#!/usr/bin/env python
# -*- coding: utf-8 -*-

# Copyright (C) 2017, Maxim Lihachev, <envrm@yandex.ru>
#
# 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, version 3.
#
# 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 <https://www.gnu.org/licenses/>.

import re
import os
import ast
import sys
import shutil
import signal
import datetime
import subprocess
import configparser

from string import Template
from contextlib import contextmanager


@contextmanager
def if_needed():
    '''Execute with error ignoring'''
    try:
        yield
    except:
        pass


class Dir:
    '''Execute procedures in directory'''
    def __init__(self, directory):
        self.current_dir = directory

    def __enter__(self):
        self.previous_dir = os.getcwd()
        os.chdir(self.current_dir)

    def __exit__(self, type, value, traceback):
        os.chdir(self.previous_dir)


# ----------------------------------------------------------------------

def readConfig(config_file):
    '''Loading configuration file'''
    global settings
    settings = configparser.ConfigParser()
    settings._interpolation = configparser.ExtendedInterpolation()
    settings.read(config_file)
    return settings


def opt(parameter):
    '''Getting parameters from file'''
    setting = parameter.split(":")
    value = settings.get(setting[0], setting[1])

    variables = re.findall(r"\$(\w+)", value)

    substr = {v: globals()[v] for v in variables if v in globals()}

    return Template(value).safe_substitute(**substr)


def saveTimestamp(outfile, mode="a"):
    '''Saving timestamt to file'''
    with open(outfile, mode) as log:
        now = datetime.datetime.now()
        log.write(now.strftime("%Y-%m-%d %H:%M:%S\n"))


# ----------------------------------------------------------------------

def git(command, stand="develop"):
    '''Executing git command'''
    with Dir(opt(stand + ':git_path')):
        git_output = subprocess.check_output('git ' + command, shell=True)

    return git_output


def stop(stand="develop"):
    '''Stop service'''
    if os.path.isfile(opt(stand + ':pid')):
        pid = opt(stand + ':pid')
    else:
        pid = os.path.join(opt(stand + ':path'), 'RUNNING_PID')

    print pid
    with if_needed():
        with open(pid, 'r') as pid_file:
            os.kill(int(pid_file.read()), signal.SIGTERM)
        os.remove(pid)
        print "#### Application stopped"


def start(stand):
    '''Start service'''
    service_dir = opt(stand + ':path')
    server = opt(stand + ':server')

    start_cmd = 'nohup java ' + opt(stand + ':java_options') \
    + ' -Dfile.encoding=UTF-8 -Dconfig.file=' + service_dir + '/conf/application.conf ' \
    + ' -Dhttp.port=' + opt(stand + ':http_port') + ' -cp "' + service_dir + '/conf/:' + opt(stand + ':class_path') + '/*" ' \
    + server + ' ' + service_dir + ' | tee -a ' + opt(stand + ':home') + '/nohup.out &'

    print start_cmd

    with Dir(service_dir):
        return_code = os.system(start_cmd)
        if return_code == 0:
            print "#### Application started"
        else:
            print return_code
            exit(1)


def restart(stand="develop"):
    '''Restart service'''
    stop(stand)
    start(stand)
    saveTimestamp(opt(stand + ':restarts_log'))


def clean_all():
    '''Remove artefacts'''
    os.system("rm -rfv " + opt('develop:targets'))


def build(target="stand", modules=None):
    '''Build service. [stand|modules|all]'''
    play_cmd = opt(SERVICE + ':play') + " " + opt(SERVICE + ':sbt_config')

    print "OK"

    if target == "modules" or target == "all":
        with Dir(opt('develop:modules_dir')):
            if modules is None:
                modules = os.walk(".").next()[1]

            modules = filter(None, set(modules))

            with open(opt('develop:modules_list')) as f:
                modules_deps = f.read().splitlines()

            for mod in modules_deps:
                if mod in modules:
                    with Dir(os.path.join(opt('develop:modules_dir'), mod)):
                        print "#### Update module " + mod
                        return_code = os.system(play_cmd + " publishLocal")

