#!/usr/bin/env python

import errno
import hashlib
import fnmatch
import os
import platform
import subprocess
import sys

from lldbbuild import *

#### SETTINGS ####

def LLVM_HASH_INCLUDES_DIFFS ():
    return False

# The use of "x = "..."; return x" here is important because tooling looks for
# it with regexps.  Only change how this works if you know what you are doing.

def LLVM_REF ():
    llvm_ref = "release_39"
    return llvm_ref

def CLANG_REF ():
    clang_ref = "release_39"
    return clang_ref

# For use with Xcode-style builds

def XCODE_REPOSITORIES ():
    return [
        { 'name':   "llvm",
          'vcs':    VCS.git,
          'root':   llvm_source_path(),
          'url':    "http://llvm.org/git/llvm.git",
          'ref':    LLVM_REF() },

        { 'name':   "clang",
          'vcs':    VCS.git,
          'root':   clang_source_path(),
          'url':    "http://llvm.org/git/clang.git",
          'ref':    CLANG_REF() },

        { 'name':   "ninja",
          'vcs':    VCS.git,
          'root':   ninja_source_path(),
          'url':    "https://github.com/ninja-build/ninja.git",
          'ref':    "master" }
    ]

def get_c_compiler ():
    return subprocess.check_output([
        'xcrun',
        '--sdk', 'macosx',
        '-find', 'clang'
        ]).rstrip()

def get_cxx_compiler ():
    return subprocess.check_output([
        'xcrun',
        '--sdk', 'macosx',
        '-find', 'clang++'
        ]).rstrip()

#                 CFLAGS="-isysroot $(xcrun --sdk macosx --show-sdk-path) -mmacosx-version-min=${DARWIN_DEPLOYMENT_VERSION_OSX}" \
#                        LDFLAGS="-mmacosx-version-min=${DARWIN_DEPLOYMENT_VERSION_OSX}" \

def get_deployment_target ():
    return os.environ.get('MACOSX_DEPLOYMENT_TARGET', None)

def get_c_flags ():
    cflags = ''
    # sdk_path = subprocess.check_output([
    #     'xcrun',
    #     '--sdk', 'macosx',
    #     '--show-sdk-path']).rstrip()
    # cflags += '-isysroot {}'.format(sdk_path)

    deployment_target = get_deployment_target() 
    if deployment_target:
        # cflags += ' -mmacosx-version-min={}'.format(deployment_target)
        pass

    return cflags

def get_cxx_flags ():
    return get_c_flags()

def get_common_linker_flags ():
    linker_flags = ""
    deployment_target = get_deployment_target() 
    if deployment_target:
        # if len(linker_flags) > 0:
        #     linker_flags += ' '
        # linker_flags += '-mmacosx-version-min={}'.format(deployment_target)
        pass

    return linker_flags

def get_exe_linker_flags ():
    return get_common_linker_flags()

def get_shared_linker_flags ():
    return get_common_linker_flags()

def CMAKE_FLAGS ():
    return {
        "Debug": [
            "-DCMAKE_BUILD_TYPE=RelWithDebInfo",
            "-DLLVM_ENABLE_ASSERTIONS=ON",
            ],
        "DebugClang": [
            "-DCMAKE_BUILD_TYPE=Debug",
            "-DLLVM_ENABLE_ASSERTIONS=ON",
            ],
        "Release": [
            "-DCMAKE_BUILD_TYPE=Release",
            "-DLLVM_ENABLE_ASSERTIONS=ON",
            ],
        "BuildAndIntegration": [
            "-DCMAKE_BUILD_TYPE=Release",
            "-DLLVM_ENABLE_ASSERTIONS=OFF",
            ],
    }

def CMAKE_ENVIRONMENT ():
    return {
    }

#### COLLECTING ALL ARCHIVES ####

def collect_archives_in_path (path): 
    files = os.listdir(path)
    return [os.path.join(path, file) for file in files if file.endswith(".a")]

def archive_list ():
    paths = library_paths()
    archive_lists = [collect_archives_in_path(path) for path in paths]
    return [archive for archive_list in archive_lists for archive in archive_list]

def write_archives_txt ():
    f = open(archives_txt(), 'w')
    for archive in archive_list():
        f.write(archive + "\n")
    f.close()

