import json
import os
import shutil
import tempfile
import unittest

from data_import.pipeline import parsers


class TestParser(unittest.TestCase):
    def setUp(self):
        self.test_dir = tempfile.mkdtemp()
        self.test_file = os.path.join(self.test_dir, 'test_file.csv')

    def tearDown(self):
        shutil.rmtree(self.test_dir)

    def create_file(self, content):
        with open(self.test_file, 'w') as f:
            f.write(content)

    def assert_record(self, content, parser, expected):
        self.create_file(content)
        it = parser.parse(self.test_file)
        for expect in expected:
            row = next(it)
            self.assertEqual(row, expect)
        with self.assertRaises(StopIteration):
            next(it)


class TestPlainParser(TestParser):

    def test_read(self):
        content = 'example'
        parser = parsers.PlainParser()
        expected = [{}]
        self.assert_record(content, parser, expected)


class TestLineParser(TestParser):

    def test_read(self):
        content = 'Hello, World!\nこんにちは'
        parser = parsers.LineParser()
        expected = [{'text': 'Hello, World!'}, {'text': 'こんにちは'}]
        self.assert_record(content, parser, expected)


class TestTextFileParser(TestParser):

    def test_read(self):
        content = 'Hello, World!\nこんにちは'
        parser = parsers.TextFileParser()
        expected = [{'text': content}]
        self.assert_record(content, parser, expected)


class TestCsvParser(TestParser):

    def test_read(self):
        content = 'label,text\nLabel,Text'
        parser = parsers.CSVParser(delimiter=',')
        expected = [{'label': 'Label', 'text': 'Text'}]
        self.assert_record(content, parser, expected)

    def test_can_change_delimiter(self):
        content = 'label\ttext\nLabel\tText'
        parser = parsers.CSVParser(delimiter='\t')
        expected = [{'label': 'Label', 'text': 'Text'}]
        self.assert_record(content, parser, expected)

    def test_can_read_null_value(self):
        content = 'text,label\nText'
        parser = parsers.CSVParser(delimiter=',')
        expected = [{'text': 'Text', 'label': None}]
        self.assert_record(content, parser, expected)


class TestJSONParser(TestParser):

    def test_read(self):
        content = json.dumps([
            {'text': 'line1', 'labels': 'Label1'},
            {'text': 'line2', 'labels': 'Label2'}
        ])
        parser = parsers.JSONParser()
        expected = json.loads(content)
        self.assert_record(content, parser, expected)


class TestJSONLParser(TestParser):

    def test_read(self):
        line1 = json.dumps({'text': 'line1', 'labels': 'Label1'})
        line2 = json.dumps({'text': 'line2', 'labels': 'Label2'})
        content = f"{line1}\n{line2}"
        parser = parsers.JSONLParser()
        expected = [json.loads(line1), json.loads(line2)]
        self.assert_record(content, parser, expected)


class TestFastTextParser(TestParser):

    def test_read(self):
        content = '__label__sauce __label__cheese Text'
        parser = parsers.FastTextParser()
        expected = [{'text': 'Text', 'label': ['sauce', 'cheese']}]
        self.assert_record(content, parser, expected)


class TestCoNLLParser(TestParser):

    def test_can_read(self):
        content = """EU\tB-ORG
rejects\tO
German\tB-MISC
call\tO
to\tO
boycott\tO
British\tB-MISC
lamb\tO
.\tO

Peter\tB-PER
Blackburn\tI-PER

"""
        parser = parsers.CoNLLParser()
        expected = [
            {
                'text': 'EU rejects German call to boycott British lamb .',
                'label': [(0, 2, 'ORG'), (11, 17, 'MISC'), (34, 41, 'MISC')]
            },
            {
                'text': 'Peter Blackburn',
                'label': [(0, 15, 'PER')]
            }
        ]
        self.assert_record(content, parser, expected)