#!/usr/bin/env python
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"""Chromium Linux implementation of the Port interface."""

import logging
import os
import signal

import chromium

_log = logging.getLogger("webkitpy.layout_tests.port.chromium_linux")


class ChromiumLinuxPort(chromium.ChromiumPort):
    """Chromium Linux implementation of the Port class."""
    SUPPORTED_ARCHITECTURES = ('x86', 'x86_64')

    FALLBACK_PATHS = {
        'x86_64': ['chromium-linux-x86_64', 'chromium-linux', 'chromium-win', 'chromium', 'win', 'mac'],
        'x86': ['chromium-linux', 'chromium-win', 'chromium', 'win', 'mac'],
    }

    def __init__(self, port_name=None, **kwargs):
        port_name = port_name or 'chromium-linux'
        chromium.ChromiumPort.__init__(self, port_name=port_name, **kwargs)

        # We re-set the port name once the base object is fully initialized
        # in order to be able to find the DRT binary properly.
        if port_name.endswith('-linux'):
            self._architecture = self._determine_architecture()
            # FIXME: this is an ugly hack to avoid renaming the GPU port.
            if port_name == 'chromium-linux':
                port_name = port_name + '-' + self._architecture
        else:
            base, arch = port_name.rsplit('-', 1)
            assert base in ('chromium-linux', 'chromium-gpu-linux')
            self._architecture = arch
        assert self._architecture in self.SUPPORTED_ARCHITECTURES
        assert port_name in ('chromium-linux', 'chromium-gpu-linux',
                             'chromium-linux-x86', 'chromium-linux-x86_64',
                             'chromium-gpu-linux-x86_64')
        self._name = port_name
        self._operating_system = 'linux'
        # FIXME: add support for 'lucid'
        self._version = 'hardy'

    def _determine_architecture(self):
        driver_path = self._path_to_driver()
        file_output = ''
        if self._filesystem.exists(driver_path):
            file_output = self._executive.run_command(['file', driver_path],
                                                      return_stderr=True)

        if 'ELF 32-bit LSB executable' in file_output:
            return 'x86'
        if 'ELF 64-bit LSB executable' in file_output:
            return 'x86_64'
        if file_output:
            _log.warning('Could not determine architecture from "file" output: %s' % file_output)

        # We don't know what the architecture is; default to 'x86' because
        # maybe we're rebaselining and the binary doesn't actually exist,
        # or something else weird is going on. It's okay to do this because
        # if we actually try to use the binary, check_build() should fail.
        return 'x86'

    def baseline_path(self):
        if self._architecture == 'x86_64':
            return self._webkit_baseline_path(self._name)
        return self._webkit_baseline_path('chromium-linux')

    def baseline_search_path(self):
        port_names = self.FALLBACK_PATHS[self._architecture]
        return map(self._webkit_baseline_path, port_names)

    def check_build(self, needs_http):
        result = chromium.ChromiumPort.check_build(self, needs_http)
        if needs_http:
            if self.get_option('use_apache'):
                result = self._check_apache_install() and result
            else:
                result = self._check_lighttpd_install() and result
        result = self._check_wdiff_install() and result

        if not result:
            _log.error('For complete Linux build requirements, please see:')
            _log.error('')
            _log.error('    http://code.google.com/p/chromium/wiki/'
                       'LinuxBuildInstructions')
        return result

    #
    # PROTECTED METHODS
    #

    def _build_path(self, *comps):
        if self.get_option('build_directory'):
            return self._filesystem.join(self.get_option('build_directory'),
                                         *comps)

        base = self.path_from_chromium_base()
        if self._filesystem.exists(self._filesystem.join(base, 'sconsbuild')):
            return self._filesystem.join(base, 'sconsbuild', *comps)
        if self._filesystem.exists(self._filesystem.join(base, 'out', *comps)):
            return self._filesystem.join(base, 'out', *comps)
        base = self.path_from_webkit_base()
        if self._filesystem.exists(self._filesystem.join(base, 'sconsbuild')):
            return self._filesystem.join(base, 'sconsbuild', *comps)
        return self._filesystem.join(base, 'out', *comps)

    def _check_apache_install(self):
        result = self._check_file_exists(self._path_to_apache(),
            "apache2")
        result = self._check_file_exists(self._path_to_apache_config_file(),
            "apache2 config file") and result
        if not result:
            _log.error('    Please install using: "sudo apt-get install '
                       'apache2 libapache2-mod-php5"')
            _log.error('')
        return result

    def _check_lighttpd_install(self):
        result = self._check_file_exists(
            self._path_to_lighttpd(), "LigHTTPd executable")
        result = self._check_file_exists(self._path_to_lighttpd_php(),
            "PHP CGI executable") and result
        result = self._check_file_exists(self._path_to_lighttpd_modules(),
            "LigHTTPd modules") and result
        if not result:
            _log.error('    Please install using: "sudo apt-get install '
                       'lighttpd php5-cgi"')
            _log.error('')
        return result

    def _check_wdiff_install(self):
        result = self._check_file_exists(self._path_to_wdiff(), 'wdiff')
        if not result:
            _log.error('    Please install using: "sudo apt-get install '
                       'wdiff"')
            _log.error('')
        # FIXME: The ChromiumMac port always returns True.
        return result

    def _path_to_apache(self):
        if self._is_redhat_based():
            return '/usr/sbin/httpd'
        else:
            return '/usr/sbin/apache2'

    def _path_to_apache_config_file(self):
        if self._is_redhat_based():
            config_name = 'fedora-httpd.conf'
        else:
            config_name = 'apache2-debian-httpd.conf'

        return self._filesystem.join(self.layout_tests_dir(), 'http', 'conf',
                            config_name)

    def _path_to_lighttpd(self):
        return "/usr/sbin/lighttpd"

    def _path_to_lighttpd_modules(self):
        return "/usr/lib/lighttpd"

    def _path_to_lighttpd_php(self):
        return "/usr/bin/php-cgi"

    def _path_to_driver(self, configuration=None):
        if not configuration:
            configuration = self.get_option('configuration')
        binary_name = 'DumpRenderTree'
        return self._build_path(configuration, binary_name)

    def _path_to_helper(self):
        return None

    def _path_to_wdiff(self):
        if self._is_redhat_based():
            return '/usr/bin/dwdiff'
        else:
            return '/usr/bin/wdiff'

    def _is_redhat_based(self):
        return self._filesystem.exists(self._filesystem.join('/etc', 'redhat-release'))

    def _shut_down_http_server(self, server_pid):
        """Shut down the lighttpd web server. Blocks until it's fully
        shut down.

        Args:
            server_pid: The process ID of the running server.
        """
        # server_pid is not set when "http_server.py stop" is run manually.
        if server_pid is None:
            # TODO(mmoss) This isn't ideal, since it could conflict with
            # lighttpd processes not started by http_server.py,
            # but good enough for now.
            self._executive.kill_all("lighttpd")
            self._executive.kill_all("apache2")
        else:
            try:
                os.kill(server_pid, signal.SIGTERM)
                # TODO(mmoss) Maybe throw in a SIGKILL just to be sure?
            except OSError:
                # Sometimes we get a bad PID (e.g. from a stale httpd.pid
                # file), so if kill fails on the given PID, just try to
                # 'killall' web servers.
                self._shut_down_http_server(None)