#!/usr/bin/env python3

import enum
import threading
import time
import i3ipc
import os
import signal
import subprocess
import logging
import coloredlogs
import updaters

coloredlogs.install(level='DEBUG', fmt='%(levelname)s %(message)s')
log = logging.getLogger()


# TODO Allow deletion of Bar, BarGroup and Section for screen changes
# IDEA Use i3 ipc events rather than relying on xrandr or Xlib (less portable
# but easier)
# TODO Optimize to use write() calls instead of string concatenation (writing
# BarGroup strings should be a good compromise)
# TODO Use bytes rather than strings
# TODO Use default colors of lemonbar sometimes
# TODO Adapt bar height with font height
# TODO OPTI Static text objects that update its parents if modified
# TODO OPTI Updater locks, do not LB screen util every updater finished


class BarGroupType(enum.Enum):
    LEFT = 0
    RIGHT = 1
    # TODO Middle
    # MID_LEFT = 2
    # MID_RIGHT = 3


class BarStdoutThread(threading.Thread):
    def run(self):
        while Bar.running:
            handle = Bar.process.stdout.readline().strip()
            if not len(handle):
                continue
            if handle not in Bar.actionsH2F:
                log.error("Unknown action: {}".format(handle))
                continue
            function = Bar.actionsH2F[handle]
            function()


class Bar:
    """
    One bar for each screen
    """

    # Constants
    FONTS = ["DejaVu Sans Mono for Powerline", "Font Awesome"]
    FONTSIZE = 10

    @staticmethod
    def init():
        Bar.running = True
        Section.init()

        cmd = ['lemonbar', '-b', '-a', '64']
        for font in Bar.FONTS:
            cmd += ["-f", "{}:size={}".format(font, Bar.FONTSIZE)]
        Bar.process = subprocess.Popen(cmd, stdin=subprocess.PIPE,
                                       stdout=subprocess.PIPE)
        Bar.stdoutThread  = BarStdoutThread()
        Bar.stdoutThread.start()

        # Debug
        Bar(0)
        # Bar(1)

    @staticmethod
    def stop():
        Bar.running = False
        Bar.process.kill()

        # TODO This is not really the best way to do it I guess
        os.killpg(os.getpid(), signal.SIGTERM)

    @staticmethod
    def run():
        Bar.forever()
        i3 = i3ipc.Connection()

        def doStop(*args):
            Bar.stop()
            print(88)

        try:
            i3.on('ipc_shutdown', doStop)
            i3.main()
        except BaseException:
            print(93)
            Bar.stop()

    # Class globals
    everyone = set()
    string = ""
    process = None
    running = False

    nextHandle = 0
    actionsF2H = dict()
    actionsH2F = dict()

    @staticmethod
    def getFunctionHandle(function):
        assert callable(function)
        if function in Bar.actionsF2H.keys():
            return Bar.actionsF2H[function]

        handle = '{:x}'.format(Bar.nextHandle).encode()
        Bar.nextHandle += 1

        Bar.actionsF2H[function] = handle
        Bar.actionsH2F[handle] = function

        return handle

    @staticmethod
    def forever():
        try:
            while True:
                time.sleep(60)
        except BaseException:
            Bar.stop()

    def __init__(self, screen):
        assert isinstance(screen, int)
        self.screen = "%{S" + str(screen) + "}"
        self.groups = dict()

        for groupType in BarGroupType:
            group = BarGroup(groupType, self)
            self.groups[groupType] = group

        self.childsChanged = False

        self.everyone.add(self)

    @staticmethod
    def addSectionAll(section, group, screens=None):
        """
        .. note::
            Add the section before updating it for the first time.
        """
        assert isinstance(section, Section)
        assert isinstance(group, BarGroupType)
        # TODO screens selection
        for bar in Bar.everyone:
            bar.addSection(section, group=group)

    def addSection(self, section, group):
        assert isinstance(section, Section)
        assert isinstance(group, BarGroupType)
        self.groups[group].addSection(section)

    def update(self):
        if self.childsChanged:
            self.string = self.screen
            self.string += self.groups[BarGroupType.LEFT].string
            self.string += self.groups[BarGroupType.RIGHT].string

            self.childsChanged = False

    @staticmethod
    def updateAll():

        if Bar.running:
            Bar.string = ""
            for bar in Bar.everyone:
                bar.update()
                Bar.string += bar.string
            # Color for empty sections
            Bar.string += BarGroup.color(*Section.EMPTY)

            Bar.process.stdin.write(bytes(Bar.string + '\n', 'utf-8'))
            Bar.process.stdin.flush()


class BarGroup:
    """
    One for each group of each bar
    """

    everyone = set()

    def __init__(self, groupType, parent):
        assert isinstance(groupType, BarGroupType)
        assert isinstance(parent, Bar)

        self.groupType = groupType
        self.parent = parent

        self.sections = list()
        self.string = ''
        self.parts = []

