import io
import sys
import time
import pprint
import os.path
import logging
import pytest
import yaml
import colorama
from piecrust.app import apply_variant_and_values
from piecrust.configuration import merge_dicts
from .mockutil import mock_fs, mock_fs_scope


def pytest_runtest_setup(item):
    pass


def pytest_addoption(parser):
    parser.addoption(
            '--log-debug',
            action='store_true',
            help="Sets the PieCrust logger to output debug info to stdout.")


def pytest_configure(config):
    if config.getoption('--log-debug'):
        hdl = logging.StreamHandler(stream=sys.stdout)
        logging.getLogger('piecrust').addHandler(hdl)
        logging.getLogger('piecrust').setLevel(logging.DEBUG)


def pytest_collect_file(parent, path):
    if path.ext == '.yaml' and path.basename.startswith("test"):
        category = os.path.basename(path.dirname)
        if category == 'bakes':
            return BakeTestFile(path, parent)
        elif category == 'procs':
            return PipelineTestFile(path, parent)
        elif category == 'cli':
            return ChefTestFile(path, parent)
        elif category == 'servings':
            return ServeTestFile(path, parent)


class YamlTestFileBase(pytest.File):
    def collect(self):
        spec = yaml.load_all(self.fspath.open())
        for i, item in enumerate(spec):
            name = '%s_%d' % (self.fspath.basename, i)
            if 'test_name' in item:
                name += '_%s' % item['test_name']
            yield self.__item_class__(name, self, item)


class YamlTestItemBase(pytest.Item):
    def __init__(self, name, parent, spec):
        super(YamlTestItemBase, self).__init__(name, parent)
        self.spec = spec

    def _prepareMockFs(self):
        fs = mock_fs()

        # Website config.
        config = {
                'site': {
                    'default_format': 'none',
                    'default_page_layout': 'none',
                    'default_post_layout': 'none'}
                }
        test_config = self.spec.get('config')
        if test_config is not None:
            merge_dicts(config, test_config)
        fs.withConfig(config)

        # Input file-system.
        input_files = self.spec.get('in')
        if input_files is not None:
            _add_mock_files(fs, '/kitchen', input_files)

        return fs


def check_expected_outputs(spec, fs, error_type):
    cctx = CompareContext()
    expected_output_files = spec.get('out')
    if expected_output_files:
        actual = fs.getStructure('kitchen/_counter')
        error = _compare_dicts(expected_output_files, actual, cctx)
        if error:
            raise error_type(error)

    expected_partial_files = spec.get('outfiles')
    if expected_partial_files:
        keys = list(sorted(expected_partial_files.keys()))
        for key in keys:
            try:
                actual = fs.getFileEntry('kitchen/_counter/' +
                                         key.lstrip('/'))
            except Exception as e:
                raise error_type([
                    "Can't access output file %s: %s" % (key, e)])

            expected = expected_partial_files[key]
            # HACK because for some reason PyYAML adds a new line for
            # those and I have no idea why.
            actual = actual.rstrip('\n')
            expected = expected.rstrip('\n')
            cctx.path = key
            cmpres = _compare_str(expected, actual, cctx)
            if cmpres:
                raise error_type(cmpres)


class ChefTestItem(YamlTestItemBase):
    __initialized_logging__ = False

    def runtest(self):
        if not ChefTestItem.__initialized_logging__:
            colorama.init()
            hdl = logging.StreamHandler(stream=sys.stdout)
            logging.getLogger().addHandler(hdl)
            logging.getLogger().setLevel(logging.INFO)
            ChefTestItem.__initialized_logging__ = True

        fs = self._prepareMockFs()

        argv = self.spec['args']
        if isinstance(argv, str):
            argv = argv.split(' ')

        expected_code = self.spec.get('code', 0)
        expected_out = self.spec.get('out', '')

        with mock_fs_scope(fs):
            memstream = io.StringIO()
            hdl = logging.StreamHandler(stream=memstream)
            logging.getLogger().addHandler(hdl)
            try:
                from piecrust.main import PreParsedChefArgs, _run_chef
                pre_args = PreParsedChefArgs(
                        root=fs.path('/kitchen'))
                exit_code = _run_chef(pre_args, argv)
            finally:
                logging.getLogger().removeHandler(hdl)

            assert expected_code == exit_code
            assert expected_out == memstream.getvalue()

