#!/usr/bin/env python3

"""
Utilities for mkdocs-macros
"""

import subprocess
from copy import deepcopy
import os, sys, importlib.util, shutil
from typing import Literal
from packaging.version import Version
import json
import inspect
from datetime import datetime
from typing import Any



from termcolor import colored
import mkdocs
import hjson



# ------------------------------------------
# Trace and debug
# ------------------------------------------
TRACE_COLOR = 'green'
TRACE_PREFIX = 'macros' 

import logging
LOG = logging.getLogger("mkdocs.plugins." + __name__)

MKDOCS_LOG_VERSION = '1.2'
if Version(mkdocs.__version__) < Version(MKDOCS_LOG_VERSION):
    # filter doesn't do anything since that version
    from mkdocs.utils import warning_filter
    LOG.addFilter(warning_filter)


def format_trace(*args, payload:str=''):
    """
    General purpose print function, as trace,
    for the mkdocs-macros framework;
    it will appear if --verbose option is activated

    The payload is simply some text that will be added after a newline.
    """
    first = args[0]
    rest = [str(el) for el in args[1:]]
    if payload:
        rest.append(f"\n{payload}")
    text = "[%s] - %s" % (TRACE_PREFIX, first)
    emphasized = colored(text, TRACE_COLOR)
    return ' '.join([emphasized] + rest)


TRACE_LEVELS = {
    'debug'   : logging.DEBUG,
    'info'    : logging.INFO,
    'warning' : logging.WARNING,
    'error'   : logging.ERROR,
    'critical': logging.CRITICAL
}

def trace(*args, payload:str='', level:str='info'):
    """
    General purpose print function, as trace,
    for the mkdocs-macros framework;
    it will appear unless --quiet option is activated.

    Payload is an information that goes to the next lines
    (typically a json dump)

    The level is 'debug', 'info', 'warning', 'error' or 'critical'.
    """
    msg = format_trace(*args, payload=payload)
    try:
        LOG.log(TRACE_LEVELS[level], msg)
    except KeyError:
        raise ValueError("Unknown level '%s' %s" % (level, 
                                                  tuple(TRACE_LEVELS.keys())
                                                  )
                            )
    return msg
    # LOG.info(msg)



def debug(*args, payload:str=''):
    """
    General purpose print function, as trace,
    for the mkdocs-macros framework;
    it will appear if --verbose option is activated
    """
    msg = format_trace(*args, payload=payload)
    LOG.debug(msg)


def get_log_level(level_name:str) -> bool:
    "Get the log level (INFO, DEBUG, etc.)"
    level = getattr(logging, level_name.upper(), None)
    return LOG.isEnabledFor(level)


def format_chatter(*args, prefix:str, color:str=TRACE_COLOR):
    """
    Format information for env.chatter() in macros.
    (This is specific for macros)
    """
    full_prefix = colored('[%s - %s] -' % (TRACE_PREFIX, prefix), 
                            color)
    args = [full_prefix] + [str(arg) for arg in args]
    msg = ' '.join(args)
    return msg



from collections import UserDict

class CustomEncoder(json.JSONEncoder):
    """
    Custom encoder for JSON serialization.
    Used for debugging purposes.
    """
    def default(self, obj: Any) -> Any:
        if isinstance(obj, datetime):
            return obj.isoformat()
        if isinstance(obj, UserDict):
            # for objects used by MkDocs (config, plugin, etc.s)
            return dict(obj)

        elif inspect.isfunction(obj):
            return f"Function: %s %s" % (inspect.signature(obj),
                                        obj.__doc__)
        try:
            return super().default(obj)
        except TypeError:
            debug(f"json: cannot encode {obj.__class__}")
            try:
                return str(obj)
            except Exception:
                # in case something happens along the line
                return f"!Non printable object: {obj.__class__}"





# ------------------------------------------
# Packages and modules
# ------------------------------------------

def parse_package(package:str):
    """
    Parse a package name

    if it is in the forme 'foo:bar' then 'foo' is the source, 
    and 'bar' is the (import) package name