        #: One of the sections that had their theme or visibility changed
        self.childsThemeChanged = False

        #: One of the sections that had their text (maybe their size) changed
        self.childsTextChanged = False

        BarGroup.everyone.add(self)

    def addSection(self, section):
        self.sections.append(section)
        section.addParent(self)

    def addSectionAfter(self, sectionRef, section):
        index = self.sections.index(sectionRef)
        self.sections.insert(index + 1, section)
        section.addParent(self)

    ALIGNS = {BarGroupType.LEFT: "%{l}", BarGroupType.RIGHT: "%{r}"}

    @staticmethod
    def fgColor(color):
        return "%{F" + (color or '-') + "}"

    @staticmethod
    def bgColor(color):
        return "%{B" + (color or '-') + "}"

    @staticmethod
    def color(fg, bg):
        return BarGroup.fgColor(fg) + BarGroup.bgColor(bg)

    def update(self):
        if self.childsThemeChanged:
            parts = [BarGroup.ALIGNS[self.groupType]]

            secs = [sec for sec in self.sections if sec.visible]
            lenS = len(secs)
            for s in range(lenS):
                sec = secs[s]
                theme = Section.THEMES[sec.theme]
                if self.groupType == BarGroupType.LEFT:
                    oSec = secs[s + 1] if s < lenS - 1 else None
                else:
                    oSec = secs[s - 1] if s > 0 else None
                oTheme = Section.THEMES[oSec.theme] \
                    if oSec is not None else Section.EMPTY

                if self.groupType == BarGroupType.LEFT:
                    if s == 0:
                        parts.append(BarGroup.bgColor(theme[1]))
                    parts.append(BarGroup.fgColor(theme[0]))
                    parts.append(sec)
                    if theme == oTheme:
                        parts.append("")
                    else:
                        parts.append(BarGroup.color(theme[1], oTheme[1]) + "")
                else:
                    if theme is oTheme:
                        parts.append("")
                    else:
                        parts.append(BarGroup.fgColor(theme[1]) + "")
                        parts.append(BarGroup.color(*theme))
                    parts.append(sec)


            # TODO OPTI Concatenate successive strings
            self.parts = parts

        if self.childsTextChanged or self.childsThemeChanged:
            self.string = ""
            for part in self.parts:
                if isinstance(part, str):
                    self.string += part
                elif isinstance(part, Section):
                    self.string += part.curText

            self.parent.childsChanged = True

            self.childsThemeChanged = False
            self.childsTextChanged = False

    @staticmethod
    def updateAll():
        for group in BarGroup.everyone:
            group.update()
        Bar.updateAll()


class SectionThread(threading.Thread):
    ANIMATION_START = 0.025
    ANIMATION_STOP = 0.001
    ANIMATION_EVOLUTION = 0.9

    def run(self):
        while Section.somethingChanged.wait():
            updaters.notBusy.wait()
            Section.updateAll()
            animTime = self.ANIMATION_START
            frameTime = time.perf_counter()
            while len(Section.sizeChanging) > 0:
                frameTime += animTime
                curTime = time.perf_counter()
                sleepTime = frameTime - curTime
                time.sleep(sleepTime if sleepTime > 0 else 0)
                Section.updateAll()
                animTime *= self.ANIMATION_EVOLUTION
                if animTime < self.ANIMATION_STOP:
                    animTime = self.ANIMATION_STOP


class Section:

    # TODO Update all of that to base16
    # COLORS = ['#272822', '#383830', '#49483e', '#75715e', '#a59f85', '#f8f8f2',
    #           '#f5f4f1', '#f9f8f5', '#f92672', '#fd971f', '#f4bf75', '#a6e22e',
    #           '#a1efe4', '#66d9ef', '#ae81ff', '#cc6633']
    COLORS = ['#181818', '#AB4642', '#A1B56C', '#F7CA88', '#7CAFC2', '#BA8BAF',
              '#86C1B9', '#D8D8D8', '#585858', '#AB4642', '#A1B56C', '#F7CA88',
              '#7CAFC2', '#BA8BAF', '#86C1B9', '#F8F8F8']
    FGCOLOR = '#F8F8F2'
    BGCOLOR = '#272822'

    THEMES = list()
    EMPTY = (FGCOLOR, BGCOLOR)

    ICON = None
    PERSISTENT = False

    #: Sections that do not have their destination size
    sizeChanging = set()
    updateThread = SectionThread(daemon=True)
    somethingChanged = threading.Event()
    lastChosenTheme = 0

