#!/usr/bin/python3
# -*- coding: utf-8 -*-

"""
Main class for inkycal Project
Copyright by aceisace
"""

from inkycal.display import Display
from inkycal.custom import *
import os
import traceback
import logging
import arrow
import time
import json

try:
  from PIL import Image
except ImportError:
  print('Pillow is not installed! Please install with:')
  print('pip3 install Pillow')

try:
  import numpy
except ImportError:
  print('numpy is not installed!. \nIf you are on Windows '
        'run: pip3 install numpy \nIf you are on Raspberry Pi '
        'remove numpy: pip3 uninstall numpy \nThen try again.')

logging.basicConfig(
  level = logging.INFO, #DEBUG > #INFO > #ERROR > #WARNING > #CRITICAL
  format='%(name)s -> %(levelname)s -> %(asctime)s -> %(message)s',
  datefmt='%d-%m-%Y %H:%M')

logger = logging.getLogger('inykcal main')

# TODO: fix issue with non-render mode requiring SPI
# TODO: fix info section not updating after a calibration
# TODO: add function to add/remove third party modules
# TODO: autostart -> supervisor?
# TODO: logging to files

class Inkycal:
  """Inkycal main class

  Main class of Inkycal, test and run the main Inkycal program.

  Args:
    - settings_path = str -> the full path to your settings.json file
      if no path is given, tries looking for settings file in /boot folder.
    - render = bool (True/False) -> show the image on the epaper display?

  Attributes:
    - optimize = True/False. Reduce number of colours on the generated image
      to improve rendering on E-Papers. Set this to False for 9.7" E-Paper.
  """
  

  def __init__(self, settings_path=None, render=True):
    """Initialise Inkycal"""

    self._release = '2.0.0'

    # Check if render was set correctly
    if render not in [True, False]:
      raise Exception('render must be True or False, not "{}"'.format(render))
    self.render = render

    # load settings file - throw an error if file could not be found
    if settings_path:
      try:
        with open(settings_path) as settings_file:
          settings = json.load(settings_file)
          self.settings = settings

      except FileNotFoundError:
        print('No settings file found in given path\n'
              'Please double check your settings_path')
        return

    else:
      try:
        with open('/boot/settings.json') as settings_file:
          settings = json.load(settings_file)
          self.settings = settings

      except FileNotFoundError:
        print('No settings file found in /boot')
        return
      

    # Option to use epaper image optimisation, reduces colours 
    self.optimize = True

    # Init Display class with model in settings file
    from inkycal.display import Display
    self.Display = Display(settings["model"])

    # Load drivers if image should be rendered
    if self.render == True:

      # check if colours can be rendered
      self.supports_colour = True if 'colour' in settings['model'] else False

      # get calibration hours
      self._calibration_hours = self.settings['calibration_hours']

      # init calibration state
      self._calibration_state = False

    # Load and intialize modules specified in the settings file
    self._module_number = 1
    for module in settings['modules']:
      module_name = module['name']
      try:
        loader = f'from inkycal.modules import {module_name}'
        # print(loader)
        exec(loader)
        setup = f'self.module_{self._module_number} = {module_name}({module})'
        # print(setup)
        exec(setup)
        logger.info(('name : {name} size : {width}x{height} px'.format(
          name = module_name,
          width = module['config']['size'][0],
          height = module['config']['size'][1])))

        self._module_number += 1

      # If a module was not found, print an error message
      except ImportError:
        print('Could not find module: "{module}". Please try to import manually')

      # If something unexpected happened, show the error message
      except Exception as e:
        print(str(e))

    # Path to store images
    self.image_folder = top_level+'/images'

    # Give an OK message
    print('loaded inkycal')

  def countdown(self, interval_mins=None):
    """Returns the remaining time in seconds until next display update"""

    # Check if empty, if empty, use value from settings file
    if interval_mins == None:
      interval_mins = self.settings["update_interval"]

    # Find out at which minutes the update should happen
    now = arrow.now()
    update_timings = [(60 - int(interval_mins)*updates) for updates in
                      range(60//int(interval_mins))][::-1]

    # Calculate time in mins until next update
    minutes = [_ for _ in update_timings if _>= now.minute][0] - now.minute

    # Print the remaining time in mins until next update
    print(f'{minutes} Minutes left until next refresh')

    # Calculate time in seconds until next update
    remaining_time = minutes*60 + (60 - now.second)

    # Return seconds until next update
    return remaining_time


  def test(self):
    """Tests if Inkycal can run without issues.

