#!/usr/bin/env python3

import json
import logging
import math
import os
import string
import subprocess
import threading
import time
from collections import OrderedDict

import bottle
import numpy as np
import scipy.misc
import serial

import config

logging.basicConfig(filename='pixelserver.log', level=config.LogLevel)
running = True


########################################################################
#                                Utils                                 #
########################################################################
class DataSource:
    def __init__(self, initial):
        self.data = initial
        self.listeners = []

    def getData(self):
        return self.data

    def addListener(self, listener):
        self.listeners.append(listener)
        return self

    def pushData(self, data):
        self.data = data
        for listener in self.listeners:
            with listener:
                listener.notify_all()


class WatchDog(threading.Thread):
    def __init__(self, check, action):
        super().__init__(daemon=True)
        self.check = check
        self.action = action
        self.running = True

    def run(self):
        while running and self.running:
            if self.check():
                logging.error("Watchdog: Executed")
                self.action()
            time.sleep(1)

    def stop(self):
        self.running = False


class LogReader(threading.Thread):
    def __init__(self, runner):
        super().__init__(daemon=True)
        self.runner = runner
        self.log = ""
        self.running = True

    def clear(self):
        self.log = ""

    def getLog(self):
        return self.log

    def run(self):
        logging.info("LogReader started")
        while running and self.running:
            try:
                self.log += self.runner.app.stderr.read(1).decode("utf-8")
            except Exception as e:
                print(e)
                logging.error(str(e))
                time.sleep(1)
        logging.info("LogReader closed")

    def stop(self):
        self.running = False


class Frame:
    def __init__(self, buffer, channels=3):
        self.buffer = buffer
        self.created = time.time()
        self.channels = channels

    def clone(self):
        f = Frame(self.buffer + 0, self.channels)
        f.created = self.created
        return f


########################################################################
#                                  GUI                                 #
########################################################################
if config.UseGui:
    import pygame


    class Gui(threading.Thread):
        def __init__(self, datasource):
            super().__init__(daemon=True)
            self.cv = threading.Condition()
            self.datasource = datasource.addListener(self.cv)

        def run(self):
            last_frame = time.time()
            logging.info("Starting GUI")
            sf = config.GuiScaleFactor
            pygame.init()
            screen = pygame.display.set_mode((sf * config.ScreenX, sf * config.ScreenY))
            pygame.display.set_caption("Pixelserver - GUI Vis")
            while running:
                for event in pygame.event.get():
                    pass
                with self.cv:
                    self.cv.wait()
                    frame = self.datasource.getData()
                screen.fill((0, 0, 0))
                if frame.channels == 3:
                    for x in range(config.ScreenX):
                        for y in range(config.ScreenY):
                            color = (frame.buffer[y, x, 0], frame.buffer[y, x, 1], frame.buffer[y, x, 2])
                            pygame.draw.rect(screen, color, pygame.Rect(sf * x, sf * y, sf, sf))
                elif frame.channels == 4:
                    for x in range(config.ScreenX):
                        for y in range(config.ScreenY):
                            w = frame.buffer[y, x, 3] // 2
                            color = (frame.buffer[y, x, 0] // 2 + w, frame.buffer[y, x, 1] // 2 + w, frame.buffer[y, x, 2] // 2 + w)
                            pygame.draw.rect(screen, color, pygame.Rect(sf * x, sf * y, sf, sf))
                # logging.debug("Time to gui: " + str(time.time() - frame.created))
                pygame.display.flip()
                if time.time() < last_frame + 1 / config.GuiFPS:
                    time.sleep(max(0.01, time.time() - (last_frame + 1 / config.GuiFPS)))
                    # time.sleep(0.01)
                last_frame = time.time()

            logging.info("Closing GUI")

        def join(self, **kwargs):
            with self.cv:
                self.cv.notify_all()
            super().join()


