import json
import sys

import click
from datetime import datetime
from great_expectations import DataContext
from great_expectations import exceptions as ge_exceptions
from great_expectations.cli.datasource import (
    get_batch_kwargs,
    select_datasource,
)
from great_expectations.cli.util import (
    cli_message,
    load_expectation_suite,
)

json_parse_exception = json.decoder.JSONDecodeError

try:
    from sqlalchemy.exc import SQLAlchemyError
except ImportError:
    # We'll redefine this error in code below to catch ProfilerError, which is caught above, so SA errors will
    # just fall through
    SQLAlchemyError = ge_exceptions.ProfilerError


@click.group()
def validation_operator():
    """validation operator operations"""
    pass


@validation_operator.command(name="run")
@click.option(
    "--validation_config_file",
    "-f",
    default=None,
    help="""The path of the validation config file (JSON). """,
)
@click.option(
    "--name",
    "-n",
    default=None,
    help="""The name of the validation operator. """,
)
@click.option(
    "--suite",
    "-s",
    default=None,
    help="""The name of the expectation suite. """,
)
@click.option(
    "--run_id",
    "-r",
    default=None,
    help="""Run id. If not specified, a timestamp-based run id will be automatically generated. """,
)
@click.option(
    "--directory",
    "-d",
    default=None,
    help="The project's great_expectations directory.",
)
def validation_operator_run(name, run_id, validation_config_file, suite, directory):
    # Note though the long lines here aren't pythonic, they look best if Click does the line wraps.
    """
    Run a validation operator against some data.

    There are two modes to run this command:

    1. Interactive (good for development):

        Specify the name of the validation operator using the --name argument
        and the name of the expectation suite using the --suite argument.

        The cli will help you specify the batch of data that you want to
        validate interactively.


    2. Non-interactive (good for production):

        Use the `--validation_config_file` argument to specify the path of the validation configuration JSON file. This file can be used to instruct a validation operator to validate multiple batches of data and use multiple expectation suites to validate each batch.

        Learn how to create a validation config file here:
        https://great-expectations.readthedocs.io/en/latest/command_line.html#great-expectations-validation-operator-run-validation-config-file-validation-config-file-path

        This command exits with 0 if the validation operator ran and the "success" attribute in its return object is True. Otherwise, the command exits with 1.

    To learn more about validation operators, go here:
    https://great-expectations.readthedocs.io/en/latest/features/validation.html#validation-operators
    """

    try:
        context = DataContext(directory)
    except ge_exceptions.ConfigNotFoundError as err:
        cli_message("Failed to process <red>{}</red>".format(err.message))
        sys.exit(1)

    if validation_config_file is not None:
        try:
            with open(validation_config_file) as f:
                validation_config = json.load(f)
        except (
            IOError,
            json_parse_exception
        ) as e:
            cli_message(f"Failed to process the --validation_config_file argument: <red>{e}</red>")
            sys.exit(1)

        validation_config_error_message = _validate_valdiation_config(validation_config)
        if validation_config_error_message is not None:
            cli_message("<red>The validation config in {0:s} is misconfigured: {1:s}</red>".format(validation_config_file, validation_config_error_message))
            sys.exit(1)

    else:
        if suite is None:
            cli_message(
"""
Please use --suite argument to specify the name of the expectation suite.
Call `great_expectation suite list` command to list the expectation suites in your project.
"""
            )
            sys.exit(0)

        suite = load_expectation_suite(context, suite)

        if name is None:
            cli_message(
"""
Please use --name argument to specify the name of the validation operator.
Call `great_expectation validation-operator list` command to list the operators in your project.
"""
            )
            sys.exit(1)
        else:
            if name not in context.list_validation_operator_names():
                cli_message(
                    f"""
Could not find a validation operator {name}.
Call `great_expectation validation-operator list` command to list the operators in your project.
"""
                )
                sys.exit(1)

        batch_kwargs = None

        cli_message(
            """
Let's help you specify the batch of data your want the validation operator to validate."""
        )

        try:
            data_source = select_datasource(context)
        except ValueError as ve:
            cli_message("<red>{}</red>".format(ve))
            sys.exit(1)

        if not data_source:
            cli_message("<red>No datasources found in the context.</red>")
            sys.exit(1)

        if batch_kwargs is None:
            (
                datasource_name,
                batch_kwarg_generator,
                data_asset,
                batch_kwargs,
            ) = get_batch_kwargs(
                context,
                datasource_name=data_source.name,
                generator_name=None,
                generator_asset=None,
                additional_batch_kwargs=None,
            )

        validation_config = {
            "validation_operator_name": name,
            "batches": [
                {
                "batch_kwargs": batch_kwargs,
                "expectation_suite_names": [suite.expectation_suite_name]
                }
            ]
        }

    try:
        validation_operator_name = validation_config["validation_operator_name"]
        batches_to_validate = []
        for entry in validation_config["batches"]:
            for expectation_suite_name in entry["expectation_suite_names"]:
                batch = context.get_batch(entry["batch_kwargs"], expectation_suite_name)
                batches_to_validate.append(batch)

        if run_id is None:
            run_id = datetime.utcnow().strftime("%Y%m%dT%H%M%S.%fZ")

        results = context.run_validation_operator(
            validation_operator_name,
            assets_to_validate=[batch],
            run_id=run_id)

    except (
        ge_exceptions.DataContextError,
        IOError,
        SQLAlchemyError,
    ) as e:
        cli_message("<red>{}</red>".format(e))
        sys.exit(1)

    if not results["success"]:
        cli_message("Validation Failed!")
        sys.exit(1)
    else:
        cli_message("Validation Succeeded!")
        sys.exit(0)


@validation_operator.command(name="list")
@click.option(
    "--directory",
    "-d",
    default=None,
    help="The project's great_expectations directory.",
)
def validation_operator_list(directory):
    """Lists the names of the validation operators configured in the project."""
    try:
        context = DataContext(directory)
    except ge_exceptions.ConfigNotFoundError as err:
        cli_message("<red>{}</red>".format(err.message))
        return

    suite_names = context.list_validation_operator_names()
    if len(suite_names) == 0:
        cli_message("No validation operators are configured in the project")
        return

    if len(suite_names) == 1:
        cli_message("1 validation operator found:")

    if len(suite_names) > 1:
        cli_message("{} validation operators found:".format(len(suite_names)))

    for name in suite_names:
        cli_message("\t{}".format(name))


def _validate_valdiation_config(valdiation_config):
    if "validation_operator_name" not in valdiation_config:
        return "validation_operator_name attribute is missing"
    if "batches" not in valdiation_config:
        return "batches attribute is missing"

    for batch in valdiation_config["batches"]:
        if "batch_kwargs" not in batch:
            return "Each batch must have a BatchKwargs dictionary in batch_kwargs attribute"
        if "expectation_suite_names" not in batch:
            return "Each batch must have a list of expectation suite names in expectation_suite_names attribute"

    return None