#! /usr/bin/env python

import os
import sys
import re
from distutils import spawn
import subprocess
from threading import Thread
import argparse


def find_react_version(lib_dir):
    "Finds the React library version number currently used."
    for filename in os.listdir(lib_dir):
        match = re.match(r"react-(.*)-prod\.js", filename)
        if (match and match.group(1)):
            return match.group(1)
    print 'Unable to find the current react version used in content.'
    print 'Please checked the %s directory.' % lib_dir
    exit(1)


def append_arguments(array1, array2):
    "Appends array2 onto the end of array1"
    result = array1[:]
    result.extend(array2)
    return result


def check_jsx(jsx_path):
    "Checks to see if jsx is installed or not"
    if jsx_path is None:
        print 'You do not have the react-tools installed'
        print 'Please do $ npm install -g react-tools and make sure it is available in PATH'
        exit(1)


def find_react_command():
    "Searches for a jsx location and forms a runnable command"
    if sys.platform != 'win32':
        jsx_path = spawn.find_executable('jsx')
        check_jsx(jsx_path)
        return [jsx_path]

    # Else windows.
    def find_excutable_no_extension(fileName):
        """
            spawn.find_executable assumes a '.exe' extension on windows
            something which jsx doesn't have...
        """
        paths = os.environ['PATH'].split(os.pathsep)
        for path in paths:
            file = os.path.join(path, fileName)
            if os.path.isfile(file):
                return path
        return None

    # jsx isn't a true windows executable, so the standard spawn
    # processes get upset. Hence, we have to use node to run the
    # jsx file direct.
    node = spawn.find_executable('node')
    if node is None:
        print 'You do not have node installed, or it is not in your PATH'
        exit(1)

    # We need the jsx path to make node happy
    jsx_path = find_excutable_no_extension('jsx')
    check_jsx(jsx_path)

    # This is what node really wants to run.
    jsx_path = os.path.join(jsx_path,
                            "node_modules", "react-tools", "bin", "jsx")

    return [node, jsx_path]


SHARED_LIBS_DIR=os.path.join(os.path.dirname(__file__), "content", "shared", "libs")
REACT_VERSION=find_react_version(SHARED_LIBS_DIR)

src_files = []  # files to be compiled

run_command = find_react_command()

if sys.platform == 'win32':
    print 'Please ensure you are running react-tools version %s' % REACT_VERSION
    print 'You may be already, but we are not currently able to detect it'
else:
    p = subprocess.Popen(append_arguments(run_command, ['-V']),
                         stdout=subprocess.PIPE,
                         stderr=subprocess.STDOUT)
    for line in iter(p.stdout.readline, b''):
        info = line.rstrip()

    if not info == REACT_VERSION:
        print 'You have the wrong version of react-tools installed'
        print 'Please use version %s' % REACT_VERSION
        exit(1)

# parse the CLI arguments
description = 'Loop build tool for JSX files. ' + \
              'Will scan entire loop directory and compile them in place. ' + \
              'Must be executed from browser/components/loop directory.'

parser = argparse.ArgumentParser(description=description)
parser.add_argument('--watch', '-w', action='store_true', help='continuous' +
                    'build based on file changes (optional)')
args = parser.parse_args()

# loop through all tuples and get unique dirs only
unique_jsx_dirs = []

# find all .jsx files
for dirname, dirnames, filenames in os.walk('.'):
    for filename in filenames:
        if '.jsx' == os.path.splitext(filename)[1]:  # (root, ext)
            src_files.append(filename)
            if dirname not in unique_jsx_dirs:
                unique_jsx_dirs.append(dirname)


def jsx_run_watcher(path):
    subprocess.call(append_arguments(run_command, ['-w', '-x', 'jsx', path, path]))


def start_jsx_watcher_threads(dirs):
    """
        starts a thread with a jsx watch process
        for every dir in the dirs argument
    """
    threads = []
    for udir in dirs:
        t = Thread(target=jsx_run_watcher, args=(udir,))
        threads.append(t)
        t.start()

    for t in threads:
        t.join()


def check_file_packaging(srcs):
    """
        get all lines from jar.mn file
        check against the files we are going to compile.
        Note that this only looks at filenames, and will miss
        the one of two identically named files.
    """
    # get all lines from jar.mn
    packaged_files = [line.strip() for line in open('./jar.mn')]

    # loop through our compiled files and compare against jar.mn
    # XXX fix to use paths so that identically named files don't get overlooked
    # and update the docstring for this function
    missing_jar_files = []  # initially empty
    for src_file in srcs:
        transpiled_file = os.path.splitext(src_file)[0] + ".js"  # (root, ext)
        if not any(transpiled_file in x for x in packaged_files):
            missing_jar_files.append(transpiled_file)

    # output a message to the user
    if len(missing_jar_files):
        for f in missing_jar_files:
            print f + ' not in jar.mn file'

check_file_packaging(src_files)

if args.watch:
    start_jsx_watcher_threads(unique_jsx_dirs)
else:
    for d in unique_jsx_dirs:
        out = subprocess.call(append_arguments(run_command, ['-x', 'jsx', d, d]))