#!/usr/bin/env python3
# Copyright 2013  Lars Wirzenius
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
# =*= License: GPL-3+ =*=


import cliapp
import collections
import locale
import logging
import os
import re
import shutil
import sys
import tempfile
import time
import ttystatus

import yarnlib


class YarnRunner(cliapp.Application):

    def add_settings(self):
        self.settings.boolean(
            ['no-act', 'dry-run', 'pretend', 'n'],
            'do not actually run any tests, merely print what would be run')

        self.settings.boolean(
            ['quiet', 'q'],
            'be quiet, avoid progress reporting, only show errors')

        self.settings.boolean(
            ['verbose', 'v'],
            'make progress reporting be more verbose ("wall of text"), '
                'instead of a one-line status info; this is turned '
                'automatically if there is not terminal')

        self.settings.string_list(
            ['shell-library', 's'],
            'include a shell library for the IMPLEMENTS sections to use')

        self.settings.string_list(
            ['run', 'r'],
            'run only SCENARIO (this option can be repeated)',
            metavar='SCENARIO')

        self.settings.string(
            ['tempdir'],
            'use DIR as the temporary directory for tests; '
                'it should be empty or not exist',
            metavar='DIR')

        self.settings.string_list(
            ['env'],
            'add NAME=VALUE to the environment when tests are run',
            metavar='NAME=VALUE')

        self.settings.boolean(
            ['snapshot'],
            'make snapshots of test working directory '
                'after each scenario step; you probably '
                'want to use this with --tempdir')

        self.settings.boolean(
            ['timings'],
            'report wall clock time for each scenario and step')

        self.settings.boolean(
            ['allow-missing-steps'],
            'allow scenarios to reference steps that do not exist, '
            'by warning about them, but otherwise ignoring the scenarios')

        self.settings.boolean(
            ['require-assumptions'],
            'require ASSUMING to always pass')

        self.settings.string(
            ['shell'],
            'run IMPLEMENTS using SHELL',
            metavar='SHELL',
            default='/bin/sh')

        self.settings.string_list(
            ['shell-arg'],
            'use ARG when running shell',
            metavar='ARG',
            default=['-xeu'])

        self.settings.boolean(
            ['cd-datadir'],
            'change to DATADIR when running commands',
            default=False)

        self.settings.boolean(
            ['stop-on-first-fail'],
            "stop if any scenario step fails, don't run more scenarios")

    def stdout(self, msg):
        self._write(sys.stdout, msg)

    def stderr(self, msg):
        self._write(sys.stderr, msg)

    def _write(self, output, msg):
        output.write(msg)
        output.flush()

    def info(self, indent, msg):
        if self.settings['verbose']:
            logging.info(msg)
            indent_size = 4
            self.stdout('%*s%s\n' % (indent * indent_size, '', msg))

    def warning(self, msg):
        if self.settings['verbose']:
            logging.warning(msg)
            self.stdout('WARNING: %s\n' % msg)
        elif not self.settings['quiet']:
            self.ts.notify('WARNING: %s' % msg)

    def error(self, msg):
        if self.settings['verbose']:
            logging.info(msg)
            self.stderr('%s\n' % msg)
        elif not self.settings['quiet']:
            self.ts.error(msg)

    def process_args(self, args):
        # Do we have tty? If not, turn on --verbose, unless --quiet.
        if not self.settings['quiet']:
            try:
                open('/dev/tty', 'w')
            except IOError:
                self.settings['verbose'] = True

        self.ts = ttystatus.TerminalStatus(period=0.001)
        if not self.settings['quiet'] and not self.settings['verbose']:
            self.ts.format(
                '%ElapsedTime() %Index(current_step,all_steps): '
                '%String(scenario_name): '
                '%String(step_name)')

        scenarios, implementations = self.parse_scenarios(args)
        self.check_there_are_scenarios(scenarios)
        self.check_for_duplicate_scenario_names(scenarios)
        self.check_for_thens(scenarios)
        scenarios = self.connect_implementations(scenarios, implementations)
        shell_prelude = self.load_shell_libraries()

        self.info(0, 'Found %d scenarios' % len(scenarios))

        all_steps = []
        for scenario in scenarios:
            all_steps.extend(scenario.steps)
        self.ts['all_steps'] = all_steps

        self.scenarios_run = 0
        self.skipped_for_assuming = 0
        self.steps_run = 0
        self.timings = []

