#!/usr/bin/env python3
#
#  Copyright (C) 2017 Codethink Limited
#
#  This program is free software; you can redistribute it and/or
#  modify it under the terms of the GNU Lesser General Public
#  License as published by the Free Software Foundation; either
#  version 2 of the License, or (at your option) any later version.
#
#  This library is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
#  Lesser General Public License for more details.
#
#  You should have received a copy of the GNU Lesser General Public
#  License along with this library. If not, see <http://www.gnu.org/licenses/>.
#
#  Authors:
#        Tristan Van Berkom <tristan.vanberkom@codethink.co.uk>
import datetime
import os
from collections import OrderedDict
from contextlib import ExitStack
from mmap import mmap
import re
import click
from ruamel import yaml

from . import Profile
from .. import Element, Scope, Consistency
from .. import _yaml
from .. import __version__ as bst_version
from .._exceptions import ImplError
from .._message import MessageType
from ..plugin import _plugin_lookup


# These messages are printed a bit differently
ERROR_MESSAGES = [MessageType.FAIL, MessageType.ERROR, MessageType.BUG]


# Widget()
#
# Args:
#    content_profile (Profile): The profile to use for rendering content
#    format_profile (Profile): The profile to use for rendering formatting
#
# An abstract class for printing output columns in our text UI.
#
class Widget():

    def __init__(self, content_profile, format_profile):

        # The content profile
        self.content_profile = content_profile

        # The formatting profile
        self.format_profile = format_profile

    # size_request()
    #
    # Gives the widget a chance to preflight the pipeline
    # and figure out what size it might need for alignment purposes
    #
    # Args:
    #    pipeline (Pipeline): The pipeline to process
    #
    def size_request(self, pipeline):
        pass

    # render()
    #
    # Renders a string to be printed in the UI
    #
    # Args:
    #    message (Message): A message to print
    #
    # Returns:
    #    (str): The string this widget prints for the given message
    #
    def render(self, message):
        raise ImplError("{} does not implement render()".format(type(self).__name__))


# Used to add spacing between columns
class Space(Widget):

    def render(self, message):
        return ' '


# Used to add fixed text between columns
class FixedText(Widget):

    def __init__(self, text, content_profile, format_profile):
        super(FixedText, self).__init__(content_profile, format_profile)
        self.text = text

    def render(self, message):
        return self.format_profile.fmt(self.text)


# Used to add the wallclock time this message was created at
class WallclockTime(Widget):
    def render(self, message):
        fields = [self.content_profile.fmt("{:02d}".format(x)) for x in
                  [message.creation_time.hour,
                   message.creation_time.minute,
                   message.creation_time.second]]
        return self.format_profile.fmt(":").join(fields)


# A widget for rendering the debugging column
class Debug(Widget):

    def render(self, message):
        unique_id = 0 if message.unique_id is None else message.unique_id

        text = self.format_profile.fmt('pid:')
        text += self.content_profile.fmt("{: <5}".format(message.pid))
        text += self.format_profile.fmt(" id:")
        text += self.content_profile.fmt("{:0>3}".format(unique_id))

        return text


# A widget for rendering the time codes
class TimeCode(Widget):
    def __init__(self, content_profile, format_profile, microseconds=False):
        self.microseconds = microseconds
        super(TimeCode, self).__init__(content_profile, format_profile)

    def render(self, message):
        return self.render_time(message.elapsed)

    def render_time(self, elapsed):
        if elapsed is None:
            fields = [
                self.content_profile.fmt('--')
                for i in range(3)
            ]
        else:
            hours, remainder = divmod(int(elapsed.total_seconds()), 60 * 60)
            minutes, seconds = divmod(remainder, 60)
            fields = [
                self.content_profile.fmt("{0:02d}".format(field))
                for field in [hours, minutes, seconds]
            ]

        text = self.format_profile.fmt(':').join(fields)

        if self.microseconds:
            if elapsed is not None:
                text += self.content_profile.fmt(".{0:06d}".format(elapsed.microseconds))
            else:
                text += self.content_profile.fmt(".------")
        return text


# A widget for rendering the MessageType
class TypeName(Widget):

    action_colors = {
        MessageType.DEBUG: "cyan",
        MessageType.STATUS: "cyan",
        MessageType.INFO: "magenta",
        MessageType.WARN: "yellow",
        MessageType.START: "blue",
        MessageType.SUCCESS: "green",
        MessageType.FAIL: "red",
        MessageType.ERROR: "red",
        MessageType.BUG: "red",
    }

    def render(self, message):
        return self.content_profile.fmt("{: <7}"
                                        .format(message.message_type.upper()),
                                        bold=True, dim=True,
                                        fg=self.action_colors[message.message_type])


