import os
import shutil
import sys
import tempfile
from unittest import mock

from pkgcore import plugin
from snakeoil.osutils import pjoin
from snakeoil.sequences import stable_unique


class LowPlug:
    priority = 1


class TestModules:
    def setup_method(self, method):
        self.dir = tempfile.mkdtemp()
        self.dir2 = tempfile.mkdtemp()

        # force plugin module to use package dir for cache dir by setting
        # system/user cache dirs to nonexistent paths
        self.patcher = mock.patch("pkgcore.plugin.const")
        const = self.patcher.start()
        const.SYSTEM_CACHE_PATH = pjoin(self.dir, "nonexistent")
        const.USER_CACHE_PATH = pjoin(self.dir, "nonexistent")

        # Set up some test modules for our use.
        self.packdir = pjoin(self.dir, "mod_testplug")
        self.packdir2 = pjoin(self.dir2, "mod_testplug")
        os.mkdir(self.packdir)
        os.mkdir(self.packdir2)
        with open(pjoin(self.packdir, "__init__.py"), "w") as init:
            init.write(
                """
from pkgcore.plugins import extend_path

extend_path(__path__, __name__)
"""
            )
        filename = pjoin(self.packdir, "plug.py")
        with open(filename, "w") as plug:
            plug.write(
                """
class DisabledPlug:
    disabled = True

class HighPlug:
    priority = 7

class LowPlug:
    priority = 1

low_plug = LowPlug()
high_plug = HighPlug()

pkgcore_plugins = {
    'plugtest': [
        DisabledPlug,
        high_plug,
        'tests.test_plugin.LowPlug',
    ]
}
"""
            )
        # Move the mtime 2 seconds into the past so the .pyc file has
        # a different mtime.
        st = os.stat(filename)
        os.utime(filename, (st.st_atime, st.st_mtime - 2))
        with open(pjoin(self.packdir, "plug2.py"), "w") as plug2:
            plug2.write("# I do not have any pkgcore_plugins for you!\n")
        with open(pjoin(self.packdir2, "plug.py"), "w") as plug:
            plug.write(
                """
# This file is later on sys.path than the plug.py in packdir, so it should
# not have any effect on the tests.

class HiddenPlug:
    priority = 8

pkgcore_plugins = {'plugtest': [HiddenPlug]}
"""
            )
        # Append it to the path
        sys.path.insert(0, self.dir2)
        sys.path.insert(0, self.dir)

    def teardown_method(self):
        # stop mocked patcher
        self.patcher.stop()
        # pop the test module dir from path
        sys.path.pop(0)
        sys.path.pop(0)
        # and kill it
        shutil.rmtree(self.dir)
        shutil.rmtree(self.dir2)
        # make sure we don't keep the sys.modules entries around
        sys.modules.pop("mod_testplug", None)
        sys.modules.pop("mod_testplug.plug", None)
        sys.modules.pop("mod_testplug.plug2", None)

    def test_extend_path(self):
        import mod_testplug

        expected = stable_unique(
            pjoin(p, "mod_testplug") for p in sys.path if os.path.isdir(p)
        )
        assert expected == mod_testplug.__path__, set(expected) ^ set(
            mod_testplug.__path__
        )

    def _runit(self, method):
        plugin._global_cache.clear()
        method()
        mtime = os.path.getmtime(pjoin(self.packdir, plugin.CACHE_FILENAME))
        method()
        plugin._global_cache.clear()
        method()
        method()
        assert mtime == os.path.getmtime(pjoin(self.packdir, plugin.CACHE_FILENAME))
        # We cannot write this since it contains an unimportable plugin.
        assert not os.path.exists(pjoin(self.packdir2, plugin.CACHE_FILENAME))

    def _test_plug(self):
        import mod_testplug

        assert plugin.get_plugin("spork", mod_testplug) is None
        plugins = list(plugin.get_plugins("plugtest", mod_testplug))
        assert len(plugins) == 2, plugins
        plugin.get_plugin("plugtest", mod_testplug)
        assert (
            "HighPlug" == plugin.get_plugin("plugtest", mod_testplug).__class__.__name__
        )
        with open(pjoin(self.packdir, plugin.CACHE_FILENAME)) as f:
            lines = f.readlines()
        assert len(lines) == 3
        assert plugin.CACHE_HEADER + "\n" == lines[0]
        lines.pop(0)
        lines.sort()
        mtime = int(os.path.getmtime(pjoin(self.packdir, "plug2.py")))
        assert f"plug2:{mtime}:\n" == lines[0]
        mtime = int(os.path.getmtime(pjoin(self.packdir, "plug.py")))
        assert (
            f"plug:{mtime}:plugtest,7,1:plugtest,1,tests.test_plugin.LowPlug:plugtest,0,0\n"
            == lines[1]
        )

    def test_plug(self):
        self._runit(self._test_plug)