        start_time = time.time()
        failed_scenarios = []
        for scenario in self.select_scenarios(scenarios):
            if not self.run_scenario(scenario, shell_prelude):
                failed_scenarios.append(scenario)
                if self.settings['stop-on-first-fail']:
                    break
        duration = time.time() - start_time

        if not self.settings['quiet']:
            self.ts.clear()
            self.ts.finish()

        if failed_scenarios:
            self.stderr('Failed scenarios:\n')
            for scenario in failed_scenarios:
                self.stderr('    - %s\n' % scenario.name)
            raise cliapp.AppException(
                'Test suite FAILED in %s scenarios' % len(failed_scenarios))

        if not self.settings['quiet']:
            self.stdout(
                'Scenario test suite PASS, with %d scenarios '
                '(%d total steps), '
                'in %.1f seconds\n' %
                (self.scenarios_run, self.steps_run, duration))
            if self.skipped_for_assuming:
                self.stdout(
                    'Scenarios SKIPPED due to ASSUMING step failing: %d\n'
                    % self.skipped_for_assuming)

        if self.settings['timings']:
            self.report_timings()

    def parse_scenarios(self, filenames):
        mdparser = yarnlib.MarkdownParser()
        for filename in filenames:
            self.info(0, 'Parsing scenario file %s' % filename)
            blocks = mdparser.parse_file(filename)

        block_parser = yarnlib.BlockParser()
        block_parser.parse_blocks(mdparser.blocks)

        return block_parser.scenarios, block_parser.implementations

    def check_there_are_scenarios(self, scenarios):
        if not scenarios:
            raise cliapp.AppException(
                'There are no scenarios; must have at least one.')

    def check_for_duplicate_scenario_names(self, scenarios):
        counts = collections.Counter()
        for s in scenarios:
            counts[s.name] += 1

        duplicates = [name for name in counts if counts[name] > 1]
        if duplicates:
            duplist = ''.join('  %s\n' % name for name in duplicates)
            raise cliapp.AppException(
                'There are scenarios with duplicate names:\n%s' % duplist)

    def check_for_thens(self, scenarios):
        no_thens = []
        for scenario in scenarios:
            for step in scenario.steps:
                if step.what == 'THEN':
                    break
            else:
                no_thens.append(scenario)

        if no_thens:
            raise cliapp.AppException(
                'Some scenarios have no THENs:\n%s' %
                ''.join('  "%s"\n' % s.name for s in no_thens))

    def connect_implementations(self, scenarios, implementations):
        new_list = []
        for scenario in scenarios:
            missing_step = False
            for step in scenario.steps:
                self.connect_implementation(
                    scenario, step, implementations)
                if step.implementation is None:
                    missing_step = True
            if not missing_step:
                new_list.append(scenario)
        return new_list

    def connect_implementation(self, scenario, step, implementations):
        matching = [i for i in implementations
                    if step.what == i.what and
                       self.implements_matches_step(i, step)]

        if len(matching) == 0:
            if self.settings['allow-missing-steps']:
                self.warning(
                    'Scenario %s has missing step %s %s' %
                    (scenario.name, step.what, step.text))
                return
            raise cliapp.AppException(
                'Scenario "%s", step "%s %s" has no matching '
                'implementation' %
                (scenario.name, step.what, step.text))
        if len(matching) > 1:
            s = '\n'.join(
                'IMPLEMENTS %s %s' % (i.what, i.regexp)
                for i in matching)
            raise cliapp.AppException(
                'Scenario "%s", step "%s %s" has more than one '
                'matching implementations:\n%s' %
                (scenario.name, step.what, step.text, s))

        assert step.implementation is None
        step.implementation = matching[0]

    def load_shell_libraries(self):
        if not self.settings['shell-library']:
            self.info(0, 'No shell libraries defined')
            return ''

        libs = []
        for filename in self.settings['shell-library']:
            self.info(0, 'Loading shell library %s' % filename)
            with open(filename) as f:
                text = f.read()
            libs.append('# Loaded from %s\n\n%s\n\n' % (filename, text))

        return ''.join(libs)

    def select_scenarios(self, scenarios):

        def normalise(s):
            return ' '.join(s.lower().split())

        def matches(a, b):
            return normalise(a) == normalise(b)

        if self.settings['run']:
            result = []
            for name in self.settings['run']:
                for s in scenarios:
                    if matches(s.name, name) and s not in result:
                        result.append(s)
                        break
                else:
                    raise cliapp.AppException(
                        'Requested scenario %s does not exist' %
                        name)
            return result

