#! /usr/bin/env python
# -*- coding: utf-8 -*-
# vim:fenc=utf-8

"""
Synchronize across config files
"""

from __future__ import annotations
from meerschaum.utils.typing import Optional, List

def sync_yaml_configs(
        config_path : pathlib.Path,
        keys : List[str],
        sub_path : pathlib.Path,
        substitute : bool = True,
        permissions : Optional[int] = None,
    ) -> None:
    """
    Synchronize sub-configuration with main configuration file.

    NOTE: This function might need refactoring to work better with the new
    `read_config` system.

    :param config_path:
        Not sure if this is necessary.

    :param keys:
        The config keys to read via `get_config()`.

    :param sub_path:
        The derivative file to write.

    :param substitute:
        If `True`, parse `MRSM{}` syntax and substitute values.
        See `get_config()` for more information.
        Defaults to `True`.

    :param permissions:
        If not `None`, set permissions of the derivative file.
        Defaults to `None`.
    """
    import os, sys
    try:
        from meerschaum.utils.yaml import yaml, _yaml
    except Exception as e:
        return
    from meerschaum.config._patch import apply_patch_to_config
    import meerschaum.config
    from meerschaum.utils.packages import reload_package
    from meerschaum.config._read_config import search_and_substitute_config
    if not os.path.isfile(config_path) or not os.path.isfile(sub_path):
        return

    def _read_config(path):
        """
        Read YAML file with header comment
        """
        header_comment = ""
        with open(path, 'r') as f:
            if _yaml is not None:
                config = yaml.load(f)
            else:
                print("PyYAML not installed!")
                sys.exit(1)
            f.seek(0)
            for line in f:
                if not line.startswith('#') and not line == '\n':
                    break
                header_comment += line
        return header_comment, config

    config_header, config = _read_config(config_path)
    sub_header, sub_config = _read_config(sub_path)

    from meerschaum.config import get_config
    c = get_config(*keys, substitute=substitute, sync_files=False)
    if substitute:
        sub_config = search_and_substitute_config(sub_config)

    if c != sub_config:
        config_time = os.path.getmtime(config_path)
        sub_time = os.path.getmtime(sub_path)

        sub_config = c
        new_config_text = yaml.dump(c, sort_keys=False)
        new_header = sub_header
        new_path = sub_path

        ### write changes
        with open(new_path, 'w+') as f:
            f.write(new_header)
            f.write(new_config_text)
    if permissions is not None:
        os.chmod(new_path, permissions)

def sync_files(keys : List[str] = []):
    def _stack():
        import os
        from meerschaum.config._paths import CONFIG_DIR_PATH, STACK_ENV_PATH, STACK_COMPOSE_PATH
        from meerschaum.config._paths import STACK_COMPOSE_FILENAME, STACK_ENV_FILENAME
        from meerschaum.config._paths import GRAFANA_DATASOURCE_PATH, GRAFANA_DASHBOARD_PATH
        from meerschaum.config._paths import MOSQUITTO_CONFIG_PATH

        sync_yaml_configs(
            CONFIG_DIR_PATH / 'stack.yaml',
            ['stack', STACK_COMPOSE_FILENAME],
            STACK_COMPOSE_PATH,
            substitute = True,
        )
        sync_yaml_configs(
            CONFIG_DIR_PATH / 'stack.yaml',
            ['stack', 'grafana', 'datasource'],
            GRAFANA_DATASOURCE_PATH,
            substitute = True,
        )
        sync_yaml_configs(
            CONFIG_DIR_PATH / 'stack.yaml',
            ['stack', 'grafana', 'dashboard'],
            GRAFANA_DASHBOARD_PATH,
            substitute = True,
        )


    key_functions = {
        'stack' : _stack,
    }
    if keys is None:
        keys = list(key_functions.keys())
    for k in keys:
        if k in key_functions:
            key_functions[k]()