    def reportinfo(self):
        return self.fspath, 0, "bake: %s" % self.name

    def repr_failure(self, excinfo):
        if isinstance(excinfo.value, ExpectedChefOutputError):
            return ('\n'.join(
                ['Unexpected command output. Left is expected output, '
                    'right is actual output'] +
                excinfo.value.args[0]))
        return super(ChefTestItem, self).repr_failure(excinfo)


class ExpectedChefOutputError(Exception):
    pass


class ChefTestFile(YamlTestFileBase):
    __item_class__ = ChefTestItem


class BakeTestItem(YamlTestItemBase):
    def runtest(self):
        fs = self._prepareMockFs()

        from piecrust.baking.baker import Baker
        with mock_fs_scope(fs):
            out_dir = fs.path('kitchen/_counter')
            app = fs.getApp()

            variant = self.spec.get('config_variant')
            values = self.spec.get('config_values')
            if values is not None:
                values = list(values.items())
            apply_variant_and_values(app, variant, values)

            baker = Baker(app, out_dir,
                          applied_config_variant=variant,
                          applied_config_values=values)
            record = baker.bake()

            if not record.success:
                errors = []
                for e in record.entries:
                    errors += e.getAllErrors()
                raise BakeError(errors)

            check_expected_outputs(self.spec, fs, ExpectedBakeOutputError)

    def reportinfo(self):
        return self.fspath, 0, "bake: %s" % self.name

    def repr_failure(self, excinfo):
        if isinstance(excinfo.value, ExpectedBakeOutputError):
            return ('\n'.join(
                ['Unexpected bake output. Left is expected output, '
                    'right is actual output'] +
                excinfo.value.args[0]))
        elif isinstance(excinfo.value, BakeError):
            return ('\n'.join(
                ['Errors occured during bake:'] +
                excinfo.value.args[0]))
        return super(BakeTestItem, self).repr_failure(excinfo)


class BakeError(Exception):
    pass


class ExpectedBakeOutputError(Exception):
    pass


class BakeTestFile(YamlTestFileBase):
    __item_class__ = BakeTestItem


class PipelineTestItem(YamlTestItemBase):
    def runtest(self):
        fs = self._prepareMockFs()

        from piecrust.processing.pipeline import ProcessorPipeline
        with mock_fs_scope(fs):
            out_dir = fs.path('kitchen/_counter')
            app = fs.getApp()
            pipeline = ProcessorPipeline(app, out_dir)

            proc_names = self.spec.get('processors')
            if proc_names:
                pipeline.enabled_processors = proc_names

            record = pipeline.run()

            if not record.success:
                errors = []
                for e in record.entries:
                    errors += e.errors
                raise PipelineError(errors)

            check_expected_outputs(self.spec, fs, ExpectedPipelineOutputError)

    def reportinfo(self):
        return self.fspath, 0, "pipeline: %s" % self.name

    def repr_failure(self, excinfo):
        if isinstance(excinfo.value, ExpectedPipelineOutputError):
            return ('\n'.join(
                ['Unexpected pipeline output. Left is expected output, '
                    'right is actual output'] +
                excinfo.value.args[0]))
        elif isinstance(excinfo.value, PipelineError):
            return ('\n'.join(
                ['Errors occured during processing:'] +
                excinfo.value.args[0]))
        return super(PipelineTestItem, self).repr_failure(excinfo)


class PipelineError(Exception):
    pass


class ExpectedPipelineOutputError(Exception):
    pass


class PipelineTestFile(YamlTestFileBase):
    __item_class__ = PipelineTestItem


class ServeTestItem(YamlTestItemBase):
    class _TestApp(object):
        def __init__(self, server):
            self.server = server

        def __call__(self, environ, start_response):
            return self.server._try_run_request(environ, start_response)

    def runtest(self):
        fs = self._prepareMockFs()

        url = self.spec.get('url')
        if url is None:
            raise Exception("Missing URL in test spec.")

