import __main__
import argparse
import contextlib
import datetime
import fileinput
import multiprocessing
import os
import re
import resource
import signal
import stat
import subprocess
import sys
import tempfile
import time
import types

from pybin import settings

################################################################################
#               shell helpers
################################################################################

# helper functions to run terminal commands
def sh(*cmd, timeout = False, output = None, input = None, error = subprocess.STDOUT):
	cmd = list(cmd)

	# if this is a dry_run, only print the commands that would be ran
	if settings.dry_run :
		cmd = "{} cmd: {}".format(os.getcwd(), ' '.join(cmd))
		if output and not isinstance(output, int):
			cmd += " > "
			cmd += output

		if error and not isinstance(error, int):
			cmd += " 2> "
			cmd += error

		if input and not isinstance(input, int) and os.path.isfile(input):
			cmd += " < "
			cmd += input

		print(cmd)
		return 0, None

	with contextlib.ExitStack() as onexit:
		# add input redirection if needed
		input = openfd(input, 'r', onexit, True)

		# add output redirection if needed
		output = openfd(output, 'w', onexit, False)

		# add error redirection if needed
		error = openfd(error, 'w', onexit, False)

		# run the desired command
		try:
			proc = subprocess.run(
				cmd,
				stdin =input,
				stdout=output,
				stderr=error,
				timeout=settings.timeout.single if timeout else None
			)
			return proc.returncode, proc.stdout.decode("utf-8") if proc.stdout else None
		except subprocess.TimeoutExpired:
			return 124, str(None)

def is_ascii(fname):
	if settings.dry_run:
		print("is_ascii: %s" % fname)
		return True

	if not os.path.isfile(fname):
		return False

	code, out = sh("file %s" % fname, output=subprocess.PIPE)
	if code != 0:
		return False

	match = re.search(".*: (.*)", out)

	if not match:
		return False

	return match.group(1).startswith("ASCII text")

def is_exe(fname):
	return os.path.isfile(fname) and os.access(fname, os.X_OK)

def openfd(file, mode, exitstack, checkfile):
	if not file:
		return file

	if isinstance(file, int):
		return file

	if checkfile and not os.path.isfile(file):
		return None

	file = open(file, mode)
	exitstack.push(file)
	return file

# Remove 1 or more files silently
def rm( files ):
	if isinstance(files, str ): files = [ files ]
	for file in files:
		sh( 'rm', '-f', file, output=subprocess.DEVNULL, error=subprocess.DEVNULL )

# Create 1 or more directory
def mkdir( files ):
	if isinstance(files, str ): files = [ files ]
	for file in files:
		p = os.path.normpath( file )
		d = os.path.dirname ( p )
		sh( 'mkdir', '-p', d, output=subprocess.DEVNULL, error=subprocess.DEVNULL )


def chdir( dest = __main__.__file__ ):
	abspath = os.path.abspath(dest)
	dname = os.path.dirname(abspath)
	os.chdir(dname)

# diff two files
def diff( lhs, rhs ):
	# fetch return code and error from the diff command
	return sh(
		'''diff''',
		'''--text''',
		'''--old-group-format=\t\tmissing lines :\n%<''',
		'''--new-line-format=\t\t%dn\t%L''',
		'''--new-group-format=\t\tnew lines : \n%>''',
		'''--old-line-format=\t\t%dn\t%L''',
		'''--unchanged-group-format=%=''',
		'''--changed-group-format=\t\texpected :\n%<\t\tgot :\n%>''',
		'''--unchanged-line-format=''',
		lhs,
		rhs,
		output=subprocess.PIPE
	)

# call make
def make(target, *, flags = '', output = None, error = None, error_file = None, silent = False):
	test_param = """test="%s" """ % (error_file) if error_file else None
	cmd = [
		*settings.make,
		'-s' if silent else None,
		test_param,
		settings.arch.flags,
		settings.debug.flags,
		settings.install.flags,
		flags,
		target
	]
	cmd = [s for s in cmd if s]
	return sh(*cmd, output=output, error=error)

def which(program):
    fpath, fname = os.path.split(program)
    if fpath:
        if is_exe(program):
            return program
    else:
        for path in os.environ["PATH"].split(os.pathsep):
            exe_file = os.path.join(path, program)
            if is_exe(exe_file):
                return exe_file

    return None

@contextlib.contextmanager
def tempdir():
	cwd = os.getcwd()
	with tempfile.TemporaryDirectory() as temp:
		os.chdir(temp)
		try:
			yield temp
		finally:
			os.chdir(cwd)

def killgroup():
	try:
		os.killpg(os.getpgrp(), signal.SIGINT)
	except KeyboardInterrupt:
		pass # expected
	except Exception as exc:
		print("Unexpected exception", file=sys.stderr)
		print(exc, file=sys.stderr)
		sys.stderr.flush()
		sys.exit(2)