# A widget for displaying the Element name
class ElementName(Widget):

    def __init__(self, content_profile, format_profile):
        super(ElementName, self).__init__(content_profile, format_profile)

        # Pre initialization format string, before we know the length of
        # element names in the pipeline
        self.fmt_string = '{: <30}'

    def size_request(self, pipeline):
        longest_name = 0
        for plugin in pipeline.dependencies(Scope.ALL, include_sources=True):
            longest_name = max(len(plugin.name), longest_name)

        # Put a cap at a specific width, usually some elements cause the line
        # to be too long, just live with the unaligned columns in that case
        longest_name = min(longest_name, 30)
        self.fmt_string = '{: <' + str(longest_name) + '}'

    def render(self, message):
        element_id = message.task_id or message.unique_id
        if element_id is None:
            return ""

        plugin = _plugin_lookup(element_id)
        name = plugin._get_full_name()

        # Sneak the action name in with the element name
        action_name = message.action_name
        if not action_name:
            action_name = "Main"

        return self.content_profile.fmt("{: >5}".format(action_name.lower())) + \
            self.format_profile.fmt(':') + \
            self.content_profile.fmt(self.fmt_string.format(name))


# A widget for displaying the primary message text
class MessageText(Widget):

    def render(self, message):

        return message.message


# A widget for formatting the element cache key
class CacheKey(Widget):

    def __init__(self, content_profile, format_profile, err_profile):
        super(CacheKey, self).__init__(content_profile, format_profile)

        self.err_profile = err_profile
        self.key_length = 0

    def size_request(self, pipeline):
        self.key_length = pipeline.context.log_key_length

    def render(self, message):

        element_id = message.task_id or message.unique_id
        if element_id is None or not self.key_length:
            return ""

        missing = False
        key = ' ' * self.key_length
        plugin = _plugin_lookup(element_id)
        if isinstance(plugin, Element):
            _, key, missing = plugin._get_full_display_key()

        if message.message_type in ERROR_MESSAGES:
            text = self.err_profile.fmt(key)
        else:
            text = self.content_profile.fmt(key, dim=missing)

        return text


# A widget for formatting the log file
class LogFile(Widget):

    def __init__(self, content_profile, format_profile, err_profile):
        super(LogFile, self).__init__(content_profile, format_profile)

        self.err_profile = err_profile
        self.logdir = ''

    def size_request(self, pipeline):

        # Hold on to the logging directory so we can abbreviate
        self.logdir = pipeline.context.logdir

    def render(self, message, abbrev=True):

        if message.logfile and message.scheduler:
            logfile = message.logfile

            if logfile.startswith(self.logdir) and abbrev:
                logfile = logfile[len(self.logdir) + 1:]

            if message.message_type in ERROR_MESSAGES:
                text = self.err_profile.fmt(logfile)
            else:
                text = self.content_profile.fmt(logfile, dim=True)
        else:
            text = ''

        return text


class MessageOrLogFile(Widget):
    """ START and SUCCESS messages are expected to have no useful
        information in the message text, so we display the logfile name for
        these messages, and the message text for other types.
    """
    def __init__(self, content_profile, format_profile, err_profile):
        super(MessageOrLogFile, self).__init__(content_profile, format_profile)
        self.message_widget = MessageText(content_profile, format_profile)
        self.logfile_widget = LogFile(content_profile, format_profile, err_profile)

    def render(self, message):
        # Show the log file only in the main start/success messages
        if message.logfile and message.scheduler and \
           message.message_type in [MessageType.START, MessageType.SUCCESS]:
            text = self.logfile_widget.render(message)
        else:
            text = self.message_widget.render(message)
        return text


# A widget for formatting a log line
class LogLine(Widget):

    def __init__(self, content_profile, format_profile, success_profile, err_profile, detail_profile,
                 indent=4,
                 log_lines=10,
                 message_lines=10,
                 debug=False,
                 message_format: str = None):
        super(LogLine, self).__init__(content_profile, format_profile)

        self.columns = []
        self.success_profile = success_profile
        self.err_profile = err_profile
        self.detail_profile = detail_profile
        self.indent = ' ' * indent
        self.log_lines = log_lines
        self.message_lines = message_lines
        self.message_format = message_format

        self.space_widget = Space(content_profile, format_profile)
        self.logfile_widget = LogFile(content_profile, format_profile, err_profile)

