import importlib
import codecs
import time
import unicodedata
import pytest
import numpy as np
from numpy.f2py.crackfortran import markinnerspaces, nameargspattern
from . import util
from numpy.f2py import crackfortran
import textwrap


class TestNoSpace(util.F2PyTest):
    # issue gh-15035: add handling for endsubroutine, endfunction with no space
    # between "end" and the block name
    sources = [util.getpath("tests", "src", "crackfortran", "gh15035.f")]

    def test_module(self):
        k = np.array([1, 2, 3], dtype=np.float64)
        w = np.array([1, 2, 3], dtype=np.float64)
        self.module.subb(k)
        assert np.allclose(k, w + 1)
        self.module.subc([w, k])
        assert np.allclose(k, w + 1)
        assert self.module.t0("23") == b"2"


class TestPublicPrivate:
    def test_defaultPrivate(self):
        fpath = util.getpath("tests", "src", "crackfortran", "privatemod.f90")
        mod = crackfortran.crackfortran([str(fpath)])
        assert len(mod) == 1
        mod = mod[0]
        assert "private" in mod["vars"]["a"]["attrspec"]
        assert "public" not in mod["vars"]["a"]["attrspec"]
        assert "private" in mod["vars"]["b"]["attrspec"]
        assert "public" not in mod["vars"]["b"]["attrspec"]
        assert "private" not in mod["vars"]["seta"]["attrspec"]
        assert "public" in mod["vars"]["seta"]["attrspec"]

    def test_defaultPublic(self, tmp_path):
        fpath = util.getpath("tests", "src", "crackfortran", "publicmod.f90")
        mod = crackfortran.crackfortran([str(fpath)])
        assert len(mod) == 1
        mod = mod[0]
        assert "private" in mod["vars"]["a"]["attrspec"]
        assert "public" not in mod["vars"]["a"]["attrspec"]
        assert "private" not in mod["vars"]["seta"]["attrspec"]
        assert "public" in mod["vars"]["seta"]["attrspec"]

    def test_access_type(self, tmp_path):
        fpath = util.getpath("tests", "src", "crackfortran", "accesstype.f90")
        mod = crackfortran.crackfortran([str(fpath)])
        assert len(mod) == 1
        tt = mod[0]['vars']
        assert set(tt['a']['attrspec']) == {'private', 'bind(c)'}
        assert set(tt['b_']['attrspec']) == {'public', 'bind(c)'}
        assert set(tt['c']['attrspec']) == {'public'}

    def test_nowrap_private_proceedures(self, tmp_path):
        fpath = util.getpath("tests", "src", "crackfortran", "gh23879.f90")
        mod = crackfortran.crackfortran([str(fpath)])
        assert len(mod) == 1
        pyf = crackfortran.crack2fortran(mod)
        assert 'bar' not in pyf

class TestModuleProcedure():
    def test_moduleOperators(self, tmp_path):
        fpath = util.getpath("tests", "src", "crackfortran", "operators.f90")
        mod = crackfortran.crackfortran([str(fpath)])
        assert len(mod) == 1
        mod = mod[0]
        assert "body" in mod and len(mod["body"]) == 9
        assert mod["body"][1]["name"] == "operator(.item.)"
        assert "implementedby" in mod["body"][1]
        assert mod["body"][1]["implementedby"] == \
            ["item_int", "item_real"]
        assert mod["body"][2]["name"] == "operator(==)"
        assert "implementedby" in mod["body"][2]
        assert mod["body"][2]["implementedby"] == ["items_are_equal"]
        assert mod["body"][3]["name"] == "assignment(=)"
        assert "implementedby" in mod["body"][3]
        assert mod["body"][3]["implementedby"] == \
            ["get_int", "get_real"]

    def test_notPublicPrivate(self, tmp_path):
        fpath = util.getpath("tests", "src", "crackfortran", "pubprivmod.f90")
        mod = crackfortran.crackfortran([str(fpath)])
        assert len(mod) == 1
        mod = mod[0]
        assert mod['vars']['a']['attrspec'] == ['private', ]
        assert mod['vars']['b']['attrspec'] == ['public', ]
        assert mod['vars']['seta']['attrspec'] == ['public', ]


class TestExternal(util.F2PyTest):
    # issue gh-17859: add external attribute support
    sources = [util.getpath("tests", "src", "crackfortran", "gh17859.f")]

    def test_external_as_statement(self):
        def incr(x):
            return x + 123