                        if return_code != 0:
                            exit(1)

    if target == "stand" or target == "all":
        print "#### Update application"
        with Dir(opt('develop:path')):
            with if_needed():
                shutil.rmtree("target")
            print play_cmd + " " + opt('build:java_options') + " stage | tee " + opt('develop:build_log_file')
            return_code = os.system(play_cmd + " " + opt('build:java_options') + " stage | tee " + opt('develop:build_log_file'))

            if return_code != 0:
                exit(1)


def update_from_git():
    '''Update app with modules'''
    git('checkout ' + opt('build:git_branch'))
    git('branch --set-upstream-to=origin/' + opt('build:git_branch') + ' ' + opt('build:git_branch'))
    print git('fetch')
    git_log = git('diff --name-only HEAD..origin/' + opt('build:git_branch'))
    git('pull')

    modules = []
    for line in git_log.splitlines():
        module = re.findall(r'commonmodules/([^/]*)/.*', line)
        if module:
            modules.extend(module)

    build("all", modules)


def copy_libs():
    '''Copy libraries'''
    with if_needed():
        shutil.rmtree(opt(SERVICE + ':class_path'))
    shutil.copytree(opt('develop:class_path'), opt(SERVICE + ':class_path'))


def update():
    '''Update current service from repository'''
    saveTimestamp(opt('develop:restarts_log'))
    stop()
    update_from_git()
    start(SERVICE)
    saveTimestamp(opt('develop:update_log'), 'w')


def upgrade():
    '''Update developing service from repository'''
    update_from_git()
    saveTimestamp(opt(SERVICE + ':restarts_log'))
    stop(SERVICE)
    git("pull", SERVICE)
    copy_libs()
    start(SERVICE)
    saveTimestamp(opt(SERVICE + ':update_log'), 'w')


# ----------------------------------------------------------------------

def show_help():
    exe = os.path.basename(sys.argv[0])

    '''Show help'''
    print "USAGE: " + exe + " [service] <" + "|".join(allowed_tasks) + ">"

    for task in allowed_tasks:
        print "\t" + task + "\t- " + globals()[task].__doc__

    print "\nTo build a specific service you need to pass a parameter [service]:"
    print "\t./" + exe, opt('service:default'), "\b build all"
    print "\n[service] can be one of «" + "», «".join(ast.literal_eval(opt('service:projects')).keys()) + "»."
    print "\nDefault value of [service] is", opt('service:default'), "\n"


settings = []

readConfig('config.ini')

allowed_tasks = ['start', 'stop', 'restart', 'build', 'update', 'upgrade']

# Services allowed for building
services = ast.literal_eval(opt('service:projects'))

# Default service
SERVICE = ast.literal_eval(opt('service:projects'))[opt('service:default')]

# Command line arguments parsing
if len(sys.argv) > 2 and sys.argv[2] in allowed_tasks:
    arg_index = 2
    if sys.argv[1] in services:
        SERVICE = ast.literal_eval(opt('service:projects'))[sys.argv[1]]
elif len(sys.argv) > 1 and sys.argv[1] in allowed_tasks:
    arg_index = 1
else:
    show_help()
    exit(1)

# Procedure for execution
task = globals()[sys.argv[arg_index]]

if task:
    target = {
        'update': 'develop',
        'upgrade': 'mroot'
    }.get(sys.argv[1], "develop")

    if len(sys.argv) > 2 and sys.argv[2] in ['start', 'stop', 'restart']:
        SERVICE = ast.literal_eval(opt('service:projects'))[sys.argv[1]]
        print "CMD:   " + sys.argv[1] + " " + sys.argv[2], "| SERVICE: ", SERVICE
        task(SERVICE)
    elif len(sys.argv) > (arg_index + 1):
        print "CMD:   " + sys.argv[arg_index] + " " + sys.argv[arg_index + 1]
        task(sys.argv[arg_index + 1])
    else:
        print "CMD:   " + sys.argv[arg_index]
        task()