#!/usr/bin/env python3
###############################################################################
# $Id$
#
# Project:  GDAL
# Purpose:  Handles progress callback functions
# Author:   Idan Miara <idan@miara.com>
#
###############################################################################
# Copyright (c) 2020, Idan Miara <idan@miara.com>
#
# SPDX-License-Identifier: MIT
###############################################################################
from enum import Enum, auto
from numbers import Real
from typing import Callable, Optional, Union

from osgeo.gdal import TermProgress_nocb


class PredefinedProgressCallback(Enum):
    TermProgress = auto()  # default gdal core term progress
    TermProgressPy = (
        auto()
    )  # use this option to be able to put a breakpoint inside the callback
    TermProgressSimple = auto()  # simple print progress


ProgressCallback = Optional[Callable[[Real], None]]
OptionalProgressCallback = Union[
    type(...), PredefinedProgressCallback, ProgressCallback
]


def simple_term_progress(progress: Real):
    print(str(round(progress * 100)) + "%", end=" ")


def term_progress_from_to(r0: Optional[Real], r1: Real):
    """prints the progress from r0 to r1"""
    i0 = 0 if (r0 is None) or (r0 > r1) else round(r0 * 100) + 1
    i1 = round(r1 * 100) + 1
    for i in range(i0, i1):
        print(str(i) if i % 5 == 0 else ".", end="", flush=True)
    if r1 >= 1:
        print("% done!")


def get_py_term_progress_callback():
    term_progress_py_last = None

    def py_term_progress(progress: Real):
        nonlocal term_progress_py_last

        r0 = term_progress_py_last
        r1 = progress
        term_progress_from_to(r0, r1)
        term_progress_py_last = progress

    return py_term_progress


def get_progress_callback(callback: OptionalProgressCallback) -> ProgressCallback:
    """returns a predefined callback or the given callback"""
    if callback is None:
        return None
    elif callback == PredefinedProgressCallback.TermProgress or callback == ...:
        return TermProgress_nocb
    elif callback == PredefinedProgressCallback.TermProgressPy:
        return get_py_term_progress_callback()
    elif callback == PredefinedProgressCallback.TermProgressSimple:
        return simple_term_progress

    return callback