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#
#   http://www.apache.org/licenses/LICENSE-2.0
#
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"""Dag sub-commands"""
import ast
import errno
import json
import logging
import signal
import subprocess
import sys
from typing import Optional

from graphviz.dot import Dot
from sqlalchemy.sql.functions import func

from airflow import settings
from airflow.api.client import get_current_api_client
from airflow.cli.simple_table import AirflowConsole
from airflow.configuration import conf
from airflow.exceptions import AirflowException, BackfillUnfinished
from airflow.executors.debug_executor import DebugExecutor
from airflow.jobs.base_job import BaseJob
from airflow.models import DagBag, DagModel, DagRun, TaskInstance
from airflow.models.dag import DAG
from airflow.utils import cli as cli_utils
from airflow.utils.cli import (
    get_dag,
    get_dag_by_file_location,
    process_subdir,
    sigint_handler,
    suppress_logs_and_warning,
)
from airflow.utils.dot_renderer import render_dag
from airflow.utils.session import create_session, provide_session
from airflow.utils.state import State


@cli_utils.action_logging
def dag_backfill(args, dag=None):
    """Creates backfill job or dry run for a DAG"""
    logging.basicConfig(level=settings.LOGGING_LEVEL, format=settings.SIMPLE_LOG_FORMAT)

    signal.signal(signal.SIGTERM, sigint_handler)

    import warnings

    warnings.warn(
        '--ignore-first-depends-on-past is deprecated as the value is always set to True',
        category=PendingDeprecationWarning,
    )

    if args.ignore_first_depends_on_past is False:
        args.ignore_first_depends_on_past = True

    if not args.start_date and not args.end_date:
        raise AirflowException("Provide a start_date and/or end_date")

    dag = dag or get_dag(args.subdir, args.dag_id)

    # If only one date is passed, using same as start and end
    args.end_date = args.end_date or args.start_date
    args.start_date = args.start_date or args.end_date

    if args.task_regex:
        dag = dag.partial_subset(
            task_ids_or_regex=args.task_regex, include_upstream=not args.ignore_dependencies
        )
        if not dag.task_dict:
            raise AirflowException(
                f"There are no tasks that match '{args.task_regex}' regex. Nothing to run, exiting..."
            )

    run_conf = None
    if args.conf:
        run_conf = json.loads(args.conf)

    if args.dry_run:
        print(f"Dry run of DAG {args.dag_id} on {args.start_date}")
        dr = DagRun(dag.dag_id, execution_date=args.start_date)
        for task in dag.tasks:
            print(f"Task {task.task_id}")
            ti = TaskInstance(task, run_id=None)
            ti.dag_run = dr
            ti.dry_run()
    else:
        if args.reset_dagruns:
            DAG.clear_dags(
                [dag],
                start_date=args.start_date,
                end_date=args.end_date,
                confirm_prompt=not args.yes,
                include_subdags=True,
                dag_run_state=State.NONE,
            )

        try:
            dag.run(
                start_date=args.start_date,
                end_date=args.end_date,
                mark_success=args.mark_success,
                local=args.local,
                donot_pickle=(args.donot_pickle or conf.getboolean('core', 'donot_pickle')),
                ignore_first_depends_on_past=args.ignore_first_depends_on_past,
                ignore_task_deps=args.ignore_dependencies,
                pool=args.pool,
                delay_on_limit_secs=args.delay_on_limit,
                verbose=args.verbose,
                conf=run_conf,
                rerun_failed_tasks=args.rerun_failed_tasks,
                run_backwards=args.run_backwards,
            )
        except ValueError as vr:
            print(str(vr))
            sys.exit(1)


@cli_utils.action_logging
def dag_trigger(args):
    """Creates a dag run for the specified dag"""
    api_client = get_current_api_client()
    try:
        message = api_client.trigger_dag(
            dag_id=args.dag_id, run_id=args.run_id, conf=args.conf, execution_date=args.exec_date
        )
        print(message)
    except OSError as err:
        raise AirflowException(err)


@cli_utils.action_logging
def dag_delete(args):
    """Deletes all DB records related to the specified dag"""
    api_client = get_current_api_client()
    if (
        args.yes
        or input("This will drop all existing records related to the specified DAG. Proceed? (y/n)").upper()
        == "Y"
    ):
        try:
            message = api_client.delete_dag(dag_id=args.dag_id)
            print(message)
        except OSError as err:
            raise AirflowException(err)
    else:
        print("Cancelled")


