#!/usr/bin/python
from __future__ import print_function

from os import listdir, environ
from os.path import isfile, join, splitext
from subprocess import Popen, PIPE, STDOUT

import argparse
import os
import re
import stat
import sys

################################################################################
#               help functions
################################################################################

# Test class that defines what a test is
class Test:
    def __init__(self, name, path):
        self.name, self.path = name, path

# parses the Makefile to find the machine type (32-bit / 64-bit)
def getMachineType():
	sh('echo "int main() { return 0; }" > .dummy.c')
	sh("make .dummy", print2stdout=False)
	_, out = sh("file .dummy", print2stdout=False)
	sh("rm -f .dummy.c > /dev/null 2>&1")
	sh("rm -f .dummy > /dev/null 2>&1")
	return re.search("ELF\s([0-9]+)-bit", out).group(1)

# reads the directory ./.expect and indentifies the tests
def listTests():
	machineType = getMachineType()

	print(machineType)

	# tests directly in the .expect folder will always be processed
	generic_list = map(lambda fname: Test(fname, fname),
		[splitext(f)[0] for f in listdir('./.expect')
		if not f.startswith('.') and f.endswith('.txt')
		])

	# tests in the machineType folder will be ran only for the corresponding compiler
	typed_list = map(lambda fname: Test( fname, "%s/%s" % (machineType, fname) ),
		[splitext(f)[0] for f in listdir("./.expect/%s" % machineType)
		if not f.startswith('.') and f.endswith('.txt')
		])

	# append both lists to get
	return generic_list + typed_list

# helper functions to run terminal commands
def sh(cmd, dry_run = False, print2stdout = True):
	if dry_run : 	# if this is a dry_run, only print the commands that would be ran
		print("cmd: %s" % cmd)
		return 0, None
	else :			# otherwise create a pipe and run the desired command
		proc = Popen(cmd, stdout=None if print2stdout else PIPE, stderr=STDOUT, shell=True)
		out, err = proc.communicate()
		return proc.returncode, out

# helper function to replace patterns in a file
def file_replace(fname, pat, s_after):
    # first, see if the pattern is even in the file.
    with open(fname) as f:
        if not any(re.search(pat, line) for line in f):
            return # pattern does not occur in file so we are done.

    # pattern is in the file, so perform replace operation.
    with open(fname) as f:
        out_fname = fname + ".tmp"
        out = open(out_fname, "w")
        for line in f:
            out.write(re.sub(pat, s_after, line))
        out.close()
        os.rename(out_fname, fname)

# tests output may differ depending on the depth of the makefile
def fix_MakeLevel(file) :
	if environ.get('MAKELEVEL') :
		file_replace(file, "make\[%i\]" % int(environ.get('MAKELEVEL')), 'make' )

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

		return result;

# check whether or not a file is executable
def fileIsExecutable(file) :
	try :
		fileinfo = os.stat(file)
		return bool(fileinfo.st_mode & stat.S_IXUSR)
	except Exception as inst:
		print(type(inst))    # the exception instance
		print(inst.args)     # arguments stored in .args
		print(inst)
		return False

# find the test data for a given test name
def filterTests(testname) :
	found = [test for test in allTests if test.name == testname]
	return (found[0] if len(found) == 1 else Test(testname, testname) )

################################################################################
#               running test functions
################################################################################
def run_test_instance(test, generate, dry_run):

	# find the output file based on the test name and options flag
	out_file = (".out/%s.log" % test.name) if not generate else (".expect/%s.txt" % test.path)

	# remove any outputs from the previous tests to prevent side effects
	sh("rm -f %s" % out_file, dry_run)
	sh("rm -f %s > /dev/null 2>&1" % test.name, dry_run)

	# build, skipping to next test on error
	make_ret, _ = sh("%s %s 2> %s 1> /dev/null" % (make_cmd, test.name, out_file), dry_run)

	# if the make command succeds continue otherwise skip to diff
	if make_ret == 0 :
		# fetch optional input
		stdinput = "< .in/%s.txt" % test.name if isfile(".in/%s.txt" % test.path) else ""

		if fileIsExecutable(test.name) :
			# run test
			sh("./%s %s > %s 2>&1" % (test.name, stdinput, out_file), dry_run)
		else :
			# simply cat the result into the output
			sh("cat %s > %s" % (test.name, out_file), dry_run)

	retcode = 0
	error = None

	# fix output to prevent make depth to cause issues
	fix_MakeLevel(out_file)

	if generate :
		# if we are ounly generating the output we still need to check that the test actually exists
		if not dry_run and fileContainsOnly(out_file, "make: *** No rule to make target `%s'.  Stop." % test.name) :
			retcode = 1;
			error = "\t\tNo make target for test %s!" % test
			sh("rm %s" % out_file, False)

	else :
		# diff the output of the files
		diff_cmd = ("diff --old-group-format='\t\tmissing lines :\n"
					"%%<' \\\n"
					"--new-group-format='\t\tnew lines :\n"
					"%%>' \\\n"
					"--unchanged-group-format='%%=' \\"
					"--changed-group-format='\t\texpected :\n"
					"%%<\n"
					"\t\tgot :\n"
					"%%>' \\\n"
					"--new-line-format='\t\t%%dn\t%%L' \\\n"
					"--old-line-format='\t\t%%dn\t%%L' \\\n"
					"--unchanged-line-format='' \\\n"
					".expect/%s.txt .out/%s.log")

