# ex:ts=4:sw=4:sts=4:et
# -*- tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*-
#
# BitBake 'Build' implementation
#
# Core code for function execution and task handling in the
# BitBake build tools.
#
# Copyright (C) 2003, 2004  Chris Larson
#
# Based on Gentoo's portage.py.
#
# 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.
#
#Based on functions from the base bb module, Copyright 2003 Holger Schurig

import os
import sys
import logging
import bb
import bb.msg
import bb.process
from contextlib import nested
from bb import data, event, mkdirhier, utils

bblogger = logging.getLogger('BitBake')
logger = logging.getLogger('BitBake.Build')

NULL = open(os.devnull, 'r+')


# When we execute a python function we'd like certain things
# in all namespaces, hence we add them to __builtins__
# If we do not do this and use the exec globals, they will
# not be available to subfunctions.
__builtins__['bb'] = bb
__builtins__['os'] = os

class FuncFailed(Exception):
    def __init__(self, name = None, logfile = None):
        self.logfile = logfile
        self.name = name
        if name:
            self.message = "Function '%s' failed" % name
        else:
            self.message = "Function failed"

    def __str__(self):
        if self.logfile and os.path.exists(self.logfile):
            msg = ("%s (see %s for further information)" %
                   (self.message, self.logfile))
        else:
            msg = self.message
        return msg

class TaskBase(event.Event):
    """Base class for task events"""

    def __init__(self, t, d ):
        self._task = t
        self._package = bb.data.getVar("PF", d, 1)
        event.Event.__init__(self)
        self._message = "package %s: task %s: %s" % (bb.data.getVar("PF", d, 1), t, bb.event.getName(self)[4:])

    def getTask(self):
        return self._task

    def setTask(self, task):
        self._task = task

    task = property(getTask, setTask, None, "task property")

class TaskStarted(TaskBase):
    """Task execution started"""

class TaskSucceeded(TaskBase):
    """Task execution completed"""

class TaskFailed(TaskBase):
    """Task execution failed"""

    def __init__(self, task, logfile, metadata):
        self.logfile = logfile
        super(TaskFailed, self).__init__(task, metadata)

class InvalidTask(Exception):
    def __init__(self, task, metadata):
        self.task = task
        self.metadata = metadata

    def __str__(self):
        return "No such task '%s'" % self.task


class LogTee(object):
    def __init__(self, logger, outfile):
        self.outfile = outfile
        self.logger = logger
        self.name = self.outfile.name

    def write(self, string):
        self.logger.plain(string)
        self.outfile.write(string)

    def __enter__(self):
        self.outfile.__enter__()
        return self

    def __exit__(self, *excinfo):
        self.outfile.__exit__(*excinfo)

    def __repr__(self):
        return '<LogTee {0}>'.format(self.name)


def exec_func(func, d, dirs = None, logfile = NULL):
    """Execute an BB 'function'"""

    body = data.getVar(func, d)
    if not body:
        if body is None:
            logger.warn("Function %s doesn't exist", func)
        return

    flags = data.getVarFlags(func, d)
    cleandirs = flags.get('cleandirs')
    if cleandirs:
        for cdir in data.expand(cleandirs, d).split():
            bb.utils.remove(cdir, True)

    if dirs is None:
        dirs = flags.get('dirs')
        if dirs:
            dirs = data.expand(dirs, d).split()

    if dirs:
        for adir in dirs:
            bb.utils.mkdirhier(adir)
        adir = dirs[-1]
    else:
        adir = data.getVar('B', d, 1)
        if not os.path.exists(adir):
            adir = None

    ispython = flags.get('python')
    fakeroot = flags.get('fakeroot')

    lockflag = flags.get('lockfiles')
    if lockflag:
        lockfiles = [data.expand(f, d) for f in lockflag.split()]
    else:
        lockfiles = None

    tempdir = data.getVar('T', d, 1)
    runfile = os.path.join(tempdir, 'run.{0}.{1}'.format(func, os.getpid()))

    with bb.utils.fileslocked(lockfiles):
        if ispython:
            exec_func_python(func, d, runfile, logfile, cwd=adir)
        else:
            exec_func_shell(func, d, runfile, logfile, cwd=adir, fakeroot=fakeroot)

_functionfmt = """
def {function}(d):
{body}

{function}(d)
"""
logformatter = bb.msg.BBLogFormatter("%(levelname)s: %(message)s")
def exec_func_python(func, d, runfile, logfile, cwd=None):
    """Execute a python BB 'function'"""

    bbfile = d.getVar('FILE', True)
    olddir = os.getcwd()
    code = _functionfmt.format(function=func, body=d.getVar(func, True))
    bb.utils.mkdirhier(os.path.dirname(runfile))
    with open(runfile, 'w') as script:
        script.write(code)

    if cwd:
        os.chdir(cwd)

    handler = logging.StreamHandler(logfile)
    handler.setFormatter(logformatter)
    bblogger.addHandler(handler)

    try:
        comp = utils.better_compile(code, func, bbfile)
        utils.better_exec(comp, {"d": d}, code, bbfile)
    except:
        if sys.exc_info()[0] in (bb.parse.SkipPackage, bb.build.FuncFailed):
            raise

        raise FuncFailed(func, None)
    finally:
        bblogger.removeHandler(handler)
        os.chdir(olddir)

def exec_func_shell(function, d, runfile, logfile, cwd=None, fakeroot=False):
    """Execute a shell function from the metadata

    Note on directory behavior.  The 'dirs' varflag should contain a list
    of the directories you need created prior to execution.  The last
    item in the list is where we will chdir/cd to.
    """

