#!/usr/bin/env python3
# Copyright 2020 The Pigweed Authors
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may not
# use this file except in compliance with the License. You may obtain a copy of
# the License at
#
#     https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations under
# the License.
"""Tests for the tokens module."""

import datetime
import io
import logging
from pathlib import Path
import tempfile
from typing import Iterator
import unittest

from pw_tokenizer import tokens
from pw_tokenizer.tokens import default_hash, _LOG

CSV_DATABASE = '''\
00000000,2019-06-10,""
141c35d5,          ,"The answer: ""%s"""
2db1515f,          ,"%u%d%02x%X%hu%hhu%d%ld%lu%lld%llu%c%c%c"
2e668cd6,2019-06-11,"Jello, world!"
31631781,          ,"%d"
61fd1e26,          ,"%ld"
68ab92da,          ,"%s there are %x (%.2f) of them%c"
7b940e2a,          ,"Hello %s! %hd %e"
851beeb6,          ,"%u %d"
881436a0,          ,"The answer is: %s"
ad002c97,          ,"%llx"
b3653e13,2019-06-12,"Jello!"
b912567b,          ,"%x%lld%1.2f%s"
cc6d3131,2020-01-01,"Jello?"
e13b0f94,          ,"%llu"
e65aefef,2019-06-10,"Won't fit : %s%d"
'''

# The date 2019-06-10 is 07E3-06-0A in hex. In database order, it's 0A 06 E3 07.
BINARY_DATABASE = (
    b'TOKENS\x00\x00\x10\x00\x00\x00\0\0\0\0'  # header (0x10 entries)
    b'\x00\x00\x00\x00\x0a\x06\xe3\x07'  # 0x01
    b'\xd5\x35\x1c\x14\xff\xff\xff\xff'  # 0x02
    b'\x5f\x51\xb1\x2d\xff\xff\xff\xff'  # 0x03
    b'\xd6\x8c\x66\x2e\x0b\x06\xe3\x07'  # 0x04
    b'\x81\x17\x63\x31\xff\xff\xff\xff'  # 0x05
    b'\x26\x1e\xfd\x61\xff\xff\xff\xff'  # 0x06
    b'\xda\x92\xab\x68\xff\xff\xff\xff'  # 0x07
    b'\x2a\x0e\x94\x7b\xff\xff\xff\xff'  # 0x08
    b'\xb6\xee\x1b\x85\xff\xff\xff\xff'  # 0x09
    b'\xa0\x36\x14\x88\xff\xff\xff\xff'  # 0x0a
    b'\x97\x2c\x00\xad\xff\xff\xff\xff'  # 0x0b
    b'\x13\x3e\x65\xb3\x0c\x06\xe3\x07'  # 0x0c
    b'\x7b\x56\x12\xb9\xff\xff\xff\xff'  # 0x0d
    b'\x31\x31\x6d\xcc\x01\x01\xe4\x07'  # 0x0e
    b'\x94\x0f\x3b\xe1\xff\xff\xff\xff'  # 0x0f
    b'\xef\xef\x5a\xe6\x0a\x06\xe3\x07'  # 0x10
    b'\x00'
    b'The answer: "%s"\x00'
    b'%u%d%02x%X%hu%hhu%d%ld%lu%lld%llu%c%c%c\x00'
    b'Jello, world!\x00'
    b'%d\x00'
    b'%ld\x00'
    b'%s there are %x (%.2f) of them%c\x00'
    b'Hello %s! %hd %e\x00'
    b'%u %d\x00'
    b'The answer is: %s\x00'
    b'%llx\x00'
    b'Jello!\x00'
    b'%x%lld%1.2f%s\x00'
    b'Jello?\x00'
    b'%llu\x00'
    b'Won\'t fit : %s%d\x00')

