# SPDX-FileCopyrightText: : 2023-2024 The PyPSA-Eur Authors
#
# SPDX-License-Identifier: MIT

import copy
from functools import partial, lru_cache

import os, sys, glob

path = workflow.source_path("../scripts/_helpers.py")
sys.path.insert(0, os.path.dirname(path))

from _helpers import validate_checksum, update_config_from_wildcards
from snakemake.utils import update_config


def get_config(config, keys, default=None):
    """Retrieve a nested value from a dictionary using a tuple of keys."""
    value = config
    for key in keys:
        if isinstance(value, list):
            value = value[key]
        else:
            value = value.get(key, default)
        if value == default:
            return default
    return value


def merge_configs(base_config, scenario_config):
    """Merge base config with a specific scenario without modifying the original."""
    merged = copy.deepcopy(base_config)
    update_config(merged, scenario_config)
    return merged


@lru_cache
def scenario_config(scenario_name):
    """Retrieve a scenario config based on the overrides from the scenario file."""
    return merge_configs(config, scenarios[scenario_name])


def static_getter(wildcards, keys, default):
    """Getter function for static config values."""
    config_with_wildcards = update_config_from_wildcards(
        config, wildcards, inplace=False
    )
    return get_config(config_with_wildcards, keys, default)


def dynamic_getter(wildcards, keys, default):
    """Getter function for dynamic config values based on scenario."""
    if "run" not in wildcards.keys():
        return get_config(config, keys, default)
    scenario_name = wildcards.run
    if scenario_name not in scenarios:
        raise ValueError(
            f"Scenario {scenario_name} not found in file {config['run']['scenarios']['file']}."
        )
    config_with_scenario = scenario_config(scenario_name)
    config_with_wildcards = update_config_from_wildcards(
        config_with_scenario, wildcards, inplace=False
    )
    return get_config(config_with_wildcards, keys, default)


def config_provider(*keys, default=None):
    """Dynamically provide config values based on 'run' -> 'name'.

    Usage in Snakemake rules would look something like:
    params:
        my_param=config_provider("key1", "key2", default="some_default_value")
    """
    # Using functools.partial to freeze certain arguments in our getter functions.
    if config["run"].get("scenarios", {}).get("enable", False):
        return partial(dynamic_getter, keys=keys, default=default)
    else:
        return partial(static_getter, keys=keys, default=default)


def solver_threads(w):
    solver_options = config_provider("solving", "solver_options")(w)
    option_set = config_provider("solving", "solver", "options")(w)
    solver_option_set = solver_options[option_set]
    threads = solver_option_set.get("threads") or solver_option_set.get("Threads") or 4
    return threads


def memory(w):
    factor = 3.0
    for o in w.opts.split("-"):
        m = re.match(r"^(\d+)h$", o, re.IGNORECASE)
        if m is not None:
            factor /= int(m.group(1))
            break
    for o in w.opts.split("-"):
        m = re.match(r"^(\d+)seg$", o, re.IGNORECASE)
        if m is not None:
            factor *= int(m.group(1)) / 8760
            break
    if w.clusters == "all":
        return int(factor * (18000 + 180 * 4000))
    else:
        return int(factor * (10000 + 195 * int(w.clusters)))


def input_custom_extra_functionality(w):
    path = config_provider(
        "solving", "options", "custom_extra_functionality", default=False
    )(w)
    if path:
        return os.path.join(os.path.dirname(workflow.snakefile), path)
    return []


def has_internet_access(url: str = "https://www.zenodo.org", timeout: int = 3) -> bool:
    """
    Checks if internet connection is available by sending a HEAD request
    to a reliable server like Google.

    Parameters:
    - url (str): The URL to check for internet connection. Default is Google.
    - timeout (int | float): The maximum time (in seconds) the request should wait.

    Returns:
    - bool: True if the internet is available, otherwise False.
    """
    try:
        # Send a HEAD request to avoid fetching full response
        response = requests.head(url, timeout=timeout, allow_redirects=True)
        return response.status_code == 200
    except requests.ConnectionError:  # (e.g., no internet, DNS issues)
        return False
    except requests.Timeout:  # (e.g., slow or no network)
        return False


def solved_previous_horizon(w):
    planning_horizons = config_provider("scenario", "planning_horizons")(w)
    i = planning_horizons.index(int(w.planning_horizons))
    planning_horizon_p = str(planning_horizons[i - 1])

    return (
        RESULTS
        + "postnetworks/base_s_{clusters}_l{ll}_{opts}_{sector_opts}_"
        + planning_horizon_p
        + ".nc"
    )