    def _test_no_unneeded_import(self):
        import mod_testplug

        list(plugin.get_plugins("spork", mod_testplug))
        sys.modules.pop("mod_testplug.plug")
        # This one is not loaded if we are testing with a good cache.
        sys.modules.pop("mod_testplug.plug2", None)
        list(plugin.get_plugins("plugtest", mod_testplug))
        # Extra messages since getting all of sys.modules printed is annoying.
        assert "mod_testplug.plug" in sys.modules, "plug not loaded"
        assert "mod_testplug.plug2" not in sys.modules, "plug2 loaded"

    def test_no_unneeded_import(self):
        self._runit(self._test_no_unneeded_import)

    def test_cache_corruption(self):
        print(plugin.const)
        print("wheeeeee")
        import mod_testplug

        list(plugin.get_plugins("spork", mod_testplug))
        filename = pjoin(self.packdir, plugin.CACHE_FILENAME)
        cachefile = open(filename, "a")
        try:
            cachefile.write("corruption\n")
        finally:
            cachefile.close()
        # Shift the file into the past a little or the rewritten file
        # will occasionally have the same mtime as the corrupt one.
        st = os.stat(filename)
        corrupt_mtime = st.st_mtime - 2
        os.utime(filename, (st.st_atime, corrupt_mtime))
        plugin._global_cache.clear()
        self._test_plug()
        good_mtime = os.path.getmtime(pjoin(self.packdir, plugin.CACHE_FILENAME))
        plugin._global_cache.clear()
        self._test_plug()
        assert good_mtime == os.path.getmtime(
            pjoin(self.packdir, plugin.CACHE_FILENAME)
        )
        assert good_mtime != corrupt_mtime

    def test_rewrite_on_remove(self):
        filename = pjoin(self.packdir, "extra.py")
        plug = open(filename, "w")
        try:
            plug.write('pkgcore_plugins = {"plugtest": [object()]}\n')
        finally:
            plug.close()

        plugin._global_cache.clear()
        import mod_testplug

        assert len(list(plugin.get_plugins("plugtest", mod_testplug))) == 3

        os.unlink(filename)

        plugin._global_cache.clear()
        self._test_plug()

    def test_priority_caching(self):
        plug3 = open(pjoin(self.packdir, "plug3.py"), "w")
        try:
            plug3.write(
                """
class LowPlug:
    priority = 6

pkgcore_plugins = {
    'plugtest': [LowPlug()],
}
"""
            )
        finally:
            plug3.close()
        plug4 = open(pjoin(self.packdir, "plug4.py"), "w")
        try:
            plug4.write(
                """
# First file tried, only a disabled plugin.
class HighDisabledPlug:
    priority = 15
    disabled = True

pkgcore_plugins = {
    'plugtest': [HighDisabledPlug()],
}
"""
            )
        finally:
            plug4.close()
        plug5 = open(pjoin(self.packdir, "plug5.py"), "w")
        try:
            plug5.write(
                """
# Second file tried, with a skipped low priority plugin.
class HighDisabledPlug:
    priority = 12
    disabled = True

class LowPlug:
    priority = 6

pkgcore_plugins = {
    'plugtest': [HighDisabledPlug(), LowPlug()],
}
"""
            )
        finally:
            plug5.close()
        plug6 = open(pjoin(self.packdir, "plug6.py"), "w")
        try:
            plug6.write(
                """
# Not tried, bogus priority.
class BogusPlug:
    priority = 'spoon'

pkgcore_plugins = {
    'plugtest': [BogusPlug()],
}
"""
            )
        finally:
            plug6.close()
        self._runit(self._test_priority_caching)

    def _test_priority_caching(self):
        import mod_testplug

        list(plugin.get_plugins("spork", mod_testplug))
        sys.modules.pop("mod_testplug.plug", None)
        sys.modules.pop("mod_testplug.plug2", None)
        sys.modules.pop("mod_testplug.plug3", None)
        sys.modules.pop("mod_testplug.plug4", None)
        sys.modules.pop("mod_testplug.plug5", None)
        sys.modules.pop("mod_testplug.plug6", None)
        best_plug = plugin.get_plugin("plugtest", mod_testplug)
        from mod_testplug import plug

        assert plug.high_plug == best_plug
        # Extra messages since getting all of sys.modules printed is annoying.
        assert "mod_testplug.plug" in sys.modules, "plug not loaded"
        assert "mod_testplug.plug2" not in sys.modules, "plug2 loaded"
        assert "mod_testplug.plug3" not in sys.modules, "plug3 loaded"
        assert "mod_testplug.plug4" in sys.modules, "plug4 not loaded"
        assert "mod_testplug.plug5" in sys.modules, "plug4 not loaded"
        assert "mod_testplug.plug6" not in sys.modules, "plug6 loaded"

    def test_header_change_invalidates_cache(self):
        # Write the cache
        plugin._global_cache.clear()
        import mod_testplug

        list(plugin.get_plugins("testplug", mod_testplug))

        # Modify the cache.
        filename = pjoin(self.packdir, plugin.CACHE_FILENAME)
        with open(filename) as f:
            cache = f.readlines()
        cache[0] = "not really a pkgcore plugin cache\n"
        with open(filename, "w") as f:
            f.write("".join(cache))

        # And test if it is properly rewritten.
        plugin._global_cache.clear()
        self._test_plug()