#
# encoding: UTF-8
# api: streamtuner2
#  .2
# type: class
# title: global config object
# description: reads ~/.config/streamtuner/*.json files
# config: {type:var, name:z, description:v}
#
# In the main application or module files which need access
# to a global conf object, just import this module as follows:
#
#   from config import conf
#
# Here conf is already an instantiation of the underlying
# Config class.
#


import os
import sys
import json
import gzip
import platform
import re
import zipfile
import inspect


# export symbols
__all__ = ["conf", "__print__", "dbg", "plugin_meta"]



#-- create a single instance of config object
conf = object()

            self.__dict__ = self  # let's pray this won't leak memory due to recursion issues

            # prepare
            self.defaults()
            self.xdg()
            
            # runtime

            self.share = os.path.dirname(__file__)
            
            # settings from last session
            last = self.load("settings")
            if (last):
                self.update(last)
                self.migrate()
            # store defaults in file

        def find_in_dirs(self, dirs, file):
            for d in dirs:
                if os.path.exists(d+"/"+file):
                    return d+"/"+file



# Plugin meta data extraction
#
# Extremely crude version for Python and streamtuner2 plugin usage.
# Doesn't check top-level comment coherency.
# But supports plugins within python zip archives.
#
rx_zipfn  = re.compile(r"""^(.+\.(?:zip|pyz|pyzw|pyzip)(?:\.py)?)/(\w.*)$""")
rx_meta   = re.compile(r"""^ {0,4}# *([\w-]+): *(.+(\n *#  +(?![\w-]+:).+)*)$""", re.M)  # Python comments only
rx_lines  = re.compile(r"""\n *# """)        # strip multi-line prefixes
rx_config = re.compile(r"""[\{\<](.+?)[\}\>]""")     # extract only from JSOL/YAML scheme
rx_fields = re.compile(r"""["']?(\w+)["']?\s*[:=]\s*["']?([^,]+)(?<!["'])""")  # simple key: value entries
#
def plugin_meta(fn=None, frame=1, src=""):

    # filename of caller
    if not fn:
        fn = inspect.getfile(sys._getframe(frame))

    # within zip archive?
    zip = rx_zipfn.match(fn)
    if zip and zipfile.is_zipfile(zip.group(1)):
        src = zipfile.ZipFile(zip.group(1), "r").read(zip.group(2))
    else:
        src = open(fn).read(4096)

    # defaults
    meta = {
        "fn": fn,
        "id": os.path.basename(fn).replace(".py", "")
    }
    # extraction
    for field in rx_meta.findall(src):
        meta[field[0]] = rx_lines.sub("", field[1])

    # unpack config: structures
    meta["config"] = [
        dict([field for field in rx_fields.findall(entry)])
        for entry in rx_config.findall(meta.get("config", ""))
    ]
        
    return meta







# wrapper for all print statements
def __print__(*args):
    if conf.debug:
        print(" ".join([str(a) for a in args]))

   
#-- actually fill global conf instance
conf = ConfigDict()
if conf:
    __print__(dbg.PROC, "ConfigDict() initialized")