# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License.  You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
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# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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"""
Common helper module for CI/CD Steps
"""

import asyncio
import logging
import os
from collections import namedtuple
from dataclasses import dataclass, fields
from pathlib import PurePath
from typing import List, Optional, Dict

from tqdm.asyncio import tqdm
import yaml
from yaml import YAMLError

from api.v1.api_pb2 import SDK_UNSPECIFIED, STATUS_UNSPECIFIED, Sdk, \
    STATUS_VALIDATING, STATUS_PREPARING, \
    STATUS_COMPILING, STATUS_EXECUTING, PRECOMPILED_OBJECT_TYPE_UNIT_TEST, \
    PRECOMPILED_OBJECT_TYPE_KATA, PRECOMPILED_OBJECT_TYPE_UNSPECIFIED, \
    PRECOMPILED_OBJECT_TYPE_EXAMPLE, PrecompiledObjectType
from config import Config, Origin, TagFields, PrecompiledExampleType, OptionalTagFields
from grpc_client import GRPCClient

Tag = namedtuple(
    "Tag",
    [
        TagFields.name,
        TagFields.complexity,
        TagFields.description,
        TagFields.multifile,
        TagFields.categories,
        TagFields.pipeline_options,
        TagFields.default_example,
        TagFields.context_line,
        TagFields.tags
    ],
    defaults=(None, None, None, False, None, None, False, None, None))


@dataclass
class Example:
    """
    Class which contains all information about beam example
    """
    name: str
    complexity: str
    sdk: SDK_UNSPECIFIED
    filepath: str
    code: str
    status: STATUS_UNSPECIFIED
    tag: Tag
    link: str
    logs: str = ""
    type: PrecompiledObjectType = PRECOMPILED_OBJECT_TYPE_UNSPECIFIED
    pipeline_id: str = ""
    output: str = ""
    compile_output: str = ""
    graph: str = ""


@dataclass
class ExampleTag:
    """
    Class which contains all information about beam playground tag
    """
    tag_as_dict: Dict[str, str]
    tag_as_string: str

def _check_no_nested(subdirs: List[str]):
    """
    Check there're no nested subdirs

    Sort alphabetically and compare the pairs of adjacent items
    using pathlib.PurePath: we don't want fs calls in this check
    """
    sorted_subdirs = sorted(PurePath(s) for s in subdirs)
    for dir1, dir2 in zip(sorted_subdirs, sorted_subdirs[1:]):
        if dir1 in [dir2, *dir2.parents]:
            raise ValueError(f"{dir2} is a subdirectory of {dir1}")

def find_examples(root_dir: str, subdirs: List[str], supported_categories: List[str],
                  sdk: Sdk) -> List[Example]:
    """
    Find and return beam examples.

    Search throws all child files of work_dir directory files with beam tag:
    Beam-playground:
        name: NameOfExample
        description: Description of NameOfExample.
        multifile: false
        default_example: false
        context_line: 10
        categories:
            - category-1
            - category-2
        pipeline_options: --inputFile your_file --outputFile your_output_file
        complexity: MEDIUM
        tags:
            - example
    If some example contains beam tag with incorrect format raise an error.

    Args:
        root_dir: project root dir
        subdirs: sub-directories where to search examples.
        supported_categories: list of supported categories.
        sdk: sdk that using to find examples for the specific sdk.

    Returns:
        List of Examples.
    """
    has_error = False
    examples = []
    _check_no_nested(subdirs)
    for subdir in subdirs:
        subdir = os.path.join(root_dir, subdir)
        logging.info("subdir: %s", subdir)
        for root, _, files in os.walk(subdir):
            for filename in files:
                filepath = os.path.join(root, filename)
                error_during_check_file = _check_file(
                    examples=examples,
                    filename=filename,
                    filepath=filepath,
                    supported_categories=supported_categories,
                    sdk=sdk)
                has_error = has_error or error_during_check_file
    if has_error:
        raise ValueError(
            "Some of the beam examples contain beam playground tag with "
            "an incorrect format")
    return examples


async def get_statuses(client: GRPCClient, examples: List[Example], concurrency: int = 10):
    """
    Receive status and update example.status and example.pipeline_id for
    each example

    Args:
        examples: beam examples for processing and updating statuses and
        pipeline_id values.
    """
    tasks = []
    try:
        concurrency = int(os.environ["BEAM_CONCURRENCY"])
        logging.info("override default concurrency: %d", concurrency)
    except (KeyError, ValueError):
        pass

    semaphore = asyncio.Semaphore(concurrency)

    async def _semaphored_task(example):
        await semaphore.acquire()
        try:
            await _update_example_status(example, client)
        finally:
            semaphore.release()

    for example in examples:
        tasks.append(_semaphored_task(example))
    await tqdm.gather(*tasks)


def get_tag(filepath) -> Optional[ExampleTag]:
    """
    Parse file by filepath and find beam tag

