'''Test functions and SearchEngine class in SearchEngine.py.'''

# With mock replacements, the module does not use any gui widgets.
# The use of tk.Text is avoided (for now, until mock Text is improved)
# by patching instances with an index function returning what is needed.
# This works because mock Text.get does not use .index.

import re
import unittest
# from test.support import requires
from tkinter import  BooleanVar, StringVar, TclError  # ,Tk, Text
import tkinter.messagebox as tkMessageBox
from idlelib import SearchEngine as se
from idlelib.idle_test.mock_tk import Var, Mbox
from idlelib.idle_test.mock_tk import Text as mockText

def setUpModule():
    # Replace s-e module tkinter imports other than non-gui TclError.
    se.BooleanVar = Var
    se.StringVar = Var
    se.tkMessageBox = Mbox

def tearDownModule():
    # Restore 'just in case', though other tests should also replace.
    se.BooleanVar = BooleanVar
    se.StringVar = StringVar
    se.tkMessageBox = tkMessageBox


class Mock:
    def __init__(self, *args, **kwargs): pass

class GetTest(unittest.TestCase):
    # SearchEngine.get returns singleton created & saved on first call.
    def test_get(self):
        saved_Engine = se.SearchEngine
        se.SearchEngine = Mock  # monkey-patch class
        try:
            root = Mock()
            engine = se.get(root)
            self.assertIsInstance(engine, se.SearchEngine)
            self.assertIs(root._searchengine, engine)
            self.assertIs(se.get(root), engine)
        finally:
            se.SearchEngine = saved_Engine  # restore class to module

class GetLineColTest(unittest.TestCase):
    #  Test simple text-independent helper function
    def test_get_line_col(self):
        self.assertEqual(se.get_line_col('1.0'), (1, 0))
        self.assertEqual(se.get_line_col('1.11'), (1, 11))

        self.assertRaises(ValueError, se.get_line_col, ('1.0 lineend'))
        self.assertRaises(ValueError, se.get_line_col, ('end'))

class GetSelectionTest(unittest.TestCase):
    # Test text-dependent helper function.
##    # Need gui for text.index('sel.first/sel.last/insert').
##    @classmethod
##    def setUpClass(cls):
##        requires('gui')
##        cls.root = Tk()
##
##    @classmethod
##    def tearDownClass(cls):
##        cls.root.destroy()
##        del cls.root

    def test_get_selection(self):
        # text = Text(master=self.root)
        text = mockText()
        text.insert('1.0',  'Hello World!')

        # fix text.index result when called in get_selection
        def sel(s):
            # select entire text, cursor irrelevant
            if s == 'sel.first': return '1.0'
            if s == 'sel.last': return '1.12'
            raise TclError
        text.index = sel  # replaces .tag_add('sel', '1.0, '1.12')
        self.assertEqual(se.get_selection(text), ('1.0', '1.12'))

        def mark(s):
            # no selection, cursor after 'Hello'
            if s == 'insert': return '1.5'
            raise TclError
        text.index = mark  # replaces .mark_set('insert', '1.5')
        self.assertEqual(se.get_selection(text), ('1.5', '1.5'))


class ReverseSearchTest(unittest.TestCase):
    # Test helper function that searches backwards within a line.
    def test_search_reverse(self):
        Equal = self.assertEqual
        line = "Here is an 'is' test text."
        prog = re.compile('is')
        Equal(se.search_reverse(prog, line, len(line)).span(), (12, 14))
        Equal(se.search_reverse(prog, line, 14).span(), (12, 14))
        Equal(se.search_reverse(prog, line, 13).span(), (5, 7))
        Equal(se.search_reverse(prog, line, 7).span(), (5, 7))
        Equal(se.search_reverse(prog, line, 6), None)


class SearchEngineTest(unittest.TestCase):
    # Test class methods that do not use Text widget.

