# -*- coding: utf-8 -*-

import imp
import os
import sys

import yaml


class PluginError(Exception):
    pass


class PluginUsageError(PluginError):
    pass


class ConfigError(Exception):

    def __init__(self, path, key):
        self.path = path
        self.key = key

    def __str__(self):
        return "invalid key: %r in %s" % (self.key, self.path)


class Config(object):

    def __init__(self, paths, valid_keys):
        self._valid_keys = valid_keys
        for path in paths:
            self.load(path)

    def __str__(self):
        ss = ["  %s: %s" % (vk, getattr(self, vk))
              for vk in self._valid_keys]
        return "\n".join(ss)

    def load(self, path):
        try:
            with open(path) as fh:
                conf = yaml.load(fh)
        except IOError:
            pass
        else:
            for key in conf.keys():
                if key in self._valid_keys:
                    setattr(self, key, conf[key])
                else:
                    raise ConfigError(path, key)


class XGPRenderer(object):

    def __init__(self, txt=None):
        self.txt = txt
        self.img = None
        self.tool = txt
        self.bar = None
        self.click = None
        self._fields = ['txt', 'img', 'tool', 'bar', 'click']

    def __str__(self):
        out = ""
        for field in self._fields:
            value = getattr(self, field, None)
            if value is not None:
                out += "<%(f)s>%(v)s</%(f)s>" % {'f': field, 'v': value}
        return out


class BasePlugin(object):

    def __init__(self, data):
        self.data = data

    def render(self):
        method_n = "render_" + self.data.fmt

        def ex(__):
            raise PluginError("plugin method not defined: " + method_n)

        render_fn = getattr(self, method_n, ex)
        return render_fn()

    def render_xgp(self):
        return XGPRenderer(self.render_plain())


class PluginData(object):

    def __init__(self, cmdargs):
        self.args = []
        self.fmt = "plain"
        self.maxlen = 40
        self.name = ""
        self._load(cmdargs)

    def _load(self, cmdargs):
        if cmdargs['--plain']:
            self.fmt = "plain"
        elif cmdargs['--xgp']:
            self.fmt = "xgp"
        self.name = cmdargs['COMMAND']
        self.args = cmdargs['ARGS']
        if cmdargs['--chars']:
            self.maxlen = int(cmdargs['--chars'])


class Subcommand(object):

    def __init__(self, cmdargs, pluginpath):
        self.plugindata = PluginData(cmdargs)
        self.name = cmdargs['COMMAND']
        self._load_plugin(pluginpath)

    def _load_plugin(self, pluginpath):
        modpath = "%s/%s.py" % (pluginpath, self.name)
        try:
            with open(modpath) as fh:
                module = imp.load_module(self.name, fh, modpath,
                                         (".py", "r", imp.PY_SOURCE))
        except IOError:
            raise PluginError("no such plugin: %s" % self.name)
        self.plugin = module.Plugin(self.plugindata)

    def _format_output(self, raw):
        suffix = u'…'
        cooked = raw.decode("utf-8")
        if self.plugindata.fmt == "plain":
            if self.plugindata.maxlen and len(cooked) > self.plugindata.maxlen:
                newlen = self.plugindata.maxlen - len(suffix)
                cooked = cooked[:newlen] + suffix
        return cooked.encode("utf-8")

    def get_output(self):
        return self._format_output(self.plugin.render())


class App:

    name = "sardine"

    cfg_paths = [
        '/etc/sardine/config',
        '%(HOME)s/.config/sardine/config' % os.environ,
        '.sardine.config'
    ]

    cfg_valid_keys = [
    ]

    def __init__(self, cmdargs):
        self.cmdargs = cmdargs
        self._set_pluginpath()
        self.config = Config(self.cfg_paths, self.cfg_valid_keys)

    def _set_pluginpath(self):
        mypath = os.path.dirname(os.path.realpath(sys.argv[0]))
        path = mypath + "/plugins"
        path = os.environ.get("SARDINE_PLUGINS", path)
        self.pluginpath = path

    def die(self, msg, rv=9):
        sys.stderr.write("%s\n" % msg)
        self.exit(rv)

    def exit(self, rv=0):
        sys.exit(rv)

    def run(self):
        try:
            self.subcommand = Subcommand(self.cmdargs, self.pluginpath)
            print self.subcommand.get_output()
        except PluginUsageError as e:
            msg = ("plugin usage: %s %s %s"
                   % (self.name, self.subcommand.name, e))
            self.die(msg, 11)
        except PluginError as e:
            self.die(e, 10)