        if debug:
            self.columns.extend([
                Debug(content_profile, format_profile)
            ])

        logfile_format = message_format

        self.logfile_variable_names = {
            "elapsed": TimeCode(content_profile, format_profile, microseconds=False),
            "elapsed-us": TimeCode(content_profile, format_profile, microseconds=True),
            "wallclock": WallclockTime(content_profile, format_profile),
            "key": CacheKey(content_profile, format_profile, err_profile),
            "element": ElementName(content_profile, format_profile),
            "action": TypeName(content_profile, format_profile),
            "message": MessageOrLogFile(content_profile, format_profile, err_profile)
        }
        logfile_tokens = self._parse_logfile_format(logfile_format, content_profile, format_profile)
        self.columns.extend(logfile_tokens)

    def _parse_logfile_format(self, format_string, content_profile, format_profile):
        logfile_tokens = []
        while format_string:
            if format_string.startswith("%%"):
                logfile_tokens.append(FixedText("%", content_profile, format_profile))
                format_string = format_string[2:]
                continue
            m = re.search(r"^%\{([^\}]+)\}", format_string)
            if m is not None:
                variable = m.group(1)
                format_string = format_string[m.end(0):]
                if variable not in self.logfile_variable_names:
                    raise Exception("'{0}' is not a valid log variable name.".format(variable))
                logfile_tokens.append(self.logfile_variable_names[variable])
            else:
                m = re.search("^[^%]+", format_string)
                if m is not None:
                    text = FixedText(m.group(0), content_profile, format_profile)
                    format_string = format_string[m.end(0):]
                    logfile_tokens.append(text)
                else:
                    # No idea what to do now
                    raise Exception("'{0}' could not be parsed into a valid logging format.".format(format_string))
        return logfile_tokens

    def size_request(self, pipeline):
        for widget in self.columns:
            widget.size_request(pipeline)

        self.space_widget.size_request(pipeline)
        self.logfile_widget.size_request(pipeline)

    def render(self, message):

        # Render the column widgets first
        text = ''
        for widget in self.columns:
            text += widget.render(message)

        text += '\n'

        extra_nl = False

        # Now add some custom things
        if message.detail is not None:

            # Identify frontend messages, we never abbreviate these
            frontend_message = not (message.task_id or message.unique_id)

            # Split and truncate message detail down to message_lines lines
            lines = message.detail.splitlines(True)

            n_lines = len(lines)
            abbrev = False
            if message.message_type not in ERROR_MESSAGES \
               and not frontend_message and n_lines > self.message_lines:
                abbrev = True
                lines = lines[0:self.message_lines]
            else:
                lines[n_lines - 1] = lines[n_lines - 1].rstrip('\n')

            detail = self.indent + self.indent.join(lines)

            text += '\n'
            if message.message_type in ERROR_MESSAGES:
                text += self.err_profile.fmt(detail, bold=True)
            else:
                text += self.detail_profile.fmt(detail)

            if abbrev:
                text += self.indent + \
                    self.content_profile.fmt('Message contains {} additional lines'
                                             .format(n_lines - self.message_lines), dim=True)
            text += '\n'

            extra_nl = True

        if message.sandbox is not None:
            sandbox = self.indent + 'Sandbox directory: ' + message.sandbox

            text += '\n'
            if message.message_type == MessageType.FAIL:
                text += self.err_profile.fmt(sandbox, bold=True)
            else:
                text += self.detail_profile.fmt(sandbox)
            text += '\n'
            extra_nl = True

        if message.scheduler and message.message_type == MessageType.FAIL:
            text += '\n'
            text += self.indent + self.err_profile.fmt("Printing the last {} lines from log file:"
                                                       .format(self.log_lines)) + '\n'
            text += self.indent + self.logfile_widget.render(message, abbrev=False) + '\n'
            text += self.indent + self.err_profile.fmt("=" * 70) + '\n'

            log_content = self.read_last_lines(message.logfile)
            log_content = self.indent + self.indent.join(log_content.splitlines(True))
            text += self.detail_profile.fmt(log_content)
            text += '\n'
            text += self.indent + self.err_profile.fmt("=" * 70) + '\n'
            extra_nl = True

        if extra_nl:
            text += '\n'

        return text

    def read_last_lines(self, logfile):
        with ExitStack() as stack:
            # mmap handles low-level memory details, allowing for
            # faster searches
            f = stack.enter_context(open(logfile, 'r+'))
            log = stack.enter_context(mmap(f.fileno(), os.path.getsize(f.name)))

            count = 0
            end = log.size() - 1

            while count < self.log_lines and end >= 0:
                location = log.rfind(b'\n', 0, end)
                count += 1

