# Path: peru/async_helpers.py
# async def gather_coalescing_exceptions(coros, display, *, verbose):
#     '''The tricky thing about running multiple coroutines in parallel is what
#     we're supposed to do when one of them raises an exception. The approach
#     we're using here is to catch exceptions and keep waiting for other tasks to
#     finish. At the end, we reraise a GatheredExceptions error, if any
#     exceptions were caught.
# 
#     Another minor detail: We also want to make sure to start coroutines in the
#     order given, so that they end up appearing to the user alphabetically in
#     the fancy display. Note that asyncio.gather() puts coroutines in a set
#     internally, so we schedule coroutines *before* we give them to gather().
#     '''
# 
#     exceptions = []
#     reprs = []
# 
#     async def catching_wrapper(coro):
#         try:
#             return (await coro)
#         except Exception as e:
#             exceptions.append(e)
#             if isinstance(e, PrintableError) and not verbose:
#                 reprs.append(e.message)
#             else:
#                 reprs.append(traceback.format_exc())
#             return None
# 
#     # Suppress a deprecation warning in Python 3.5, while continuing to support
#     # 3.3 and early 3.4 releases.
#     if hasattr(asyncio, 'ensure_future'):
#         schedule = getattr(asyncio, 'ensure_future')
#     else:
#         schedule = getattr(asyncio, 'async')
# 
#     futures = [schedule(catching_wrapper(coro)) for coro in coros]
# 
#     results = await asyncio.gather(*futures)
# 
#     if exceptions:
#         raise GatheredExceptions(exceptions, reprs)
#     else:
#         return results
# 
# Path: peru/merge.py
# async def merge_imports_tree(cache, imports, target_trees, base_tree=None):
#     '''Take an Imports struct and a dictionary of resolved trees and merge the
#     unified imports tree. If base_tree is supplied, merge that too. There are a
#     couple reasons for structuring this function the way it is:
#         - We want to cache merged trees, so that we don't have to do expensive
#           git operations just to check whether a module is in cache.
#         - We want tree merging to know about target names, so that it can write
#           good error messages when there are conflicts.
#         - We need to use this for both toplevel imports and recursive module
#           imports.
#     '''
#     key = _cache_key(imports, target_trees, base_tree)
#     if key in cache.keyval:
#         return cache.keyval[key]
#     # We always want to merge imports in the same order, so that any conflicts
#     # we run into will be deterministic. Sort the imports alphabetically by
#     # target name.
#     unified_tree = base_tree or (await cache.get_empty_tree())
#     for target, paths in imports.items():
#         for path in paths:
#             try:
#                 unified_tree = await cache.merge_trees(
#                     unified_tree, target_trees[target], path)
#             except MergeConflictError as e:
#                 message = 'Merge conflict in import "{}" at "{}":\n\n{}'
#                 e.message = message.format(target, path,
#                                            textwrap.indent(e.message, '  '))
#                 raise
#     cache.keyval[key] = unified_tree
#     return unified_tree


import os
from pathlib import Path
from .async_helpers import gather_coalescing_exceptions
from . import compat
from .error import error_context
from .merge import merge_imports_tree



async def checkout(runtime, scope, imports, path):
    imports_tree = await get_imports_tree(runtime, scope, imports)
    last_imports_tree = _get_last_imports(runtime)
    index = _last_imports_index(runtime)
    await runtime.cache.export_tree(
        imports_tree,
        path,
        last_imports_tree,
        force=runtime.force,
        previous_index_file=index)
    _set_last_imports(runtime, imports_tree)


async def get_imports_tree(runtime, scope, imports, base_tree=None):
    target_trees = await get_trees(runtime, scope, imports.keys())
    imports_tree = await merge_imports_tree(runtime.cache, imports,
                                            target_trees, base_tree)
    return imports_tree


async def get_trees(runtime, scope, targets):
    futures = [get_tree(runtime, scope, target) for target in targets]