    Args:
        filepath: path of the file

    Returns:
        If file contains tag, returns tag as a map.
        If file doesn't contain tag, returns None
    """
    add_to_yaml = False
    yaml_string = ""
    tag_string = ""

    with open(filepath, encoding="utf-8") as parsed_file:
        lines = parsed_file.readlines()

    for line in lines:
        formatted_line = line.replace("//", "").replace("#",
                                                        "").replace("\t", "    ")
        if add_to_yaml is False:
            if formatted_line.lstrip() == Config.BEAM_PLAYGROUND_TITLE:
                add_to_yaml = True
                yaml_string += formatted_line.lstrip()
                tag_string += line
        else:
            yaml_with_new_string = yaml_string + formatted_line
            try:
                yaml.load(yaml_with_new_string, Loader=yaml.SafeLoader)
                yaml_string += formatted_line
                tag_string += line
            except YAMLError:
                break

    if add_to_yaml:
        tag_object = yaml.load(yaml_string, Loader=yaml.SafeLoader)
        return ExampleTag(tag_object[Config.BEAM_PLAYGROUND], tag_string)

    return None


def _check_file(examples, filename, filepath, supported_categories, sdk: Sdk):
    """
    Check file by filepath for matching to beam example. If file is beam example,
    then add it to list of examples

    Args:
        examples: list of examples.
        filename: name of the file.
        filepath: path to the file.
        supported_categories: list of supported categories.
        sdk: sdk that using to find examples for the specific sdk.

    Returns:
        True if file has beam playground tag with incorrect format.
        False if file has correct beam playground tag.
        False if file doesn't contains beam playground tag.
    """
    if filepath.endswith("infrastructure/helper.py"):
        return False

    has_error = False
    extension = filepath.split(os.extsep)[-1]
    if extension == Config.SDK_TO_EXTENSION[sdk]:
        tag = get_tag(filepath)
        if tag is not None:
            if _validate(tag.tag_as_dict, supported_categories) is False:
                logging.error(
                    "%s contains beam playground tag with incorrect format", filepath)
                has_error = True
            else:
                examples.append(_get_example(filepath, filename, tag))
    return has_error


def get_supported_categories(categories_path: str) -> List[str]:
    """
    Return list of supported categories from categories_path file

    Args:
        categories_path: path to the file with categories.

    Returns:
        All supported categories as a list.
    """
    with open(categories_path, encoding="utf-8") as supported_categories:
        yaml_object = yaml.load(supported_categories.read(), Loader=yaml.SafeLoader)
        return yaml_object[TagFields.categories]


def _get_example(filepath: str, filename: str, tag: ExampleTag) -> Example:
    """
    Return an Example by filepath and filename.

    Args:
         tag: tag of the example.
         filepath: path of the example's file.
         filename: name of the example's file.

    Returns:
        Parsed Example object.
    """
    name = tag.tag_as_dict[TagFields.name]
    complexity = tag.tag_as_dict[TagFields.complexity]
    sdk = Config.EXTENSION_TO_SDK[filename.split(os.extsep)[-1]]
    object_type = _get_object_type(filename, filepath)
    with open(filepath, encoding="utf-8") as parsed_file:
        content = parsed_file.read()
    content = content.replace(tag.tag_as_string, "")
    tag.tag_as_dict[TagFields.context_line] -= tag.tag_as_string.count("\n")
    root_dir = os.getenv("BEAM_ROOT_DIR", "")
    file_path_without_root = filepath.replace(root_dir, "", 1)
    if file_path_without_root.startswith("/"):
        link = "{}{}".format(Config.LINK_PREFIX, file_path_without_root)
    else:
        link = "{}/{}".format(Config.LINK_PREFIX, file_path_without_root)

    example = Example(
        name=name,
        complexity=complexity,
        sdk=sdk,
        filepath=filepath,
        code=content,
        status=STATUS_UNSPECIFIED,
        tag=Tag(**tag.tag_as_dict),
        type=object_type,
        link=link)

    validate_example_fields(example)
    return example


def _validate(tag: dict, supported_categories: List[str]) -> bool:
    """
    Validate all tag's fields

    Validate that tag contains all required fields and all fields have required
    format.

    Args:
        tag: beam tag to validate.
        supported_categories: list of supported categories.

    Returns:
        In case tag is valid, True
        In case tag is not valid, False
    """
    valid = True
    required_tag_fields = {
        f.default
        for f in fields(TagFields)
        if f.default not in {o_f.default
                             for o_f in fields(OptionalTagFields)}
    }
    # check that all fields exist and they have no empty value
    for field in required_tag_fields:
        if field not in tag:
            logging.error(
                "tag doesn't contain %s field: %s \n"
                "Please, check that this field exists in the beam playground tag."
                "If you are sure that this field exists in the tag"
                " check the format of indenting.",
                field,
                tag)
            valid = False
        if valid is True:
            value = tag.get(field)
            if (value == "" or value is None) and field != TagFields.pipeline_options:
                logging.error(
                    "tag's value is incorrect: %s\n%s field can not be empty.",
                    tag,
                    field)
                valid = False

    if valid is False:
        return valid

    # check that multifile's value is boolean
    multifile = tag.get(TagFields.multifile)
    if str(multifile).lower() not in ["true", "false"]:
        logging.error(
            "tag's field multifile is incorrect: %s \n"
            "multifile variable should be boolean format, but tag contains: %s",
            tag,
            multifile)
        valid = False

