"""
Utilities for mermaid2 module
"""
import os
import requests
import logging
from packaging.version import Version

import mkdocs



# -------------------
# 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)

MERMAID_LABEL = "MERMAID2  -" # plugin's signature label


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

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

    The level is 'debug', 'info', 'warning', 'error' or 'critical'.
    """
    args = [MERMAID_LABEL] + [str(arg) for arg in args]
    msg = ' '.join(args)
    try:
        log.log(TRACE_LEVELS[level], msg)
    except KeyError:
        raise ValueError("Unknown level '%s' %s" % (level, 
                                                  tuple(TRACE_LEVELS.keys())
                                                  )
                            )
    return msg



def info(*args) -> str:
    "Write information on the console, preceded by the signature label"
    # args = [MERMAID_LABEL] + [str(arg) for arg in args]
    # msg = ' '.join(args)
    # log.info(msg)
    return trace(*args)
 
# -------------------
# Paths and URLs
# -------------------
def libname(lib:str) -> str:
    "Get the library name from a path -- not used"
    basename = os.path.basename(lib)
    # remove extension three times, e.g. mermaid.min.js => mermaid
    t = basename
    for _ in range(3):
        t = os.path.splitext(t)[0]
    return t



def url_exists(url:str, local_base_dir:str='') -> bool:
    "Checks that a url exists"
    if url.startswith('http'):
        try:
            request = requests.get(url)
            return request.status_code == 200
        except requests.exceptions.RequestException as e:
            trace("Cannot check URL, no Internet access? (%s):\n\n%s" % (url, e),
                  level='warning')
            return True
    else:
        pathname = os.path.join(local_base_dir, url)
        return os.path.exists(pathname)