proj_name = 'sample_mm'
proj_srcs = [
  'sample_mm.cpp',
]
proj_c_flags = [
  '-Wall',
  '-Wno-non-virtual-dtor',
  '-Wno-overloaded-virtual',
  '-Werror',
  '-Wno-unused',
]
proj_c_flags_opt = [
  '-O3',
  '-funroll-loops',
  '-pipe',
]
proj_c_flags_dbg = [
  '-g',
  '-ggdb3',
]

import os, sys

class SDK(object):
  def __init__(self, sdk, ext, aDef, name, platform, dir):
    self.folder = 'hl2sdk-' + dir
    self.envvar = sdk
    self.ext = ext
    self.code = aDef
    self.define = name
    self.name = dir
    self.path = None # Actual path
    self.platformSpec = platform

    # By default, nothing supports x64.
    if type(platform) is list:
      self.platformSpec = {p: ['x86'] for p in platform}
    else:
      self.platformSpec = platform

  def shouldBuild(self, target, archs):
    if target.platform not in self.platformSpec:
      return False
    if not len([i for i in self.platformSpec[target.platform] if i in archs]):
      return False
    return True

WinOnly = ['windows']
WinLinux = ['windows', 'linux']
WinLinuxMac = ['windows', 'linux', 'mac']
CSGO = {
  'windows': ['x86'],
  'linux': ['x86', 'x64'],
  'mac': ['x64']
}
Source2 = {
  'windows': ['x86', 'x64'],
  'linux': ['x64'],
}

PossibleSDKs = {
  'episode1':  SDK('HL2SDK', '2.ep1', '1', 'EPISODEONE', WinLinux, 'episode1'),
  'ep2':  SDK('HL2SDKOB', '2.ep2', '3', 'ORANGEBOX', WinLinux, 'orangebox'),
  'css':  SDK('HL2SDKCSS', '2.css', '6', 'CSS', WinLinuxMac, 'css'),
  'hl2dm':  SDK('HL2SDKHL2DM', '2.hl2dm', '7', 'HL2DM', WinLinuxMac, 'hl2dm'),
  'dods': SDK('HL2SDKDODS', '2.dods', '8', 'DODS', WinLinuxMac, 'dods'),
  'sdk2013': SDK('HL2SDK2013', '2.sdk2013', '9', 'SDK2013', WinLinuxMac, 'sdk2013'),
  'tf2':  SDK('HL2SDKTF2', '2.tf2', '11', 'TF2', WinLinuxMac, 'tf2'),
  'l4d':  SDK('HL2SDKL4D', '2.l4d', '12', 'LEFT4DEAD', WinLinuxMac, 'l4d'),
  'nucleardawn': SDK('HL2SDKND', '2.nd', '13', 'NUCLEARDAWN', WinLinuxMac, 'nucleardawn'),
  'l4d2': SDK('HL2SDKL4D2', '2.l4d2', '15', 'LEFT4DEAD2', WinLinuxMac, 'l4d2'),
  'darkm':  SDK('HL2SDK-DARKM', '2.darkm', '2', 'DARKMESSIAH', WinOnly, 'darkm'),
  'swarm':  SDK('HL2SDK-SWARM', '2.swarm', '16', 'ALIENSWARM', WinOnly, 'swarm'),
  'bgt':  SDK('HL2SDK-BGT', '2.bgt', '4', 'BLOODYGOODTIME', WinOnly, 'bgt'),
  'eye':  SDK('HL2SDK-EYE', '2.eye', '5', 'EYE', WinOnly, 'eye'),
  'csgo': SDK('HL2SDKCSGO', '2.csgo', '21', 'CSGO', CSGO, 'csgo'),
  'dota': SDK('HL2SDKDOTA', '2.dota', '22', 'DOTA', Source2, 'dota'),
  'portal2':  SDK('HL2SDKPORTAL2', '2.portal2', '17', 'PORTAL2', [], 'portal2'),
  'blade':  SDK('HL2SDKBLADE', '2.blade', '18', 'BLADE', WinLinux, 'blade'),
  'insurgency':  SDK('HL2SDKINSURGENCY', '2.insurgency', '19', 'INSURGENCY', WinLinuxMac, 'insurgency'),
  'doi':  SDK('HL2SDKDOI', '2.doi', '20', 'DOI', WinLinuxMac, 'doi'),
  'contagion':  SDK('HL2SDKCONTAGION', '2.contagion', '14', 'CONTAGION', WinOnly, 'contagion'),
  'bms':  SDK('HL2SDKBMS', '2.bms', '10', 'BMS', WinLinux, 'bms'),
}

