#! /usr/bin/env python

# Validates the OpenAPI definitions under `../data/api`. Checks the request
# parameters and body, and response body. The schemas are validated against the
# JSON Schema 2020-12 specification and the examples are validated against those
# schemas.

# Copyright 2016 OpenMarket Ltd
#
# Licensed 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.

import helpers
import sys
import json
import os


def import_error(module, package, debian, error):
    sys.stderr.write((
        "Error importing %(module)s: %(error)r\n"
        "To install %(module)s run:\n"
        "  pip install %(package)s\n"
        "or on Debian run:\n"
        "  sudo apt-get install python-%(debian)s\n"
    ) % locals())
    if __name__ == '__main__':
        sys.exit(1)

try:
    import jsonschema
except ImportError as e:
    import_error("jsonschema", "jsonschema", "jsonschema", e)
    raise

try:
    import referencing
except ImportError as e:
    import_error("referencing", "referencing", "referencing", e)
    raise

try:
    import yaml
except ImportError as e:
    import_error("yaml", "PyYAML", "yaml", e)
    raise


def check_schema(filepath, example, schema):
    # $id as a URI with scheme is necessary to make registry resolver work.
    schema["$id"] = filepath

    registry = referencing.Registry(retrieve=helpers.load_resource_from_uri)
    validator = jsonschema.validators.Draft202012Validator(schema, registry=registry)
    validator.validate(example)


def check_parameter(filepath, request, parameter):
    schema = parameter.get('schema')
    example = parameter.get('example')

    if not example:
        example = schema.get('example')

    if example and schema:
        try:
            print("Checking schema for request parameter: %r %r %r" % (
                filepath, request, parameter.get("name")
            ))
            check_schema(filepath, example, schema)
        except Exception as e:
            raise ValueError("Error validating JSON schema for %r" % (
                request
            ), e)

def check_request_body(filepath, request, body):
    schema = body.get('schema')
    example = body.get('example')

    if not example:
        example = schema.get('example')

    if example and schema:
        try:
            print("Checking schema for request body: %r %r" % (
                filepath, request,
            ))
            check_schema(filepath, example, schema)
        except Exception as e:
            raise ValueError("Error validating JSON schema for %r" % (
                request
            ), e)


def check_response(filepath, request, code, response):
    schema = response.get('schema')
    if schema:
        for name, example in response.get('examples', {}).items():
            value = example.get('value')
            if value:
                try:
                    print ("Checking response schema for: %r %r %r %r" % (
                        filepath, request, code, name
                    ))
                    check_schema(filepath, value, schema)
                except jsonschema.SchemaError as error:
                    for suberror in sorted(error.context, key=lambda e: e.schema_path):
                        print(list(suberror.schema_path), suberror.message, sep=", ")
                    raise ValueError("Error validating JSON schema for %r %r" % (
                        request, code
                    ), e)
                except Exception as e:
                    raise ValueError("Error validating JSON schema for %r %r" % (
                        request, code
                    ), e)


def check_openapi_file(filepath):
    with open(filepath) as f:
        openapi = yaml.safe_load(f)

    openapi = helpers.resolve_references(filepath, openapi)

    openapi_version = openapi.get('openapi')
    if not openapi_version:
        # This is not an OpenAPI file, skip.
        return
    elif openapi_version != '3.1.0':
        raise ValueError("File %r is not using the proper OpenAPI version: expected '3.1.0', got %r" % (filepath, openapi_version))

    for path, path_api in openapi.get('paths', {}).items():

        for method, request_api in path_api.items():
            request = "%s %s" % (method.upper(), path)
            for parameter in request_api.get('parameters', ()):
                check_parameter(filepath, request, parameter)
            
            json_body = request_api.get('requestBody', {}).get('content', {}).get('application/json')
            if json_body:
                check_request_body(filepath, request, json_body)

            try:
                responses = request_api['responses']
            except KeyError:
                raise ValueError("No responses for %r" % (request,))
            for code, response in responses.items():
                json_response = response.get('content', {}).get('application/json')

                if json_response:
                    check_response(filepath, request, code, json_response)


if __name__ == '__main__':
    # Get the directory that this script is residing in
    script_directory = os.path.dirname(os.path.realpath(__file__))

    # Resolve the directory containing the OpenAPI sources,
    # relative to the script path
    source_files_directory = os.path.realpath(os.path.join(script_directory, "../data/api"))

    # Walk the source path directory, looking for YAML files to check
    for (root, dirs, files) in os.walk(source_files_directory):
        for filename in files:
            if not filename.endswith(".yaml"):
                continue

            path = os.path.join(root, filename)

            try:
                check_openapi_file(path)
            except Exception as e:
                raise ValueError("Error checking file %s" % (path,), e)