# Copyright 2013 The Servo Project Developers. See the COPYRIGHT
# file at the top-level directory of this distribution.
#
# Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
# http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
# <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
# option. This file may not be copied, modified, or distributed
# except according to those terms.

import os
from os import path
import contextlib
import subprocess
from subprocess import PIPE
import sys
import platform

import toml

from mach.registrar import Registrar

BIN_SUFFIX = ".exe" if sys.platform == "win32" else ""


@contextlib.contextmanager
def cd(new_path):
    """Context manager for changing the current working directory"""
    previous_path = os.getcwd()
    try:
        os.chdir(new_path)
        yield
    finally:
        os.chdir(previous_path)


def host_triple():
    os_type = platform.system().lower()
    if os_type == "linux":
        os_type = "unknown-linux-gnu"
    elif os_type == "darwin":
        os_type = "apple-darwin"
    elif os_type == "android":
        os_type = "linux-androideabi"
    elif os_type == "windows":
        os_type = "pc-windows-msvc"
    elif os_type.startswith("mingw64_nt-") or os_type.startswith("cygwin_nt-"):
        os_type = "pc-windows-gnu"
    elif os_type == "freebsd":
        os_type = "unknown-freebsd"
    else:
        os_type = "unknown"

    cpu_type = platform.machine().lower()
    if cpu_type in ["i386", "i486", "i686", "i768", "x86"]:
        cpu_type = "i686"
    elif cpu_type in ["x86_64", "x86-64", "x64", "amd64"]:
        cpu_type = "x86_64"
    elif cpu_type == "arm":
        cpu_type = "arm"
    else:
        cpu_type = "unknown"

    return "%s-%s" % (cpu_type, os_type)


def call(*args, **kwargs):
    """Wrap `subprocess.call`, printing the command if verbose=True."""
    verbose = kwargs.pop('verbose', False)
    if verbose:
        print(' '.join(args[0]))
    # we have to use shell=True in order to get PATH handling
    # when looking for the binary on Windows
    return subprocess.call(*args, shell=sys.platform == 'win32', **kwargs)


def normalize_env(env):
    # There is a bug in subprocess where it doesn't like unicode types in
    # environment variables. Here, ensure all unicode are converted to
    # binary. utf-8 is our globally assumed default. If the caller doesn't
    # want UTF-8, they shouldn't pass in a unicode instance.
    normalized_env = {}
    for k, v in env.items():
        if isinstance(k, unicode):
            k = k.encode('utf-8', 'strict')

        if isinstance(v, unicode):
            v = v.encode('utf-8', 'strict')

        normalized_env[k] = v

    return normalized_env


def check_call(*args, **kwargs):
    """Wrap `subprocess.check_call`, printing the command if verbose=True.

    Also fix any unicode-containing `env`, for subprocess """
    verbose = kwargs.pop('verbose', False)

    if 'env' in kwargs:
        kwargs['env'] = normalize_env(kwargs['env'])

    if verbose:
        print(' '.join(args[0]))
    # we have to use shell=True in order to get PATH handling
    # when looking for the binary on Windows
    proc = subprocess.Popen(*args, shell=sys.platform == 'win32', **kwargs)
    status = None
    # Leave it to the subprocess to handle Ctrl+C. If it terminates as
    # a result of Ctrl+C, proc.wait() will return a status code, and,
    # we get out of the loop. If it doesn't, like e.g. gdb, we continue
    # waiting.
    while status is None:
        try:
            status = proc.wait()
        except KeyboardInterrupt:
            pass

    if status:
        raise subprocess.CalledProcessError(status, ' '.join(*args))


def is_windows():
    """ Detect windows, mingw, cygwin """
    return sys.platform == 'win32' or sys.platform == 'msys' or sys.platform == 'cygwin'


def is_macosx():
    return sys.platform == 'darwin'


class BuildNotFound(Exception):
    def __init__(self, message):
        self.message = message

    def __str__(self):
        return self.message


class CommandBase(object):
    """Base class for mach command providers.