@cli_utils.action_logging
def dag_pause(args):
    """Pauses a DAG"""
    set_is_paused(True, args)


@cli_utils.action_logging
def dag_unpause(args):
    """Unpauses a DAG"""
    set_is_paused(False, args)


def set_is_paused(is_paused, args):
    """Sets is_paused for DAG by a given dag_id"""
    dag = DagModel.get_dagmodel(args.dag_id)

    if not dag:
        raise SystemExit(f"DAG: {args.dag_id} does not exist in 'dag' table")

    dag.set_is_paused(is_paused=is_paused)

    print(f"Dag: {args.dag_id}, paused: {is_paused}")


def dag_show(args):
    """Displays DAG or saves it's graphic representation to the file"""
    dag = get_dag(args.subdir, args.dag_id)
    dot = render_dag(dag)
    filename = args.save
    imgcat = args.imgcat

    if filename and imgcat:
        raise SystemExit(
            "Option --save and --imgcat are mutually exclusive. "
            "Please remove one option to execute the command.",
        )
    elif filename:
        _save_dot_to_file(dot, filename)
    elif imgcat:
        _display_dot_via_imgcat(dot)
    else:
        print(dot.source)


def _display_dot_via_imgcat(dot: Dot):
    data = dot.pipe(format='png')
    try:
        with subprocess.Popen("imgcat", stdout=subprocess.PIPE, stdin=subprocess.PIPE) as proc:
            out, err = proc.communicate(data)
            if out:
                print(out.decode('utf-8'))
            if err:
                print(err.decode('utf-8'))
    except OSError as e:
        if e.errno == errno.ENOENT:
            raise SystemExit(
                "Failed to execute. Make sure the imgcat executables are on your systems \'PATH\'"
            )
        else:
            raise


def _save_dot_to_file(dot: Dot, filename: str):
    filename_without_ext, _, ext = filename.rpartition('.')
    dot.render(filename=filename_without_ext, format=ext, cleanup=True)
    print(f"File {filename} saved")


@cli_utils.action_logging
def dag_state(args):
    """
    Returns the state (and conf if exists) of a DagRun at the command line.
    >>> airflow dags state tutorial 2015-01-01T00:00:00.000000
    running
    >>> airflow dags state a_dag_with_conf_passed 2015-01-01T00:00:00.000000
    failed, {"name": "bob", "age": "42"}
    """
    if args.subdir:
        dag = get_dag(args.subdir, args.dag_id)
    else:
        dag = get_dag_by_file_location(args.dag_id)
    dr = DagRun.find(dag.dag_id, execution_date=args.execution_date)
    out = dr[0].state if dr else None
    conf_out = ''
    if out and dr[0].conf:
        conf_out = ', ' + json.dumps(dr[0].conf)
    print(str(out) + conf_out)


@cli_utils.action_logging
def dag_next_execution(args):
    """
    Returns the next execution datetime of a DAG at the command line.
    >>> airflow dags next-execution tutorial
    2018-08-31 10:38:00
    """
    dag = get_dag(args.subdir, args.dag_id)

    if dag.get_is_paused():
        print("[INFO] Please be reminded this DAG is PAUSED now.", file=sys.stderr)

    with create_session() as session:
        max_date_subq = (
            session.query(func.max(DagRun.execution_date).label("max_date"))
            .filter(DagRun.dag_id == dag.dag_id)
            .subquery()
        )
        max_date_run: Optional[DagRun] = (
            session.query(DagRun)
            .filter(DagRun.dag_id == dag.dag_id, DagRun.execution_date == max_date_subq.c.max_date)
            .one_or_none()
        )

        if max_date_run is None:
            print("[WARN] Only applicable when there is execution record found for the DAG.", file=sys.stderr)
            print(None)
            return

    next_info = dag.next_dagrun_info(dag.get_run_data_interval(max_date_run), restricted=False)
    if next_info is None:
        print(
            "[WARN] No following schedule can be found. "
            "This DAG may have schedule interval '@once' or `None`.",
            file=sys.stderr,
        )
        print(None)
        return

    print(next_info.logical_date.isoformat())
    for _ in range(1, args.num_executions):
        next_info = dag.next_dagrun_info(next_info.data_interval, restricted=False)
        print(next_info.logical_date.isoformat())


