import re
import math
import random
import string
import urllib2
from datetime import datetime, timedelta

import supybot.log as log
import supybot.conf as conf
import supybot.world as world
import supybot.ircutils as ircutils
import supybot.registry as registry

import globals

def registryValue(plugin, name, channel=None, value=True):
    group = conf.supybot.plugins.get(plugin)
    names = registry.split(name)
    for name in names:
        group = group.get(name)
    if channel is not None:
        try:
            if ircutils.isChannel(channel):
                group = group.get(channel)
            else:
                log.debug('registryValue got channel=%r', channel)
        except registry.NonExistentRegistryEntry:
            log.debug('non existent registry entry %r for channel %r', name, channel)
            pass
    if value:
        return group()
    else:
        return group

def configValue(name, channel=None, repo=None, type=None, module=None):
    if globals.configOverrides and name.lower() in globals.configOverrides:
        return globals.configOverrides[name.lower()]

    if channel == None and name not in ['channel', 'passcode', 'disallowChannelOverride', 'disallowConfigOverride']:
        channel = globals.channel

    return registryValue("Github", name, channel)

def addConfigOverride(name, value):
    if value.lower() == 'false':
        value = False;
    elif value.lower() == 'true':
        value = True;

    name = name.strip().lower()

    if name in [ 'passcode', 'disallowConfigOverride', 'allowArbitraryMessages' ]:
        return

    globals.configOverrides[name] = value

def resetConfigOverrides():
    globals.configOverrides = {}

def plural(number, s, p):
    if number != 1:
        return p
    return s

def parseBrackets(bracketConfig):
    if " " in bracketConfig:
        return tuple(bracketConfig.split(' ', 1))
    else:
        # Cut the config in the middle
        mid = len(bracketConfig)/2
        return (bracketConfig[:mid], bracketConfig[mid:])


def maxLen(msg, maxn=400, splitLines=True):
    """Cut down a string if its longer than `maxn` chars"""

    if splitLines is True:
        lines = msg.splitlines()
        line = lines[0]
    else:
        line = msg

    if len(line) > maxn:
        ret = "%s..." % (line[0:(maxn-3)])
    elif splitLines is True and len(lines) > 1:
        ret = "%s..." % (line)
    else:
        ret = msg
    return ret

def colorAction(action):
    """Give an action string (e.g. created, edited) and get a nice IRC colouring"""
    if action in [ "created", "opened", "tagged", "success", "passed", "fixed",
                   "published", "completed" ]:
        return ircutils.bold(ircutils.mircColor(action, "green"))
    if action in [ "deleted" ,"closed", "re-tagged", "deleted tag",
                   "failed", "errored", "failure", "still failing",
                   "broken" ]:
        return ircutils.bold(ircutils.mircColor(action, "red"))
    if action in [ "assigned", "merged" ]:
        return ircutils.bold(ircutils.mircColor(action, "light blue"))
    if action in [ "reopened", "pending" ]:
        return ircutils.bold(ircutils.mircColor(action, "blue"))
    if action in [ "forced the creation of", "forced the deletion of" ]:
        return ircutils.bold(ircutils.mircColor(action,"brown"))
    return action

def getShortURL(longurl):
    """ Returns a short URL generated by git.io"""
    if configValue("hideURL") is True:
        return None
    if configValue("shortURL") is False or not getShortURL.github.match(longurl):
        url = longurl
    else:
        data = 'url=%s' % (longurl)
        # Temporarily disabled
        url = longurl
        #req = urllib2.Request("https://git.io/", data)
        #response = urllib2.urlopen(req)
        #url = response.info().getheader('Location')
    return ircutils.mircColor(url, "purple")
getShortURL.github = re.compile('^([a-z]*\:\/\/)?([^\/]+.)?github.com')

def saveMessages(msgs):
    """ Saves the last messages so that the plugin can be easily tested """
    if not world.testing:
        return
    globals.messageList = msgs

def isYes(string):
    """Returns True if the string represents a yes, False, if it represents
    no, and another string if it represents something else"""
    value = string.strip().lower()

    if value in ['yes', 'always', 'on', 'true']:
        return True
    if value in ['no', 'never', 'off', 'false', 'null']:
        return False
    if value in ['changed', 'change', 'on_change', 'diff']:
        return 'change'

def isStatusVisible(repo, status):
    """Returns whether the build status message should be shown"""
    config = isYes(configValue('showSuccessfulBuildMessages'))

    changed = False
    if status != "passed":
        changed = True
    elif type(config) is bool:
        changed = config
    elif repo not in globals.travisStatuses or status != globals.travisStatuses[repo]:
        # Config is 'on_change'
        changed = True

    globals.travisStatuses[repo] = status
    return changed

def randomString(length):
    """Returns a securely generated random string of a specific length"""
    return ''.join(random.SystemRandom().choice(
        string.ascii_uppercase + string.ascii_lowercase + string.digits
    ) for _ in range(length))

def secureCompare(s1, s2):
    """Securely compare two strings"""
    return sum(i != j for i, j in zip(s1, s2)) is 0

def getChannelSecret(channel):
    """Returns a secret for a channel, or None if that channel has no secret"""
    if globals.secretDB is None:
        return None
    try:
        record = globals.secretDB.get(channel, 1)
        return record.secret
    except KeyError:
        return None

def showIssueName(repoId, issueId):
    """Returns whether we should show the issue name for a repo issue"""
    now = datetime.now()

    if not configValue("preventIssueNameSpam"):
        globals.shownIssues.clear()
        return True

    if not repoId in globals.shownIssues:
        globals.shownIssues[repoId] = {}

    # Clean up old issues
    remove = [k for k in globals.shownIssues[repoId] if now - globals.shownIssues[repoId][k] > timedelta(seconds = 15)]
    for k in remove: del globals.shownIssues[repoId][k]

    exists = issueId in globals.shownIssues[repoId]

    # Add our issue to the list
    globals.shownIssues[repoId][issueId] = now

    return not exists

def hexToMirc(hash):
    colors = {
        'white': (255, 255, 255),
        'black': (0, 0, 0),
        'blue': (0, 0, 127),
        'green': (0, 147, 0),
        'red': (255, 0, 0),
        'brown': (127, 0, 0),
        'purple': (156, 0, 156),
        'orange': (252, 127, 0),
        'yellow': (255, 255, 0),
        'light green': (0, 252, 0),
        'teal': (0, 147, 147),
        'light blue': (84, 255, 255),
        'dark blue': (84, 84, 255),
        'pink': (255, 0, 255),
        'dark grey': (127, 127, 127),
        'light grey': (230, 230, 230)
    }

    rgb = _hex_to_rgb(hash)

    return min(colors, key = lambda x:_colourDistance(colors[x], rgb))

def _hex_to_rgb(value):
    value = value.lstrip('#')
    lv = len(value)
    return tuple(int(value[i:i + lv // 3], 16) for i in range(0, lv, lv // 3))

def _colourDistance(a, b):
    # Source: http://www.compuphase.com/cmetric.htm
    rmean = (a[0] + b[0]) /2
    red = a[0] - b[0]
    green = a[1] - b[1]
    blue = a[2] - b[2]

    return math.sqrt((((512+rmean)*red*red)>>8) + 4*green*green + (((767-rmean)*blue*blue)>>8))
# Possible colours:
# white, black, (light/dark) blue, (light) green, red, brown, purple,
# orange, yellow, teal, pink, light/dark gray/grey