                # If location is -1 (none found), this will print the
                # first character because of the later +1
                end = location

            # end+1 is correct whether or not a newline was found at
            # that location. If end is -1 (seek before beginning of file)
            # then we get the first characther. If end is a newline position,
            # we discard it and only want to print the beginning of the next
            # line.
            lines = log[(end + 1):].splitlines()
            return '\n'.join([line.decode('utf-8') for line in lines]).rstrip()

    #
    # A message to be printed at program startup, indicating
    # some things about user configuration and BuildStream version
    # and so on.
    #
    # Args:
    #    pipeline (Pipeline): The pipeline to print the heading of
    #    log_file (file): An optional file handle for additional logging
    #    deps (list): Optional list of elements, default is to use the whole pipeline
    #    styling (bool): Whether to enable ansi escape codes in the output
    #
    def print_heading(self, pipeline, log_file, deps=None, styling=False):
        context = pipeline.context
        project = pipeline.project
        starttime = datetime.datetime.now()
        text = ''

        # Main invocation context
        text += '\n'
        text += self.content_profile.fmt("BuildStream Version {}\n".format(bst_version), bold=True)
        values = OrderedDict()
        values["Session Start"] = starttime.strftime('%A, %d-%m-%Y at %H:%M:%S')
        values["Project"] = "{} ({})".format(project.name, project.directory)
        values["Targets"] = ", ".join([t.name for t in pipeline.targets])
        text += self.format_values(values)

        # User configurations
        text += '\n'
        text += self.content_profile.fmt("User Configuration\n", bold=True)
        values = OrderedDict()
        values["Configuration File"] = \
            "Default Configuration" if not context.config_origin else context.config_origin
        values["Log Files"] = context.logdir
        values["Source Mirrors"] = context.sourcedir
        values["Build Area"] = context.builddir
        values["Artifact Cache"] = context.artifactdir
        values["Maximum Fetch Tasks"] = context.sched_fetchers
        values["Maximum Build Tasks"] = context.sched_builders
        values["Maximum Push Tasks"] = context.sched_pushers
        values["Maximum Network Retries"] = context.sched_network_retries
        text += self.format_values(values)
        text += '\n'

        # Project Options
        if project._options.variables:
            text += self.content_profile.fmt("Project Options\n", bold=True)
            values = OrderedDict()
            for key in sorted(project._options.variables):
                values[key] = project._options.variables[key]
            text += self.format_values(values)
            text += '\n'

        # Plugins
        text += self.format_plugins(project._element_factory.loaded_dependencies,
                                    project._source_factory.loaded_dependencies)

        # Pipeline state
        text += self.content_profile.fmt("Pipeline\n", bold=True)
        if deps is None:
            deps = pipeline.dependencies(Scope.ALL)
        text += self.show_pipeline(deps, context.log_element_format)
        text += '\n'

        # Separator line before following output
        text += self.format_profile.fmt("~" * 79 + '\n')

        click.echo(text, color=styling, nl=False, err=True)
        if log_file:
            click.echo(text, file=log_file, color=False, nl=False)

    # Print queue summaries at the end of a scheduler run
    #
    def print_summary(self, pipeline, scheduler, log_file, styling=False):

        # Early silent return if there are no queues, can happen
        # only in the case that the pipeline early returned due to
        # an inconsistent pipeline state.
        if scheduler.queues is None:
            return

        text = self.content_profile.fmt("Pipeline Summary\n", bold=True)
        values = OrderedDict()
        values['Total'] = self.content_profile.fmt(str(pipeline.total_elements))
        values['Session'] = self.content_profile.fmt(str(pipeline.session_elements))

        processed_maxlen = 1
        skipped_maxlen = 1
        failed_maxlen = 1
        for queue in scheduler.queues:
            processed_maxlen = max(len(str(len(queue.processed_elements))), processed_maxlen)
            skipped_maxlen = max(len(str(len(queue.skipped_elements))), skipped_maxlen)
            failed_maxlen = max(len(str(len(queue.failed_elements))), failed_maxlen)

        for queue in scheduler.queues:
            processed = str(len(queue.processed_elements))
            skipped = str(len(queue.skipped_elements))
            failed = str(len(queue.failed_elements))

            processed_align = ' ' * (processed_maxlen - len(processed))
            skipped_align = ' ' * (skipped_maxlen - len(skipped))
            failed_align = ' ' * (failed_maxlen - len(failed))