def ResolveEnvPath(env, folder):
  if env in os.environ:
    path = os.environ[env]
    if os.path.isdir(path):
      return path
  else:
    head = os.getcwd()
    oldhead = None
    while head != None and head != oldhead:
      path = os.path.join(head, folder)
      if os.path.isdir(path):
        return path
      oldhead = head
      head, tail = os.path.split(head)
  return None

def Normalize(path):
  return os.path.abspath(os.path.normpath(path))
  
def SetArchFlags(compiler, arch, platform):
  if compiler.behavior == 'gcc':
    if arch == 'x86':
      compiler.cflags += ['-m32']
      compiler.linkflags += ['-m32']
      if platform == 'mac':
        compiler.linkflags += ['-arch', 'i386']
    elif arch == 'x64':
      compiler.cflags += ['-m64', '-fPIC']
      compiler.linkflags += ['-m64']
      if platform == 'mac':
        compiler.linkflags += ['-arch', 'x86_64']
  elif compiler.like('msvc'):
    if arch == 'x86':
      compiler.linkflags += ['/MACHINE:X86']
    elif arch == 'x64':
      compiler.linkflags += ['/MACHINE:X64']

def AppendArchSuffix(binary, name, arch):
  if arch == 'x64':
    binary.localFolder = name + '.x64'

class MMSConfig(object):
  def __init__(self):
    self.sdks = {}
    self.binaries = []
    self.generated_headers = None
    self.mms_root = None
    self.archs = builder.target.arch.replace('x86_64', 'x64').split(',')

  def detectProductVersion(self):
    builder.AddConfigureFile('product.version')

    # For OS X dylib versioning
    import re
    with open(os.path.join(builder.sourcePath, 'product.version'), 'r') as fp:
      productContents = fp.read()
    m = re.match('(\d+)\.(\d+)\.(\d+).*', productContents)
    if m == None:
      self.productVersion = '1.0.0'
    else:
      major, minor, release = m.groups()
      self.productVersion = '{0}.{1}.{2}'.format(major, minor, release)

  def detectSDKs(self):
    sdk_list = builder.options.sdks.split(',')
    use_all = sdk_list[0] == 'all'
    use_present = sdk_list[0] == 'present'
    if sdk_list[0] == '':
        sdk_list = []

    for sdk_name in PossibleSDKs:
      sdk = PossibleSDKs[sdk_name]
      if sdk.shouldBuild(builder.target, self.archs):
        if builder.options.hl2sdk_root:
          sdk_path = os.path.join(builder.options.hl2sdk_root, sdk.folder)
        else:
          sdk_path = ResolveEnvPath(sdk.envvar, sdk.folder)
        if sdk_path is None:
          if use_all or sdk_name in sdk_list:
            raise Exception('Could not find a valid path for {0}'.format(sdk.envvar))
          continue
        if use_all or use_present or sdk_name in sdk_list:
          sdk.path = sdk_path
          self.sdks[sdk_name] = sdk

    if len(self.sdks) < 1 and len(sdk_list):
      raise Exception('No SDKs were found that build on {0}-{1}, nothing to do.'.format(
        builder.target.platform, builder.target.arch))

