#
# encoding: UTF-8
# api: streamtuner2
# 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 *
#
# Here conf is already an instantiation of the underlying
# ConfigDoct class.
#
# Also provides the logging function __print__, and basic
# plugin handling code: plugin_meta() and module_list(),
# and the relative get_data() alias (files from pyzip/path).
#


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

# find_executable() is only needed by channels/configwin
try:
    from distutils.spawn import find_executable
except:
    def find_executable(bin):
        exists = [os.path.exists(dir+"/"+bin) for dir in os.environ.get("PATH").split(":")+["/"]]
        return exists[0] if len(exists) else None


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


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

# separate instance of netrc, if needed
netrc = None




# Global configuration store
#
# Autointializes itself on startup, makes conf.vars available.
# Also provides .load() and .save() for JSON data/cache files.
#
class ConfigDict(dict):


    # start
    def __init__(self):
    
        # object==dict means conf.var is conf["var"]
        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(os.path.abspath(__file__))
        
        # settings from last session
        last = self.load("settings")
        if (last):
            if "share" in last:
                del last["share"]
            self.update(last)
            self.migrate()
        # store defaults in file
        else:
            self.save("settings")
            self.firstrun = 1


    # some defaults
    def defaults(self):
        self.play = {
           "audio/mpeg": "audacious ",	# %u for url to .pls, %g for downloaded .m3u
           "audio/ogg": "audacious ",
           "audio/*": "audacious ",
           "video/youtube": "totem $(youtube-dl -g %srv)",
           "video/*": "vlc --one-instance %srv",
           "url/http": "sensible-browser",
        }
        self.record = {
           "audio/*": "xterm -e streamripper %srv",   # -d /home/***USERNAME***/Musik
           "video/youtube": "xterm -e \"youtube-dl %srv\"",
        }
        self.plugins = {
            "bookmarks": 1, # built-in plugin, cannot be disabled
            "search": 1,
            "streamedit": 1,
            "configwin": 1,
            "shoutcast": 1,
            "xiph": 1,
            "modarchive": 0, # disable per default
            "file": 0,      # disable per default
            "punkcast": 0,  # disable per default
            "history": 0,
            "basicch": 0,   # ceased
            "tv": 0,        # ceased
        }
        self.tmp = os.environ.get("TEMP", "/tmp")
        self.max_streams = "500"
        self.show_bookmarks = 1
        self.show_favicons = 1
        self.load_favicon = 1
        self.heuristic_bookmark_update = 0
        self.retain_deleted = 0
        self.auto_save_appstate = 1
        self.theme = "" #"MountainDew"
        self.channel_order = "shoutcast, xiph, internet_radio, jamendo, myoggradio, .."
        self.reuse_m3u = 1
        self.google_homepage = 0
        self.windows = platform.system()=="Windows"
        self.pyquery = 1
        self.debug = 0

        
    # each plugin has a .config dict list, we add defaults here
    def add_plugin_defaults(self, meta, module=""):
    
        # options
        config = meta.get("config", [])
        for opt in config:
            if ("name" in opt) and ("value" in opt) and (opt["name"] not in vars(self)):
                self.__dict__[opt["name"]] = opt["value"]

        # plugin state
        if module and module not in conf.plugins:
             conf.plugins[module] = meta.get("priority") in ("core", "builtin", "default", "standard")

    
        
    # http://standards.freedesktop.org/basedir-spec/basedir-spec-0.6.html
    def xdg(self, path="/streamtuner2"):
        home = os.environ.get("HOME", self.tmp)
        config = os.environ.get("XDG_CONFIG_HOME", os.environ.get("APPDATA", home+"/.config"))
        
        # storage dir
        self.dir = config + path
        
        # create if necessary
        if (not os.path.exists(self.dir)):
            os.makedirs(self.dir)
       

    # store some configuration list/dict into a file                
    def save(self, name="settings", data=None, gz=0, nice=0):
        name = name + ".json"
        if (data is None):
            data = dict(self.__dict__)  # ANOTHER WORKAROUND: typecast to plain dict(), else json filter_data sees it as object and str()s it
            nice = 1
        # check for subdir
        if (name.find("/") > 0):
            subdir = name[0:name.find("/")]
            subdir = self.dir + "/" + subdir
            if (not os.path.exists(subdir)):
                os.mkdir(subdir)
                open(subdir+"/.nobackup", "w").close()
        # write                        
        file = self.dir + "/" + name
        # .gz or normal file
        if gz:
            f = gzip.open(file+".gz", "w")
            if os.path.exists(file):
                os.unlink(file)
        else:
            f = open(file, "w")
        # encode
        data = json.dumps(data, indent=(4 if nice else None))
        try:
            f.write(data.encode("utf-8"))
        except TypeError as e:
            f.write(data)  # Python3 sometimes wants to write strings rather than bytes
        f.close()


    # retrieve data from config file            
    def load(self, name):
        name = name + ".json"
        file = self.dir + "/" + name
        try:
            # .gz or normal file
            if os.path.exists(file + ".gz"):
                f = gzip.open(file + ".gz", "rt")
            elif os.path.exists(file):
                f = open(file, "rt")
            else:
                return # file not found
            # decode
            r = json.load(f)
            f.close()
            return r
        except Exception as e:
            __print__(dbg.ERR, "JSON parsing error (in "+name+")", e)
        