    def setUp(self):
        self.engine = se.SearchEngine(root=None)
        # Engine.root is only used to create error message boxes.
        # The mock replacement ignores the root argument.

    def test_is_get(self):
        engine = self.engine
        Equal = self.assertEqual

        Equal(engine.getpat(), '')
        engine.setpat('hello')
        Equal(engine.getpat(), 'hello')

        Equal(engine.isre(), False)
        engine.revar.set(1)
        Equal(engine.isre(), True)

        Equal(engine.iscase(), False)
        engine.casevar.set(1)
        Equal(engine.iscase(), True)

        Equal(engine.isword(), False)
        engine.wordvar.set(1)
        Equal(engine.isword(), True)

        Equal(engine.iswrap(), True)
        engine.wrapvar.set(0)
        Equal(engine.iswrap(), False)

        Equal(engine.isback(), False)
        engine.backvar.set(1)
        Equal(engine.isback(), True)

    def test_setcookedpat(self):
        engine = self.engine
        engine.setcookedpat('\s')
        self.assertEqual(engine.getpat(), '\s')
        engine.revar.set(1)
        engine.setcookedpat('\s')
        self.assertEqual(engine.getpat(), r'\\s')

    def test_getcookedpat(self):
        engine = self.engine
        Equal = self.assertEqual

        Equal(engine.getcookedpat(), '')
        engine.setpat('hello')
        Equal(engine.getcookedpat(), 'hello')
        engine.wordvar.set(True)
        Equal(engine.getcookedpat(), r'\bhello\b')
        engine.wordvar.set(False)

        engine.setpat('\s')
        Equal(engine.getcookedpat(), r'\\s')
        engine.revar.set(True)
        Equal(engine.getcookedpat(), '\s')

    def test_getprog(self):
        engine = self.engine
        Equal = self.assertEqual

        engine.setpat('Hello')
        temppat = engine.getprog()
        Equal(temppat.pattern, re.compile('Hello', re.IGNORECASE).pattern)
        engine.casevar.set(1)
        temppat = engine.getprog()
        Equal(temppat.pattern, re.compile('Hello').pattern, 0)

        engine.setpat('')
        Equal(engine.getprog(), None)
        engine.setpat('+')
        engine.revar.set(1)
        Equal(engine.getprog(), None)
        self.assertEqual(Mbox.showerror.message,
                         'Error: nothing to repeat at position 0\nPattern: +')

    def test_report_error(self):
        showerror = Mbox.showerror
        Equal = self.assertEqual
        pat = '[a-z'
        msg = 'unexpected end of regular expression'

        Equal(self.engine.report_error(pat, msg), None)
        Equal(showerror.title, 'Regular expression error')
        expected_message = ("Error: " + msg + "\nPattern: [a-z")
        Equal(showerror.message, expected_message)

        Equal(self.engine.report_error(pat, msg, 5), None)
        Equal(showerror.title, 'Regular expression error')
        expected_message += "\nOffset: 5"
        Equal(showerror.message, expected_message)


class SearchTest(unittest.TestCase):
    # Test that search_text makes right call to right method.

    @classmethod
    def setUpClass(cls):
##        requires('gui')
##        cls.root = Tk()
##        cls.text = Text(master=cls.root)
        cls.text = mockText()
        test_text = (
            'First line\n'
            'Line with target\n'
            'Last line\n')
        cls.text.insert('1.0', test_text)
        cls.pat = re.compile('target')

        cls.engine = se.SearchEngine(None)
        cls.engine.search_forward = lambda *args: ('f', args)
        cls.engine.search_backward = lambda *args: ('b', args)