		# fetch return code and error from the diff command
		retcode, error = sh(diff_cmd % (test.path, test.name), dry_run, False)

	# clean the executable
	sh("rm -f %s > /dev/null 2>&1" % test.name, dry_run)

	return retcode, error

# run the given list of tests with the given parameters
def run_tests(tests, generate, dry_run, jobs) :
	# clean the sandbox from previous commands
	sh("%s clean > /dev/null 2>&1" % make_cmd, dry_run)

	#make sure the required folder are present
	sh('mkdir -p .out .expect', dry_run)

	if generate :
		print( "Regenerate tests for: " )

	failed = False;
	# for eeach test to run
	for t in tests:
		# print formated name
		name_txt = "%20s  " % t.name

		#run the test instance and collect the result
		test_failed, error = run_test_instance(t, generate, dry_run)

		# aggregate test suite result
		failed = test_failed or failed

		# update output based on current action
		if generate :
			failed_txt = "ERROR"
			success_txt = "Done"
		else :
			failed_txt = "FAILED"
			success_txt = "PASSED"

		#print result with error if needed
		text = name_txt + (failed_txt if test_failed else success_txt)
		out = sys.stdout
		if error :
			text = text + "\n" + error
			out = sys.stderr

		print(text, file = out);
		sys.stdout.flush()
		sys.stderr.flush()


	#clean the workspace
	sh("%s clean > /dev/null 2>&1" % make_cmd, dry_run)

	return 1 if failed else 0

################################################################################
#               main loop
################################################################################
# create a parser with the arguments for the tests script
parser = argparse.ArgumentParser(description='Script which runs cforall tests')
parser.add_argument('--dry-run', help='Don\'t run the tests, only output the commands', action='store_true')
parser.add_argument('--list', help='List all test available', action='store_true')
parser.add_argument('--all', help='Run all test available', action='store_true')
parser.add_argument('--regenerate-expected', help='Regenerate the .expect by running the specified tets, can be used with --all option', action='store_true')
parser.add_argument('-j', '--jobs', help='Number of tests to run simultaneously', type=int, default='8')
parser.add_argument('tests', metavar='test', type=str, nargs='*', help='a list of tests to run')

# parse the command line arguments
options = parser.parse_args()

# script must have at least some tests to run
if (len(options.tests) > 0  and     options.all and not options.list) \
or (len(options.tests) == 0 and not options.all and not options.list) :
	print('ERROR: must have option \'--all\' or non-empty test list', file=sys.stderr)
	parser.print_help()
	sys.exit(1)

# fetch the liest of all valid tests
allTests = listTests()

# if user wants all tests than no other treatement of the test list is required
if options.all or options.list :
	tests = allTests

else :
	#otherwise we need to validate that the test list that was entered is valid
	tests = []

	# if we are regenerating the tests we need to find the information of the
	# already existing tests and create new info for the new tests
	if options.regenerate_expected :
		tests = map(filterTests, options.tests)

	else :
		# otherwise we only need to validate that all tests are present in the complete list
		for testname in options.tests:
			test = [t for t in allTests if t.name == testname]

			if len(test) != 0 :
				tests.append( test[0] )
			else :
				print('ERROR: No expected file for test %s, ignoring it' % testname, file=sys.stderr)

	# make sure we have at least some test to run
	if len(tests) == 0 :
		print('ERROR: No valid test to run', file=sys.stderr)
		sys.exit(1)

# sort the test alphabetically for convenience
tests.sort(key=lambda t: t.name)

# check if the user already passed in a number of jobs for multi-threading
make_flags = environ.get('MAKEFLAGS')
make_has_max_jobs = re.search("(-j|--jobs)\s*([0-9]+)", make_flags) if make_flags else None
make_max_jobs = make_has_max_jobs.group(2) if make_has_max_jobs else None
make_cmd = "make" if make_flags and "-j" in make_flags else "make -j8"

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

# users may want to simply list the tests
if options.list :
	print("\n".join(map(lambda t: "%s (%s)" % (t.name, t.path), tests)))

else :
	# otherwise run all tests and make sure to return the correct error code
	sys.exit( run_tests(tests, options.regenerate_expected, options.dry_run, options.jobs) )