#!/usr/bin/python
# 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 logging
import os
import re
import shutil
import sys
import tempfile
import time
import ttystatus

import cmdtestlib
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 TEST (this option can be repeated)',
            metavar='TEST')

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

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

    def info(self, msg):
        if self.settings['verbose']:
            logging.info(msg)
            self.output.write('%s\n' % msg)

    def warning(self, msg):
        if self.settings['verbose']:
            logging.warning(msg)
            self.output.write('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)
            sys.stderr.write('%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(scenario,scenarios): '
                '%String(scenario_name): '
                'step %Index(step,steps): %String(step_name)')

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

        self.ts['scenarios'] = scenarios
        self.ts['num_scenarios'] = len(scenarios)
        self.info('Found %d scenarios' % len(scenarios))

        self.scenarios_run = 0
        self.steps_run = 0

        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)
        duration = time.time() - start_time

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

        if failed_scenarios:
            raise cliapp.AppException(
                'Test suite FAILED in %s scenarios' % len(failed_scenarios))

        if not self.settings['quiet']:
            print (
                'Scenario test suite PASS, with %d scenarios '
                '(%d total steps), '
                'in %.1f seconds' %
                (self.scenarios_run, self.steps_run, duration))

    def parse_scenarios(self, filenames):
        mdparser = yarnlib.MarkdownParser()
        for filename in filenames:
            self.info('Parsing scenario file %s' % filename)
            blocks = mdparser.parse_file(filename)
            if not blocks:
                self.warning('No scenario code blocks in %s' % filename)

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

        return block_parser.scenarios, block_parser.implementations

    def connect_implementations(self, scenarios, implementations):
        for scenario in scenarios:
            for step in scenario.steps:
                self.connect_implementation(scenario, step, implementations)

    def connect_implementation(self, scenario, step, implementations):
        matching = [i for i in implementations
                    if step.what == i.what and
                       re.match('(%s)$' % i.regexp, step.text, re.I)]

        if len(matching) == 0:
            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('No shell libraries defined')
            return ''

        libs = []
        for filename in self.settings['shell-library']:
            self.info('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
            return result

        return scenarios

    def run_scenario(self, scenario, shell_prelude):
        self.info('Running scenario %s' % scenario.name)
        self.ts['scenario'] = scenario
        self.ts['scenario_name'] = scenario.name
        self.ts['steps'] = scenario.steps
        self.scenarios_run += 1

        if self.settings['no-act']:
            self.info('Pretending everything went OK')
            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('DATADIR is %s' % datadir)

        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 exit != 0:
                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)

        return ok

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

        whitelisted = [
            'TERM',
            'USER',
            'USERNAME',
            'PATH',
            'HOME',
            'LOGNAME',
        ]

        hardcoded = {
            'SHELL': '/bin/sh',
            'LC_ALL': 'C',
        }

        env = {}
        for key in whitelisted:
            if key in os.environ:
                env[key] = os.environ[key]
        for key in hardcoded:
            env[key] = hardcoded[key]
        return env

    def run_step(self, datadir, scenario, step, shell_prelude, report_error):
        self.info('Running step "%s %s"' % (step.what, step.text))
        self.ts['step'] = step
        self.ts['step_name'] = '%s %s' % (step.what, step.text)
        self.steps_run += 1

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

        shell_script = '%s\n\n%s\n' % (
            shell_prelude, step.implementation.shell)
        exit, stdout, stderr = cliapp.runcmd_unchecked(
            ['sh', '-xeuc', shell_script], env=env)

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

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

        return exit

    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):
        snapshot = self.snapshot_dir(tempdir, scenario, step, step_number)
        cliapp.runcmd(['cp', '-a', datadir, snapshot])

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


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