#### COLLECTING REPOSITORY MD5S ####

def source_control_status (spec):
    vcs_for_spec = vcs(spec)
    if LLVM_HASH_INCLUDES_DIFFS():
        return vcs_for_spec.status() + vcs_for_spec.diff()
    else:
        return vcs_for_spec.status()

def source_control_status_for_specs (specs):
    statuses = [source_control_status(spec) for spec in specs]
    return "".join(statuses)

def all_source_control_status ():
    return source_control_status_for_specs(XCODE_REPOSITORIES())

def md5 (string):
    m = hashlib.md5()
    m.update(string)
    return m.hexdigest()

def all_source_control_status_md5 ():
    return md5(all_source_control_status())

#### CHECKING OUT AND BUILDING LLVM ####

def apply_patches(spec):
    files = os.listdir(os.path.join(lldb_source_path(), 'scripts'))
    patches = [f for f in files if fnmatch.fnmatch(f, spec['name'] + '.*.diff')]
    for p in patches:
        run_in_directory(["patch", "-p0", "-i", os.path.join(lldb_source_path(), 'scripts', p)], spec['root'])

def check_out_if_needed(spec):
    if not os.path.isdir(spec['root']):
        vcs(spec).check_out()
        apply_patches(spec)

def all_check_out_if_needed ():
    map (check_out_if_needed, XCODE_REPOSITORIES())

def should_build_llvm ():
    if build_type() == BuildType.Xcode:
        # TODO use md5 sums
        return True

def do_symlink (source_path, link_path):
    print "Symlinking " + source_path + " to " + link_path
    if not os.path.exists(link_path):
        os.symlink(source_path, link_path)

def setup_source_symlink (repo):
    source_path = repo["root"]
    link_path = os.path.join(lldb_source_path(), os.path.basename(source_path))
    do_symlink(source_path, link_path)

def setup_source_symlinks ():
    map(setup_source_symlink, XCODE_REPOSITORIES())

def setup_build_symlink ():
    # We don't use the build symlinks in llvm.org Xcode-based builds.
    if build_type() != BuildType.Xcode:
        source_path = package_build_path()
        link_path = expected_package_build_path()
        do_symlink(source_path, link_path)

def should_run_cmake (cmake_build_dir):
    # We need to run cmake if our llvm build directory doesn't yet exist.
    if not os.path.exists(cmake_build_dir):
        return True

    # Wee also need to run cmake if for some reason we don't have a ninja
    # build file.  (Perhaps the cmake invocation failed, which this current
    # build may have fixed).
    ninja_path = os.path.join(cmake_build_dir, "build.ninja")
    return not os.path.exists(ninja_path)

def cmake_environment ():
    cmake_env = join_dicts(os.environ, CMAKE_ENVIRONMENT())
    return cmake_env

def is_executable(path):
    return os.path.isfile(path) and os.access(path, os.X_OK)

def find_executable_in_paths (program, paths_to_check):
    program_dir, program_name = os.path.split(program)
    if program_dir:
        if is_executable(program):
            return program
    else:
        for path_dir in paths_to_check:
            path_dir = path_dir.strip('"')
            executable_file = os.path.join(path_dir, program)
            if is_executable(executable_file):
                return executable_file
    return None

def find_cmake ():
    # First check the system PATH env var for cmake
    cmake_binary = find_executable_in_paths("cmake", os.environ["PATH"].split(os.pathsep))
    if cmake_binary:
        # We found it there, use it.
        return cmake_binary

    # Check a few more common spots.  Xcode launched from Finder 
    # will have the default environment, and may not have
    # all the normal places present.
    extra_cmake_dirs = [
        "/usr/local/bin",
        "/opt/local/bin",
        os.path.join(os.path.expanduser("~"), "bin")
    ]

    if platform.system() == "Darwin":
        # Add locations where an official CMake.app package may be installed.
        extra_cmake_dirs.extend([
           os.path.join(
               os.path.expanduser("~"),
               "Applications",
               "CMake.app",
               "Contents",
               "bin"),
           os.path.join(
               os.sep,
               "Applications",
               "CMake.app",
               "Contents",
               "bin")])

    cmake_binary = find_executable_in_paths("cmake", extra_cmake_dirs)
    if cmake_binary:
        # We found it in one of the usual places.  Use that.
        return cmake_binary