            status_text = self.content_profile.fmt("processed ") + \
                self.success_profile.fmt(processed) + \
                self.format_profile.fmt(', ') + processed_align

            status_text += self.content_profile.fmt("skipped ") + \
                self.content_profile.fmt(skipped) + \
                self.format_profile.fmt(', ') + skipped_align

            status_text += self.content_profile.fmt("failed ") + \
                self.err_profile.fmt(failed) + ' ' + failed_align
            values["{} Queue".format(queue.action_name)] = status_text

        text += self.format_values(values, style_value=False)

        click.echo(text, color=styling, nl=False, err=True)
        if log_file:
            click.echo(text, file=log_file, color=False, nl=False)

    def format_plugins(self, element_plugins, source_plugins):
        text = ""

        if not (element_plugins or source_plugins):
            return text

        text += self.content_profile.fmt("Loaded Plugins\n", bold=True)

        if element_plugins:
            text += self.format_profile.fmt("  Element Plugins\n")
            for plugin in element_plugins:
                text += self.content_profile.fmt("    - {}\n".format(plugin))

        if source_plugins:
            text += self.format_profile.fmt("  Source Plugins\n")
            for plugin in source_plugins:
                text += self.content_profile.fmt("    - {}\n".format(plugin))

        text += '\n'

        return text

    def format_values(self, values, style_value=True):
        text = ''
        max_key_len = 0
        for key, value in values.items():
            max_key_len = max(len(key), max_key_len)

        for key, value in values.items():
            text += self.format_profile.fmt("  {}: {}".format(key, ' ' * (max_key_len - len(key))))
            if style_value:
                text += self.content_profile.fmt(str(value))
            else:
                text += str(value)
            text += '\n'

        return text

    def show_pipeline(self, dependencies, format_):
        report = ''
        p = Profile()

        for element in dependencies:
            line = format_

            full_key, cache_key, dim_keys = element._get_full_display_key()

            line = p.fmt_subst(line, 'name', element._get_full_name(), fg='blue', bold=True)
            line = p.fmt_subst(line, 'key', cache_key, fg='yellow', dim=dim_keys)
            line = p.fmt_subst(line, 'full-key', full_key, fg='yellow', dim=dim_keys)

            consistency = element._consistency()
            if consistency == Consistency.INCONSISTENT:
                line = p.fmt_subst(line, 'state', "no reference", fg='red')
            else:
                if element._cached():
                    line = p.fmt_subst(line, 'state', "cached", fg='magenta')
                elif element._remotely_cached():
                    line = p.fmt_subst(line, 'state', "downloadable", fg='cyan')
                elif consistency == Consistency.RESOLVED:
                    line = p.fmt_subst(line, 'state', "fetch needed", fg='red')
                elif element._buildable():
                    line = p.fmt_subst(line, 'state', "buildable", fg='green')
                else:
                    line = p.fmt_subst(line, 'state', "waiting", fg='blue')

            # Element configuration
            if "%{config" in format_:
                config = _yaml.node_sanitize(element._Element__config)
                line = p.fmt_subst(
                    line, 'config',
                    yaml.round_trip_dump(config, default_flow_style=False, allow_unicode=True))

            # Variables
            if "%{vars" in format_:
                variables = _yaml.node_sanitize(element._Element__variables.variables)
                line = p.fmt_subst(
                    line, 'vars',
                    yaml.round_trip_dump(variables, default_flow_style=False, allow_unicode=True))

            # Environment
            if "%{env" in format_:
                environment = _yaml.node_sanitize(element._Element__environment)
                line = p.fmt_subst(
                    line, 'env',
                    yaml.round_trip_dump(environment, default_flow_style=False, allow_unicode=True))

            # Public
            if "%{public" in format_:
                environment = _yaml.node_sanitize(element._Element__public)
                line = p.fmt_subst(
                    line, 'public',
                    yaml.round_trip_dump(environment, default_flow_style=False, allow_unicode=True))

            # Workspaced
            if "%{workspaced" in format_:
                line = p.fmt_subst(
                    line, 'workspaced',
                    '(workspaced)' if element._workspaced() else '', fg='yellow')

            # Workspace-dirs
            if "%{workspace-dirs" in format_:
                dirs = [path.replace(os.getenv('HOME', '/root'), '~')
                        for path in element._workspace_dirs()]
                if dirs:
                    line = p.fmt_subst(
                        line, 'workspace-dirs', "Workspaces: " + ", ".join(dirs))
                else:
                    line = p.fmt_subst(
                        line, 'workspace-dirs', '')

            report += line + '\n'

        return report.rstrip('\n')