    # check that categories' value is a list of supported categories
    categories = tag.get(TagFields.categories)
    if not isinstance(categories, list):
        logging.error(
            "tag's field categories is incorrect: %s \n"
            "categories variable should be list format, but tag contains: %s",
            tag,
            type(categories))
        valid = False
    else:
        for category in categories:
            if category not in supported_categories:
                logging.error(
                    "tag contains unsupported category: %s \n"
                    "If you are sure that %s category should be placed in "
                    "Beam Playground, you can add it to the "
                    "`playground/categories.yaml` file",
                    category,
                    category)
                valid = False

    # check that context line's value is integer
    context_line = tag.get(TagFields.context_line)
    if not isinstance(context_line, int):
        logging.error(
            "Tag's field context_line is incorrect: %s \n"
            "context_line variable should be integer format, "
            "but tag contains: %s",
            tag,
            context_line)
        valid = False
    return valid


def _get_name(filename: str) -> str:
    """
    Return name of the example by his filepath.

    Get name of the example by his filename.

    Args:
        filename: filename of the beam example file.

    Returns:
        example's name.
    """
    return filename.split(os.extsep)[0]


async def _update_example_status(example: Example, client: GRPCClient):
    """
    Receive status for examples and update example.status and pipeline_id

    Use client to send requests to the backend:
    1. Start code processing.
    2. Ping the backend while status is STATUS_VALIDATING/
      STATUS_PREPARING/STATUS_COMPILING/STATUS_EXECUTING
    Update example.status with resulting status.

    Args:
        example: beam example for processing and updating status and pipeline_id.
        client: client to send requests to the server.
    """
    pipeline_id = await client.run_code(
        example.code, example.sdk, example.tag.pipeline_options)
    example.pipeline_id = pipeline_id
    status = await client.check_status(pipeline_id)
    while status in [STATUS_VALIDATING,
                     STATUS_PREPARING,
                     STATUS_COMPILING,
                     STATUS_EXECUTING]:
        await asyncio.sleep(Config.PAUSE_DELAY)
        status = await client.check_status(pipeline_id)
    example.status = status


def _get_object_type(filename, filepath):
    """
    Get type of an object based on it filename/filepath

    Args:
        filename: object's filename
        filepath: object's filepath

    Returns: type of the object (example, kata, unit-test)
    """
    filename_no_ext = (os.path.splitext(filename)[0]).lower()
    if filename_no_ext.endswith(PrecompiledExampleType.test_ends):
        object_type = PRECOMPILED_OBJECT_TYPE_UNIT_TEST
    elif PrecompiledExampleType.katas in filepath.split(os.sep):
        object_type = PRECOMPILED_OBJECT_TYPE_KATA
    elif PrecompiledExampleType.examples in filepath.split(os.sep):
        object_type = PRECOMPILED_OBJECT_TYPE_EXAMPLE
    else:
        object_type = PRECOMPILED_OBJECT_TYPE_UNSPECIFIED
    return object_type


def validate_examples_for_duplicates_by_name(examples: List[Example]):
    """
    Validate examples for duplicates by example name to avoid duplicates in the Cloud Datastore
    :param examples: examples from the repository for saving to the Cloud Datastore
    """
    duplicates = {str: Example}
    for example in examples:
        if example.name not in duplicates.keys():
            duplicates[example.name] = example
        else:
            err_msg = f"Examples have duplicate names.\nDuplicates: \n - path #1: {duplicates[example.name].filepath} \n - path #2: {example.filepath}"
            logging.error(err_msg)
            raise ValidationException(err_msg)


def validate_example_fields(example: Example):
    """
    Validate example fields to avoid side effects in the next step
    :param example: example from the repository
    """
    if example.filepath == "":
        err_msg = f"Example doesn't have a file path field. Example: {example}"
        logging.error(err_msg)
        raise ValidationException(err_msg)
    if example.name == "":
        err_msg = f"Example doesn't have a name field. Path: {example.filepath}"
        logging.error(err_msg)
        raise ValidationException(err_msg)
    if example.sdk == SDK_UNSPECIFIED:
        err_msg = f"Example doesn't have a sdk field. Path: {example.filepath}"
        logging.error(err_msg)
        raise ValidationException(err_msg)
    if example.code == "":
        err_msg = f"Example doesn't have a code field. Path: {example.filepath}"
        logging.error(err_msg)
        raise ValidationException(err_msg)
    if example.link == "":
        err_msg = f"Example doesn't have a link field. Path: {example.filepath}"
        logging.error(err_msg)
        raise ValidationException(err_msg)
    if example.complexity == "":
        err_msg = f"Example doesn't have a complexity field. Path: {example.filepath}"
        logging.error(err_msg)
        raise ValidationException(err_msg)


class ValidationException(Exception):
    def __init__(self, error: str):
        super().__init__()
        self.msg = error

    def __str__(self):
        return self.msg
