#!/usr/bin/env python
# ex:ts=4:sw=4:sts=4:et
# -*- tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*-
#
# Copyright 2011 Intel Corporation
# Authored-by:  Yu Ke <ke.yu@intel.com>
#               Paul Eggleton <paul.eggleton@intel.com>
#               Richard Purdie <richard.purdie@intel.com>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 as
# published by the Free Software Foundation.
#
# 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.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

import os, sys
import optparse
import logging
import subprocess
import ConfigParser

__version__ = "0.1.0"

def logger_create():
    logger = logging.getLogger("")
    loggerhandler = logging.StreamHandler()
    loggerhandler.setFormatter(logging.Formatter("[%(asctime)s] %(message)s","%H:%M:%S"))
    logger.addHandler(loggerhandler)
    logger.setLevel(logging.INFO)
    return logger

logger = logger_create()

class Configuration(object):
    """
    Manages the configuration

    A valid conf looks like:

# component name
[bitbake]

# mandatory options

# git upstream uri
src_uri = git://git.openembedded.org/bitbake

# the directory to clone the component repo
local_repo_dir = ~/src/bitbake

# the relative dir to commit the repo patch
# use "." if it is root dir
dest_dir = bitbake

# the updated revision last time.
# leave it empty if no commit updated yet, and then the tool
# will start from the first commit
last_revision =

# optional options

# file_filter: only include the interested file
# file_filter = [path] [path] ...
# example:
#   file_filter = src/  : only include the subdir src
#   file_filter = src/*.c : only include the src *.c file
#   file_filter = src/main.c src/Makefile.am : only include these two files

[oe-core]
src_uri = git://git.openembedded.org/openembedded-core
local_repo_dir = ~/src/oecore
dest_dir = .
last_revision =

# it's also possible to embed python code in the config values. Similar
# to bitbake it considers every value starting with @ to be a python script. 
# So local_repo could be easily configured using an environment variable as:
#
# [bitbake]
# local_repo = @os.getenv("LOCAL_REPO_DIR") + "/bitbake"
#

# more components ...

    """
    def __init__(self, options):
        for key, val in options.__dict__.items():
            setattr(self, key, val)
        self.parser = ConfigParser.ConfigParser()
        self.parser.readfp(open(self.conffile))
        self.repos = {}
        for repo in self.parser.sections():
            self.repos[repo] = {}
            for (name, value) in self.parser.items(repo):
                if value.startswith("@"):
                    self.repos[repo][name] = eval(value.strip("@"))
                else:
                    self.repos[repo][name] = value

    def update(self, repo, option, value):
        self.parser.set(repo, option, value)
        self.parser.write(open(self.conffile, "w"))

    def sanity_check(self):
        required_options=["src_uri", "local_repo_dir", "dest_dir", "last_revision"]
        msg = ""
        for name in self.repos:
            for option in required_options:
                if option not in self.repos[name]:
                    msg = "%s\nOption %s is not defined for component %s" %(msg, option, name)
        if msg != "":
            logger.error("configuration file %s has the following error:%s" % (self.conffile,msg))
            sys.exit(1)

        # filterdiff is required by action_splitpatch, so check its availability
        if subprocess.call("which filterdiff &>/dev/null", shell=True) != 0:
            logger.error("ERROR: patchutils package is missing, please install it (e.g. # apt-get install patchutils)")
            sys.exit(1)

def runcmd(cmd,destdir=None):
    """
        execute command, raise CalledProcessError if fail
        return output if succeed
    """
    logger.debug("run cmd '%s' in %s" % (cmd, os.getcwd() if destdir is None else destdir))
    out = os.tmpfile()
    try:
        subprocess.check_call(cmd, stdout=out, stderr=out, cwd=destdir, shell=True)
    except subprocess.CalledProcessError,e:
        out.seek(0)
        logger.error("%s" % out.read())
        raise e

    out.seek(0)
    output = out.read()
    logger.debug("output: %s" % output )
    return output

