from flask import render_template, redirect, request, flash, Blueprint, current_app, url_for, Response

import json

from .book import Book
from . import isbn_db
from . import sse

bp = Blueprint("app", __name__, url_prefix="/app")

announcer = sse.MessageAnnouncer()

def announce_book(book, msg_type: str="add_book") -> None:
    """
    msg_type must either be "update_book",  "add_book" or "delete_book"
    """
    msg = sse.format_sse({
        "type": msg_type,
        "book": book.to_json()
    })
    announcer.announce(msg)


@bp.route("/submit-isbn")
def submit_isbn():
    if "isbn" not in request.args:
        return "/submit-isbn?isbn=xxxxxx"

    if request.args["isbn"] == "":
        return "Pas d'ISBN spécifié"

    try:
        book = Book(request.args["isbn"])
    except ValueError:
        return "Pas le bon format de QR code"

    try:
        book = isbn_db.get_book(book.isbn)
        assert isbn_db.add_book(book) == "duplicate" # duplicate
        announce_book(isbn_db.get_book(book.isbn), msg_type="update_book")
        return f"{book.title} ajouté (plusieurs occurrences)"
    except IndexError:
        pass

    try:
        book.load(loader="google_books", config=current_app.config)
        print("Got ", book, "[Google]")
    except KeyError:
        try:
            book.load(loader="openlibrary", config=current_app.config)
            print("Got ", book, "[OpenLibrary]")
        except KeyError:
            isbn_db.add_book(book)
            announce_book(book)
            return "Pas trouvé, à rajouter manuellement"

    isbn_db.add_book(book)
    announce_book(book)
    return f"{book.title} ajouté"


@bp.route("/web-submit-isbn")
def web_submit_isbn():
    flash(submit_isbn())
    return redirect(url_for("app.index"))


@bp.route("/")
def index():
    return render_template("index.html", books=isbn_db.get_all_books())


@bp.route("/delete-book", methods=["POST"])
def delete_book():
    if "isbn" not in request.form:
        return "missing isbn"

    isbn_db.delete_book(request.form["isbn"])
    msg = sse.format_sse({
        "type": "delete_book",
        "book": {
            "isbn": request.form["isbn"]
        }
    })
    announcer.announce(msg)
    return redirect(url_for("app.index"))


@bp.route("/update-book", methods=["POST"])
def update_book():
    attributes = ["isbn", "count", "title", "author", "publisher", "publish_date"]
    if True in [i not in request.form for i in attributes]:
        return "missing an attribute"
    
    form_data = request.form.copy()

    for attribute in attributes:
        if form_data[attribute] == "None":
            form_data[attribute] = None

    book = Book(form_data["isbn"])
    book._manual_load(
        form_data["title"],
        publisher=form_data["publisher"],
        publish_date=form_data["publish_date"],
        author=form_data["author"],
        count=int(form_data["count"])
    )
    isbn_db.update_book(book)
    announce_book(book, msg_type="update_book")
    return redirect(url_for("app.index"))


@bp.route("/export-csv")
def export_csv():
    books = isbn_db.get_all_books()

    csv = "ISBN;Titre;Auteur;Éditeur;Date;Nombre\n"
    for book in books:
        csv += f"{book.isbn};{book.title};{book.author};{book.publisher};{book.publish_date};{book.count}\n"

    # return as file with a good filename
    return current_app.response_class(
        csv,
        mimetype="text/csv",
        headers={"Content-Disposition": "attachment;filename=books.csv"}
    )


@bp.route('/listen', methods=['GET'])
def listen():
    def stream():
        messages = announcer.listen()  # returns a queue.Queue
        while True:
            msg = messages.get()  # blocks until a new message arrives
            yield msg

    return Response(stream(), mimetype='text/event-stream')


@bp.route('/ping')
def ping():
    msg = sse.format_sse(data={"type": "pong"})
    announcer.announce(msg=msg)
    return {}, 200