# -*- coding: utf-8  -*-
#
# Copyright (C) 2016 Ben Kurtovic <ben.kurtovic@gmail.com>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

from collections import deque
from datetime import datetime
from threading import Thread

from earwigbot.commands import Command
from earwigbot.irc import RC

class RCMonitor(Command):
    """Monitors the recent changes feed for certain edits and reports them to a
    dedicated channel."""
    name = "rc_monitor"
    hooks = ["msg", "rc"]

    def setup(self):
        try:
            self._channel = self.config.commands[self.name]["channel"]
        except KeyError:
            self._channel = None
            log = ('Cannot use without a report channel set as '
                   'config.commands["{0}"]["channel"]')
            self.logger.warn(log.format(self.name))

        self._stats = {
            "start": datetime.utcnow(),
            "edits": 0,
            "hits": 0,
            "max_backlog": 0
        }
        self._levels = {}
        self._issues = {}
        self._descriptions = {}
        self._queue = deque()

        self._thread = Thread(target=self._callback, name="rc_monitor")
        self._thread.daemon = True
        self._thread.running = True
        self._prepare_reports()
        self._thread.start()

    def check(self, data):
        if not self._channel:
            return
        return isinstance(data, RC) or (
            data.is_command and data.command == self.name)

    def process(self, data):
        if isinstance(data, RC):
            newlen = len(self._queue) + 1
            self._queue.append(data)
            if newlen > self._stats["max_backlog"]:
                self._stats["max_backlog"] = newlen
            return

        if not self.config.irc["permissions"].is_admin(data):
            self.reply(data, "You must be a bot admin to use this command.")
            return

        since = self._stats["start"].strftime("%H:%M:%S, %d %B %Y")
        seconds = (datetime.utcnow() - self._stats["start"]).total_seconds()
        rate = self._stats["edits"] / seconds
        msg = ("\x02{edits:,}\x0F edits checked since {since} "
               "(\x02{rate:.2f}\x0F edits/sec); \x02{hits:,}\x0F hits; "
               "\x02{backlog:,}\x0F-edit backlog (\x02{max_backlog:,}\x0F "
               "max).")
        self.reply(data, msg.format(
            since=since, rate=rate, backlog=len(self._queue), **self._stats))

    def unload(self):
        self._thread.running = False
        self._queue.append(None)

    def _prepare_reports(self):
        """Set up internal tables for storing report information."""
        routine = 1
        alert = 2
        urgent = 3

        self._levels = {
            routine: "routine",
            alert: "alert",
            urgent: "URGENT"
        }
        self._issues = {
            "random": routine,
            "random2": urgent,
            # ...
            "g10": alert
        }
        self._descriptions = {
            "random": "common random test",
            "random2": "rare random test",
            # ...
            "g10": "CSD G10 nomination"
        }

    def _evaluate(self, event):
        """Return heuristic information about the given RC event."""
        issues = []

        # TODO
        from random import random
        rand = random()
        if rand < 0.05:
            issues.append("random")
        if rand < 0.01:
            issues.append("random2")
        # END TODO

        issues.sort(key=lambda issue: self._issues[issue], reverse=True)
        return issues

    def _format(self, rc, report):
        """Format a RC event for the report channel."""
        level = self._levels[max(self._issues[issue] for issue in report)]
        descr = ", ".join(self._descriptions[issue] for issue in report)
        notify = " ".join("!rcm-" + issue for issue in report)
        cmnt = rc.comment if len(rc.comment) <= 50 else rc.comment[:47] + "..."

        msg = ("[\x02{level}\x0F] ({descr}) [\x02{notify}\x0F]\x0306 * "
               "\x0314[[\x0307{title}\x0314]]\x0306 * \x0303{user}\x0306 * "
               "\x0302{url}\x0306 * \x0310{comment}")
        return msg.format(
            level=level, descr=descr, notify=notify, title=rc.page,
            user=rc.user, url=rc.url, comment=cmnt)

    def _handle_event(self, event):
        """Process a recent change event."""
        if not event.is_edit:
            return
        report = self._evaluate(event)
        self._stats["edits"] += 1
        if report:
            self.say(self._channel, self._format(event, report))
            self._stats["hits"] += 1

    def _callback(self):
        """Internal callback for the RC monitor thread."""
        while self._thread.running:
            event = self._queue.popleft()
            if not self._thread.running:
                break
            self._handle_event(event)