def action_init(conf, args):
    """
        Clone component repositories
        Check git initialised and working tree is clean
    """
    for name in conf.repos:
        ldir = conf.repos[name]['local_repo_dir']
        if not os.path.exists(ldir):
            logger.info("cloning %s to %s" %(conf.repos[name]['src_uri'], ldir))
            subprocess.check_call("git clone %s %s" % (conf.repos[name]['src_uri'], ldir), shell=True)
    if not os.path.exists(".git"):
        runcmd("git init")

def check_repo_clean(repodir):
    """
        check if the repo is clean
        exit if repo is dirty
    """
    try:
        runcmd("git diff --quiet", repodir)
        #TODO: also check the index using "git diff --cached"
        #      but this will fail in just initialized git repo
        #      so need figure out a way
    except:
        logger.error("git repo %s is dirty, please fix it first", repodir)
        sys.exit(1)

def action_update(conf, args):
    """
        update the component repo
        generate the patch list
        apply the generated patches
    """
    # make sure all repos are clean
    for name in conf.repos:
        check_repo_clean(conf.repos[name]['local_repo_dir'])
    check_repo_clean(os.getcwd())

    import uuid
    patch_dir = "patch-%s" % uuid.uuid4()
    os.mkdir(patch_dir)

    for name in conf.repos:
        repo = conf.repos[name]
        ldir = repo['local_repo_dir']
        dest_dir = repo['dest_dir']
        repo_patch_dir = os.path.join(os.getcwd(), patch_dir, name)

        # Step 1: update the component repo
        logger.info("git pull for component repo %s in %s ..." % (name, ldir))
        output=runcmd("git pull", ldir)
        logger.info(output)

        # Step 2: generate the patch list and store to patch dir
        logger.info("generating patches for %s" % name)
        if dest_dir != ".":
            prefix = "--src-prefix=a/%s/ --dst-prefix=b/%s/" % (dest_dir, dest_dir)
        else:
            prefix = ""
        if repo['last_revision'] == "":
            logger.info("Warning: last_revision of component %s is not set, so start from the first commit" % name)
            patch_cmd_range = "--root master"
            rev_cmd_range = "master"
        else:
            patch_cmd_range = "%s..master" % repo['last_revision']
            rev_cmd_range = "%s..master" % repo['last_revision']

        file_filter = repo.get('file_filter',"")

        patch_cmd = "git format-patch -N %s --output-directory %s %s -- %s" % \
            (prefix,repo_patch_dir, patch_cmd_range, file_filter)
        output = runcmd(patch_cmd, ldir)
        logger.debug("generated patch set:\n%s" % output)
        patchlist = output.splitlines()

        rev_cmd = 'git log --pretty=format:"%H" ' + rev_cmd_range
        revlist = runcmd(rev_cmd, ldir).splitlines()

        # Step 3: Call repo specific hook to adjust patch
        if 'hook' in repo:
            # hook parameter is: ./hook patchpath revision reponame
            count=len(revlist)-1
            for patch in patchlist:
                runcmd("%s %s %s %s" % (repo['hook'], patch, revlist[count], name))
                count=count-1

        # Step 4: write patch list and revision list to file, for user to edit later
        patchlist_file = os.path.join(os.getcwd(), patch_dir, "patchlist-%s" % name)
        repo['patchlist'] = patchlist_file
        f = open(patchlist_file, 'w')
        count=len(revlist)-1
        for patch in patchlist:
            f.write("%s %s\n" % (patch, revlist[count]))
            count=count-1
        f.close()

    # Step 5: invoke bash for user to edit patch and patch list
    if conf.interactive:
        print   'Edit the patch and patch list in %s\n' \
                'For example, remove the unwanted patch entry from patchlist-*, so that it will be not applied later\n' \
                'After finish, press following command to continue\n' \
                '       exit 0  -- exit and continue to apply the patch\n' \
                '       exit 1  -- abort and not apply patch\n' % patch_dir
        ret = subprocess.call(["bash"], cwd=patch_dir)
        if ret != 0:
            print "Abort without applying patch"
            sys.exit(0)