# Path: peru/async_helpers.py
# async def gather_coalescing_exceptions(coros, display, *, verbose):
#     '''The tricky thing about running multiple coroutines in parallel is what
#     we're supposed to do when one of them raises an exception. The approach
#     we're using here is to catch exceptions and keep waiting for other tasks to
#     finish. At the end, we reraise a GatheredExceptions error, if any
#     exceptions were caught.
# 
#     Another minor detail: We also want to make sure to start coroutines in the
#     order given, so that they end up appearing to the user alphabetically in
#     the fancy display. Note that asyncio.gather() puts coroutines in a set
#     internally, so we schedule coroutines *before* we give them to gather().
#     '''
# 
#     exceptions = []
#     reprs = []
# 
#     async def catching_wrapper(coro):
#         try:
#             return (await coro)
#         except Exception as e:
#             exceptions.append(e)
#             if isinstance(e, PrintableError) and not verbose:
#                 reprs.append(e.message)
#             else:
#                 reprs.append(traceback.format_exc())
#             return None
# 
#     # Suppress a deprecation warning in Python 3.5, while continuing to support
#     # 3.3 and early 3.4 releases.
#     if hasattr(asyncio, 'ensure_future'):
#         schedule = getattr(asyncio, 'ensure_future')
#     else:
#         schedule = getattr(asyncio, 'async')
# 
#     futures = [schedule(catching_wrapper(coro)) for coro in coros]
# 
#     results = await asyncio.gather(*futures)
# 
#     if exceptions:
#         raise GatheredExceptions(exceptions, reprs)
#     else:
#         return results
# 
# Path: peru/merge.py
# async def merge_imports_tree(cache, imports, target_trees, base_tree=None):
#     '''Take an Imports struct and a dictionary of resolved trees and merge the
#     unified imports tree. If base_tree is supplied, merge that too. There are a
#     couple reasons for structuring this function the way it is:
#         - We want to cache merged trees, so that we don't have to do expensive
#           git operations just to check whether a module is in cache.
#         - We want tree merging to know about target names, so that it can write
#           good error messages when there are conflicts.
#         - We need to use this for both toplevel imports and recursive module
#           imports.
#     '''
#     key = _cache_key(imports, target_trees, base_tree)
#     if key in cache.keyval:
#         return cache.keyval[key]
#     # We always want to merge imports in the same order, so that any conflicts
#     # we run into will be deterministic. Sort the imports alphabetically by
#     # target name.
#     unified_tree = base_tree or (await cache.get_empty_tree())
#     for target, paths in imports.items():
#         for path in paths:
#             try:
#                 unified_tree = await cache.merge_trees(
#                     unified_tree, target_trees[target], path)
#             except MergeConflictError as e:
#                 message = 'Merge conflict in import "{}" at "{}":\n\n{}'
#                 e.message = message.format(target, path,
#                                            textwrap.indent(e.message, '  '))
#                 raise
#     cache.keyval[key] = unified_tree
#     return unified_tree


# Path: peru/imports.py
import os
from pathlib import Path
from .async_helpers import gather_coalescing_exceptions
from . import compat
from .error import error_context
from .merge import merge_imports_tree




async def checkout(runtime, scope, imports, path):
    imports_tree = await get_imports_tree(runtime, scope, imports)
    last_imports_tree = _get_last_imports(runtime)
    index = _last_imports_index(runtime)
    await runtime.cache.export_tree(
        imports_tree,
        path,
        last_imports_tree,
        force=runtime.force,
        previous_index_file=index)
    _set_last_imports(runtime, imports_tree)


async def get_imports_tree(runtime, scope, imports, base_tree=None):
    target_trees = await get_trees(runtime, scope, imports.keys())
    imports_tree = await merge_imports_tree(runtime.cache, imports,
                                            target_trees, base_tree)
    return imports_tree


async def get_trees(runtime, scope, targets):
    futures = [get_tree(runtime, scope, target) for target in targets]

    trees = await gather_coalescing_exceptions(