########################################################################
#                                 Serial                               #
########################################################################
class SerialWriter(threading.Thread):
    def __init__(self, datasource):
        super().__init__(daemon=True)
        self.cv = threading.Condition()
        self.datasource = datasource.addListener(self.cv)
        self.updateGamma = False

    def run(self):
        should_connect = True
        ser = None
        logging.info("Starting SerialWriter")
        while running:
            try:
                if should_connect:
                    ser = serial.Serial(config.Serial)
                    should_connect = False
                    logging.info("Serial Opened")
                with self.cv:
                    self.cv.wait(timeout=1 / 30)
                    frame = self.datasource.getData()
                    data = frame.buffer.reshape((config.ScreenX * config.ScreenY * frame.channels,)).astype(np.uint8).tobytes()
                    if self.updateGamma:
                        buf = bytearray(b"\x00") * 4 * 256
                        for i in range(256):
                            apply = lambda x, g: max(0, min(255, int(math.pow(x / 255, g) * 255)))
                            buf[i] = apply(i, self.r)
                            buf[i + 256] = apply(i, self.g)
                            buf[i + 512] = apply(i, self.b)
                            buf[i + 512 + 256] = apply(i, self.w)
                        ser.write(b"\x02")
                        ser.write(buf)
                        self.updateGamma = False
                if frame.channels == 3:
                    ser.write(b"\01")
                    ser.write(data)
                elif frame.channels == 4:
                    ser.write(b"\03")
                    ser.write(data)
                logging.debug("Time to gui: " + str(time.time() - frame.created))
                ser.flush()
            except Exception as e:
                if ser is not None:
                    ser.close()
                    ser = None
                logging.warning(f"Serial was close because: {e}")
                should_connect = True
                time.sleep(5)
        logging.info("Closing SerialWriter")

    def join(self, **kwargs):
        with self.cv:
            self.cv.notify_all()
        super().join()

    def setGamma(self, r, g, b, w):
        with self.cv:
            self.r, self.g, self.b, self.w = r, g, b, w
            self.updateGamma = True
            self.cv.notify_all()


########################################################################
#                                   App                                #
########################################################################
class App(threading.Thread):
    def __init__(self, cmd, param, listener, is_persistent, is_white=False, path="."):
        super().__init__(daemon=True)
        # start app
        args = cmd + [str(config.ScreenX), str(config.ScreenY), param]
        self.app = subprocess.Popen(args, stdout=subprocess.PIPE, stderr=subprocess.PIPE, close_fds=True, cwd=path)
        self.last_update = time.time()
        self.cv = threading.Condition()
        self.watchdog = WatchDog(lambda: self.isAppTimedOut(), lambda: self.terminateApp())
        self.watchdog.start()
        self.logreader = LogReader(self)
        self.logreader.start()
        self.datasource = DataSource(Frame(np.zeros((config.ScreenY, config.ScreenX, 3))))
        self.running = True
        self.listener = listener
        self.is_persistent = is_persistent
        self.is_white = is_white

    def run(self):
        while running and self.running and self.alive():
            oshandle = self.app.stdout.fileno()
            try:
                channels = 4 if self.is_white else 3
                data = os.read(oshandle, config.ScreenX * config.ScreenY * channels)
                assert len(data) == config.ScreenX * config.ScreenY * channels
                buffer = np.frombuffer(data, dtype=np.uint8, count=config.ScreenX * config.ScreenY * channels)
                buffer = buffer.reshape((config.ScreenY, config.ScreenX, channels))

                frame = Frame(buffer, channels=channels)
                self.last_update = time.time()
                self.datasource.pushData(frame)
            except:
                logging.debug("Exception in App.run")
        with self.listener:
            self.listener.notify_all()
        self.watchdog.stop()
        self.logreader.stop()
        self.watchdog.join()
        self.logreader.join()
        self.app.wait()
        logging.debug("App stopped")

    def alive(self):
        return self.app.poll() is None

    def stop(self):
        self.running = False
        self.app.kill()
        self.app.stdout.close()
        self.app.stderr.close()
        self.watchdog.stop()
        self.logreader.stop()
        self.app.wait()
        logging.debug("App stopped")

    def getLog(self):
        return self.logreader.getLog()

    def terminateApp(self):
        logging.error("Terminate app!")
        self.stop()

    def isAppTimedOut(self):
        return time.time() - self.last_update > config.NoDataTimeout


