# -*- coding: utf-8 -*-
"""The code for async support. Importing this patches Jinja on supported
Python versions.
"""
import asyncio
import inspect
from functools import update_wrapper

from markupsafe import Markup

from .environment import TemplateModule
from .runtime import LoopContext
from .utils import concat
from .utils import internalcode
from .utils import missing


async def concat_async(async_gen):
 rv = []

 async def collect():
 async for event in async_gen:
 rv.append(event)

 await collect()
 return concat(rv)


async def generate_async(self, *args, **kwargs):
 vars = dict(*args, **kwargs)
 try:
 async for event in self.root_render_func(self.new_context(vars)):
 yield event
 except Exception:
 yield self.environment.handle_exception()


def wrap_generate_func(original_generate):
 def _convert_generator(self, loop, args, kwargs):
 async_gen = self.generate_async(*args, **kwargs)
 try:
 while 1:
 yield loop.run_until_complete(async_gen.__anext__())
 except StopAsyncIteration:
 pass

 def generate(self, *args, **kwargs):
 if not self.environment.is_async:
 return original_generate(self, *args, **kwargs)
 return _convert_generator(self, asyncio.get_event_loop(), args, kwargs)

 return update_wrapper(generate, original_generate)


async def render_async(self, *args, **kwargs):
 if not self.environment.is_async:
 raise RuntimeError("The environment was not created with async mode enabled.")

 vars = dict(*args, **kwargs)
 ctx = self.new_context(vars)

 try:
 return await concat_async(self.root_render_func(ctx))
 except Exception:
 return self.environment.handle_exception()


def wrap_render_func(original_render):
 def render(self, *args, **kwargs):
 if not self.environment.is_async:
 return original_render(self, *args, **kwargs)
 loop = asyncio.get_event_loop()
 return loop.run_until_complete(self.render_async(*args, **kwargs))

 return update_wrapper(render, original_render)


def wrap_block_reference_call(original_call):
 @internalcode
 async def async_call(self):
 rv = await concat_async(self._stack[self._depth](self._context))
 if self._context.eval_ctx.autoescape:
 rv = Markup(rv)
 return rv

 @internalcode
 def __call__(self):
 if not self._context.environment.is_async:
 return original_call(self)
 return async_call(self)

 return update_wrapper(__call__, original_call)


def wrap_macro_invoke(original_invoke):
 @internalcode
 async def async_invoke(self, arguments, autoescape):
 rv = await self._func(*arguments)
 if autoescape:
 rv = Markup(rv)
 return rv

 @internalcode
 def _invoke(self, arguments, autoescape):
 if not self._environment.is_async:
 return original_invoke(self, arguments, autoescape)
 return async_invoke(self, arguments, autoescape)

 return update_wrapper(_invoke, original_invoke)


@internalcode
async def get_default_module_async(self):
 if self._module is not None:
 return self._module
 self._module = rv = await self.make_module_async()
 return rv


def wrap_default_module(original_default_module):
 @internalcode
 def _get_default_module(self):
 if self.environment.is_async:
 raise RuntimeError("Template module attribute is unavailable in async mode")
 return original_default_module(self)

 return _get_default_module


async def make_module_async(self, vars=None, shared=False, locals=None):
 context = self.new_context(vars, shared, locals)
 body_stream = []
 async for item in self.root_render_func(context):
 body_stream.append(item)
 return TemplateModule(self, context, body_stream)


def patch_template():
 from . import Template

 Template.generate = wrap_generate_func(Template.generate)
 Template.generate_async = update_wrapper(generate_async, Template.generate_async)
 Template.render_async = update_wrapper(render_async, Template.render_async)
 Template.render = wrap_render_func(Template.render)
 Template._get_default_module = wrap_default_module(Template._get_default_module)
 Template._get_default_module_async = get_default_module_async
 Template.make_module_async = update_wrapper(
 make_module_async, Template.make_module_async
 )


def patch_runtime():
 from .runtime import BlockReference, Macro

 BlockReference.__call__ = wrap_block_reference_call(BlockReference.__call__)
 Macro._invoke = wrap_macro_invoke(Macro._invoke)


def patch_filters():
 from .filters import FILTERS
 from .asyncfilters import ASYNC_FILTERS

 FILTERS.update(ASYNC_FILTERS)


def patch_all():
 patch_template()
 patch_runtime()
 patch_filters()


async def auto_await(value):
 if inspect.isawaitable(value):
 return await value
 return value


async def auto_aiter(iterable):
 if hasattr(iterable, "__aiter__"):
 async for item in iterable:
 yield item
 return
 for item in iterable:
 yield item


class AsyncLoopContext(LoopContext):
 _to_iterator = staticmethod(auto_aiter)

 @property
 async def length(self):
 if self._length is not None:
 return self._length

 try:
 self._length = len(self._iterable)
 except TypeError:
 iterable = [x async for x in self._iterator]
 self._iterator = self._to_iterator(iterable)
 self._length = len(iterable) + self.index + (self._after is not missing)

 return self._length

 @property
 async def revindex0(self):
 return await self.length - self.index

 @property
 async def revindex(self):
 return await self.length - self.index0

 async def _peek_next(self):
 if self._after is not missing:
 return self._after

 try:
 self._after = await self._iterator.__anext__()
 except StopAsyncIteration:
 self._after = missing

 return self._after

 @property
 async def last(self):
 return await self._peek_next() is missing

 @property
 async def nextitem(self):
 rv = await self._peek_next()

 if rv is missing:
 return self._undefined("there is no next item")

 return rv

 def __aiter__(self):
 return self

 async def __anext__(self):
 if self._after is not missing:
 rv = self._after
 self._after = missing
 else:
 rv = await self._iterator.__anext__()

 self.index0 += 1
 self._before = self._current
 self._current = rv
 return rv, self


async def make_async_loop_context(iterable, undefined, recurse=None, depth0=0):
 import warnings

 warnings.warn(
 "This template must be recompiled with at least Jinja 2.11, or"
 " it will fail in 3.0.",
 DeprecationWarning,
 stacklevel=2,
 )
 return AsyncLoopContext(iterable, undefined, recurse, depth0)


patch_all()