    # Step 6: apply the generated and revised patch
    action_apply_patch(conf, args)
    runcmd("rm -rf %s" % patch_dir)

def action_apply_patch(conf, args):
    """
        apply the generated patch list to combo repo
    """
    for name in conf.repos:
        repo = conf.repos[name]
        lastrev = repo["last_revision"]
        for line in open(repo['patchlist']):
            patchfile = line.split()[0]
            lastrev = line.split()[1]
            cmd = "git am --keep-cr -s -p1 %s" % patchfile
            logger.info("Apply %s" % patchfile )
            try:
                runcmd(cmd)
            except subprocess.CalledProcessError:
                logger.info('"git am --abort" is executed to cleanup repo')
                runcmd("git am --abort")
                logger.error('"%s" failed' % cmd)
                logger.info("please manually apply patch %s" % patchfile)
                logger.info("After applying, run this tool again to apply the rest patches")
                conf.update(name, "last_revision", lastrev)
                sys.exit(0)
        conf.update(name, "last_revision", lastrev)

def action_splitpatch(conf, args):
    """
        generate the commit patch and
        split the patch per repo
    """
    logger.debug("action_splitpatch")
    if len(args) > 1:
        commit = args[1]
    else:
        commit = "HEAD"
    patchdir = "splitpatch-%s" % commit
    if not os.path.exists(patchdir):
        os.mkdir(patchdir)

    # filerange_root is for the repo whose dest_dir is root "."
    # and it should be specified by excluding all other repo dest dir
    # like "-x repo1 -x repo2 -x repo3 ..."
    filerange_root = ""
    for name in conf.repos:
        dest_dir = conf.repos[name]['dest_dir']
        if dest_dir != ".":
            filerange_root = '%s -x "%s/*"' % (filerange_root, dest_dir)

    for name in conf.repos:
        dest_dir = conf.repos[name]['dest_dir']
        patch_filename = "%s/%s.patch" % (patchdir, name)
        if dest_dir == ".":
            cmd = "git format-patch -n1 --stdout %s^..%s | filterdiff -p1 %s > %s" % (commit, commit, filerange_root, patch_filename)
        else:
            cmd = "git format-patch --no-prefix -n1 --stdout %s^..%s -- %s > %s" % (commit, commit, dest_dir, patch_filename)
        runcmd(cmd)
        # Detect empty patches (including those produced by filterdiff above
        # that contain only preamble text)
        if os.path.getsize(patch_filename) == 0 or runcmd("filterdiff %s" % patch_filename) == "":
            os.remove(patch_filename)
            logger.info("(skipping %s - no changes)", name)
        else:
            logger.info(patch_filename)

def action_error(conf, args):
    logger.info("invalid action %s" % args[0])

actions = {
    "init": action_init,
    "update": action_update,
    "splitpatch": action_splitpatch,
}

def main():
    parser = optparse.OptionParser(
        version = "Combo Layer Repo Tool version %s" % __version__,
        usage = """%prog [options] action

Create and update a combination layer repository from multiple component repositories.

Action:
  init              initialise the combo layer repo
  update            get patches from component repos and apply them to the combo repo
  splitpatch [commit] generate commit patch and split per component, default commit is HEAD""")

    parser.add_option("-c", "--conf", help = "specify the config file (conf/combo-layer.conf is the default).",
               action = "store", dest = "conffile", default = "conf/combo-layer.conf")

    parser.add_option("-i", "--interactive", help = "interactive mode, user can edit the patch list and patches",
               action = "store_true", dest = "interactive", default = False)

    parser.add_option("-D", "--debug", help = "output debug information",
               action = "store_true", dest = "debug", default = False)

    options, args = parser.parse_args(sys.argv)

    # Dispatch to action handler
    if len(args) == 1:
        logger.error("No action specified, exiting")
        parser.print_help()
    elif args[1] not in actions:
        logger.error("Unsupported action %s, exiting\n" % (args[1]))
        parser.print_help()
    elif not os.path.exists(options.conffile):
        logger.error("No valid config file, exiting\n")
        parser.print_help()
    else:
        if options.debug:
            logger.setLevel(logging.DEBUG)
        confdata = Configuration(options)
        confdata.sanity_check()
        actions.get(args[1], action_error)(confdata, args[1:])

if __name__ == "__main__":
    try:
        ret = main()
    except Exception:
        ret = 1
        import traceback
        traceback.print_exc(5)
    sys.exit(ret)