########################################################################
#                                  Main                                #
########################################################################
class AppRunner(threading.Thread):
    def __init__(self):
        super().__init__(daemon=True)
        self.last_crashlog = ""
        self.currentApp = -1
        self.requestedApp = 0
        self.app = None
        self.cv = threading.Condition()
        self.param = ""
        self.datasource = DataSource(Frame(np.zeros((config.ScreenY, config.ScreenX, 3))))
        self.serial = SerialWriter(self.datasource)
        self.serial.start()
        self.persistent_apps = {}
        self.filters = OrderedDict()
        # start persistent apps
        for i, app in enumerate(config.Apps):
            if app.persistent:
                self.startApp(i)
        if config.UseGui:
            self.gui = Gui(self.datasource)
            self.gui.start()

    def requestApp(self, app, param=""):
        with self.cv:
            self.requestedApp = app
            self.param = param
            self.cv.notify_all()
        logging.info("Requesting app: " + str(app))

    def startApp(self, i, param=""):
        app = config.Apps[i]
        newapp = App(app.cmd, param, self.cv, is_persistent=app.persistent, is_white=app.white, path=app.path)
        newapp.datasource.addListener(self.cv)
        newapp.start()
        if app.persistent:
            self.persistent_apps[self.currentApp] = newapp
        return newapp

    def updateApp(self):
        try:
            if self.app is not None and not self.app.is_persistent:
                self.app.stop()
            self.currentApp = self.requestedApp
            if self.currentApp in self.persistent_apps.keys() and self.persistent_apps[self.currentApp].alive():
                self.app = self.persistent_apps[self.currentApp]
            else:
                self.app = self.startApp(self.requestedApp, self.param)
        except FileNotFoundError as e:
            print(e)

    def run(self):
        logging.info("Starting Apprunner")
        while running:
            with self.cv:
                if self.app is None or not self.app.alive():
                    if self.app is not None:
                        self.last_crashlog = self.app.getLog()
                    self.requestedApp = 0
                if self.requestedApp is not None:
                    self.updateApp()
                    self.requestedApp = None

                if self.app is not None:
                    frame = self.app.datasource.getData().clone()
                    # logging.debug("Runner in time: " + str(time.time() - frame.created))
                    for _, f in self.filters.items():
                        frame.buffer = f(frame.buffer)
                    # logging.debug("Runner out  time: " + str(time.time() - frame.created))
                    self.datasource.pushData(frame)
                self.cv.wait()
        self.serial.join()
        if config.UseGui:
            self.gui.join()
        logging.info("Close Apprunner")

    def getLog(self):
        if self.app is None:
            return ""
        return self.app.getLog()

    def setGamma(self, r, g, b, w):
        self.serial.setGamma(r, g, b, w)

    def setFilter(self, name, filter):
        self.filters[name] = filter

    def removeFilter(self, name):
        if name in self.filters.keys():
            del self.filters[name]


########################################################################
#                           Filter Api                                 #
########################################################################
def MakeBrightnessFilter(intensity):
    def filter(img):
        return (img * intensity).astype(np.uint8)

    return filter


def FlipXFilter(intensity):
    return intensity[:, ::-1, :]


def FlipYFilter(intensity):
    return intensity[::-1, :, :]


def MakeBrightnessImageFilter(name):
    img = scipy.misc.imread("filter/" + name + ".png", flatten=True) / 255

    # img = np.transpose(img)
    def filter(intensity):
        intensity = intensity.astype(float)
        for i in range(intensity.shape[2]):
            intensity[:, :, i] *= img
        return intensity.astype(np.uint8)

    return filter


def strings(s):
    allowed_chars = string.ascii_letters + string.digits + "+-*/()."
    i = 0
    outlist = []
    while i != len(s):
        if s[i] not in allowed_chars:
            raise Exception("Unexpected char " + s[i])
        if s[i] not in string.ascii_letters:
            i += 1
            continue
        out = ""
        while i != len(s) and s[i] in string.ascii_letters + string.digits:
            out += s[i]
            i += 1
        outlist.append(out)
    return outlist


def eval_safer(expr, x, y, t):
    symbols = {"x": x, "y": y, "t": t,
               "sin": np.sin, "cos": np.cos, "exp": np.exp, "tan": np.tan}
    strs = strings(expr)
    for s in strs:
        if s not in symbols.keys():
            raise Exception("unexpected symbol: " + s)
    return eval(expr, {}, symbols)