        expected_status = self.spec.get('status', 200)
        expected_headers = self.spec.get('headers')
        expected_output = self.spec.get('out')
        expected_contains = self.spec.get('out_contains')

        from werkzeug.test import Client
        from werkzeug.wrappers import BaseResponse
        from piecrust.serving.server import Server
        with mock_fs_scope(fs):
            server = Server(fs.path('/kitchen'))
            test_app = self._TestApp(server)
            client = Client(test_app, BaseResponse)
            resp = client.get(url)
            assert expected_status == resp.status_code

            if expected_headers:
                for k, v in expected_headers.items():
                    assert v == resp.headers.get(k)

            actual = resp.data.decode('utf8').rstrip()
            if expected_output:
                assert expected_output.rstrip() == actual

            if expected_contains:
                assert expected_contains.rstrip() in actual

    def reportinfo(self):
        return self.fspath, 0, "serve: %s" % self.name


class ServeTestFile(YamlTestFileBase):
    __item_class__ = ServeTestItem


def _add_mock_files(fs, parent_path, spec):
    for name, subspec in spec.items():
        path = os.path.join(parent_path, name)
        if isinstance(subspec, str):
            fs.withFile(path, subspec)
        elif isinstance(subspec, dict):
            _add_mock_files(fs, path, subspec)


class CompareContext(object):
    def __init__(self, path=None, t=None):
        self.path = path or ''
        self.time = t or time.time()

    def createChildContext(self, name):
        ctx = CompareContext(
                path='%s/%s' % (self.path, name),
                t=self.time)
        return ctx


def _compare(left, right, ctx):
    if type(left) != type(right):
        return (["Different items: ",
                 "%s: %s" % (ctx.path, pprint.pformat(left)),
                 "%s: %s" % (ctx.path, pprint.pformat(right))])
    if isinstance(left, str):
        return _compare_str(left, right, ctx)
    elif isinstance(left, dict):
        return _compare_dicts(left, right, ctx)
    elif isinstance(left, list):
        return _compare_lists(left, right, ctx)
    elif left != right:
        return (["Different items: ",
                 "%s: %s" % (ctx.path, pprint.pformat(left)),
                 "%s: %s" % (ctx.path, pprint.pformat(right))])


def _compare_dicts(left, right, ctx):
    key_diff = set(left.keys()) ^ set(right.keys())
    if key_diff:
        extra_left = set(left.keys()) - set(right.keys())
        if extra_left:
            return (["Left contains more items: "] +
                    ['- %s/%s' % (ctx.path, k) for k in extra_left])
        extra_right = set(right.keys()) - set(left.keys())
        if extra_right:
            return (["Right contains more items: "] +
                    ['- %s/%s' % (ctx.path, k) for k in extra_right])
        return ["Unknown difference"]

    for key in left.keys():
        lv = left[key]
        rv = right[key]
        child_ctx = ctx.createChildContext(key)
        cmpres = _compare(lv, rv, child_ctx)
        if cmpres:
            return cmpres
    return None


def _compare_lists(left, right, ctx):
    for i in range(min(len(left), len(right))):
        l = left[i]
        r = right[i]
        cmpres = _compare(l, r, ctx)
        if cmpres:
            return cmpres
    if len(left) > len(right):
        return (["Left '%s' contains more items. First extra item: " %
                 ctx.path, left[len(right)]])
    if len(right) > len(left):
        return (["Right '%s' contains more items. First extra item: " %
                 ctx.path, right[len(left)]])
    return None


def _compare_str(left, right, ctx):
    if left == right:
        return None

    test_time_iso8601 = time.strftime('%Y-%m-%dT%H:%M:%SZ',
                                      time.gmtime(ctx.time))
    replacements = {
            '%test_time_iso8601%': test_time_iso8601}
    for token, repl in replacements.items():
        left = left.replace(token, repl)
        right = right.replace(token, repl)

    for i in range(min(len(left), len(right))):
        if left[i] != right[i]:
            start = max(0, i - 15)
            l_end = min(len(left), i + 15)
            r_end = min(len(right), i + 15)

            l_str = ''
            l_offset = 0
            for j in range(start, l_end):
                c = repr(left[j]).strip("'")
                l_str += c
                if j < i:
                    l_offset += len(c)

            r_str = ''
            r_offset = 0
            for j in range(start, r_end):
                c = repr(right[j]).strip("'")
                r_str += c
                if j < i:
                    r_offset += len(c)

            return ["Items '%s' differ at index %d:" % (ctx.path, i), '',
                    "Left:", left, '',
                    "Right:", right, '',
                    "Difference:",
                    l_str, (' ' * l_offset + '^'),
                    r_str, (' ' * r_offset + '^')]
    if len(left) > len(right):
        return ["Left is longer.",
                "Left '%s': " % ctx.path, left,
                "Right '%s': " % ctx.path, right,
                "Extra items: %r" % left[len(right):]]
    if len(right) > len(left):
        return ["Right is longer.",
                "Left '%s': " % ctx.path, left,
                "Right '%s': " % ctx.path, right,
                "Extra items: %r" % right[len(left):]]