    @staticmethod
    def init():
        for t in range(8, 16):
            Section.THEMES.append((Section.COLORS[0], Section.COLORS[t]))

        Section.updateThread.start()

    def __init__(self, theme=None):
        #: Displayed section
        #: Note: A section can be empty and displayed!
        self.visible = False

        if theme is None:
            theme = Section.lastChosenTheme
            Section.lastChosenTheme = (Section.lastChosenTheme + 1) \
                % len(Section.THEMES)
        self.theme = theme

        #: Displayed text
        self.curText = ''
        #: Displayed text size
        self.curSize = 0

        #: Destination text
        self.dstText = Text(' ', Text(), ' ')
        #: Destination size
        self.dstSize = 0

        #: Groups that have this section
        self.parents = set()

        self.icon = self.ICON
        self.persistent = self.PERSISTENT


    def __str__(self):
        try:
            return "<{}><{}>{:01d}{}{:02d}/{:02d}" \
                .format(self.curText, self.dstText,
                        self.theme, "+" if self.visible else "-",
                        self.curSize, self.dstSize)
        except:
            return super().__str__()

    def addParent(self, parent):
        self.parents.add(parent)

    def appendAfter(self, section):
        assert len(self.parents)
        for parent in self.parents:
            parent.addSectionAfter(self, section)

    def informParentsThemeChanged(self):
        for parent in self.parents:
            parent.childsThemeChanged = True

    def informParentsTextChanged(self):
        for parent in self.parents:
            parent.childsTextChanged = True

    def updateText(self, text):
        if isinstance(text, str):
            text = Text(text)
        elif isinstance(text, Text) and not len(text.elements):
            text = None

        self.dstText[0] = None if (text is None and not self.persistent) else ((' ' + self.icon + ' ') if self.icon else ' ')
        self.dstText[1] = text
        self.dstText[2] = ' ' if self.dstText[1] is not None and len(self.dstText[1]) else None

        self.dstSize = len(self.dstText)
        self.dstText.setSection(self)

        if self.curSize == self.dstSize:
            if self.dstSize > 0:
                self.curText = str(self.dstText)
                self.informParentsTextChanged()
        else:
            Section.sizeChanging.add(self)
        Section.somethingChanged.set()

    def setDecorators(self, **kwargs):
        self.dstText.setDecorators(**kwargs)
        self.curText = str(self.dstText)
        self.informParentsTextChanged()
        Section.somethingChanged.set()

    def updateTheme(self, theme):
        assert isinstance(theme, int)
        assert theme < len(Section.THEMES)
        if theme == self.theme:
            return
        self.theme = theme
        self.informParentsThemeChanged()
        Section.somethingChanged.set()

    def updateVisibility(self, visibility):
        assert isinstance(visibility, bool)

        self.visible = visibility
        self.informParentsThemeChanged()
        Section.somethingChanged.set()

    @staticmethod
    def fit(text, size):
        t = len(text)
        return text[:size] if t >= size else text + [" "] * (size - t)

    def update(self):
        # TODO Might profit of a better logic
        if not self.visible:
            self.updateVisibility(True)
            return

        if self.dstSize > self.curSize:
            self.curSize += 1
        elif self.dstSize < self.curSize:
            self.curSize -= 1
        else:
            # Visibility toggling must be done one step after curSize = 0
            if self.dstSize == 0:
                self.updateVisibility(False)
            Section.sizeChanging.remove(self)
            return

        self.curText = self.dstText.text(size=self.curSize, pad=True)
        self.informParentsTextChanged()

    @staticmethod
    def updateAll():
        """
        Process all sections for text size changes
        """

        for sizeChanging in Section.sizeChanging.copy():
            sizeChanging.update()

        BarGroup.updateAll()

        Section.somethingChanged.clear()

    @staticmethod
    def ramp(p, ramp=" ▁▂▃▄▅▆▇█"):
        if p > 1:
            return ramp[-1]
        elif p < 0:
            return ramp[0]
        else:
            return ramp[round(p * (len(ramp)-1))]


class StatefulSection(Section):
    # TODO FEAT Allow to temporary expand the section (e.g. when important change)
    NUMBER_STATES = None
    DEFAULT_STATE = 0

    def __init__(self, *args, **kwargs):
        Section.__init__(self, *args, **kwargs)
        self.state = self.DEFAULT_STATE
        if hasattr(self, 'onChangeState'):
            self.onChangeState(self.state)
        self.setDecorators(clickLeft=self.incrementState,
                                   clickRight=self.decrementState)

    def incrementState(self):
        newState = min(self.state + 1, self.NUMBER_STATES - 1)
        self.changeState(newState)

    def decrementState(self):
        newState = max(self.state - 1, 0)
        self.changeState(newState)

    def changeState(self, state):
        assert isinstance(state, int)
        assert state < self.NUMBER_STATES
        self.state = state
        if hasattr(self, 'onChangeState'):
            self.onChangeState(state)
        self.refreshData()

class ColorCountsSection(StatefulSection):
    # TODO FEAT Blend colors when not expanded
    # TODO FEAT Blend colors with importance of count
    # TODO FEAT Allow icons instead of counts
    NUMBER_STATES = 3
    COLORABLE_ICON = '?'