################################################################################
#               file handling
################################################################################
# move a file
def mv(source, dest):
	ret, _ = sh("mv", source, dest)
	return ret

# cat one file into the other
def cat(source, dest):
	ret, _ = sh("cat", source, output=dest)
	return ret

# helper function to replace patterns in a file
def file_replace(fname, pat, s_after):
	if settings.dry_run:
		print("replacing '%s' with '%s' in %s" % (pat, s_after, fname))
		return

	file = fileinput.FileInput(fname, inplace=True, backup='.bak')
	for line in file:
		print(line.replace(pat, s_after), end='')
	file.close()

# helper function to check if a files contains only a specific string
def file_contains_only(file, text) :
	with open(file) as f:
		ff = f.read().strip()
		result = ff == text.strip()

		return result

# transform path to canonical form
def canonical_path(path):
	abspath = os.path.abspath(__main__.__file__)
	dname = os.path.dirname(abspath)
	return os.path.join(dname, os.path.normpath(path) )

# compare path even if form is different
def path_cmp(lhs, rhs):
	return canonical_path( lhs ) == canonical_path( rhs )

# walk all files in a path
def path_walk( op ):
	dname = settings.SRCDIR
	for dirname, _, names in os.walk(dname):
		for name in names:
			path = os.path.join(dirname, name)
			op( path )

################################################################################
#               system
################################################################################
# count number of jobs to create
def job_count( options, tests ):
	# check if the user already passed in a number of jobs for multi-threading
	if not options.jobs:
		make_flags = os.environ.get('MAKEFLAGS')
		force = bool(make_flags)
		make_jobs_fds = re.search("--jobserver-(auth|fds)=\s*([0-9]+),([0-9]+)", make_flags) if make_flags else None
		if make_jobs_fds :
			tokens = os.read(int(make_jobs_fds.group(2)), 1024)
			options.jobs = len(tokens)
			os.write(int(make_jobs_fds.group(3)), tokens)
		else :
			options.jobs = multiprocessing.cpu_count()
	else :
		force = True

	# make sure we have a valid number of jobs that corresponds to user input
	if options.jobs <= 0 :
		print('ERROR: Invalid number of jobs', file=sys.stderr)
		sys.exit(1)

	return min( options.jobs, len(tests) ), force

# enable core dumps for all the test children
resource.setrlimit(resource.RLIMIT_CORE, (resource.RLIM_INFINITY, resource.RLIM_INFINITY))

################################################################################
#               misc
################################################################################

def pretty_now():
	ts = time.time()
	print(ts, file=sys.stderr)
	return datetime.datetime.fromtimestamp(ts).strftime('%Y-%m-%d_%H:%M:%S')

# check if arguments is yes or no
def yes_no(string):
	if string == "yes" :
		return True
	if string == "no" :
		return False
	raise argparse.ArgumentTypeError(msg)

def fancy_print(text):
	column = which('column')
	if column:
		subprocess.run(column, input=bytes(text + "\n", "UTF-8"))
	else:
		print(text)


def core_info(path):
	if not os.path.isfile(path):
		return 1, "ERR Executable path is wrong"

	cmd   = os.path.join(settings.SRCDIR, "pybin/print-core.gdb")
	if not os.path.isfile(cmd):
		return 1, "ERR Printing format for core dumps not found"

	core  = os.path.join(os.getcwd(), "core" )

	if not os.path.isfile(core):
		return 1, "ERR No core dump"

	return sh('gdb', '-n', path, core, '-batch', '-x', cmd, output=subprocess.PIPE)

def core_archive(dst, name, exe):
	# Get the files to copy
	core = os.path.join(os.getcwd(), "core" )

	# Uncomment if we want timestamps on coredumps
	# dst  = os.path.join(dst, "%s_%s" % (name, pretty_now()))

	# make a directory for this test
	mkdir(os.path.join(dst, "dir"))

	# moves the files
	mv( core, os.path.join(dst, "core" ) )
	mv( exe , os.path.join(dst, name   ) )

	# return explanatory test
	return "Archiving %s (executable and core) to %s" % (os.path.relpath(exe, settings.BUILDDIR), os.path.relpath(dst, settings.original_path))

class Timed:
    def __enter__(self):
        self.start = time.time()
        return self

    def __exit__(self, *args):
        self.end = time.time()
        self.duration = self.end - self.start

def timed(src, timeout):
	expire = time.time() + timeout
	i = iter(src)
	while True:
		yield i.next(max(expire - time.time(), 0))