"""! @file main.py
@brief Main file for the application
@author xlanro00
"""

# Import basic libraries
import argparse as ap
import sys
import json
#from datetime import datetime

# Libraries for image processing
import numpy as np
import matplotlib.pyplot as plt
#from PIL import Image
import cv2 as cv

# Import custom image filter library
import filters as flt


class apply_filters:
    def __init__(self):
        # Parse arguments from command line
        self.parse_arguments()
        self.params = {}
        self.filters = []
        
        # Parse configuration from json file
        if self.args.config:
            self.config_file = self.args.config[0]
            self.preset_name = self.args.config[1]
            self.config = json.load(open(self.config_file))
            print("Config loaded")
            self.parse_conf()

        # If no config file given, expect filters in command line
        else:
            print("No config file given, using command line arguments")
            i = 0
            for filter in self.args.filters:
                if filter.find('=') == -1:
                    self.filters.append(filter)
                    i += 1
                    self.params[i] = {}
                else:
                    key, value = filter.split('=')
                    self.params[i][key] = value
                self.parse_params(self.params[i])

        self.input_file = self.args.input_file
        self.output_file = self.args.output_file
        self.dpi = self.args.dpi
        self.mirror = self.args.mirror if self.args.mirror else 0

        #read as numpy.array
        self.img = cv.imread(self.input_file, cv.IMREAD_GRAYSCALE)
    
        self.width = self.img.shape[1]
        self.height = self.img.shape[0]
        #print(self.width, self.height)
        
        fig = plt.figure(figsize = (self.width, self.height), 
            frameon = False, dpi = self.dpi / 100) # dpi is in cm
    
        ax = plt.Axes(fig, [0., 0., 1., 1.])
        ax.set_axis_off()
        fig.add_axes(ax)
        
        if self.mirror:
            self.mirror_image()

        # Apply all filters and save image
        self.apply_filter()
        self.save_image(fig, ax)


    def check_param(self, params, key):
        try:
            params[key] = params[key]
        except KeyError:
            params[key] = None


    def parse_params(self, params):
        possible_params = {"h", "searchWindowSize","templateWindowSize", 
                            "ksize", "kernel", "sigmaX" , "sigmaY",
                           "sigmaColor", "sigmaSpace", "d", "anchor", "iterations", "op"}
        for key in possible_params:
            self.check_param(params, key)


    def parse_conf(self):
        # Parse configuration file if given.
        try:
            filter_array = self.config[self.preset_name]
            for i, filter in enumerate(range(len(filter_array)), start=1):
                self.filters.append(filter_array[filter]["name"])
                self.params[i] = {}
                for attribute, value in filter_array[filter].items():
                    if attribute != "name":
                        self.params[i][attribute] = value
                self.parse_params(self.params[i])

        except(KeyError):
            print("Preset not found", file = sys.stderr)


    def parse_arguments(self):

        # Parse arguments
        parser = ap.ArgumentParser(prog = 'main.py', 
            description = 'Program for processing a 2D image into 3D fingerprint.', 
                                   usage='%(prog)s [-h] [-m | --mirror | --no-mirror] input_file output_file dpi ([-c config_file preset | --config config_file preset] | [filters ...])')

        # positional arguments
        parser.add_argument("input_file", type = str, help = "location with input file")
        parser.add_argument("output_file", type = str, help = "output file location")
        parser.add_argument("dpi", type = int, help = "scanner dpi")

        # boolean switch
        parser.add_argument('-m', "--mirror", help = "mirror input image",
                            type = bool, action = ap.BooleanOptionalAction)

        # file with configuration containing presets, new preset name
        # pair argument - give both or none
        parser.add_argument('-c','--config', nargs = 2, metavar = ('config_file', 'preset'),
                            help = 'pair: name of the config file with presets, name of the preset')

        # array of unknown length, all filter names saved inside
        parser.add_argument('filters', type = str, nargs = '*',
                            help="list of filter names and their parameters in form [filter_name1 param1=value1 param2=value2 filter_name2 param1=value1...]")

        self.args = parser.parse_args()


    def filter_factory(self, filter_name):
        # selects filter method of filters library
        # better this than a 100 if/else
        print("Applying " + filter_name + " filter", file = sys.stderr)
        return getattr(flt, filter_name)


    def resize_image(self):

        print("Resize image", file = sys.stderr)
        self.img = self.img.resize((np.array(self.width, self.height)).astype(int))


    def mirror_image(self):

        # mirror image when mirroring is needed
        # should be used only if we want a positive form
        print("Mirroring image", file=sys.stderr)
        self.img = cv.flip(self.img, 1)  # 1 for vertical mirror


    def apply_filter(self):

        if len(self.filters) == 0:
            # No filter given, just save the image
            pass
        else:
            # Apply all filters
            for i, filter_name in enumerate(self.filters):
                filter = self.filter_factory(filter_name)
                filter.apply(self, self.params[i+1])
        

    def print_size(self, size):
        print("Width: " + str(size[0]), file = sys.stderr)
        print("Height: " + str(size[1]), file = sys.stderr)


    def save_image(self, fig, ax):
        # Save processed image.
        print("Saving image", file = sys.stderr)
        ax.imshow(self.img, cmap="gray")
        fig.savefig(fname=self.output_file)


app = apply_filters()