    def __init__(self, theme=None):
        StatefulSection.__init__(self, theme=theme)

    def fetcher(self):
        counts = self.subfetcher()
        # Nothing
        if not len(counts):
            return None
        # Icon colored
        elif self.state == 0 and len(counts) == 1:
            count, color = counts[0]
            return Text(self.COLORABLE_ICON, fg=color)
        # Icon
        elif self.state == 0 and len(counts) > 1:
            return Text(self.COLORABLE_ICON)
        # Icon + Total
        elif self.state == 1 and len(counts) > 1:
            total = sum([count for count, color in counts])
            return Text(self.COLORABLE_ICON, ' ', total)
        # Icon + Counts
        else:
            text = Text(self.COLORABLE_ICON)
            for count, color in counts:
                text.append(' ', Text(count, fg=color))
            return text


class Text:
    def _setElements(self, elements):
        # TODO OPTI Concatenate consecutrive string
        self.elements = list(elements)

    def _setDecorators(self, decorators):
        # TODO OPTI Convert no decorator to strings
        self.decorators = decorators
        self.prefix = None
        self.suffix = None

    def __init__(self, *args, **kwargs):
        self._setElements(args)
        self._setDecorators(kwargs)
        self.section = None

    def append(self, *args):
        self._setElements(self.elements + list(args))

    def prepend(self, *args):
        self._setElements(list(args) + self.elements)

    def setElements(self, *args):
        self._setElements(args)

    def setDecorators(self, **kwargs):
        self._setDecorators(kwargs)

    def setSection(self, section):
        assert isinstance(section, Section)
        self.section = section
        for element in self.elements:
            if isinstance(element, Text):
                element.setSection(section)

    def _genFixs(self):
        if self.prefix is not None and self.suffix is not None:
            return

        self.prefix = ''
        self.suffix = ''

        def nest(prefix, suffix):
            self.prefix = self.prefix + '%{' + prefix + '}'
            self.suffix = '%{' + suffix + '}' + self.suffix

        def getColor(val):
            # TODO Allow themes
            assert isinstance(val, str) and len(val) == 7
            return val

        def button(number, function):
            handle = Bar.getFunctionHandle(function)
            nest('A' + number + ':' + handle.decode() + ':', 'A' + number)

        for key, val in self.decorators.items():
            if val is None:
                continue
            if key == 'fg':
                reset = self.section.THEMES[self.section.theme][0]
                nest('F' + getColor(val), 'F' + reset)
            elif key == 'bg':
                reset = self.section.THEMES[self.section.theme][1]
                nest('B' + getColor(val), 'B' + reset)
            elif key == "clickLeft":
                button('1', val)
            elif key == "clickMiddle":
                button('2', val)
            elif key == "clickRight":
                button('3', val)
            elif key == "scrollUp":
                button('4', val)
            elif key == "scrollDown":
                button('5', val)
            else:
                log.warn("Unkown decorator: {}".format(key))

    def _text(self, size=None, pad=False):
        self._genFixs()
        curString = self.prefix
        curSize = 0
        remSize = size

        for element in self.elements:
            if element is None:
                continue
            elif isinstance(element, Text):
                newString, newSize = element._text(size=remSize)
            else:
                newString = str(element)
                if remSize is not None:
                    newString = newString[:remSize]
                newSize = len(newString)

            curString += newString
            curSize += newSize

            if remSize is not None:
                remSize -= newSize
                if remSize <= 0:
                    break

        curString += self.suffix

        if pad and remSize > 0:
            curString += ' ' * remSize
            curSize += remSize

        if size is not None:
            if pad:
                assert size == curSize
            else:
                assert size >= curSize
        return curString, curSize

    def text(self, *args, **kwargs):
        string, size = self._text(*args, **kwargs)
        return string

    def __str__(self):
        self._genFixs()
        curString = self.prefix
        for element in self.elements:
            if element is None:
                continue
            else:
                curString += str(element)
        curString += self.suffix
        return curString

    def __len__(self):
        curSize = 0
        for element in self.elements:
            if element is None:
                continue
            elif isinstance(element, Text):
                curSize += len(element)
            else:
                curSize += len(str(element))
        return curSize


    def __getitem__(self, index):
        return self.elements[index]

    def __setitem__(self, index, data):
        self.elements[index] = data