import tkinter as tk
from buttonfade import buttonfade 
from request_api import request_api
import requests
from io import BytesIO
from PIL import Image, ImageTk

# request_api class from request_api.py instantiated to use its api features inside this program.
rq = request_api()

class BookSelection():
    # Initialized with 0, the first book in the list (0).
    def __init__(self):
        self.x = 0
        #self.imageisbn = None

    # When search button pressed the method starts from 0 to allow for multiple searches during program use without conflict.
    # Initializes self.image_frame() and self.text_configuration() methods to process data for GUI. 
    # Then runs through forloop in range of return_isbn() list range to fill right side of GUI with ISBN numbers.
    def on_searchbutton(self):
        self.x = 0
        searchbar_input = searchbar.get()
        rq.search(searchbar_input)
        self.image_frame()
        self.text_configuration()
        for number in range(len(rq.return_isbn())):
                tk.Label(frame_two, text=f"{rq.return_isbn(number)}").grid(row=number, column=0, pady=10, padx=20, sticky="ew")   
        
    def text_configuration(self):
        try:
                resulttext.config(
                     text=(
                            	          f"{rq.Booktitle}" + "\n" 
                                        + f"{rq.Bookauthor}" + "\n"
                                        + f"{rq.Bookisbn[self.x]}" + "\n"
                                        + f"{rq.Bookdate[self.x]}" + "\n"
                                    )
                                )
        # If out of bounds start at position 0 and reinitialize.        
        except UnboundLocalError:
            self.x = len(rq.return_isbn())
            imageisbn = (rq.return_isbn(self.x))
            print(imageisbn)
            self.text_configuration()
            self.image_frame(imageisbn)

        # If IndexError (like out of bounds but went backwards) start at position 0 and reinitialize.
        except IndexError:
            self.x = 0
            imageisbn = (rq.return_isbn(self.x))
            self.text_configuration()
            self.image_frame(imageisbn)

    def image_frame(self, imageisbn=None):
        # Assign image url to variable. Then get image url through requests module.
        # Decode output through BytesIO module. Open decoded image data through Image module.
        # Create an object of opened decoded image through ImageTK module. Configure Imagelabel
        # to use it through .config method parameter assignment and then assign imagelabel.image method as = img.
        # This method is solely responsible for 3 module implementations.
        imager = rq.out_image(imageisbn)
        response = requests.get(imager)
        img_data = BytesIO(response.content)
        photo = Image.open(img_data)
        img = ImageTk.PhotoImage(photo)
        imagelabel.config(image=img)
        imagelabel.image = img

    # Button functionality made to be called by tkinter GUI buttons.
    def on_leftright_button(self, direction):
        internal_direction = direction
        if internal_direction == "left":
            self.x += 1
            imageisbn = (rq.return_isbn(self.x))
        else:
                self.x -= 1
                imageisbn = (rq.return_isbn(self.x))
        self.image_frame(imageisbn)
        self.text_configuration()

# If __name__ == "__main__" - Only runs when run directly (not through import).
if __name__ == "__main__":

    # Instantiates BookSelection Class for button usage.
    BS = BookSelection()


    main = tk.Tk()
    main.geometry("600x800")
    main.minsize(600, 800)
    main.maxsize(600, 800)
    main.title("Book Finder")

    main.rowconfigure(0, weight=1, minsize=50)
    main.rowconfigure(1, weight=1, minsize=660)
    main.rowconfigure(2, weight=1, minsize=90)

    main.columnconfigure(0, weight=1, minsize=200)  
    main.columnconfigure(1, weight=1, minsize=200)  
    main.columnconfigure(2, weight=1, minsize=200)


    searchbar = buttonfade(main, placeholder="Search here", justify="center")
    searchbar.grid(row=0, column=0, columnspan=3, sticky="nesw")

    resulttext = tk.Label(main, text="", wraplength=600)
    resulttext.grid(row=2, column=0, columnspan=2, sticky="nesw")

    imagelabel = tk.Label(main)
    imagelabel.grid(row=1, column=0, columnspan=2, sticky="nesw")

    # Button usage is here. 3 Buttons.
    searchbutton = tk.Button(main, text="Search", command=BS.on_searchbutton)
    searchbutton.grid(row=2, column=2, sticky="nsew", pady=(40,0))
    buttonleft = tk.Button(main, text="forward", command=lambda: BS.on_leftright_button("left"))
    buttonleft.grid(row=2, column=2, sticky="nsew", padx=(100, 0), pady=(0,50))
    buttonright = tk.Button(main, text="back", command=lambda: BS.on_leftright_button("right"))
    buttonright.grid(row=2, column=2, sticky="nswe", padx=(0, 100), pady=(0,50))


    
    canvas = tk.Canvas(main)
    canvas.grid(row=1, column=2, sticky="nsew")

    # Failed attempts at adding scrollbar functionality to ISBN-Book list on the right.
    #scrollbar = tk.Scrollbar(main, orient=tk.VERTICAL, command=canvas.yview)
    #scrollbar.grid(row=1, column=2, sticky="nsw")
    #
    #canvas.configure(yscrollcommand=scrollbar.set)
    #canvas.bind('<Configure>', lambda e: canvas.configure(scrollregion = canvas.bbox("all")))
    #
    
    # Seperate canvas for Book image stretched to all four direction by sticky.
    frame_two = tk.Frame(canvas)
    frame_two.grid(sticky="nsew")

    canvas.create_window((0, 0), window=frame_two, anchor="nw")
    
    main.mainloop()