#!/usr/bin/env python
# ex:ts=4:sw=4:sts=4:et
# -*- tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*-
"""
OpenEmbedded 'Build' implementation

Core code for function execution and task handling in the
OpenEmbedded (http://openembedded.org) build infrastructure.

Copyright: (c) 2003 Chris Larson

Based on functions from the base oe module, Copyright 2003 Holger Schurig
"""

from oe import debug, data, fetch, fatal, error, note, event, mkdirhier
import oe, os

# data holds flags and function name for a given task
_task_data = data.init()

# graph represents task interdependencies
_task_graph = oe.digraph()

# stack represents execution order, excepting dependencies
_task_stack = []

# events
class FuncFailed(Exception):
    """Executed function failed"""

class EventException(Exception):
    """Exception which is associated with an Event."""

    def __init__(self, msg, event):
        self.event = event

    def getEvent(self):
        return self._event

    def setEvent(self, event):
        self._event = event

    event = property(getEvent, setEvent, None, "event property")

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

    def __init__(self, t, d = {}):
        self.task = t
        self.data = d

    def getTask(self):
        return self._task

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

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

    def getData(self):
        return self._data

    def setData(self, data):
        self._data = data

    data = property(getData, setData, None, "data property")

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

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

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

class InvalidTask(TaskBase):
    """Invalid Task"""

# functions

def init(data):
    global _task_data, _task_graph, _task_stack
    _task_data = data.init()
    _task_graph = oe.digraph()
    _task_stack = []


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

    body = data.getVar(func, d)
    if not body:
        return

    if not dirs:
        dirs = (data.getVarFlag(func, 'dirs', d) or "").split()
    for adir in dirs:
        adir = data.expand(adir, d)
        mkdirhier(adir)

    if len(dirs) > 0:
        adir = dirs[-1]
    else:
        adir = data.getVar('B', d, 1)

    adir = data.expand(adir, d)

    try:
        prevdir = os.getcwd()
    except OSError:
        prevdir = data.expand('${TOPDIR}', d)
    if adir and os.access(adir, os.F_OK):
        os.chdir(adir)

    if data.getVarFlag(func, "python", d):
        exec_func_python(func, d)
    else:
        exec_func_shell(func, d)
    os.chdir(prevdir)

def exec_func_python(func, d):
    """Execute a python OE 'function'"""
    import re, os

    tmp = "def " + func + "():\n%s" % data.getVar(func, d)
    comp = compile(tmp + '\n' + func + '()', oe.data.getVar('FILE', d, 1) + ':' + func, "exec")
    prevdir = os.getcwd()
    g = {} # globals
    g['oe'] = oe
    g['os'] = os
    g['d'] = d
    exec comp in g
    if os.path.exists(prevdir):
        os.chdir(prevdir)

def exec_func_shell(func, d):
    """Execute a shell OE 'function' Returns true if execution was successful.

    For this, it creates a bash shell script in the tmp dectory, writes the local
    data into it and finally executes. The output of the shell will end in a log file and stdout.

    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.
    """
    import sys

    deps = data.getVarFlag(func, 'deps', d)
    check = data.getVarFlag(func, 'check', d)
    if check in globals():
        if globals()[check](func, deps):
            return

    global logfile
    t = data.getVar('T', d, 1)
    if not t:
        return 0
    mkdirhier(t)
    logfile = "%s/log.%s.%s" % (t, func, str(os.getpid()))
    runfile = "%s/run.%s.%s" % (t, func, str(os.getpid()))

    f = open(runfile, "w")
    f.write("#!/bin/sh -e\n")
    if data.getVar("OEDEBUG", d): f.write("set -x\n")
    data.emit_env(f, d)

    f.write("cd %s\n" % os.getcwd())
    if func: f.write("%s\n" % func)
    f.close()
    os.chmod(runfile, 0775)
    if not func:
        error("Function not specified")
        raise FuncFailed()

    # open logs
    si = file('/dev/null', 'r')
    try:
        if data.getVar("OEDEBUG", d):
            so = os.popen("tee \"%s\"" % logfile, "w")
        else:
            so = file(logfile, 'w')
    except OSError, e:
        oe.error("opening log file: %s" % e)
        pass

    se = so

    # dup the existing fds so we dont lose them
    osi = [os.dup(sys.stdin.fileno()), sys.stdin.fileno()]
    oso = [os.dup(sys.stdout.fileno()), sys.stdout.fileno()]
    ose = [os.dup(sys.stderr.fileno()), sys.stderr.fileno()]

    # replace those fds with our own
    os.dup2(si.fileno(), osi[1])
    os.dup2(so.fileno(), oso[1])
    os.dup2(se.fileno(), ose[1])

    # execute function
    prevdir = os.getcwd()
    if data.getVarFlag(func, "fakeroot", d):
        maybe_fakeroot = "PATH=\"%s\" fakeroot " % oe.data.getVar("PATH", d, 1)
    else:
        maybe_fakeroot = ''
    ret = os.system('%ssh -e %s' % (maybe_fakeroot, runfile))
    os.chdir(prevdir)