    This mostly handles configuration management, such as .servobuild."""

    def __init__(self, context):
        self.context = context

        def get_env_bool(var, default):
            # Contents of env vars are strings by default. This returns the
            # boolean value of the specified environment variable, or the
            # speciried default if the var doesn't contain True or False
            return {'True': True, 'False': False}.get(os.environ.get(var), default)

        def resolverelative(category, key):
            # Allow ~
            self.config[category][key] = path.expanduser(self.config[category][key])
            # Resolve relative paths
            self.config[category][key] = path.join(context.topdir,
                                                   self.config[category][key])

        if not hasattr(self.context, "bootstrapped"):
            self.context.bootstrapped = False

        config_path = path.join(context.topdir, ".servobuild")
        if path.exists(config_path):
            with open(config_path) as f:
                self.config = toml.loads(f.read())
        else:
            self.config = {}

        # Handle missing/default items
        self.config.setdefault("tools", {})
        default_cache_dir = os.environ.get("SERVO_CACHE_DIR",
                                           path.join(context.topdir, ".servo"))
        self.config["tools"].setdefault("cache-dir", default_cache_dir)
        resolverelative("tools", "cache-dir")

        default_cargo_home = os.environ.get("CARGO_HOME",
                                            path.join(context.topdir, ".cargo"))
        self.config["tools"].setdefault("cargo-home-dir", default_cargo_home)
        resolverelative("tools", "cargo-home-dir")

        context.sharedir = self.config["tools"]["cache-dir"]

        self.config["tools"].setdefault("system-rust", False)
        self.config["tools"].setdefault("system-cargo", False)
        self.config["tools"].setdefault("rust-root", "")
        self.config["tools"].setdefault("cargo-root", "")
        self.set_use_stable_rust(False)
        if not self.config["tools"]["system-cargo"]:
            self.config["tools"]["cargo-root"] = path.join(
                context.sharedir, "cargo", self.cargo_build_id())
        self.config["tools"].setdefault("rustc-with-gold", get_env_bool("SERVO_RUSTC_WITH_GOLD", True))

        self.config.setdefault("build", {})
        self.config["build"].setdefault("android", False)
        self.config["build"].setdefault("mode", "")
        self.config["build"].setdefault("debug-mozjs", False)
        self.config["build"].setdefault("ccache", "")

        self.config.setdefault("android", {})
        self.config["android"].setdefault("sdk", "")
        self.config["android"].setdefault("ndk", "")
        self.config["android"].setdefault("toolchain", "")
        self.config["android"].setdefault("platform", "android-18")
        self.config["android"].setdefault("target", "arm-linux-androideabi")

    _use_stable_rust = False
    _rust_version = None
    _rust_version_is_stable = False
    _cargo_build_id = None

    def set_use_stable_rust(self, use_stable_rust=True):
        self._use_stable_rust = use_stable_rust
        if not self.config["tools"]["system-rust"]:
            self.config["tools"]["rust-root"] = path.join(
                self.context.sharedir, "rust", self.rust_path())

    def use_stable_rust(self):
        return self._use_stable_rust

    def rust_path(self):
        version = self.rust_version()
        if self._use_stable_rust:
            return "%s/rustc-%s-%s" % (version, version, host_triple())
        else:
            return "%s/rustc-nightly-%s" % (version, host_triple())

    def rust_version(self):
        if self._rust_version is None or self._use_stable_rust != self._rust_version_is_stable:
            filename = path.join(self.context.topdir,
                                 "rust-stable-version" if self._use_stable_rust else "rust-nightly-date")
            with open(filename) as f:
                self._rust_version = f.read().strip()
        return self._rust_version

    def cargo_build_id(self):
        if self._cargo_build_id is None:
            filename = path.join(self.context.topdir, "cargo-nightly-build")
            with open(filename) as f:
                self._cargo_build_id = f.read().strip()
        return self._cargo_build_id

    def get_top_dir(self):
        return self.context.topdir

    def get_target_dir(self):
        if "CARGO_TARGET_DIR" in os.environ:
            return os.environ["CARGO_TARGET_DIR"]
        else:
            return path.join(self.context.topdir, "target")

    def get_binary_path(self, release, dev, android=False):
        # TODO(autrilla): this function could still use work - it shouldn't
        # handle quitting, or printing. It should return the path, or an error.
        base_path = self.get_target_dir()

        if android:
            base_path = path.join(base_path, self.config["android"]["target"])

        binary_name = "servo" + BIN_SUFFIX
        release_path = path.join(base_path, "release", binary_name)
        dev_path = path.join(base_path, "debug", binary_name)