    Attempts to import module names from settings file. Loads the config
    for each module and initializes the module. Tries to run the module and
    checks if the images could be generated correctly.

    Generated images can be found in the /images folder of Inkycal.
    """

    print(f'Inkycal version: v{self._release}')
    print(f'Selected E-paper display: {self.settings["model"]}')

    # store module numbers in here
    errors = []

    for number in range(1, self._module_number):
      name = eval(f"self.module_{number}.name")
      generate_im = f'black,colour=self.module_{number}.generate_image()'
      save_black = f'black.save("{self.image_folder}/module{number}_black.png", "PNG")'
      save_colour = f'colour.save("{self.image_folder}/module{number}_colour.png", "PNG")'
      full_command = generate_im+'\n'+save_black+'\n'+save_colour
      #print(full_command)

      print(f'generating image(s) for {name}...')
      try:
        exec(full_command)
      except Exception as Error:
        errors.append(number)
        print('Error!')
        print(traceback.format_exc())

    if errors:
      print('Error/s in modules:',*errors)
    del errors

  def run(self):
    """Runs main programm in nonstop mode.

    Uses a infinity loop to run Inkycal nonstop. Inkycal generates the image
    from all modules, assembles them in one image, refreshed the E-Paper and
    then sleeps until the next sheduled update.
    """

    # Get the time of initial run
    runtime = arrow.now()

    # Function to flip images upside down
    upside_down = lambda image: image.rotate(180, expand=True)

    # Count the number of times without any errors
    counter = 0

    print(f'Inkycal version: v{self._release}')
    print(f'Selected E-paper display: {self.settings["model"]}')

    while True:
      print(f"Date: {runtime.format('D MMM YY')} | Time: {runtime.format('HH:mm')}")
      print('Generating images for all modules...')
                  
      errors = [] # store module numbers in here

      # short info for info-section
      self.info = f"{runtime.format('D MMM @ HH:mm')}  "

      for number in range(1, self._module_number):
        name = eval(f"self.module_{number}.name")
        generate_im = f'black,colour=self.module_{number}.generate_image()'
        save_black = f'black.save("{self.image_folder}/module{number}_black.png", "PNG")'
        save_colour = f'colour.save("{self.image_folder}/module{number}_colour.png", "PNG")'
        full_command = generate_im+'\n'+save_black+'\n'+save_colour

        try:
          exec(full_command)
          print('OK!')
          self.info += f"module {number}: OK  "
        except Exception as Error:
          errors.append(number)
          print('Error!')
          print(traceback.format_exc())
          self.info += f"module {number}: Error!  "

      if errors:
        print('Error/s in modules:',*errors)
        counter = 0
      else:
        counter += 1
        print('successful')
      del errors

      # Assemble image from each module - add info section if specified
      self._assemble()

      # Check if image should be rendered
      if self.render == True:
        Display = self.Display

        self._calibration_check()

        if self.supports_colour == True:
          im_black = Image.open(f"{self.image_folder}/canvas.png")
          im_colour = Image.open(f"{self.image_folder}/canvas_colour.png")

          # Flip the image by 180° if required
          if self.settings['orientation'] == 180:
            im_black = upside_down(im_black)
            im_colour = upside_down(im_colour)

          # render the image on the display
          Display.render(im_black, im_colour)

        # Part for black-white ePapers
        elif self.supports_colour == False:

          im_black = self._merge_bands()

          # Flip the image by 180° if required
          if self.settings['orientation'] == 180:
            im_black = upside_down(im_black)

          Display.render(im_black)

      print('\ninkycal has been running without any errors for '
            f"{counter} display updates \n"
            f'Programm started {runtime.humanize()}')

      sleep_time = self.countdown()
      time.sleep(sleep_time)

  def _merge_bands(self):
    """Merges black and coloured bands for black-white ePapers
    returns the merged image
    """

    im_path = images

    im1_path, im2_path = images+'canvas.png', images+'canvas_colour.png'

    # If there is an image for black and colour, merge them
    if os.path.exists(im1_path) and os.path.exists(im2_path):

      im1 = Image.open(im1_path).convert('RGBA')
      im2 = Image.open(im2_path).convert('RGBA')

      def clear_white(img):
        """Replace all white pixels from image with transparent pixels
        """
        x = numpy.asarray(img.convert('RGBA')).copy()
        x[:, :, 3] = (255 * (x[:, :, :3] != 255).any(axis=2)).astype(numpy.uint8)
        return Image.fromarray(x)

      im2 = clear_white(im2)
      im1.paste(im2, (0,0), im2)