    if builder.options.mms_path:
      self.mms_root = builder.options.mms_path
    else:
      self.mms_root = ResolveEnvPath('MMSOURCE110', 'mmsource-1.10')
      if not self.mms_root:
        self.mms_root = ResolveEnvPath('MMSOURCE_DEV', 'metamod-source')
      if not self.mms_root:
        self.mms_root = ResolveEnvPath('MMSOURCE_DEV', 'mmsource-central')

    if not self.mms_root or not os.path.isdir(self.mms_root):
      raise Exception('Could not find a source copy of Metamod:Source')
    self.mms_root = Normalize(self.mms_root)

  def configure(self):
    if not set(self.archs).issubset(['x86', 'x64']):
      raise Exception('Unknown target architecture: {0}'.format(builder.target.arch))

    cxx = builder.DetectCxx()

    if cxx.like('msvc') and len(self.archs) > 1:
      raise Exception('Building multiple archs with MSVC is not currently supported')

    if cxx.behavior == 'gcc':
      cxx.defines += [
        'stricmp=strcasecmp',
        '_stricmp=strcasecmp',
        '_snprintf=snprintf',
        '_vsnprintf=vsnprintf',
        '_alloca=alloca',
        'GNUC'
      ]
      cxx.cflags += proj_c_flags
      cxx.cflags += [ # todo: what is the difference between cflags and cxxflags
        '-fPIC',
        '-fno-exceptions',
        '-fno-rtti',
        '-msse',
        '-fno-strict-aliasing',
      ]

      if (cxx.version >= 'gcc-4.0') or cxx.family == 'clang':
        cxx.cflags += [
          '-fvisibility=hidden',
          '-fvisibility-inlines-hidden',
          '-std=c++11',
        ]
      # apple clang <-> llvm clang version correspondence is just a guess as there is no way to figure it out for real
      if (cxx.version >= 'gcc-4.7' or cxx.version >= 'clang-3.0' or cxx.version >= 'apple-clang-5.1'):
        cxx.cflags += [
          '-Wno-delete-non-virtual-dtor',
          '-Wno-unused-private-field',
          '-Wno-deprecated-register',
        ]
      if cxx.family == 'clang':
        if cxx.version >= 'clang-3.9' or cxx.version >= 'apple-clang-10.0':
          cxx.cxxflags += ['-Wno-expansion-to-defined']

    elif cxx.like('msvc'):
      raise Exception('MSVC builds should use the Visual Studio projects until somebody implements support') # todo: implement MSVC support

    # Optimization
    if builder.options.opt == '1':
      if cxx.behavior == 'gcc':
        cxx.cflags += proj_c_flags_opt
      # elif cxx.behavior == 'msvc': # todo: implement MSVC support

    # Debugging
    if builder.options.debug == '1':
      cxx.defines += ['_DEBUG']
      if cxx.behavior == 'gcc':
        cxx.cflags += proj_c_flags_dbg
      # elif cxx.behavior == 'msvc': # todo: implement MSVC support

    # This needs to be after our optimization flags which could otherwise disable it.
    # if cxx.family == 'msvc': # todo: implement MSVC support

    # Platform-specifics
    if builder.target.platform == 'linux':
      cxx.defines += [
        'POSIX',
        '_LINUX',
      ]
      cxx.linkflags += ['-shared']
      if cxx.family == 'gcc':
        cxx.linkflags += ['-static-libgcc']
    elif builder.target.platform == 'mac':
      cxx.defines += [
        'POSIX',
        'OSX',
        '_OSX',
      ]
      cxx.cflags += ['-mmacosx-version-min=10.9']
      cxx.linkflags += [
        '-dynamiclib',
        '-lc++',
        '-mmacosx-version-min=10.9',
      ]
    # elif builder.target.platform == 'windows': # todo: implement MSVC support

  def HL2Compiler(self, context, sdk, arch):
    compiler = context.cxx.clone()

