                    os.unlink(rootdir + "/etc/localtime")
                shutil.copyfile("/etc/localtime", rootdir + "/etc/localtime")
            except:
                pass

        def sync_passwdfile(rootdir):
            try:
                # sync passwd file to bootstrap, saving the user info
                if os.path.exists(rootdir + "/etc/passwd"):
                    os.unlink(rootdir + "/etc/passwd")
                shutil.copyfile("/etc/passwd", rootdir + "/etc/passwd")
            except:
                pass

        if not rootdir:
            rootdir = self.rootdir

        if isinstance(cmd, list):
            shell = False
        else:
            shell = True

        env = os.environ
        env['PATH'] = "%s:%s" % (PATH_BOOTSTRAP, env['PATH'])

        retcode = 0
        gloablmounts = None
        try:
            proxy.set_proxy_environ()
            gloablmounts = setup_chrootenv(rootdir, bindmounts)
            sync_timesetting(rootdir)
            sync_passwdfile(rootdir)
            retcode = subprocess.call(cmd, preexec_fn=mychroot, env=env, shell=shell)
        except (OSError, IOError):
            # add additional information to original exception
            value, tb = sys.exc_info()[1:]
            value = '%s: %s' % (value, ' '.join(cmd))
            raise RuntimeError, value, tb
        finally:
            #if self.logfile and os.path.isfile(self.logfile):
            #    msger.log(file(self.logfile).read())
            cleanup_chrootenv(rootdir, bindmounts, gloablmounts)
            proxy.unset_proxy_environ()
        return retcode

    def cleanup(self):
        try:
            # clean mounts
            cleanup_mounts(self.rootdir)
            # remove rootdir
            shutil.rmtree(self.rootdir, ignore_errors=True)
        except:
            pass