    # restore the backups
    os.dup2(osi[0], osi[1])
    os.dup2(oso[0], oso[1])
    os.dup2(ose[0], ose[1])

    # close our logs
    si.close()
    so.close()
    se.close()

    # close the backup fds
    os.close(osi[0])
    os.close(oso[0])
    os.close(ose[0])

    if ret==0:
        if not data.getVar("OEDEBUG", d):
            os.remove(runfile)
#            os.remove(logfile)
        return
    else:
        error("function %s failed" % func)
        if data.getVar("OEINCLUDELOGS", d):
            error("log data follows (%s)" % logfile)
            f = open(logfile, "r")
            while True:
                l = f.readline()
                if l == '':
                    break
                l = l.rstrip()
                print '| %s' % l
            f.close()
        else:
            error("see log in %s" % logfile)
        raise FuncFailed()


_task_cache = []

def exec_task(task, d):
    """Execute an OE 'task'

       The primary difference between executing a task versus executing
       a function is that a task exists in the task digraph, and therefore
       has dependencies amongst other tasks."""

    # check if the task is in the graph..
    task_graph = data.getVar('_task_graph', d)
    if not task_graph:
        task_graph = oe.digraph()
        data.setVar('_task_graph', task_graph, d)
    task_cache = data.getVar('_task_cache', d)
    if not task_cache:
        task_cache = []
        data.setVar('_task_cache', task_cache, d)
    if not task_graph.hasnode(task):
        raise EventException("", InvalidTask(task, d))

    # check whether this task needs executing..
    if not data.getVarFlag(task, 'force', d):
        if stamp_is_current(task, d):
            return 1

    # follow digraph path up, then execute our way back down
    def execute(graph, item):
        if data.getVarFlag(item, 'task', d):
            if item in task_cache:
                return 1

            if task != item:
                # deeper than toplevel, exec w/ deps
                exec_task(item, d)
                return 1

            try:
                debug(1, "Executing task %s" % item)
                event.fire(TaskStarted(item, d))
                exec_func(item, d)
                event.fire(TaskSucceeded(item, d))
                task_cache.append(item)
            except FuncFailed, reason:
                note( "Task failed: %s" % reason )
                failedevent = TaskFailed(item, d)
                event.fire(failedevent)
                raise EventException(None, failedevent)

    # execute
    task_graph.walkdown(task, execute)

    # make stamp, or cause event and raise exception
    if not data.getVarFlag(task, 'nostamp', d):
        mkstamp(task, d)


def stamp_is_current(task, d, checkdeps = 1):
    """Check status of a given task's stamp. returns 0 if it is not current and needs updating."""
    task_graph = data.getVar('_task_graph', d)
    if not task_graph:
        task_graph = oe.digraph()
        data.setVar('_task_graph', task_graph, d)
    stamp = data.getVar('STAMP', d)
    if not stamp:
        return 0
    stampfile = "%s.%s" % (data.expand(stamp, d), task)
    if not os.access(stampfile, os.F_OK):
        return 0

    if checkdeps == 0:
        return 1

    import stat
    tasktime = os.stat(stampfile)[stat.ST_MTIME]

    _deps = []
    def checkStamp(graph, task):
        # check for existance
        if data.getVarFlag(task, 'nostamp', d):
            return 1

        if not stamp_is_current(task, d, 0):
            return 0

        depfile = "%s.%s" % (data.expand(stamp, d), task)
        deptime = os.stat(depfile)[stat.ST_MTIME]
        if deptime > tasktime:
            return 0
        return 1

    return task_graph.walkdown(task, checkStamp)


def md5_is_current(task):
    """Check if a md5 file for a given task is current"""


def mkstamp(task, d):
    """Creates/updates a stamp for a given task"""
    stamp = data.getVar('STAMP', d)
    if not stamp:
        return
    stamp = "%s.%s" % (data.expand(stamp, d), task)
    mkdirhier(os.path.dirname(stamp))
    open(stamp, "w+")


def add_task(task, deps, d):
    task_graph = data.getVar('_task_graph', d)
    if not task_graph:
        task_graph = oe.digraph()
        data.setVar('_task_graph', task_graph, d)
    data.setVarFlag(task, 'task', 1, d)
    task_graph.addnode(task, None)
    for dep in deps:
        if not task_graph.hasnode(dep):
            task_graph.addnode(dep, None)
        task_graph.addnode(task, dep)


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

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

    task_graph = data.getVar('_task_graph', d)
    if not task_graph:
        task_graph = oe.digraph()
        data.setVar('_task_graph', task_graph, d)
    if not task_graph.hasnode(task):
        return

    data.delVarFlag(task, 'task', d)
    ref = 1
    if kill == 1:
        ref = 2
    task_graph.delnode(task, ref)

def task_exists(task, d):
    task_graph = data.getVar('_task_graph', d)
    if not task_graph:
        task_graph = oe.digraph()
        data.setVar('_task_graph', task_graph, d)
    return task_graph.hasnode(task)

def get_task_data():
    return _task_data