@cli_utils.action_logging
@suppress_logs_and_warning
def dag_list_dags(args):
    """Displays dags with or without stats at the command line"""
    dagbag = DagBag(process_subdir(args.subdir))
    AirflowConsole().print_as(
        data=sorted(dagbag.dags.values(), key=lambda d: d.dag_id),
        output=args.output,
        mapper=lambda x: {
            "dag_id": x.dag_id,
            "filepath": x.filepath,
            "owner": x.owner,
            "paused": x.get_is_paused(),
        },
    )


@cli_utils.action_logging
@suppress_logs_and_warning
def dag_report(args):
    """Displays dagbag stats at the command line"""
    dagbag = DagBag(process_subdir(args.subdir))
    AirflowConsole().print_as(
        data=dagbag.dagbag_stats,
        output=args.output,
        mapper=lambda x: {
            "file": x.file,
            "duration": x.duration,
            "dag_num": x.dag_num,
            "task_num": x.task_num,
            "dags": sorted(ast.literal_eval(x.dags)),
        },
    )


@cli_utils.action_logging
@suppress_logs_and_warning
def dag_list_jobs(args, dag=None):
    """Lists latest n jobs"""
    queries = []
    if dag:
        args.dag_id = dag.dag_id
    if args.dag_id:
        dagbag = DagBag()

        if args.dag_id not in dagbag.dags:
            error_message = f"Dag id {args.dag_id} not found"
            raise AirflowException(error_message)
        queries.append(BaseJob.dag_id == args.dag_id)

    if args.state:
        queries.append(BaseJob.state == args.state)

    fields = ['dag_id', 'state', 'job_type', 'start_date', 'end_date']
    with create_session() as session:
        all_jobs = (
            session.query(BaseJob)
            .filter(*queries)
            .order_by(BaseJob.start_date.desc())
            .limit(args.limit)
            .all()
        )
        all_jobs = [{f: str(job.__getattribute__(f)) for f in fields} for job in all_jobs]

    AirflowConsole().print_as(
        data=all_jobs,
        output=args.output,
    )


@cli_utils.action_logging
@suppress_logs_and_warning
def dag_list_dag_runs(args, dag=None):
    """Lists dag runs for a given DAG"""
    if dag:
        args.dag_id = dag.dag_id

    dagbag = DagBag()

    if args.dag_id is not None and args.dag_id not in dagbag.dags:
        error_message = f"Dag id {args.dag_id} not found"
        raise AirflowException(error_message)

    state = args.state.lower() if args.state else None
    dag_runs = DagRun.find(
        dag_id=args.dag_id,
        state=state,
        no_backfills=args.no_backfill,
        execution_start_date=args.start_date,
        execution_end_date=args.end_date,
    )

    dag_runs.sort(key=lambda x: x.execution_date, reverse=True)
    AirflowConsole().print_as(
        data=dag_runs,
        output=args.output,
        mapper=lambda dr: {
            "dag_id": dr.dag_id,
            "run_id": dr.run_id,
            "state": dr.state,
            "execution_date": dr.execution_date.isoformat(),
            "start_date": dr.start_date.isoformat() if dr.start_date else '',
            "end_date": dr.end_date.isoformat() if dr.end_date else '',
        },
    )


@provide_session
@cli_utils.action_logging
def dag_test(args, session=None):
    """Execute one single DagRun for a given DAG and execution date, using the DebugExecutor."""
    dag = get_dag(subdir=args.subdir, dag_id=args.dag_id)
    dag.clear(start_date=args.execution_date, end_date=args.execution_date, dag_run_state=State.NONE)
    try:
        dag.run(
            executor=DebugExecutor(),
            start_date=args.execution_date,
            end_date=args.execution_date,
            # Always run the DAG at least once even if no logical runs are
            # available. This does not make a lot of sense, but Airflow has
            # been doing this prior to 2.2 so we keep compatibility.
            run_at_least_once=True,
        )
    except BackfillUnfinished as e:
        print(str(e))

    show_dagrun = args.show_dagrun
    imgcat = args.imgcat_dagrun
    filename = args.save_dagrun
    if show_dagrun or imgcat or filename:
        tis = (
            session.query(TaskInstance)
            .filter(
                TaskInstance.dag_id == args.dag_id,
                TaskInstance.execution_date == args.execution_date,
            )
            .all()
        )

        dot_graph = render_dag(dag, tis=tis)
        print()
        if filename:
            _save_dot_to_file(dot_graph, filename)
        if imgcat:
            _display_dot_via_imgcat(dot_graph)
        if show_dagrun:
            print(dot_graph.source)