# 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
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""
Helpers for validating and coercing service template inputs.
"""

import os
import glob
from ruamel import yaml

from .env import logger
from .exceptions import AriaCliError


def inputs_to_dict(resources):
    """
    Returns a dictionary of inputs

    :param resources: can be:

     * list of files
     * single file
     * directory containing multiple input files
     * ``key1=value1;key2=value2`` pairs string.
     * string formatted as JSON/YAML
     * wildcard based string (e.g. ``*-inputs.yaml``)
    """
    if not resources:
        return dict()

    parsed_dict = {}

    for resource in resources:
        logger.debug('Processing inputs source: {0}'.format(resource))
        # Workflow parameters always pass an empty dictionary. We ignore it
        if isinstance(resource, basestring):
            try:
                parsed_dict.update(_parse_single_input(resource))
            except AriaCliError:
                raise AriaCliError(
                    "Invalid input: {0}. It must represent a dictionary. "
                    "Valid values can be one of:{1} "
                    "- A path to a YAML file{1} "
                    "- A path to a directory containing YAML files{1} "
                    "- A single quoted wildcard based path "
                    "(e.g. '*-inputs.yaml'){1} "
                    "- A string formatted as JSON/YAML{1} "
                    "- A string formatted as key1=value1;key2=value2".format(
                        resource, os.linesep))
    return parsed_dict


def _parse_single_input(resource):
    try:
        # parse resource as string representation of a dictionary
        return _plain_string_to_dict(resource)
    except AriaCliError:
        input_files = glob.glob(resource)
        parsed_dict = dict()
        if os.path.isdir(resource):
            for input_file in os.listdir(resource):
                parsed_dict.update(
                    _parse_yaml_path(os.path.join(resource, input_file)))
        elif input_files:
            for input_file in input_files:
                parsed_dict.update(_parse_yaml_path(input_file))
        else:
            parsed_dict.update(_parse_yaml_path(resource))
    return parsed_dict


def _parse_yaml_path(resource):

    try:
        # if resource is a path - parse as a yaml file
        if os.path.isfile(resource):
            with open(resource) as f:
                content = yaml.load(f.read())
        else:
            # parse resource content as yaml
            content = yaml.load(resource)
    except yaml.error.YAMLError as e:
        raise AriaCliError("'{0}' is not a valid YAML. {1}".format(
            resource, str(e)))

    # Emtpy files return None
    content = content or dict()
    if not isinstance(content, dict):
        raise AriaCliError()

    return content


def _plain_string_to_dict(input_string):
    input_string = input_string.strip()
    input_dict = {}
    mapped_inputs = input_string.split(';')
    for mapped_input in mapped_inputs:
        mapped_input = mapped_input.strip()
        if not mapped_input:
            continue
        split_mapping = mapped_input.split('=')
        try:
            key = split_mapping[0].strip()
            value = split_mapping[1].strip()
        except IndexError:
            raise AriaCliError(
                "Invalid input format: {0}, the expected format is: "
                "key1=value1;key2=value2".format(input_string))
        input_dict[key] = value
    return input_dict