# treebuilder.py - handle arch-specific tree building stuff using templates
#
# Copyright (C) 2011  Red Hat, 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; 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, see <http://www.gnu.org/licenses/>.
#
# Author(s):  Will Woods <wwoods@redhat.com>

import logging
logger = logging.getLogger("pylorax.treebuilder")

import os, re, glob
from subprocess import check_call, PIPE
from tempfile import NamedTemporaryFile

from sysutils import joinpaths, cpfile, replace, remove
from ltmpl import LoraxTemplate
from base import DataHolder
from imgutils import mkcpio

templatemap = {'i386':    'x86.tmpl',
               'x86_64':  'x86.tmpl',
               'ppc':     'ppc.tmpl',
               'ppc64':   'ppc.tmpl',
               'sparc':   'sparc.tmpl',
               'sparc64': 'sparc.tmpl',
               's390':    's390.tmpl',
               's390x':   's390.tmpl',
               }

def findkernels(root="/", kdir="boot"):
    # To find flavors, awk '/BuildKernel/ { print $4 }' kernel.spec
    flavors = ('debug', 'PAE', 'PAEdebug', 'smp', 'xen')
    kre = re.compile(r"vmlinuz-(?P<version>.+?\.(?P<arch>[a-z0-9_]+)"
                     r"(\.(?P<flavor>{0}))?)$".format("|".join(flavors)))
    kernels = []
    for f in os.listdir(joinpaths(root, kdir)):
        match = kre.match(f)
        if match:
            kernel = DataHolder(path=joinpaths(kdir, f))
            kernel.update(match.groupdict()) # sets version, arch, flavor
            kernels.append(kernel)

    # look for associated initrd/initramfs
    for kernel in kernels:
        # NOTE: if both exist, the last one found will win
        for imgname in ("initrd", "initramfs"):
            i = kernel.path.replace("vmlinuz", imgname, 1) + ".img"
            if os.path.exists(joinpaths(root, i)):
                kernel.initrd = DataHolder(path=i)

    return kernels

def _exists(root, p):
    if p[0] != '/': p = joinpaths(root, p)
    return (len(glob.glob(p)) > 0)

class BaseBuilder(object):
    def __init__(self, product, arch, inroot, outroot):
        self.arch = arch
        self.product = product
        self.inroot = inroot
        self.outroot = outroot
        self.runner = None

    def getdefaults(self):
        return dict(arch=self.arch, product=self.product,
                    inroot=self.inroot, outroot=self.outroot,
                    basearch=self.arch.basearch, libdir=self.arch.libdir,
                    exists=lambda p: _exists(self.inroot, p))

    def runtemplate(self, templatefile, **variables):
        for k,v in self.getdefaults():
            variables.setdefault(k,v) # setdefault won't override existing args
        t = LoraxTemplate()
        logger.info("parsing %s with the following variables", templatefile)
        for key, val in variables.items():
            logger.info("  %s: %s", key, val)
        template = t.parse(templatefile, variables)
        self.runner = TemplateRunner(self.inroot, self.outroot, template)
        logger.info("running template commands")
        self.runner.run()

class TreeBuilder(BaseBuilder):
    '''Builds the arch-specific boot images.
    inroot should be the installtree root (the newly-built runtime dir)'''
    def build(self):
        self.runtemplate(templatemap[self.arch.basearch], kernels=self.kernels)
        self.implantisomd5()

    @property
    def treeinfo_data(self):
        if self.runner:
            return self.runner.treeinfo_data

    @property
    def kernels(self):
        return findkernels(root=self.inroot)

    def rebuild_initrds(self, add_args=[], backup=""):
        '''Rebuild all the initrds in the tree. If backup is specified, each
        initrd will be renamed with backup as a suffix before rebuilding.
        If backup is empty, the existing initrd files will be overwritten.'''
        dracut = ["/sbin/dracut", "--nomdadmconf", "--nolvmconf"] + add_args
        if not backup:
            dracut.append("--force")
        for kernel in self.kernels:
            logger.info("rebuilding %s", kernel.initrd.path)
            if backup:
                initrd = joinpaths(self.inroot, kernel.initrd.path)
                os.rename(initrd, initrd + backup)
            check_call(["chroot", self.inroot] + \
                       dracut + [kernel.initrd.path, kernel.version])

    def initrd_append(self, rootdir):
        '''Place the given files into a cpio archive and append that archive
        to the initrds.'''
        cpio = NamedTemporaryFile(prefix="lorax.") # XXX workdir?
        mkcpio(rootdir, cpio.name, compression=None)
        for kernel in self.kernels:
            cpio.seek(0)
            initrd_path = joinpaths(self.inroot, kernel.initrd.path)
            with open(initrd_path, "ab") as initrd:
                logger.info("%s size before appending: %i",
                    kernel.initrd.path, os.path.getsize(initrd.name))
                initrd.write(cpio.read())

    def implantisomd5(self):
        for section, data in self.treeinfo_data:
            if 'boot.iso' in data:
                iso = joinpaths(self.outputdir, data['boot.iso'])
                check_call(["implantisomd5", iso])