def MakeBrightnessExprFilter(expr):
    t0 = time.time()
    x, y = np.meshgrid(np.arange(config.ScreenX), np.arange(config.ScreenY))
    eval_safer(expr, 0, 0, 0)

    def filter(intensity):
        t = time.time() - t0
        intensity = intensity.astype(float)
        filter = 0 * x + eval_safer(expr, x, y, t)
        filter = np.clip(np.nan_to_num(filter), 0, 1)
        for i in range(intensity.shape[2]):
            intensity[:, :, i] *= filter
        return intensity.astype(np.uint8)

    return filter


########################################################################
#                              Web Api                                 #
########################################################################
@bottle.route('/<:re:.*>', method='OPTIONS')
def enable_cors_generic_route():
    add_cors_headers()


@bottle.hook('after_request')
def enable_cors_after_request_hook():
    add_cors_headers()


def add_cors_headers():
    bottle.response.headers['Access-Control-Allow-Origin'] = '*'
    bottle.response.headers['Access-Control-Allow-Methods'] = 'GET, POST, PUT, OPTIONS'
    bottle.response.headers['Access-Control-Allow-Headers'] = 'Origin, Accept, Content-Type, X-Requested-With, X-CSRF-Token'


def startApp(name, param=""):
    for i, app in enumerate(config.Apps):
        if app.name == name:
            runner.requestApp(i, param)
            return "ok"
    return "not_found"


@bottle.route("/apps/list")
def apps_list():
    return json.dumps([
        {
            "name": app.name,
            "guiname": app.guiname,
            "persistent": app.persistent,
        } for app in config.Apps
    ])


@bottle.route("/apps/start/<name>")
def apps_start_param(name):
    return startApp(name)


@bottle.post("/apps/start/<name>")
def apps_start_post(name):
    param = bottle.request.forms.get('param')
    return startApp(name, param)


@bottle.route("/apps/start/<name>/<param>")
def apps_start(name, param):
    return startApp(name, param)


@bottle.route("/apps/log")
def apps_log():
    return runner.getLog()


@bottle.route("/apps/crashlog")
def apps_log():
    return runner.last_crashlog


@bottle.route("/apps/running")
def apps_running():
    return config.Apps[runner.currentApp].name


@bottle.route("/")
def index():
    return bottle.static_file("index.html", root='html')


@bottle.route("/setgamma/<r>/<g>/<b>/<w>")
def setGamma(r, g, b, w):
    r = float(r)
    g = float(g)
    b = float(b)
    w = float(w)
    runner.setGamma(r, g, b, w)
    return "ok"


@bottle.route("/setbrightness/<i>")
def setIntensity(i):
    i = float(i)
    if not 0 <= i <= 1:
        return "bad_value"
    runner.setFilter("0_intensity", MakeBrightnessFilter(i))
    return "ok"


@bottle.route("/filter/flipx/<do>")
def flipx(do):
    if do == "true":
        runner.setFilter("1_flipx", FlipXFilter)
    else:
        runner.removeFilter("1_flipx")
    return "ok"


@bottle.route("/filter/flipy/<do>")
def flipy(do):
    if do == "true":
        runner.setFilter("1_flipy", FlipYFilter)
    else:
        runner.removeFilter("1_flipy")
    return "ok"


@bottle.route("/filter/img/<name>")
def setfilter(name):
    if name == "none":
        runner.removeFilter("3_imgfilter")
    else:
        runner.setFilter("3_imgfilter", MakeBrightnessImageFilter(name))
    return "ok"


@bottle.post("/filter/expr/")
def filter_expr():
    expr = bottle.request.forms.get('expr')
    if expr == "" or expr == "none":
        runner.removeFilter("5_brightnessfunction")
    else:
        runner.setFilter("5_brightnessfunction", MakeBrightnessExprFilter(expr))
    return "ok"


########################################################################
#                              Startup                                 #
########################################################################
runner = AppRunner()
runner.start()

# runner.setFilter("5_crazy", MakeBrightnessExprFilter("0.5+0.25*sin(x/3)/x"))
bottle.run(host=config.WebHost, port=config.WebPort)

########################################################################
#                              Shutdown                                #
########################################################################
running = False
runner.join()