    # Don't let the emitted shell script override PWD
    d.delVarFlag('PWD', 'export')

    with open(runfile, 'w') as script:
        script.write('#!/bin/sh -e\n')
        data.emit_func(function, script, d)

        script.write("set -x\n")
        script.write("%s\n" % function)
        os.fchmod(script.fileno(), 0775)

    if fakeroot:
        cmd = ['fakeroot', runfile]
    else:
        cmd = runfile

    if logger.isEnabledFor(logging.DEBUG):
        logfile = LogTee(logger, logfile)

    try:
        bb.process.run(cmd, cwd=cwd, shell=False, stdin=NULL, log=logfile)
    except bb.process.CmdError:
        raise FuncFailed(function, logfile.name)

def _task_data(fn, task, d):
    localdata = data.createCopy(d)
    localdata.setVar('BB_FILENAME', fn)
    localdata.setVar('BB_CURRENTTASK', task[3:])
    localdata.setVar('OVERRIDES', 'task-%s:%s' %
                     (task[3:], d.getVar('OVERRIDES', False)))
    localdata.finalize()
    data.expandKeys(localdata)
    return localdata

def exec_task(fn, task, d):
    """Execute a BB 'task'

    Execution of a task involves a bit more setup than executing a function,
    running it with its own local metadata, and with some useful variables set.
    """
    if not data.getVarFlag(task, 'task', d):
        raise InvalidTask(task, d)

    logger.debug(1, "Executing task %s", task)

    localdata = _task_data(fn, task, d)
    tempdir = localdata.getVar('T', True)
    if not tempdir:
        bb.fatal("T variable not set, unable to build")

    bb.utils.mkdirhier(tempdir)
    loglink = os.path.join(tempdir, 'log.{0}'.format(task))
    logfn = os.path.join(tempdir, 'log.{0}.{1}'.format(task, os.getpid()))
    if loglink:
        bb.utils.remove(loglink)

        try:
           os.symlink(logfn, loglink)
        except OSError:
           pass

    prefuncs = localdata.getVarFlag(task, 'prefuncs', expand=True)
    postfuncs = localdata.getVarFlag(task, 'postfuncs', expand=True)

    logfile = open(logfn, 'w')
    event.fire(TaskStarted(task, localdata), localdata)
    try:
        for func in (prefuncs or '').split():
            exec_func(func, localdata, logfile=logfile)
        exec_func(task, localdata, logfile=logfile)
        for func in (postfuncs or '').split():
            exec_func(func, localdata, logfile=logfile)
    except FuncFailed as exc:
        event.fire(TaskFailed(exc.name, exc.logfile, localdata), localdata)
        raise
    finally:
        logfile.close()
        if os.path.exists(logfn) and os.path.getsize(logfn) == 0:
            logger.debug(2, "Zero size logfn %s, removing", logfn)
            bb.utils.remove(logfn)
            bb.utils.remove(loglink)
    event.fire(TaskSucceeded(task, localdata), localdata)

    if not localdata.getVarFlag(task, 'nostamp') and not localdata.getVarFlag(task, 'selfstamp'):
        make_stamp(task, localdata)

def stamp_internal(taskname, d, file_name):
    """
    Internal stamp helper function
    Makes sure the stamp directory exists
    Returns the stamp path+filename

    In the bitbake core, d can be a CacheData and file_name will be set.
    When called in task context, d will be a data store, file_name will not be set
    """
    if file_name:
        stamp = d.stamp[file_name]
    else:
        stamp = d.getVar('STAMP', True)
        file_name = d.getVar('BB_FILENAME', True)

    if not stamp:
        return

    stamp = bb.parse.siggen.stampfile(stamp, file_name, taskname)

    bb.utils.mkdirhier(os.path.dirname(stamp))

    return stamp

def make_stamp(task, d, file_name = None):
    """
    Creates/updates a stamp for a given task
    (d can be a data dict or dataCache)
    """
    stamp = stamp_internal(task, d, file_name)
    # Remove the file and recreate to force timestamp
    # change on broken NFS filesystems
    if stamp:
        bb.utils.remove(stamp)
        f = open(stamp, "w")
        f.close()

def del_stamp(task, d, file_name = None):
    """
    Removes a stamp for a given task
    (d can be a data dict or dataCache)
    """
    stamp = stamp_internal(task, d, file_name)
    bb.utils.remove(stamp)

def stampfile(taskname, d):
    return stamp_internal(taskname, d, None)

def add_tasks(tasklist, d):
    task_deps = data.getVar('_task_deps', d)
    if not task_deps:
        task_deps = {}
    if not 'tasks' in task_deps:
        task_deps['tasks'] = []
    if not 'parents' in task_deps:
        task_deps['parents'] = {}

    for task in tasklist:
        task = data.expand(task, d)
        data.setVarFlag(task, 'task', 1, d)

        if not task in task_deps['tasks']:
            task_deps['tasks'].append(task)

        flags = data.getVarFlags(task, d)
        def getTask(name):
            if not name in task_deps:
                task_deps[name] = {}
            if name in flags:
                deptask = data.expand(flags[name], d)
                task_deps[name][task] = deptask
        getTask('depends')
        getTask('deptask')
        getTask('rdeptask')
        getTask('recrdeptask')
        getTask('nostamp')
        getTask('noexec')
        task_deps['parents'][task] = []
        for dep in flags['deps']:
            dep = data.expand(dep, d)
            task_deps['parents'][task].append(dep)

    # don't assume holding a reference
    data.setVar('_task_deps', task_deps, d)

def remove_task(task, kill, d):
    """Remove an BB 'task'.

       If kill is 1, also remove tasks that depend on this task."""

    data.delVarFlag(task, 'task', d)