    if sdk.name == 'episode1' or sdk.name == 'darkm':
      compiler.cxxincludes += [
        os.path.join(context.currentSourcePath),
        os.path.join(self.mms_root, 'core-legacy'),
        os.path.join(self.mms_root, 'core-legacy', 'sourcehook'),
    ]
    else:
      compiler.cxxincludes += [
        os.path.join(context.currentSourcePath),
        os.path.join(self.mms_root, 'core'),
        os.path.join(self.mms_root, 'core', 'sourcehook'),
    ]

    defines = ['SE_' + PossibleSDKs[i].define + '=' + PossibleSDKs[i].code for i in PossibleSDKs]
    compiler.defines += defines
    paths = [
              ['public'],
              ['public', 'engine'],
              ['public', 'mathlib'],
              ['public', 'vstdlib'],
              ['public', 'tier0'],
              ['public', 'tier1'],
            ]

    if sdk.name == 'episode1' or sdk.name == 'darkm':
      paths.append(['public', 'dlls'])
    else:
      paths.append(['public', 'game', 'server'])

    compiler.defines += ['SOURCE_ENGINE=' + sdk.code]

    if sdk.name in ['sdk2013', 'bms'] and compiler.like('gcc'):
      # The 2013 SDK already has these in public/tier0/basetypes.h
      compiler.defines.remove('stricmp=strcasecmp')
      compiler.defines.remove('_stricmp=strcasecmp')
      compiler.defines.remove('_snprintf=snprintf')
      compiler.defines.remove('_vsnprintf=vsnprintf')

    if compiler.family == 'msvc':
      # todo: verify this for MSVC support
      compiler.defines += ['COMPILER_MSVC']
      if arch == 'x86':
        compiler.defines += ['COMPILER_MSVC32']
      elif arch == 'x64':
        compiler.defines += ['COMPILER_MSVC64']

      if compiler.version >= 1900:
        compiler.linkflags += ['legacy_stdio_definitions.lib']
    else: # todo: is it better to check compiler.behavior?
      compiler.defines += ['COMPILER_GCC']

    for path in paths:
      compiler.cxxincludes += [os.path.join(sdk.path, *path)]

    return compiler

  def AddVersioning(self, binary, arch):
    if builder.target.platform == 'windows':
      # todo: verify this for MSVC support
      binary.sources += ['version.rc']
      binary.compiler.rcdefines += [
        'BINARY_NAME="{0}"'.format(binary.outputFile),
        'RC_COMPILE'
      ]
    elif builder.target.platform == 'mac' and binary.type == 'library':
      binary.compiler.postlink += [
        '-compatibility_version', '1.0.0',
        '-current_version', self.productVersion
      ]

    return binary

  def LibraryBuilder(self, compiler, name, arch):
    binary = compiler.Library(name)
    AppendArchSuffix(binary, name, arch)
    self.AddVersioning(binary, arch)
    return binary

  def HL2Library(self, context, name, sdk, arch):
    compiler = self.HL2Compiler(context, sdk, arch)

    SetArchFlags(compiler, arch, builder.target.platform)

    if builder.target.platform == 'linux':
      if sdk.name == 'episode1':
        lib_folder = os.path.join(sdk.path, 'linux_sdk')
      elif sdk.name in ['sdk2013', 'bms']:
        lib_folder = os.path.join(sdk.path, 'lib', 'public', 'linux32')
      elif arch == 'x64':
        lib_folder = os.path.join(sdk.path, 'lib', 'linux64')
      else:
        lib_folder = os.path.join(sdk.path, 'lib', 'linux')
    elif builder.target.platform == 'mac':
      if sdk.name in ['sdk2013', 'bms']:
        lib_folder = os.path.join(sdk.path, 'lib', 'public', 'osx32')
      elif arch == 'x64':
        lib_folder = os.path.join(sdk.path, 'lib', 'osx64')
      else:
        lib_folder = os.path.join(sdk.path, 'lib', 'mac')