        # Prefer release if both given
        if release and dev:
            dev = False

        release_exists = path.exists(release_path)
        dev_exists = path.exists(dev_path)

        if not release_exists and not dev_exists:
            raise BuildNotFound('No Servo binary found.'
                                ' Perhaps you forgot to run `./mach build`?')

        if release and release_exists:
            return release_path

        if dev and dev_exists:
            return dev_path

        if not dev and not release and release_exists and dev_exists:
            print("You have multiple profiles built. Please specify which "
                  "one to run with '--release' or '--dev'.")
            sys.exit()

        if not dev and not release:
            if release_exists:
                return release_path
            else:
                return dev_path

        print("The %s profile is not built. Please run './mach build%s' "
              "and try again." % ("release" if release else "dev",
                                  " --release" if release else ""))
        sys.exit()

    def build_env(self, hosts_file_path=None, target=None):
        """Return an extended environment dictionary."""
        env = os.environ.copy()
        if sys.platform == "win32" and type(env['PATH']) == unicode:
            # On win32, the virtualenv's activate_this.py script sometimes ends up
            # turning os.environ['PATH'] into a unicode string.  This doesn't work
            # for passing env vars in to a process, so we force it back to ascii.
            # We don't use UTF8 since that won't be correct anyway; if you actually
            # have unicode stuff in your path, all this PATH munging would have broken
            # it in any case.
            env['PATH'] = env['PATH'].encode('ascii', 'ignore')
        extra_path = []
        extra_lib = []
        if not self.config["tools"]["system-rust"] \
                or self.config["tools"]["rust-root"]:
            env["RUST_ROOT"] = self.config["tools"]["rust-root"]
            # Add mingw64 binary path before rust paths to avoid conflict with libstdc++-6.dll
            if sys.platform == "msys":
                extra_path += [path.join(os.sep, "mingw64", "bin")]
            # These paths are for when rust-root points to an unpacked installer
            extra_path += [path.join(self.config["tools"]["rust-root"], "rustc", "bin")]
            extra_lib += [path.join(self.config["tools"]["rust-root"], "rustc", "lib")]
            # These paths are for when rust-root points to a rustc sysroot
            extra_path += [path.join(self.config["tools"]["rust-root"], "bin")]
            extra_lib += [path.join(self.config["tools"]["rust-root"], "lib")]

        if not self.config["tools"]["system-cargo"] \
                or self.config["tools"]["cargo-root"]:
            # This path is for when rust-root points to an unpacked installer
            extra_path += [
                path.join(self.config["tools"]["cargo-root"], "cargo", "bin")]
            # This path is for when rust-root points to a rustc sysroot
            extra_path += [
                path.join(self.config["tools"]["cargo-root"], "bin")]

        if extra_path:
            env["PATH"] = "%s%s%s" % (os.pathsep.join(extra_path), os.pathsep, env["PATH"])

        env["CARGO_HOME"] = self.config["tools"]["cargo-home-dir"]

        env["CARGO_TARGET_DIR"] = path.join(self.context.topdir, "target")

        if extra_lib:
            if sys.platform == "darwin":
                env["DYLD_LIBRARY_PATH"] = "%s%s%s" % \
                                           (os.pathsep.join(extra_lib),
                                            os.pathsep,
                                            env.get("DYLD_LIBRARY_PATH", ""))
            else:
                env["LD_LIBRARY_PATH"] = "%s%s%s" % \
                                         (os.pathsep.join(extra_lib),
                                          os.pathsep,
                                          env.get("LD_LIBRARY_PATH", ""))

        # Paths to Android build tools:
        if self.config["android"]["sdk"]:
            env["ANDROID_SDK"] = self.config["android"]["sdk"]
        if self.config["android"]["ndk"]:
            env["ANDROID_NDK"] = self.config["android"]["ndk"]
        if self.config["android"]["toolchain"]:
            env["ANDROID_TOOLCHAIN"] = self.config["android"]["toolchain"]
        if self.config["android"]["platform"]:
            env["ANDROID_PLATFORM"] = self.config["android"]["platform"]