INVALID_CSV = """\
1,,"Whoa there!"
2,this is totally invalid,"Whoa there!"
3,,"This one's OK"
,,"Also broken"
5,1845-2-2,"I'm %s fine"
6,"Missing fields"
"""


def read_db_from_csv(csv_str: str) -> tokens.Database:
    with io.StringIO(csv_str) as csv_db:
        return tokens.Database(tokens.parse_csv(csv_db))


def _entries(*strings: str) -> Iterator[tokens.TokenizedStringEntry]:
    for string in strings:
        yield tokens.TokenizedStringEntry(default_hash(string), string)


class TokenDatabaseTest(unittest.TestCase):
    """Tests the token database class."""
    def test_csv(self):
        db = read_db_from_csv(CSV_DATABASE)
        self.assertEqual(str(db), CSV_DATABASE)

        db = read_db_from_csv('')
        self.assertEqual(str(db), '')

    def test_csv_formatting(self):
        db = read_db_from_csv('')
        self.assertEqual(str(db), '')

        db = read_db_from_csv('abc123,2048-4-1,Fake string\n')
        self.assertEqual(str(db), '00abc123,2048-04-01,"Fake string"\n')

        db = read_db_from_csv('1,1990-01-01,"Quotes"""\n'
                              '0,1990-02-01,"Commas,"",,"\n')
        self.assertEqual(str(db), ('00000000,1990-02-01,"Commas,"",,"\n'
                                   '00000001,1990-01-01,"Quotes"""\n'))

    def test_bad_csv(self):
        with self.assertLogs(_LOG, logging.ERROR) as logs:
            db = read_db_from_csv(INVALID_CSV)

        self.assertGreaterEqual(len(logs.output), 3)
        self.assertEqual(len(db.token_to_entries), 3)

        self.assertEqual(db.token_to_entries[1][0].string, 'Whoa there!')
        self.assertFalse(db.token_to_entries[2])
        self.assertEqual(db.token_to_entries[3][0].string, "This one's OK")
        self.assertFalse(db.token_to_entries[4])
        self.assertEqual(db.token_to_entries[5][0].string, "I'm %s fine")
        self.assertFalse(db.token_to_entries[6])

    def test_lookup(self):
        db = read_db_from_csv(CSV_DATABASE)
        self.assertEqual(db.token_to_entries[0x9999], [])

        matches = db.token_to_entries[0x2e668cd6]
        self.assertEqual(len(matches), 1)
        jello = matches[0]

        self.assertEqual(jello.token, 0x2e668cd6)
        self.assertEqual(jello.string, 'Jello, world!')
        self.assertEqual(jello.date_removed, datetime.datetime(2019, 6, 11))

        matches = db.token_to_entries[0xe13b0f94]
        self.assertEqual(len(matches), 1)
        llu = matches[0]
        self.assertEqual(llu.token, 0xe13b0f94)
        self.assertEqual(llu.string, '%llu')
        self.assertIsNone(llu.date_removed)

        answer, = db.token_to_entries[0x141c35d5]
        self.assertEqual(answer.string, 'The answer: "%s"')

    def test_collisions(self):
        hash_1 = tokens.pw_tokenizer_65599_fixed_length_hash('o000', 96)
        hash_2 = tokens.pw_tokenizer_65599_fixed_length_hash('0Q1Q', 96)
        self.assertEqual(hash_1, hash_2)

        db = tokens.Database.from_strings(['o000', '0Q1Q'])

        self.assertEqual(len(db.token_to_entries[hash_1]), 2)
        self.assertCountEqual(
            [entry.string for entry in db.token_to_entries[hash_1]],
            ['o000', '0Q1Q'])

    def test_purge(self):
        db = read_db_from_csv(CSV_DATABASE)
        original_length = len(db.token_to_entries)

        self.assertEqual(db.token_to_entries[0][0].string, '')
        self.assertEqual(db.token_to_entries[0x31631781][0].string, '%d')
        self.assertEqual(db.token_to_entries[0x2e668cd6][0].string,
                         'Jello, world!')
        self.assertEqual(db.token_to_entries[0xb3653e13][0].string, 'Jello!')
        self.assertEqual(db.token_to_entries[0xcc6d3131][0].string, 'Jello?')
        self.assertEqual(db.token_to_entries[0xe65aefef][0].string,
                         "Won't fit : %s%d")

