"""
Build support for geant4_
=========================
"""
import os.path

from ApeTools import Config, Build
from ApeTools.Build import call, InstallError

class Geant4(Build.Package):
    def __init__(self, name):
        """Add the :attr:`g4system` attribute and read it from the
        configuration..
        """
        Build.Package.__init__(self, name)
        self.setAttributes("g4system")

    def call_and_check(self, cmd, cwd, package, stage, log, env, append=False):
        """Execute command and check logfile for errors.

        The makefiles of Geant4 suppress non-zero exit codes. That means that the normal mechanism to detect build
        failure does not work.
        """
        call(cmd, cwd=cwd, output=log, package=package, stage=stage, env=env, append=append)

        lf = open(log)
        for line in lf:
            if "error:" in line:
                raise InstallError(cwd=cwd, pack=package, stage=stage,
                                   log=log, cmd=cmd)


    def g4make(self, logFile, env):
        """Build and install geant4_. Set up the build environment with
        all :envvar:`G4...` environment variables required to run
        :command:`make` successfully.
        """
        if not "CLHEPHOME" in env:
            raise InstallError(pack=self.name,
                               args=["CLHEPHOME is not defined!"],
                               stage="prepare make")

        env.update(
            CLHEP_BASE_DIR=env["CLHEPHOME"],
            G4SYSTEM=self.g4system,
            Geant4_DATA_DIR=os.path.join(self.prefix, "data"),
            G4INSTALL=os.path.dirname(self.buildDirectory),
            G4INCLUDE=os.path.join(self.prefix, "include"),
            G4LIB=os.path.join(self.prefix, "lib"),
            G4LISTS_BASE=os.path.join(self.prefix, "data"),
            G4LEDATA=os.path.join(self.prefix, "data/G4EMLOW"),
            G4LEVELGAMMADATA=os.path.join(self.prefix,
                                          "data/PhotonEvaporation"),
            G4RADIOACTIVEDATA=os.path.join(self.prefix, "data/RadiativeDecay"),
            G4ELASTICDATA=os.path.join(self.prefix, "data/Elastic"),
            G4TMP=os.path.join(self.buildDirectory, "tmp"),
            G4UI_NONE="1",
            G4LIB_BUILD_SHARED="1",
            )

        buildCmd = ["make"]

        jobs = Config.getint("ape", "jobs")
        if jobs > 1:
            buildCmd += ["-j", str(jobs)]
        print "  ... Building and installing"
        self.call_and_check(buildCmd, cwd=self.buildDirectory, log=logFile,
             env=env, package="geant4", stage="make")

        print "  ... Installing headers"
        self.call_and_check(["make", "includes"], cwd=self.buildDirectory,
             log=logFile, append=True, env=env,
             package="geant4", stage="make includes")


    def make(self, logFile, env):
        try:
            self.g4make(logFile, env)
        except:
            self.removePrefixDir()
            raise