# note: "install", "replace", "exists" allow globs
# "install" and "exist" assume their first argument is in inroot
# everything else operates on outroot
# "mkdir", "treeinfo", "runcmd", "remove", "replace" will take multiple args

# TODO: replace installtree:
#       glob(), find(glob)
#       installpkg/removepkg pkgglob [pkgglob..]
#       run_pkg_transaction
#       removefrom [pkgname] glob [glob..]
#       module modname [modname...]

class TemplateRunner(object):
    commands = ('install', 'mkdir', 'replace', 'append', 'treeinfo',
                'installkernel', 'installinitrd', 'hardlink', 'symlink',
                'copy', 'copyif', 'move', 'moveif', 'remove', 'chmod',
                'runcmd', 'log')

    def __init__(self, inroot, outroot, parsed_template, fatalerrors=False):
        self.inroot = inroot
        self.outroot = outroot
        self.template = parsed_template
        self.fatalerrors = fatalerrors

        self.treeinfo_data = dict()
        self.exists = lambda p: _exists(inroot, p)

    def _out(self, path):
        return joinpaths(self.outroot, path)
    def _in(self, path):
        return joinpaths(self.inroot, path)

    def run(self):
        for (num, line) in enumerate(self.template,1):
            logger.debug("template line %i: %s", num, line)
            (cmd, args) = (line[0], line[1:])
            try:
                if cmd not in self.commands:
                    raise ValueError, "unknown command %s" % cmd
                # grab the method named in cmd and pass it the given arguments
                f = getattr(self, cmd)
                f(*args)
            except Exception as e:
                logger.error("template command error: %s", str(line))
                if self.fatalerrors:
                    raise
                logger.error(str(e))

    def install(self, srcglob, dest):
        sources = glob.glob(self._in(srcglob))
        if not sources:
            raise IOError, "couldn't find %s" % srcglob
        for src in sources:
            cpfile(src, self._out(dest))

    def mkdir(self, *dirs):
        for d in dirs:
            d = self._out(d)
            if not os.path.isdir(d):
                os.makedirs(d)

    def replace(self, pat, repl, *files):
        for f in files:
            replace(pat, repl, self._out(f))

    def append(self, filename, data):
        with open(self._out(filename), "a") as fobj:
            fobj.write(data+"\n")

    def treeinfo(self, section, key, *valuetoks):
        if section not in self.treeinfo:
            self.treeinfo_data[section] = dict()
        self.treeinfo_data[section][key] = " ".join(valuetoks)

    def installkernel(self, section, src, dest):
        self.install(src, dest)
        self.treeinfo(section, "kernel", dest)

    def installinitrd(self, section, src, dest):
        self.install(src, dest)
        self.treeinfo(section, "initrd", dest)

    def hardlink(self, src, dest):
        os.link(self._out(src), self._out(dest))

    def symlink(self, target, dest):
        os.symlink(target, self._out(dest))

    def copy(self, src, dest):
        cpfile(self._out(src), self._out(dest))

    def copyif(self, src, dest):
        if self.exists(src):
            self.copy(src, dest)
            return True

    def move(self, src, dest):
        self.copy(src, dest)
        self.remove(src)

    def moveif(self, src, dest):
        if self.copyif(src, dest):
            self.remove(src)
            return True

    def remove(self, *targets):
        for t in targets:
            remove(self._out(t))

    def chmod(self, target, mode):
        os.chmod(self._out(target), int(mode,8))

    def gconfset(self, path, keytype, value, outfile=None):
        if outfile is None:
            outfile = self._out("etc/gconf/gconf.xml.defaults")
        check_call(["gconftool-2", "--direct",
                    "--config-source=xml:readwrite:%s" % outfile,
                    "--set", "--type", keytype, path, value])

    def log(self, msg):
        logger.info(msg)

    def runcmd(self, *cmdlist):
        '''Note that we need full paths for everything here'''
        chdir = lambda: None
        cmd = cmdlist
        if cmd[0].startswith("chdir="):
            dirname = cmd[0].split('=',1)[1]
            chdir = lambda: os.chdir(dirname)
            cmd = cmd[1:]
        logger.info("runcmd: %s", cmd)
        check_call(cmd, preexec_fn=chdir)