        # These are set because they are the variable names that build-apk
        # expects. However, other submodules have makefiles that reference
        # the env var names above. Once glutin is enabled and set as the
        # default, we could modify the subproject makefiles to use the names
        # below and remove the vars above, to avoid duplication.
        if "ANDROID_SDK" in env:
            env["ANDROID_HOME"] = env["ANDROID_SDK"]
        if "ANDROID_NDK" in env:
            env["NDK_HOME"] = env["ANDROID_NDK"]
        if "ANDROID_TOOLCHAIN" in env:
            env["NDK_STANDALONE"] = env["ANDROID_TOOLCHAIN"]

        if hosts_file_path:
            env['HOST_FILE'] = hosts_file_path

        env['RUSTDOC'] = path.join(self.context.topdir, 'etc', 'rustdoc-with-private')

        # Don't run the gold linker if on Windows https://github.com/servo/servo/issues/9499
        if self.config["tools"]["rustc-with-gold"] and sys.platform not in ("win32", "msys"):
            if subprocess.call(['which', 'ld.gold'], stdout=PIPE, stderr=PIPE) == 0:
                env['RUSTFLAGS'] = env.get('RUSTFLAGS', "") + " -C link-args=-fuse-ld=gold"

        if not (self.config["build"]["ccache"] == ""):
            env['CCACHE'] = self.config["build"]["ccache"]

        # Ensure Rust uses hard floats and SIMD on ARM devices
        if target:
            if target.startswith('arm') or target.startswith('aarch64'):
                env['RUSTFLAGS'] = env.get('RUSTFLAGS', "") + " -C target-feature=+neon"

        env['RUSTFLAGS'] = env.get('RUSTFLAGS', "") + " -W unused-extern-crates"

        git_info = []
        if os.path.isdir('.git'):
            git_sha = subprocess.check_output([
                'git', 'rev-parse', '--short', 'HEAD'
            ]).strip()
            git_is_dirty = bool(subprocess.check_output([
                'git', 'status', '--porcelain'
            ]).strip())

            git_info.append('')
            git_info.append(git_sha)
            if git_is_dirty:
                git_info.append('dirty')

        env['GIT_INFO'] = '-'.join(git_info)

        return env

    def servo_crate(self):
        return path.join(self.context.topdir, "components", "servo")

    def servo_features(self):
        """Return a list of optional features to enable for the Servo crate"""
        features = []
        if self.config["build"]["debug-mozjs"]:
            features += ["script/debugmozjs"]
        return features

    def android_support_dir(self):
        return path.join(self.context.topdir, "support", "android")

    def android_build_dir(self, dev):
        return path.join(self.get_target_dir(), "arm-linux-androideabi", "debug" if dev else "release")

    def ensure_bootstrapped(self, target=None):
        if self.context.bootstrapped:
            return

        rust_root = self.config["tools"]["rust-root"]
        rustc_path = path.join(
            rust_root, "rustc", "bin", "rustc" + BIN_SUFFIX
        )
        rustc_binary_exists = path.exists(rustc_path)

        base_target_path = path.join(rust_root, "rustc", "lib", "rustlib")

        target_path = path.join(base_target_path, target or host_triple())
        target_exists = path.exists(target_path)

        if not (self.config['tools']['system-rust'] or (rustc_binary_exists and target_exists)):
            print("looking for rustc at %s" % (rustc_path))
            Registrar.dispatch("bootstrap-rust", context=self.context, target=filter(None, [target]),
                               stable=self._use_stable_rust)

        cargo_path = path.join(self.config["tools"]["cargo-root"], "cargo", "bin",
                               "cargo" + BIN_SUFFIX)
        cargo_binary_exists = path.exists(cargo_path)

        if not self.config["tools"]["system-cargo"] and not cargo_binary_exists:
            Registrar.dispatch("bootstrap-cargo", context=self.context)

        self.context.bootstrapped = True