    # recursive dict update
    def update(self, with_new_data):
        for key,value in with_new_data.items():
            if type(value) == dict:
                self[key].update(value)
            else:
                self[key] = value
        # descends into sub-dicts instead of wiping them with subkeys

    # update old setting names
    def migrate(self):
        # 2.1.1
        if "audio/mp3" in self.play:
            self.play["audio/mpeg"] = self.play["audio/mp3"]
            del self.play["audio/mp3"]

         
    # check for existing filename in directory list
    def find_in_dirs(self, dirs, file):
        for d in dirs:
            if os.path.exists(d+"/"+file):
                return d+"/"+file

    # standard user account storage in ~/.netrc or less standard but contemporarily in ~/.config/netrc
    def netrc(self, varhosts=("shoutcast.com")):
        global netrc
        if not netrc:
            netrc = {}
            try:
                from netrc import netrc as parser
                try:
                     netrc = parser().hosts
                except:
                     netrc = parser(self.xdg() + "/netrc").hosts
            except:
                pass
        for server in varhosts:
            if server in netrc:
                return netrc[server]
        


# Retrieve content from install path or pyzip archive (alias for pkgutil.get_data)
#
def get_data(fn, decode=False):
    try:
        bin = pkgutil.get_data("config", fn)
        if decode:
            return bin.decode("utf-8")
        else:
            return str(bin)
    except:
        pass


# Search through ./channels/ and get module basenames.
# Also order them by conf.channel_order
#
def module_list():

    # Should list plugins within zips as well as local paths
    ls = pkgutil.iter_modules([conf.share+"/channels", "channels"])
    ls = [name for loader,name,ispkg in ls]
    
    # resort with tab order
    order = [module.strip() for module in conf.channel_order.lower().replace(".","_").replace("-","_").split(",")]
    ls = [module for module in (order) if (module in ls)] + [module for module in (ls) if (module not in order)]

    return ls



# Plugin meta data extraction
#
# Extremely crude version for Python and streamtuner2 plugin usage.
# Fetches module source, or reads from filename / out of zip package.
#
def plugin_meta(fn=None, src=None, frame=1):

    # get source directly from caller
    if not src and not fn:
        module = inspect.getmodule(sys._getframe(frame))
        fn = inspect.getsourcefile(module)
        src = inspect.getcomments(module)

    # within zip archive or dir?
    elif fn:
        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 = {
        "id": re.sub("\.\w+$", "", os.path.basename(fn or "")),
        "fn": fn,
        "title": fn, "description": "no description", "config": [],
        "type": "module", "api": "python", "doc": ""
    }

    # extract coherent comment block, split doc section
    src = rx.comment.search(src)
    if not src:
        __print__(dbg.ERR, "Couldn't read source meta information", fn)
        return meta
    src = src.group(0)
    src = rx.hash.sub("", src).strip()
    if src.find("\n\n") > 0:
        src, meta["doc"] = src.split("\n\n", 1)
    

    # split into dict
    for field in rx.keyval.findall(src):
        meta[field[0]] = field[1].strip()
    meta["config"] = plugin_meta_config(meta.get("config") or "")

    return meta

# unpack config: structures
def plugin_meta_config(str):
    config = []
    for entry in rx.config.findall(str):
        opt = { "type": None, "name": None, "description": "", "value": None }
        for field in rx.options.findall(entry):
            opt[field[0]] = (field[1] or field[2] or field[3] or "").strip()
        config.append(opt)
    return config

# Comment extraction regexps
class rx:
    zipfn   = re.compile(r"""
        ^ (.+  \.(?:zip|pyz|pyzw|pyzip)        # zip-wrapping extensions
        (?:\.py)? ) /(\w.*) $
    """, re.X)
    comment = re.compile(r"""(^ {0,4}#.*\n)+""", re.M)
    hash    = re.compile(r"""(^ {0,4}# *)""", re.M)
    keyval  = re.compile(r"""
        ^([\w-]+):(.*$(?:\n(?![\w-]+:).+$)*)      # plain key:value lines
    """, re.M|re.X)
    config  = re.compile(r"""
        [\{\<] (.+?) [\}\>]                    # JSOL/YAML scheme {...} dicts
    """, re.X)
    options = re.compile(r"""
        ["':$]?   (\w*)  ["']?                 # key or ":key" or '$key'
        \s* [:=] \s*                           # "=" or ":"
     (?:  "  ([^"]*)  " 
       |  '  ([^']*)  '                        #  "quoted" or 'singl' values
       |     ([^,]*)                           #  or unquoted literals
     )
    """, re.X)




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


# error colorization
dbg = type('obj', (object,), {
    "ERR":  r"[31m[ERR][0m",  # red    ERROR
    "INIT": r"[31m[INIT][0m", # red    INIT ERROR
    "PROC": r"[32m[PROC][0m", # green  PROCESS
    "CONF": r"[33m[CONF][0m", # brown  CONFIG DATA
    "UI":   r"[34m[UI][0m",   # blue   USER INTERFACE BEHAVIOUR
    "HTTP": r"[35m[HTTP][0m", # magenta HTTP REQUEST
    "DATA": r"[36m[DATA][0m", # cyan   DATA
    "INFO": r"[37m[INFO][0m", # gray   INFO
    "STAT": r"[37m[STATE][0m", # gray  CONFIG STATE
})




   

#-- populate global conf instance
conf = ConfigDict()
__print__(dbg.PROC, "ConfigDict() initialized")
