from io import BytesIO
from json import load as json_load, loads as json_loads, dumps as json_dumps
from os import environ
from sys import executable
from pathlib import Path
from subprocess import run as subprocess_run, PIPE
from typing import Optional
from unittest import TestCase, skip

from pyGHDL.lsp.lsp import LanguageProtocolServer, LSPConn


class StrConn:
	__res: str

	def __init__(self):
		self.__res = ''

	def write(self, s):
		self.__res += s

	@property
	def res(self):
		return self.__res


def show_diffs(name, ref, res):
	if isinstance(ref, dict) and isinstance(res, dict):
		for k in ref:
			if k not in res:
				print('{}.{} not in the result'.format(name, k))
			else:
				show_diffs('{}.{}'.format(name, k), ref[k], res[k])
		for k in res:
			if k not in ref:
				print('{}.{} unexpected in the result'.format(name, k))
	elif isinstance(ref, str) and isinstance(res, str):
		if res != ref:
			print('{}: mismatch (ref: {}, result: {})'.format(name, ref, res))
	elif isinstance(ref, int) and isinstance(res, int):
		if res != ref:
			print('{}: mismatch (ref: {}, result: {})'.format(name, ref, res))
	elif isinstance(ref, list) and isinstance(res, list):
		for i in range(max(len(ref), len(res))):
			if i >= len(ref):
				print('{}[{}]: missing element:'.format(name, i))
				print(' {}'.format(res[i]))
			elif i >= len(res):
				print('{}[{}]: extra elements'.format(name, i))
			else:
				show_diffs('{}[{}]'.format(name, i), ref[i], res[i])
	else:
		print('unhandle type {} in {}'.format(type(ref), name))


class JSONTest(TestCase):
	_LSPTestDirectory = Path(__file__).parent.resolve()

	subdir = None

	def _RequestResponse(self, requestName: str, responseName: Optional[str] = None):
		requestFile = self._LSPTestDirectory / self.subdir / requestName
		# Convert the JSON input file to an LSP string.
		with requestFile.open('r') as file:
			res = json_load(file)

		conn = StrConn()
		ls = LanguageProtocolServer(None, conn)
		for req in res:
			ls.write_output(req)

		# Run
		p = subprocess_run(
			[executable, '-m', 'pyGHDL.cli.lsp'],
			input=conn.res.encode('utf-8'),
			cwd=self._LSPTestDirectory / self.subdir,
			stdout=PIPE)
		self.assertEqual(p.returncode, 0, "Language server executable exit with a non-zero return code.")

		if responseName is None:
			return
		responseFile = self._LSPTestDirectory / self.subdir / responseName

		# Check output
		in_io = BytesIO(p.stdout)
		conn = LSPConn(in_io, None)
		ls = LanguageProtocolServer(None, conn)
		with responseFile.open('r') as file:
			ref = json_load(file)

		errs = 0
		json_res = []
		for i, r in enumerate(ref):
			rep = ls.read_request()
			if rep is None:
				print('FAIL: number of reply does not match')
				errs += 1
				break

			rep = json_loads(rep)
			json_res.append(rep)
#			self.assertEqual(rep, r, "reply does not match for {!s}".format(requestFile))
			if rep != r:
				print(self.__class__.__name__)
				show_diffs("[{}]".format(i), r, rep)
				errs += 1

		rep = ls.read_request()
		self.assertIsNone(rep, "Too many replies.")

		if errs != 0:
			print('FAILURE between output and {!s} (for {!s})'.format(responseFile, requestFile))
			print('Writing result output to result.json')
			with open('result.json', 'w') as f:
				f.write(json_dumps(json_res, indent=2))
				f.write('\n')

			self.fail()


class Test001_Simple(JSONTest):
	subdir = Path("001simple")

	def test_Request_Response(self):
		self._RequestResponse("cmds.json", "replies.json")


class Test002_Coverage(JSONTest):
	subdir = Path("002coverage")

	def test_Request_Response(self):
		self._RequestResponse("cmds.json", "replies.json")


class Test003_Errors(JSONTest):
	subdir = Path("003errors")

	def test_Crash1(self):
		self._RequestResponse("crash1.json")

	def test_Crash2(self):
		self._RequestResponse("crash2.json")

	def test_Request_Response(self):
		self._RequestResponse("cmds.json", "replies.json")


class Test004_Error_Project(JSONTest):
	subdir = Path("004errprj")

	def test_Request_Response(self):
		self._RequestResponse("cmds.json", "replies.json")


class Test005_Create(JSONTest):
	subdir = Path("005create")

	def test_Request_Response(self):
		self._RequestResponse("cmds.json", "replies.json")


class Test006_Option_Error(JSONTest):
	subdir = Path("006opterr")

	def test_Request_Response(self):
		self._RequestResponse("cmds.json", "replies.json")


class Test007_Error_Project(JSONTest):
	subdir = Path("007errprj")

	def test_Request_Response(self):
		self._RequestResponse("cmds.json", "replies.json")


class Test008_Error_NoFile(JSONTest):
	subdir = Path("008errnofile")

	def test_Request_Response(self):
		self._RequestResponse("cmds.json", "replies.json")