        db.purge(datetime.datetime(2019, 6, 11))
        self.assertLess(len(db.token_to_entries), original_length)

        self.assertFalse(db.token_to_entries[0])
        self.assertEqual(db.token_to_entries[0x31631781][0].string, '%d')
        self.assertFalse(db.token_to_entries[0x2e668cd6])
        self.assertEqual(db.token_to_entries[0xb3653e13][0].string, 'Jello!')
        self.assertEqual(db.token_to_entries[0xcc6d3131][0].string, 'Jello?')
        self.assertFalse(db.token_to_entries[0xe65aefef])

    def test_merge(self):
        """Tests the tokens.Database merge method."""

        db = tokens.Database()

        # Test basic merging into an empty database.
        db.merge(
            tokens.Database([
                tokens.TokenizedStringEntry(
                    1, 'one', date_removed=datetime.datetime.min),
                tokens.TokenizedStringEntry(
                    2, 'two', date_removed=datetime.datetime.min),
            ]))
        self.assertEqual({str(e) for e in db.entries()}, {'one', 'two'})
        self.assertEqual(db.token_to_entries[1][0].date_removed,
                         datetime.datetime.min)
        self.assertEqual(db.token_to_entries[2][0].date_removed,
                         datetime.datetime.min)

        # Test merging in an entry with a removal date.
        db.merge(
            tokens.Database([
                tokens.TokenizedStringEntry(3, 'three'),
                tokens.TokenizedStringEntry(
                    4, 'four', date_removed=datetime.datetime.min),
            ]))
        self.assertEqual({str(e)
                          for e in db.entries()},
                         {'one', 'two', 'three', 'four'})
        self.assertIsNone(db.token_to_entries[3][0].date_removed)
        self.assertEqual(db.token_to_entries[4][0].date_removed,
                         datetime.datetime.min)

        # Test merging in one entry.
        db.merge(tokens.Database([
            tokens.TokenizedStringEntry(5, 'five'),
        ]))
        self.assertEqual({str(e)
                          for e in db.entries()},
                         {'one', 'two', 'three', 'four', 'five'})
        self.assertEqual(db.token_to_entries[4][0].date_removed,
                         datetime.datetime.min)
        self.assertIsNone(db.token_to_entries[5][0].date_removed)

        # Merge in repeated entries different removal dates.
        db.merge(
            tokens.Database([
                tokens.TokenizedStringEntry(
                    4, 'four', date_removed=datetime.datetime.max),
                tokens.TokenizedStringEntry(
                    5, 'five', date_removed=datetime.datetime.max),
            ]))
        self.assertEqual(len(db.entries()), 5)
        self.assertEqual({str(e)
                          for e in db.entries()},
                         {'one', 'two', 'three', 'four', 'five'})
        self.assertEqual(db.token_to_entries[4][0].date_removed,
                         datetime.datetime.max)
        self.assertIsNone(db.token_to_entries[5][0].date_removed)

        # Merge in the same repeated entries now without removal dates.
        db.merge(
            tokens.Database([
                tokens.TokenizedStringEntry(4, 'four'),
                tokens.TokenizedStringEntry(5, 'five')
            ]))
        self.assertEqual(len(db.entries()), 5)
        self.assertEqual({str(e)
                          for e in db.entries()},
                         {'one', 'two', 'three', 'four', 'five'})
        self.assertIsNone(db.token_to_entries[4][0].date_removed)
        self.assertIsNone(db.token_to_entries[5][0].date_removed)