        r = self.module.external_as_statement(incr)
        assert r == 123

    def test_external_as_attribute(self):
        def incr(x):
            return x + 123

        r = self.module.external_as_attribute(incr)
        assert r == 123


class TestCrackFortran(util.F2PyTest):
    # gh-2848: commented lines between parameters in subroutine parameter lists
    sources = [util.getpath("tests", "src", "crackfortran", "gh2848.f90")]

    def test_gh2848(self):
        r = self.module.gh2848(1, 2)
        assert r == (1, 2)


class TestMarkinnerspaces:
    # gh-14118: markinnerspaces does not handle multiple quotations

    def test_do_not_touch_normal_spaces(self):
        test_list = ["a ", " a", "a b c", "'abcdefghij'"]
        for i in test_list:
            assert markinnerspaces(i) == i

    def test_one_relevant_space(self):
        assert markinnerspaces("a 'b c' \\' \\'") == "a 'b@_@c' \\' \\'"
        assert markinnerspaces(r'a "b c" \" \"') == r'a "b@_@c" \" \"'

    def test_ignore_inner_quotes(self):
        assert markinnerspaces("a 'b c\" \" d' e") == "a 'b@_@c\"@_@\"@_@d' e"
        assert markinnerspaces("a \"b c' ' d\" e") == "a \"b@_@c'@_@'@_@d\" e"

    def test_multiple_relevant_spaces(self):
        assert markinnerspaces("a 'b c' 'd e'") == "a 'b@_@c' 'd@_@e'"
        assert markinnerspaces(r'a "b c" "d e"') == r'a "b@_@c" "d@_@e"'


class TestDimSpec(util.F2PyTest):
    """This test suite tests various expressions that are used as dimension
    specifications.

    There exists two usage cases where analyzing dimensions
    specifications are important.

    In the first case, the size of output arrays must be defined based
    on the inputs to a Fortran function. Because Fortran supports
    arbitrary bases for indexing, for instance, `arr(lower:upper)`,
    f2py has to evaluate an expression `upper - lower + 1` where
    `lower` and `upper` are arbitrary expressions of input parameters.
    The evaluation is performed in C, so f2py has to translate Fortran
    expressions to valid C expressions (an alternative approach is
    that a developer specifies the corresponding C expressions in a
    .pyf file).

    In the second case, when user provides an input array with a given
    size but some hidden parameters used in dimensions specifications
    need to be determined based on the input array size. This is a
    harder problem because f2py has to solve the inverse problem: find
    a parameter `p` such that `upper(p) - lower(p) + 1` equals to the
    size of input array. In the case when this equation cannot be
    solved (e.g. because the input array size is wrong), raise an
    error before calling the Fortran function (that otherwise would
    likely crash Python process when the size of input arrays is
    wrong). f2py currently supports this case only when the equation
    is linear with respect to unknown parameter.

    """

    suffix = ".f90"

    code_template = textwrap.dedent("""
      function get_arr_size_{count}(a, n) result (length)
        integer, intent(in) :: n
        integer, dimension({dimspec}), intent(out) :: a
        integer length
        length = size(a)
      end function

      subroutine get_inv_arr_size_{count}(a, n)
        integer :: n
        ! the value of n is computed in f2py wrapper
        !f2py intent(out) n
        integer, dimension({dimspec}), intent(in) :: a
      end subroutine
    """)

    linear_dimspecs = [
        "n", "2*n", "2:n", "n/2", "5 - n/2", "3*n:20", "n*(n+1):n*(n+5)",
        "2*n, n"
    ]
    nonlinear_dimspecs = ["2*n:3*n*n+2*n"]
    all_dimspecs = linear_dimspecs + nonlinear_dimspecs

    code = ""
    for count, dimspec in enumerate(all_dimspecs):
        lst = [(d.split(":")[0] if ":" in d else "1") for d in dimspec.split(',')]
        code += code_template.format(
            count=count,
            dimspec=dimspec,
            first=", ".join(lst),
        )

    @pytest.mark.parametrize("dimspec", all_dimspecs)
    def test_array_size(self, dimspec):

        count = self.all_dimspecs.index(dimspec)
        get_arr_size = getattr(self.module, f"get_arr_size_{count}")

        for n in [1, 2, 3, 4, 5]:
            sz, a = get_arr_size(n)
            assert a.size == sz

