import tempfile
import unittest
from pathlib import Path

from bpython.config import getpreferredencoding
from bpython.history import History


class TestHistory(unittest.TestCase):
    def setUp(self):
        self.history = History(f"#{x}" for x in range(1000))

    def test_is_at_start(self):
        self.history.first()

        self.assertNotEqual(self.history.index, 0)
        self.assertTrue(self.history.is_at_end)
        self.history.forward()
        self.assertFalse(self.history.is_at_end)

    def test_is_at_end(self):
        self.history.last()

        self.assertEqual(self.history.index, 0)
        self.assertTrue(self.history.is_at_start)
        self.assertFalse(self.history.is_at_end)

    def test_first(self):
        self.history.first()

        self.assertFalse(self.history.is_at_start)
        self.assertTrue(self.history.is_at_end)

    def test_last(self):
        self.history.last()

        self.assertTrue(self.history.is_at_start)
        self.assertFalse(self.history.is_at_end)

    def test_back(self):
        self.assertEqual(self.history.back(), "#999")
        self.assertNotEqual(self.history.back(), "#999")
        self.assertEqual(self.history.back(), "#997")
        for x in range(997):
            self.history.back()
        self.assertEqual(self.history.back(), "#0")

    def test_forward(self):
        self.history.first()

        self.assertEqual(self.history.forward(), "#1")
        self.assertNotEqual(self.history.forward(), "#1")
        self.assertEqual(self.history.forward(), "#3")
        #  1000 == entries   4 == len(range(1, 3) ===> '#1000' (so +1)
        for x in range(1000 - 4 - 1):
            self.history.forward()
        self.assertEqual(self.history.forward(), "#999")

    def test_append(self):
        self.history.append('print "foo\n"\n')
        self.history.append("\n")

        self.assertEqual(self.history.back(), 'print "foo\n"')

    def test_enter(self):
        self.history.enter("#lastnumber!")

        self.assertEqual(self.history.back(), "#lastnumber!")
        self.assertEqual(self.history.forward(), "#lastnumber!")

    def test_enter_2(self):
        self.history.enter("#50")

        self.assertEqual(self.history.back(), "#509")
        self.assertEqual(self.history.back(), "#508")
        self.assertEqual(self.history.forward(), "#509")

    def test_reset(self):
        self.history.enter("#lastnumber!")
        self.history.reset()

        self.assertEqual(self.history.back(), "#999")
        self.assertEqual(self.history.forward(), "")


class TestHistoryFileAccess(unittest.TestCase):
    def setUp(self):
        self.tempdir = tempfile.TemporaryDirectory()
        self.filename = str(Path(self.tempdir.name) / "history_temp_file")
        self.encoding = getpreferredencoding()

        with open(
            self.filename, "w", encoding=self.encoding, errors="ignore"
        ) as f:
            f.write(b"#1\n#2\n".decode())

    def test_load(self):
        history = History()

        history.load(self.filename, self.encoding)
        self.assertEqual(history.entries, ["#1", "#2"])

    def test_append_reload_and_write(self):
        history = History()

        history.append_reload_and_write("#3", self.filename, self.encoding)
        self.assertEqual(history.entries, ["#1", "#2", "#3"])

        history.append_reload_and_write("#4", self.filename, self.encoding)
        self.assertEqual(history.entries, ["#1", "#2", "#3", "#4"])

    def test_save(self):
        history = History()
        for line in ("#1", "#2", "#3", "#4"):
            history.append_to(history.entries, line)

        # save only last 2 lines
        history.save(self.filename, self.encoding, lines=2)

        # load again from the file
        history = History()
        history.load(self.filename, self.encoding)

        self.assertEqual(history.entries, ["#3", "#4"])

    def tearDown(self):
        self.tempdir = None