        # Merge in an empty databsse.
        db.merge(tokens.Database([]))
        self.assertEqual({str(e)
                          for e in db.entries()},
                         {'one', 'two', 'three', 'four', 'five'})

    def test_merge_multiple_datbases_in_one_call(self):
        """Tests the merge and merged methods with multiple databases."""
        db = tokens.Database.merged(
            tokens.Database([
                tokens.TokenizedStringEntry(1,
                                            'one',
                                            date_removed=datetime.datetime.max)
            ]),
            tokens.Database([
                tokens.TokenizedStringEntry(2,
                                            'two',
                                            date_removed=datetime.datetime.min)
            ]),
            tokens.Database([
                tokens.TokenizedStringEntry(1,
                                            'one',
                                            date_removed=datetime.datetime.min)
            ]))
        self.assertEqual({str(e) for e in db.entries()}, {'one', 'two'})

        db.merge(
            tokens.Database([
                tokens.TokenizedStringEntry(4,
                                            'four',
                                            date_removed=datetime.datetime.max)
            ]),
            tokens.Database([
                tokens.TokenizedStringEntry(2,
                                            'two',
                                            date_removed=datetime.datetime.max)
            ]),
            tokens.Database([
                tokens.TokenizedStringEntry(3,
                                            'three',
                                            date_removed=datetime.datetime.min)
            ]))
        self.assertEqual({str(e)
                          for e in db.entries()},
                         {'one', 'two', 'three', 'four'})

    def test_entry_counts(self):
        self.assertEqual(len(CSV_DATABASE.splitlines()), 16)

        db = read_db_from_csv(CSV_DATABASE)
        self.assertEqual(len(db.entries()), 16)
        self.assertEqual(len(db.token_to_entries), 16)

        # Add two strings with the same hash.
        db.add(_entries('o000', '0Q1Q'))

        self.assertEqual(len(db.entries()), 18)
        self.assertEqual(len(db.token_to_entries), 17)

    def test_mark_removals(self):
        """Tests that date_removed field is set by mark_removals."""
        db = tokens.Database.from_strings(
            ['MILK', 'apples', 'oranges', 'CHEESE', 'pears'])

        self.assertTrue(
            all(entry.date_removed is None for entry in db.entries()))
        date_1 = datetime.datetime(1, 2, 3)

        db.mark_removals(_entries('apples', 'oranges', 'pears'), date_1)

        self.assertEqual(
            db.token_to_entries[default_hash('MILK')][0].date_removed, date_1)
        self.assertEqual(
            db.token_to_entries[default_hash('CHEESE')][0].date_removed,
            date_1)

        now = datetime.datetime.now()
        db.mark_removals(_entries('MILK', 'CHEESE', 'pears'))

        # New strings are not added or re-added in mark_removed().
        self.assertGreaterEqual(
            db.token_to_entries[default_hash('MILK')][0].date_removed, date_1)
        self.assertGreaterEqual(
            db.token_to_entries[default_hash('CHEESE')][0].date_removed,
            date_1)

        # These strings were removed.
        self.assertGreaterEqual(
            db.token_to_entries[default_hash('apples')][0].date_removed, now)
        self.assertGreaterEqual(
            db.token_to_entries[default_hash('oranges')][0].date_removed, now)
        self.assertIsNone(
            db.token_to_entries[default_hash('pears')][0].date_removed)

    def test_add(self):
        db = tokens.Database()
        db.add(_entries('MILK', 'apples'))
        self.assertEqual({e.string for e in db.entries()}, {'MILK', 'apples'})

        db.add(_entries('oranges', 'CHEESE', 'pears'))
        self.assertEqual(len(db.entries()), 5)

        db.add(_entries('MILK', 'apples', 'only this one is new'))
        self.assertEqual(len(db.entries()), 6)

        db.add(_entries('MILK'))
        self.assertEqual({e.string
                          for e in db.entries()}, {
                              'MILK', 'apples', 'oranges', 'CHEESE', 'pears',
                              'only this one is new'
                          })

    def test_binary_format_write(self):
        db = read_db_from_csv(CSV_DATABASE)

        with io.BytesIO() as fd:
            tokens.write_binary(db, fd)
            binary_db = fd.getvalue()

        self.assertEqual(BINARY_DATABASE, binary_db)

    def test_binary_format_parse(self):
        with io.BytesIO(BINARY_DATABASE) as binary_db:
            db = tokens.Database(tokens.parse_binary(binary_db))