    Returns the source name (for pip install) and the package name (for import)
    """
    l =  package.split(':')
    if len(l) == 1:
        source_name = package_name = l[0]
    else:
        source_name, package_name = l[:2]
    return source_name, package_name

def install_package(package:str):
    """
    Install a package from pip
    """
    try:
        subprocess.check_call(["pip3", "install", package])
    except subprocess.CalledProcessError:
        raise NameError("Could not install package '%s'" % package)


def import_local_module(project_dir, module_name):
    """
    Import a module from a pathname.
    """
    # get the full path
    if not os.path.isdir(project_dir):
        raise FileNotFoundError("Project dir does not exist: %s" % project_dir) 
    # there are 2 possibilities: dir or file
    pathname_dir = os.path.join(project_dir, module_name)
    pathname_file = pathname_dir + '.py'
    if os.path.isfile(pathname_file):
        spec = importlib.util.spec_from_file_location(module_name, 
                                                pathname_file)
        module = importlib.util.module_from_spec(spec)
        # execute the module
        spec.loader.exec_module(module)
        return module
    elif os.path.isdir(pathname_dir):
        # directory
        sys.path.insert(0, project_dir)
        # If the import is relative, then the package name must be given,
        # so that Python always knows how to call it.
        try:
            return importlib.import_module(module_name, package='main')
        except ImportError as e:
            # BUT Python will NOT allow an import past the root of the project;
            # this will fail when the module will actually be loaded.
            # the only way, is to insert the directory into the path
            sys.path.insert(0, module_name)
            module_name = os.path.basename(module_name)
            return importlib.import_module(module_name, package='main')
    else:
        return None


# ------------------------------------------
# Arithmetic
# ------------------------------------------
def update(d1, d2):
    """
    Update object d1, with object d2, recursively
    It has a simple behaviour:
    - if these are dictionaries, attempt to merge keys
      (recursively).
    - otherwise simply makes a deep copy.
    """
    BASIC_TYPES = (int, float, str, bool, complex)
    if isinstance(d1, dict) and isinstance(d2, dict):
        for key, value in d2.items():
            # print(key, value)
            if key in d1:
                # key exists
                if isinstance(d1[key], BASIC_TYPES):
                    d1[key] = value
                else:
                    update(d1[key], value)

            else:
                d1[key] = deepcopy(value)
    else:
        # if it is any kind of object
        d1 = deepcopy(d2)




# ------------------------------------------
# File system
# ------------------------------------------


def setup_directory(reference_dir: str, dir_name: str,
                    recreate:bool=True) -> str:
    """
    Create a new directory beside the specified one.
    
    Parameters:
    - reference_dir (str): The path of the current (reference) directory.
    - dir_name (str): The name of the new directory to be created beside the current directory.
    
    Returns
    - the directory
    """
    # Find the parent directory and define new path:
    parent_dir = os.path.dirname(reference_dir)
    new_dir = os.path.join(parent_dir, dir_name)
    # Safety: prevent deletion of current_dir
    if new_dir == parent_dir:
        raise FileExistsError("Cannot recreate the current dir!")
    # Safety: check if the new directory exists
    if os.path.exists(new_dir):
        # If it exists, empty its contents
        shutil.rmtree(new_dir)
    # Recreate the new directory
    if recreate:
        os.makedirs(new_dir)
    return new_dir

if __name__ == '__main__':
    # test merging of dictionaries
    a = {'foo': 4, 'bar': 5}
    b = {'foo': 5, 'baz': 6}
    update(a, b)
    print(a)
    assert a['foo'] == 5
    assert a['baz'] == 6

    a = {'foo': 4, 'bar': 5}
    b = {'foo': 5, 'baz': ['hello', 'world']}
    update(a, b)
    print(a)
    assert a['baz'] == ['hello', 'world']


    a = {'foo': 4, 'bar': {'first': 1, 'second': 2}}
    b = {'foo': 5, 'bar': {'first': 2, 'third': 3}}
    update(a, b)
    print(a)
    assert a['bar'] == {'first': 2, 'second': 2, 'third': 3}
    NEW =  {'hello': 5}
    c = {'bar': {'third': NEW}}
    update(a, c)
    print(a)
    assert a['bar']['third'] == NEW


    NEW = {'first': 2, 'third': 3}
    a = {'foo': 4}
    b = {'bar': NEW}
    update(a, b)
    print(a)
    assert a['bar'] == NEW