    if builder.target.platform in ['linux', 'mac']:
      if sdk.name in ['sdk2013', 'bms'] or arch == 'x64':
        compiler.postlink += [compiler.Dep(os.path.join(lib_folder, 'tier1.a'))]
      else:
        compiler.postlink += [compiler.Dep(os.path.join(lib_folder, 'tier1_i486.a'))]

      if sdk.name in ['blade', 'insurgency', 'doi', 'csgo', 'dota']:
        if arch == 'x64':
          compiler.postlink += [compiler.Dep(os.path.join(lib_folder, 'interfaces.a'))]
        else:
          compiler.postlink += [compiler.Dep(os.path.join(lib_folder, 'interfaces_i486.a'))]

      if sdk.name == 'bms':
        compiler.postlink += [compiler.Dep(os.path.join(lib_folder, 'mathlib.a'))]

    binary = self.LibraryBuilder(compiler, name, arch)

    dynamic_libs = [] # todo: this whole section is slightly different, but I imagine it is "more correct"
    if builder.target.platform == 'linux':
      compiler.linkflags[0:0] = ['-lm', '-ldl'] # todo: do we need -ldl?
      if sdk.name in ['css', 'hl2dm', 'dods', 'tf2', 'sdk2013', 'bms', 'nucleardawn', 'l4d2', 'insurgency', 'doi']:
        dynamic_libs = ['libtier0_srv.so', 'libvstdlib_srv.so']
      elif arch == 'x64' and sdk.name == 'csgo':
        dynamic_libs = ['libtier0_client.so', 'libvstdlib_client.so']
      elif sdk.name in ['l4d', 'blade', 'insurgency', 'doi', 'csgo', 'dota']:
        dynamic_libs = ['libtier0.so', 'libvstdlib.so']
      else:
        dynamic_libs = ['tier0_i486.so', 'vstdlib_i486.so']
    elif builder.target.platform == 'mac':
      binary.compiler.linkflags.append('-liconv')
      dynamic_libs = ['libtier0.dylib', 'libvstdlib.dylib']
    elif builder.target.platform == 'windows':
      # todo: verify this for MSVC support
      libs = ['tier0', 'tier1', 'vstdlib']
      if sdk.name in ['swarm', 'blade', 'insurgency', 'doi', 'csgo', 'dota']:
        libs.append('interfaces')
      if sdk.name == 'bms':
        libs.append('mathlib')
      for lib in libs:
        if arch == 'x86':
          lib_path = os.path.join(sdk.path, 'lib', 'public', lib) + '.lib'
        elif arch == 'x64':
          lib_path = os.path.join(sdk.path, 'lib', 'public', 'win64', lib) + '.lib'
        binary.compiler.linkflags.append(binary.Dep(lib_path))

    for library in dynamic_libs:
      source_path = os.path.join(lib_folder, library)
      output_path = os.path.join(binary.localFolder, library)

      def make_linker(source_path, output_path):
        def link(context, binary):
          cmd_node, (output,) = context.AddSymlink(source_path, output_path)
          return output
        return link

      linker = make_linker(source_path, output_path)
      binary.compiler.linkflags[0:0] = [binary.Dep(library, linker)]

    return binary

MMS = MMSConfig()
MMS.detectProductVersion()
MMS.detectSDKs()
MMS.configure()

BuildScripts = [] # add sub-modules here
if getattr(builder.options, 'enable_tests', False):
    BuildScripts += [] # add tests here

import os

for sdk_name in MMS.sdks:
  for arch in MMS.archs:
    sdk = MMS.sdks[sdk_name]

    if not arch in sdk.platformSpec[builder.target.platform]:
      continue

    name = proj_name + sdk.ext
    binary = MMS.HL2Library(builder, name, sdk, arch)

    binary.sources += proj_srcs

    nodes = builder.Add(binary)
    MMS.binaries += [nodes]

builder.Build(BuildScripts, { 'MMS': MMS })