        return scenarios

    def run_scenario(self, scenario, shell_prelude):
        self.start_scenario_timing(scenario.name)
        started = time.time()

        self.info(0, 'Running scenario %s' % scenario.name)
        self.ts['scenario_name'] = scenario.name
        self.ts.flush()
        self.scenarios_run += 1

        if self.settings['no-act']:
            self.info(0, 'Pretending everything went OK')
            for step in scenario.steps:
                self.ts['current_step'] = step
                self.ts.flush()
            self.remember_scenario_timing(time.time() - started)
            return True

        if self.settings['tempdir']:
            tempdir = os.path.abspath(self.settings['tempdir'])
            if not os.path.exists(tempdir):
                os.mkdir(tempdir)
        else:
            tempdir = tempfile.mkdtemp()

        os.mkdir(self.scenario_dir(tempdir, scenario))
        datadir = self.datadir(tempdir, scenario)
        os.mkdir(datadir)
        self.info(1, 'DATADIR is %s' % datadir)
        homedir = self.homedir(datadir)
        os.mkdir(homedir)
        self.info(1, 'HOME for tests is %s' % homedir)

        assuming = [s for s in scenario.steps if s.what == 'ASSUMING']
        cleanup = [s for s in scenario.steps if s.what == 'FINALLY']
        normal = [s for s in scenario.steps if s not in assuming + cleanup]

        ok = True
        step_number = 0

        for step in assuming:
            exit = self.run_step(datadir, scenario, step, shell_prelude, False)
            step_number += 1
            self.snapshot_datadir(
                tempdir, datadir, scenario, step_number, step)
            if self.settings['require-assumptions'] and exit != 0:
                ok = False
                break
            elif exit != 0:
                self.ts.notify(
                    'Skipping "%s" because "%s %s" failed' %
                    (scenario.name, step.what, step.text))
                self.skipped_for_assuming += 1
                break
        else:
            for step in normal:
                exit = self.run_step(
                    datadir, scenario, step, shell_prelude, True)
                step_number += 1
                self.snapshot_datadir(
                    tempdir, datadir, scenario, step_number, step)
                if exit != 0:
                    ok = False
                    break

            for step in cleanup:
                exit = self.run_step(
                    datadir, scenario, step, shell_prelude, True)
                step_number += 1
                self.snapshot_datadir(
                    tempdir, datadir, scenario, step_number, step)
                if exit != 0:
                    ok = False
                    break

        if not self.settings['snapshot']:
            shutil.rmtree(tempdir, ignore_errors=True)

        self.remember_scenario_timing(time.time() - started)
        return ok

    def homedir(self, datadir):
        return os.path.join(datadir, 'HOME')

    def clean_env(self):
        '''Return a clean environment for running tests.'''

        whitelisted = [
            'PATH',
        ]

        hardcoded = {
            'TERM': 'dumb',
            'SHELL': '/bin/sh',
            'LC_ALL': 'C',
            'USER': 'tomjon',
            'USERNAME': 'tomjon',
            'LOGNAME': 'tomjon',
        }

        env = {}

        for key in whitelisted:
            if key in os.environ:
                env[key] = os.environ[key]

        for key in hardcoded:
            env[key] = hardcoded[key]

        for option_arg in self.settings['env']:
            if '=' not in option_arg:
                raise cliapp.AppException(
                    '--env argument must contain "=" '
                    'to separate environment variable name and value')
            key, value = option_arg.split('=', 1)
            env[key] = value

        return env

    def run_step(self, datadir, scenario, step, shell_prelude, report_error):
        started = time.time()

        self.info(1, 'Running step "%s %s"' % (step.what, step.text))
        self.ts['current_step'] = step
        self.ts['step_name'] = '%s %s' % (step.what, step.text)
        self.ts.flush()
        self.steps_run += 1

        m = self.implements_matches_step(step.implementation, step)
        assert m is not None
        env = self.clean_env()
        env['DATADIR'] = datadir
        env['SRCDIR'] = os.getcwd()
        env['HOME'] = self.homedir(datadir)
        for i, match in enumerate(m.groups('')):
            env['MATCH_%d' % (i+1)] = match
        self.add_srcdir_to_pythonpath(env, env['SRCDIR'])

        if self.settings['cd-datadir']:
            cwd = datadir
        else:
            cwd = '.'