    @pytest.mark.parametrize("dimspec", all_dimspecs)
    def test_inv_array_size(self, dimspec):

        count = self.all_dimspecs.index(dimspec)
        get_arr_size = getattr(self.module, f"get_arr_size_{count}")
        get_inv_arr_size = getattr(self.module, f"get_inv_arr_size_{count}")

        for n in [1, 2, 3, 4, 5]:
            sz, a = get_arr_size(n)
            if dimspec in self.nonlinear_dimspecs:
                # one must specify n as input, the call we'll ensure
                # that a and n are compatible:
                n1 = get_inv_arr_size(a, n)
            else:
                # in case of linear dependence, n can be determined
                # from the shape of a:
                n1 = get_inv_arr_size(a)
            # n1 may be different from n (for instance, when `a` size
            # is a function of some `n` fraction) but it must produce
            # the same sized array
            sz1, _ = get_arr_size(n1)
            assert sz == sz1, (n, n1, sz, sz1)


class TestModuleDeclaration:
    def test_dependencies(self, tmp_path):
        fpath = util.getpath("tests", "src", "crackfortran", "foo_deps.f90")
        mod = crackfortran.crackfortran([str(fpath)])
        assert len(mod) == 1
        assert mod[0]["vars"]["abar"]["="] == "bar('abar')"


class TestEval(util.F2PyTest):
    def test_eval_scalar(self):
        eval_scalar = crackfortran._eval_scalar

        assert eval_scalar('123', {}) == '123'
        assert eval_scalar('12 + 3', {}) == '15'
        assert eval_scalar('a + b', dict(a=1, b=2)) == '3'
        assert eval_scalar('"123"', {}) == "'123'"


class TestFortranReader(util.F2PyTest):
    @pytest.mark.parametrize("encoding",
                             ['ascii', 'utf-8', 'utf-16', 'utf-32'])
    def test_input_encoding(self, tmp_path, encoding):
        # gh-635
        f_path = tmp_path / f"input_with_{encoding}_encoding.f90"
        with f_path.open('w', encoding=encoding) as ff:
            ff.write("""
                     subroutine foo()
                     end subroutine foo
                     """)
        mod = crackfortran.crackfortran([str(f_path)])
        assert mod[0]['name'] == 'foo'


class TestUnicodeComment(util.F2PyTest):
    sources = [util.getpath("tests", "src", "crackfortran", "unicode_comment.f90")]

    @pytest.mark.skipif(
        (importlib.util.find_spec("charset_normalizer") is None),
        reason="test requires charset_normalizer which is not installed",
    )
    def test_encoding_comment(self):
        self.module.foo(3)


class TestNameArgsPatternBacktracking:
    @pytest.mark.parametrize(
        ['adversary'],
        [
            ('@)@bind@(@',),
            ('@)@bind                         @(@',),
            ('@)@bind foo bar baz@(@',)
        ]
    )
    def test_nameargspattern_backtracking(self, adversary):
        '''address ReDOS vulnerability:
        https://github.com/numpy/numpy/issues/23338'''
        trials_per_batch = 12
        batches_per_regex = 4
        start_reps, end_reps = 15, 25
        for ii in range(start_reps, end_reps):
            repeated_adversary = adversary * ii
            # test times in small batches.
            # this gives us more chances to catch a bad regex
            # while still catching it before too long if it is bad
            for _ in range(batches_per_regex):
                times = []
                for _ in range(trials_per_batch):
                    t0 = time.perf_counter()
                    mtch = nameargspattern.search(repeated_adversary)
                    times.append(time.perf_counter() - t0)
                # our pattern should be much faster than 0.2s per search
                # it's unlikely that a bad regex will pass even on fast CPUs
                assert np.median(times) < 0.2
            assert not mtch
            # if the adversary is capped with @)@, it becomes acceptable
            # according to the old version of the regex.
            # that should still be true.
            good_version_of_adversary = repeated_adversary + '@)@'
            assert nameargspattern.search(good_version_of_adversary)


class TestFunctionReturn(util.F2PyTest):
    sources = [util.getpath("tests", "src", "crackfortran", "gh23598.f90")]

    def test_function_rettype(self):
        # gh-23598
        assert self.module.intproduct(3, 4) == 12


class TestFortranGroupCounters(util.F2PyTest):
    def test_end_if_comment(self):
        # gh-23533
        fpath = util.getpath("tests", "src", "crackfortran", "gh23533.f")
        try:
            crackfortran.crackfortran([str(fpath)])
        except Exception as exc:
            assert False, f"'crackfortran.crackfortran' raised an exception {exc}"