    # We couldn't find cmake.  Tell the user what to do.
    raise Exception(
        "could not find cmake in PATH ({}) or in any of these locations ({}), "
        "please install cmake or add a link to it in one of those locations".format(
            os.environ["PATH"],
            extra_cmake_dirs))

def cmake_flags ():
    cmake_flags = CMAKE_FLAGS()[lldb_configuration()]
    cmake_flags += [
            "-GNinja",
            "-DCMAKE_C_COMPILER={}".format(get_c_compiler()),
            "-DCMAKE_CXX_COMPILER={}".format(get_cxx_compiler()),
            "-DCMAKE_INSTALL_PREFIX={}".format(expected_package_build_path_for("llvm")),
            "-DCMAKE_C_FLAGS={}".format(get_c_flags()),
            "-DCMAKE_CXX_FLAGS={}".format(get_cxx_flags()),
            "-DCMAKE_EXE_LINKER_FLAGS={}".format(get_exe_linker_flags()),
            "-DCMAKE_SHARED_LINKER_FLAGS={}".format(get_shared_linker_flags())
            ]
    deployment_target = get_deployment_target()
    if deployment_target:
        cmake_flags.append("-DCMAKE_OSX_DEPLOYMENT_TARGET={}".format(deployment_target))
    return cmake_flags

def run_cmake (cmake_build_dir, ninja_binary_path):
    cmake_binary = find_cmake()
    print "found cmake binary: using \"{}\"".format(cmake_binary)

    command_line = [cmake_binary] + cmake_flags() + [
            "-DCMAKE_MAKE_PROGRAM={}".format(ninja_binary_path),
            llvm_source_path()]
    print "running cmake like so: ({}) in dir ({})".format(command_line, cmake_build_dir)

    subprocess.check_call(command_line, cwd=cmake_build_dir, env=cmake_environment())

def create_directories_as_needed (path):
    try:
        os.makedirs(path)
    except OSError as error:
        # An error indicating that the directory exists already is fine.
        # Anything else should be passed along.
        if error.errno != errno.EEXIST:
            raise error

def run_cmake_if_needed (ninja_binary_path):
    cmake_build_dir = package_build_path()
    if should_run_cmake(cmake_build_dir):
        # Create the build directory as needed
        create_directories_as_needed (cmake_build_dir)
        run_cmake(cmake_build_dir, ninja_binary_path)

def build_ninja_if_needed ():
    # First check if ninja is in our path.  If so, there's nothing to do.
    ninja_binary_path = find_executable_in_paths("ninja", os.environ["PATH"].split(os.pathsep))
    if ninja_binary_path:
        # It's on the path.  cmake will find it.  We're good.
        print "found ninja here: \"{}\"".format(ninja_binary_path)
        return ninja_binary_path

    # Figure out if we need to build it.
    ninja_build_dir = ninja_source_path()
    ninja_binary_path = os.path.join(ninja_build_dir, "ninja")
    if not is_executable(ninja_binary_path):
        # Build ninja
        command_line = ["python", "configure.py", "--bootstrap"]
        print "building ninja like so: ({}) in dir ({})".format(command_line, ninja_build_dir)
        subprocess.check_call(command_line, cwd=ninja_build_dir, env=os.environ)

    return ninja_binary_path

def join_dicts (dict1, dict2):
    d = dict1.copy()
    d.update(dict2)
    return d

def build_llvm (ninja_binary_path):
    cmake_build_dir = package_build_path()
    subprocess.check_call([ninja_binary_path], cwd=cmake_build_dir, env=cmake_environment())

def build_llvm_if_needed ():
    if should_build_llvm():
        ninja_binary_path = build_ninja_if_needed()
        run_cmake_if_needed(ninja_binary_path)
        build_llvm(ninja_binary_path)
        setup_build_symlink()

#### MAIN LOGIC ####

all_check_out_if_needed()
build_llvm_if_needed()
write_archives_txt()

sys.exit(0)