        fd, shell_script = tempfile.mkstemp()
        os.close(fd)
        with open(shell_script, 'w') as f:
            f.write(shell_prelude)
            f.write(step.implementation.shell)
            f.flush()
        shell = self.settings['shell']
        shell_args = [x for x in self.settings['shell-arg'] if x]
        logging.debug('shell: %r', shell)
        logging.debug('shell_args: %r', shell_args)
        logging.debug('shell_script: %r', shell_script)
        exit, stdout, stderr = cliapp.runcmd_unchecked(
            [shell] + shell_args + [shell_script],
            env=env, cwd=cwd)
        os.remove(shell_script)

        logging.debug('Exit code: %d' % exit)
        if stdout:
            logging.debug('Standard output:\n%s' % self.indent(stdout.decode()))
        else:
            logging.debug('Standard output: empty')
        if stderr:
            logging.debug('Standard error:\n%s' % self.indent(stderr.decode()))
        else:
            logging.debug('Standard error: empty')

        if exit != 0 and report_error:
            self.error('ERROR: In scenario "%s"' % scenario.name)
            self.error('step "%s %s" failed,' % (step.what, step.text))
            self.error('with exit code %d:' % exit)
            self.error('Standard output from shell command:\n%s' %
                       self.indent(stdout.decode()))
            self.error('Standard error from shell command:\n%s' %
                       self.indent(stderr.decode()))

        self.remember_step_timing(
            '%s %s' % (step.what, step.text), time.time() - started)

        return exit

    def add_srcdir_to_pythonpath(self, env, srcdir):
        # Special handling of PYTHONPATH. Add $SRCDIR to it so that
        # Python IMPLEMENTS can use it. But only if --shell=python is
        # used. This is a bit of magic that hopefully won't surprise
        # users too much.

        if 'python' in self.settings['shell']:
            pythonpath = env.get('PYTHONPATH', None)
            if pythonpath:
                pythonpath += ':' + srcdir
            else:
                pythonpath = srcdir
            env['PYTHONPATH'] = pythonpath

    def scenario_dir(self, tempdir, scenario):
        return os.path.join(tempdir, self.nice(scenario.name))

    def datadir(self, tempdir, scenario):
        sd = self.scenario_dir(tempdir, scenario)
        return os.path.join(sd, 'datadir')

    def snapshot_dir(self, tempdir, scenario, step, step_number):
        sd = self.scenario_dir(tempdir, scenario)
        base = '%03d-%s-%s' % (step_number, step.what, self.nice(step.text))
        return os.path.join(sd, base)

    def snapshot_datadir(self, tempdir, datadir, scenario, step_number, step):
        if self.settings['snapshot']:
            snapshot = self.snapshot_dir(tempdir, scenario, step, step_number)
            exit, out, err = cliapp.runcmd_unchecked(
                ['cp', '-ax', datadir, snapshot])
            if exit != 0:
                logging.warning(
                    'Snapshot copy failed:\n%s\n%s' %
                    (out.decode(), err.decode ()))

    def nice(self, name):
        # Quote a scenario or step name so it forms a nice filename.
        nice_chars = "abcdefghijklmnopqrstuvwxyz"
        nice_chars += nice_chars.upper()
        nice_chars += "0123456789-."

        nice = []
        for c in name:
            if c in nice_chars:
                nice.append(c)
            elif not nice or nice[-1] != '_':
                nice.append('_')
        nice = ''.join(nice)
        return nice

    def implements_matches_step(self, implements, step):
        '''Return re.Match if implements matches the step.

        Otherwise, return None.

        '''

        m = re.match(implements.regexp, step.text, re.I)
        if m and m.end() != len(step.text):
            return None
        return m

    def indent(self, s):
        return ''.join('    %s\n' % line for line in s.splitlines())

    def start_scenario_timing(self, scenario_name):
        self.timings.append((scenario_name, None, []))

    def remember_scenario_timing(self, duration):
        scenario_name, _, step_tuples = self.timings[-1]
        self.timings[-1] = (scenario_name, duration, step_tuples)

    def remember_step_timing(self, step_name, step_duration):
        scenario_name, scenario_duration, step_tuples = self.timings[-1]
        step_tuples = step_tuples + [(step_name, step_duration)]
        self.timings[-1] = (scenario_name, scenario_duration, step_tuples)

    def report_timings(self):
        for scenario_name, scenario_duration, step_tuples in self.timings:
            self.stdout('%5.1f %s\n' % (scenario_duration, scenario_name))
            for step_name, step_duration in step_tuples:
                self.stdout('  %5.1f %s\n' % (step_duration, step_name))


YarnRunner(version=yarnlib.__version__).run()