import sys
import os
import multiprocessing
import SCons.Util

## Configuration

opts = Variables('Local.sc')

opts.AddVariables(
    ("CC", "C Compiler"),
    ("CXX", "C++ Compiler"),
    ("AS", "Assembler"),
    ("LINK", "Linker"),
    ("BUILDTYPE", "Build type (RELEASE, DEBUG, or PERF)", "RELEASE"),
    ("VERBOSE", "Show full build information (0 or 1)", "0"),
    ("NUMCPUS", "Number of CPUs to use for build (0 means auto).", "0"),
    ("WITH_GPROF", "Include gprof profiling (0 or 1).", "0"),
    ("PREFIX", "Installation target directory.", "#pxelinux"),
    ("ARCH", "Target Architecture", "amd64")
)

env = Environment(options = opts,
                  tools = ['default'],
                  ENV = os.environ)
Help(opts.GenerateHelpText(env))

# Copy environment variables
if os.environ.has_key('CC'):
    env["CC"] = os.getenv('CC')
if os.environ.has_key('CXX'):
    env["CXX"] = os.getenv('CXX')
if os.environ.has_key('AS'):
    env["AS"] = os.getenv('AS')
if os.environ.has_key('LD'):
    env["LINK"] = os.getenv('LD')
if os.environ.has_key('CFLAGS'):
    env.Append(CCFLAGS = SCons.Util.CLVar(os.environ['CFLAGS']))
if os.environ.has_key('CPPFLAGS'):
    env.Append(CPPFLAGS = SCons.Util.CLVar(os.environ['CPPFLAGS']))
if os.environ.has_key('CXXFLAGS'):
    env.Append(CXXFLAGS = SCons.Util.CLVar(os.environ['CXXFLAGS']))
if os.environ.has_key('LDFLAGS'):
    env.Append(LINKFLAGS = SCons.Util.CLVar(os.environ['LDFLAGS']))

#env.Append(CPPFLAGS = [ "-Wall", "-Wformat=2", "-Wextra", "-Wwrite-strings",
#                        "-Wno-unused-parameter", "-Wmissing-format-attribute",
#                        "-Werror" ])
#env.Append(CFLAGS = [ "-Wmissing-prototypes", "-Wmissing-declarations",
#                      "-Wshadow", "-Wbad-function-cast", "-Werror" ])
#env.Append(CXXFLAGS = [ "-Wno-non-template-friend", "-Woverloaded-virtual",
#                        "-Wcast-qual", "-Wcast-align", "-Wconversion",
#                        "-Weffc++", "-std=c++0x", "-Werror" ])

if env["WITH_GPROF"] == "1":
    env.Append(CPPFLAGS = [ "-pg" ])
    env.Append(LINKFLAGS = [ "-pg" ])

if env["BUILDTYPE"] == "DEBUG":
    env.Append(CPPFLAGS = [ "-g", "-DDEBUG", "-Wall", 
        "-Wno-deprecated-declarations" ])
    env.Append(LINKFLAGS = [ "-g", "-rdynamic" ])
elif env["BUILDTYPE"] == "PERF":
    env.Append(CPPFLAGS = [ "-g", "-DNDEBUG", "-Wall", "-O2"])
    env.Append(LDFLAGS = [ "-g", "-rdynamic" ])
elif env["BUILDTYPE"] == "RELEASE":
    env.Append(CPPFLAGS = ["-DNDEBUG", "-Wall", "-O2"])
else:
    print "Error BUILDTYPE must be RELEASE or DEBUG"
    sys.exit(-1)

if env["ARCH"] != "amd64":
    print "Unsupported architecture: " + env["ARCH"]
    sys.exit(-1)

try:
    hf = open(".git/HEAD", 'r')
    head = hf.read()
    if head.startswith("ref: "):
        if head.endswith("\n"):
            head = head[0:-1]
        with open(".git/" + head[5:]) as bf:
            branch = bf.read()
            if branch.endswith("\n"):
                branch = branch[0:-1]
            env.Append(CPPFLAGS = [ "-DGIT_VERSION=\\\"" + branch + "\\\""])
except IOError:
    pass

if env["VERBOSE"] == "0":
    env["CCCOMSTR"] = "Compiling $SOURCE"
    env["CXXCOMSTR"] = "Compiling $SOURCE"
    env["SHCCCOMSTR"] = "Compiling $SOURCE"
    env["SHCXXCOMSTR"] = "Compiling $SOURCE"
    env["ARCOMSTR"] = "Creating library $TARGET"
    env["RANLIBCOMSTR"] = "Indexing library $TARGET"
    env["LINKCOMSTR"] = "Linking $TARGET"

def GetNumCPUs(env):
    if env["NUMCPUS"] != "0":
        return int(env["NUMCPUS"])
    return 2*multiprocessing.cpu_count()

env.SetOption('num_jobs', GetNumCPUs(env))

# XXX: Hack to support clang static analyzer
def CheckFailed():
    if os.getenv('CCC_ANALYZER_OUTPUT_FORMAT') != None:
        return
    Exit(1)

# Configuration
conf = env.Configure()

if not conf.CheckCC():
    print 'Your C compiler and/or environment is incorrectly configured.'
    CheckFailed()

if not conf.CheckCXX():
    print 'Your C++ compiler and/or environment is incorrectly configured.'
    CheckFailed()

conf.Finish()

Export('env')

# Debugging Tools

# Build Targets
SConscript('sys/SConscript', variant_dir='build/sys')

# Install Targets
env.Install('$PREFIX/','build/sys/castor')
env.Alias('install','$PREFIX')