        self.assertEqual(str(db), CSV_DATABASE)


class TestDatabaseFile(unittest.TestCase):
    """Tests the DatabaseFile class."""
    def setUp(self):
        file = tempfile.NamedTemporaryFile(delete=False)
        file.close()
        self._path = Path(file.name)

    def tearDown(self):
        self._path.unlink()

    def test_update_csv_file(self):
        self._path.write_text(CSV_DATABASE)
        db = tokens.DatabaseFile(self._path)
        self.assertEqual(str(db), CSV_DATABASE)

        db.add([tokens.TokenizedStringEntry(0xffffffff, 'New entry!')])

        db.write_to_file()

        self.assertEqual(self._path.read_text(),
                         CSV_DATABASE + 'ffffffff,          ,"New entry!"\n')

    def test_csv_file_too_short_raises_exception(self):
        self._path.write_text('1234')

        with self.assertRaises(tokens.DatabaseFormatError):
            tokens.DatabaseFile(self._path)

    def test_csv_invalid_format_raises_exception(self):
        self._path.write_text('MK34567890')

        with self.assertRaises(tokens.DatabaseFormatError):
            tokens.DatabaseFile(self._path)

    def test_csv_not_utf8(self):
        self._path.write_bytes(b'\x80' * 20)

        with self.assertRaises(tokens.DatabaseFormatError):
            tokens.DatabaseFile(self._path)


class TestFilter(unittest.TestCase):
    """Tests the filtering functionality."""
    def setUp(self):
        self.db = tokens.Database([
            tokens.TokenizedStringEntry(1, 'Luke'),
            tokens.TokenizedStringEntry(2, 'Leia'),
            tokens.TokenizedStringEntry(2, 'Darth Vader'),
            tokens.TokenizedStringEntry(2, 'Emperor Palpatine'),
            tokens.TokenizedStringEntry(3, 'Han'),
            tokens.TokenizedStringEntry(4, 'Chewbacca'),
            tokens.TokenizedStringEntry(5, 'Darth Maul'),
            tokens.TokenizedStringEntry(6, 'Han Solo'),
        ])

    def test_filter_include_single_regex(self):
        self.db.filter(include=[' '])  # anything with a space
        self.assertEqual(
            set(e.string for e in self.db.entries()),
            {'Darth Vader', 'Emperor Palpatine', 'Darth Maul', 'Han Solo'})

    def test_filter_include_multiple_regexes(self):
        self.db.filter(include=['Darth', 'cc', '^Han$'])
        self.assertEqual(set(e.string for e in self.db.entries()),
                         {'Darth Vader', 'Darth Maul', 'Han', 'Chewbacca'})

    def test_filter_include_no_matches(self):
        self.db.filter(include=['Gandalf'])
        self.assertFalse(self.db.entries())

    def test_filter_exclude_single_regex(self):
        self.db.filter(exclude=['^[^L]'])
        self.assertEqual(set(e.string for e in self.db.entries()),
                         {'Luke', 'Leia'})

    def test_filter_exclude_multiple_regexes(self):
        self.db.filter(exclude=[' ', 'Han', 'Chewbacca'])
        self.assertEqual(set(e.string for e in self.db.entries()),
                         {'Luke', 'Leia'})

    def test_filter_exclude_no_matches(self):
        self.db.filter(exclude=['.*'])
        self.assertFalse(self.db.entries())

    def test_filter_include_and_exclude(self):
        self.db.filter(include=[' '], exclude=['Darth', 'Emperor'])
        self.assertEqual(set(e.string for e in self.db.entries()),
                         {'Han Solo'})

    def test_filter_neither_include_nor_exclude(self):
        self.db.filter()
        self.assertEqual(
            set(e.string for e in self.db.entries()), {
                'Luke', 'Leia', 'Darth Vader', 'Emperor Palpatine', 'Han',
                'Chewbacca', 'Darth Maul', 'Han Solo'
            })


if __name__ == '__main__':
    unittest.main()