"""CLI commands for saving, resetting, etc of the database"""

from datetime import datetime
import subprocess

from flask import current_app as app
from flask.cli import with_appcontext
import flask_migrate as migrate
import click

from flexmeasures.cli.utils import MsgStyle

BACKUP_PATH: str = app.config.get("FLEXMEASURES_DB_BACKUP_PATH")  # type: ignore


@click.group("db-ops")
def fm_db_ops():
    """FlexMeasures: Reset, Dump/Restore or Save/Load the DB data."""


@fm_db_ops.command()
@with_appcontext
def reset():
    """Reset database data and re-create tables from data model."""
    if not app.debug:
        prompt = (
            "This deletes all data and re-creates the tables on %s.\nDo you want to continue?"
            % app.db.engine
        )
        if not click.confirm(prompt):
            click.secho("I did nothing.", **MsgStyle.WARN)
            raise click.Abort()
    from flexmeasures.data.scripts.data_gen import reset_db

    current_version = migrate.current()
    reset_db(app.db)
    migrate.stamp(current_version)


@fm_db_ops.command()
@with_appcontext
@click.option("--name", help="Unique name for saving the backup.")
@click.option("--dir", default=BACKUP_PATH, help="Directory for saving backups.")
@click.option(
    "--structure/--no-structure",
    default=True,
    help="Save structural data like asset (types), market (types),"
    " weather (sensors), users, roles.",
)
@click.option(
    "--data/--no-data",
    default=False,
    help="Save (time series) data to a backup. Only do this for small data sets!",
)
def save(name: str, dir: str = BACKUP_PATH, structure: bool = True, data: bool = False):
    """Backup db content to files."""
    if name:
        from flexmeasures.data.scripts.data_gen import save_tables

        save_tables(app.db, name, structure=structure, data=data, backup_path=dir)
    else:
        click.secho(
            "You must specify a unique name for the backup: --name <unique name>",
            **MsgStyle.ERROR,
        )


@fm_db_ops.command()
@with_appcontext
@click.option("--name", help="Name of the backup.")
@click.option("--dir", default=BACKUP_PATH, help="Directory for loading backups.")
@click.option(
    "--structure/--no-structure",
    default=True,
    help="Load structural data like asset (types), market (types),"
    " weather (sensors), users, roles.",
)
@click.option("--data/--no-data", default=False, help="Load (time series) data.")
def load(name: str, dir: str = BACKUP_PATH, structure: bool = True, data: bool = False):
    """Load backed-up contents (see `db-ops save`), run `reset` first."""
    if name:
        from flexmeasures.data.scripts.data_gen import load_tables

        load_tables(app.db, name, structure=structure, data=data, backup_path=dir)
    else:
        click.secho(
            "You must specify the name of the backup: --name <unique name>",
            **MsgStyle.ERROR,
        )


@fm_db_ops.command()
@with_appcontext
def dump():
    """
    Create a dump of all current data (using `pg_dump`).

    If you have a version mismatch between server and client, here is an alternative:


    $ docker run --pull=always -it postgres:15.7 bash  # use server version here

    $ docker exec -it <container> <the pg_dump command (see code)>

    $ docker cp <container>:<your-dump-filename> .

    $ docker stop <container>; docker rm <container>
    """
    db_uri = app.config.get("SQLALCHEMY_DATABASE_URI")
    db_host_and_db_name = db_uri.split("@")[-1]
    click.echo(f"Backing up {db_host_and_db_name} database")
    db_name = db_host_and_db_name.split("/")[-1]
    time_of_saving = datetime.now().strftime("%F-%H%M")
    dump_filename = f"pgbackup_{db_name}_{time_of_saving}.dump"
    command_for_dumping = f"pg_dump --no-privileges --no-owner --data-only --format=c --file={dump_filename} '{db_uri}'"
    try:
        subprocess.check_output(command_for_dumping, shell=True)
        click.secho(f"db dump successful: saved to {dump_filename}", **MsgStyle.SUCCESS)

    except Exception as e:
        click.secho(f"Exception happened during dump: {e}", **MsgStyle.ERROR)
        click.secho("db dump unsuccessful", **MsgStyle.ERROR)


@fm_db_ops.command()
@with_appcontext
@click.argument("file", type=click.Path(exists=True))
def restore(file: str):
    """Restore the dump file, see `db-ops dump` (run `reset` first).

    From the command line:

        % flexmeasures db-ops dump
        % flexmeasures db-ops reset
        % flexmeasures db-ops restore FILE

    """

    db_uri: str = app.config.get("SQLALCHEMY_DATABASE_URI")  # type: ignore
    db_host_and_db_name = db_uri.split("@")[-1]
    click.echo(f"Restoring {db_host_and_db_name} database from file {file}")
    command_for_restoring = f"pg_restore -d {db_uri} {file}"
    try:
        subprocess.check_output(command_for_restoring, shell=True)
        click.secho("db restore successful", **MsgStyle.SUCCESS)

    except Exception as e:
        click.secho(f"Exception happened during restore: {e}", **MsgStyle.ERROR)
        click.secho("db restore unsuccessful", **MsgStyle.ERROR)


app.cli.add_command(fm_db_ops)