    # If there is no image for the coloured-band, return the bw-image
    elif os.path.exists(im1_path) and not os.path.exists(im2_path):
      im1 = Image.open(im1_name).convert('RGBA')

    return im1


  def _assemble(self):
    """Assembles all sub-images to a single image"""

    # Create 2 blank images with the same resolution as the display
    width, height = self.Display.get_display_size(self.settings["model"])

    # Since Inkycal runs in vertical mode, switch the height and width
    width, height = height, width

    im_black = Image.new('RGB', (width, height), color = 'white')
    im_colour = Image.new('RGB', (width ,height), color = 'white')

    # Set cursor for y-axis
    im1_cursor = 0
    im2_cursor = 0

    for number in range(1, self._module_number):

      # get the path of the current module's generated images
      im1_path = f"{self.image_folder}/module{number}_black.png"
      im2_path = f"{self.image_folder}/module{number}_colour.png"

      # Check if there is an image for the black band
      if os.path.exists(im1_path):

        # Get actual size of image
        im1 = Image.open(im1_path).convert('RGBA')
        im1_size = im1.size

        # Get the size of the section
        section_size = [i for i in self.settings['modules'] if \
                        i['position'] == number][0]['config']['size']

        # Calculate coordinates to center the image
        x = int( (section_size[0] - im1_size[0]) /2)

        # If this is the first module, use the y-offset
        if im1_cursor == 0:
          y = int( (section_size[1]-im1_size[1]) /2)
        else:
          y = im1_cursor + int( (section_size[1]-im1_size[1]) /2)

        # center the image in the section space
        im_black.paste(im1, (x,y), im1)

        # Shift the y-axis cursor at the beginning of next section
        im1_cursor += section_size[1]

      # Check if there is an image for the coloured band
      if os.path.exists(im2_path):

        # Get actual size of image
        im2 = Image.open(im2_path).convert('RGBA')
        im2_size = im2.size

        # Get the size of the section
        section_size = [i for i in self.settings['modules'] if \
                        i['position'] == number][0]['config']['size']

        # Calculate coordinates to center the image
        x = int( (section_size[0]-im2_size[0]) /2)

        # If this is the first module, use the y-offset
        if im2_cursor == 0:
          y = int( (section_size[1]-im2_size[1]) /2)
        else:
          y = im2_cursor + int( (section_size[1]-im2_size[1]) /2)

        # center the image in the section space
        im_colour.paste(im2, (x,y), im2)

        # Shift the y-axis cursor at the beginning of next section
        im2_cursor += section_size[1]


    # Add info-section if specified --

    # Calculate the max. fontsize for info-section
    if self.settings['info_section'] == True:
      info_height = self.settings["info_section_height"]
      info_width = width
      font = self.font = ImageFont.truetype(
        fonts['NotoSansUI-Regular'], size = 14)

      info_x = im_black.size[1] - info_height
      write(im_black, (0, info_x), (info_width, info_height),
            self.info, font = font)

    # optimize the image by mapping colours to pure black and white
    if self.optimize == True:
      im_black = self._optimize_im(im_black)
      im_colour = self._optimize_im(im_colour)

    im_black.save(self.image_folder+'/canvas.png', 'PNG')
    im_colour.save(self.image_folder+'/canvas_colour.png', 'PNG')

  def _optimize_im(self, image, threshold=220):
    """Optimize the image for rendering on ePaper displays"""

    buffer = numpy.array(image.convert('RGB'))
    red, green = buffer[:, :, 0], buffer[:, :, 1]

    # grey->black
    buffer[numpy.logical_and(red <= threshold, green <= threshold)] = [0,0,0]
    image = Image.fromarray(buffer)
    return image

  def calibrate(self):
    """Calibrate the E-Paper display

    Uses the Display class to calibrate the display with the default of 3
    cycles. After a refresh cycle, a new image is generated and shown.
    """

    self.Display.calibrate()

  def _calibration_check(self):
    """Calibration sheduler
    uses calibration hours from settings file to check if calibration is due"""
    now = arrow.now()
    # print('hour:', now.hour, 'hours:', self._calibration_hours)
    # print('state:', self._calibration_state)
    if now.hour in self._calibration_hours and self._calibration_state == False:
      self.calibrate()
      self._calibration_state = True
    else:
      self._calibration_state = False

  # Work in progress : Adding and removing modules - Please stand by

if __name__ == '__main__':
  print('running {0} in standalone/debug mode'.format('inkycal main'))