##    @classmethod
##    def tearDownClass(cls):
##        cls.root.destroy()
##        del cls.root

    def test_search(self):
        Equal = self.assertEqual
        engine = self.engine
        search = engine.search_text
        text = self.text
        pat = self.pat

        engine.patvar.set(None)
        #engine.revar.set(pat)
        Equal(search(text), None)

        def mark(s):
            # no selection, cursor after 'Hello'
            if s == 'insert': return '1.5'
            raise TclError
        text.index = mark
        Equal(search(text, pat), ('f', (text, pat, 1, 5, True, False)))
        engine.wrapvar.set(False)
        Equal(search(text, pat), ('f', (text, pat, 1, 5, False, False)))
        engine.wrapvar.set(True)
        engine.backvar.set(True)
        Equal(search(text, pat), ('b', (text, pat, 1, 5, True, False)))
        engine.backvar.set(False)

        def sel(s):
            if s == 'sel.first': return '2.10'
            if s == 'sel.last': return '2.16'
            raise TclError
        text.index = sel
        Equal(search(text, pat), ('f', (text, pat, 2, 16, True, False)))
        Equal(search(text, pat, True), ('f', (text, pat, 2, 10, True, True)))
        engine.backvar.set(True)
        Equal(search(text, pat), ('b', (text, pat, 2, 10, True, False)))
        Equal(search(text, pat, True), ('b', (text, pat, 2, 16, True, True)))


class ForwardBackwardTest(unittest.TestCase):
    # Test that search_forward method finds the target.
##    @classmethod
##    def tearDownClass(cls):
##        cls.root.destroy()
##        del cls.root

    @classmethod
    def setUpClass(cls):
        cls.engine = se.SearchEngine(None)
##        requires('gui')
##        cls.root = Tk()
##        cls.text = Text(master=cls.root)
        cls.text = mockText()
        # search_backward calls index('end-1c')
        cls.text.index = lambda index: '4.0'
        test_text = (
            'First line\n'
            'Line with target\n'
            'Last line\n')
        cls.text.insert('1.0', test_text)
        cls.pat = re.compile('target')
        cls.res = (2, (10, 16))  # line, slice indexes of 'target'
        cls.failpat = re.compile('xyz')  # not in text
        cls.emptypat = re.compile('\w*')  # empty match possible

    def make_search(self, func):
        def search(pat, line, col, wrap, ok=0):
            res = func(self.text, pat, line, col, wrap, ok)
            # res is (line, matchobject) or None
            return (res[0], res[1].span()) if res else res
        return search

    def test_search_forward(self):
        # search for non-empty match
        Equal = self.assertEqual
        forward = self.make_search(self.engine.search_forward)
        pat = self.pat
        Equal(forward(pat, 1, 0, True), self.res)
        Equal(forward(pat, 3, 0, True), self.res)  # wrap
        Equal(forward(pat, 3, 0, False), None)  # no wrap
        Equal(forward(pat, 2, 10, False), self.res)

        Equal(forward(self.failpat, 1, 0, True), None)
        Equal(forward(self.emptypat, 2,  9, True, ok=True), (2, (9, 9)))
        #Equal(forward(self.emptypat, 2, 9, True), self.res)
        # While the initial empty match is correctly ignored, skipping
        # the rest of the line and returning (3, (0,4)) seems buggy - tjr.
        Equal(forward(self.emptypat, 2, 10, True), self.res)

    def test_search_backward(self):
        # search for non-empty match
        Equal = self.assertEqual
        backward = self.make_search(self.engine.search_backward)
        pat = self.pat
        Equal(backward(pat, 3, 5, True), self.res)
        Equal(backward(pat, 2, 0, True), self.res)  # wrap
        Equal(backward(pat, 2, 0, False), None)  # no wrap
        Equal(backward(pat, 2, 16, False), self.res)

        Equal(backward(self.failpat, 3, 9, True), None)
        Equal(backward(self.emptypat, 2,  10, True, ok=True), (2, (9,9)))
        # Accepted because 9 < 10, not because ok=True.
        # It is not clear that ok=True is useful going back - tjr
        Equal(backward(self.emptypat, 2, 9, True), (2, (5, 9)))


if __name__ == '__main__':
    unittest.main(verbosity=2, exit=2)