from flask import Blueprint, redirect, render_template, request, session

from . import db


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


@bp.get("/")
def index():
    location = session.get("location", None)
    items = db.run_query("get_inventory_overview.sql", {
        "location_id": None if location is None else location["location_id"]
    }).fetchall()

    return render_template("inventory/index.html", **{
        "items": items
    })


@bp.get("/report")
def read_report():
    location = session.get("location", None)
    items = db.run_query("get_inventory_report.sql", {
        "location_id": None if location is None else location["location_id"]
    }).fetchall()

    return render_template("inventory/read_report.html", **{
        "items": items
    })


@bp.get("/item/<item_id>")
def read_item(item_id: int):
    item = db.run_query("get_item_by_id.sql", {
        "item_id": item_id
    }).fetchone()

    snacks = db.run_query("get_snacks_by_item_id.sql", {
        "item_id": item_id
    }).fetchall()

    same_barcode_items = db.run_query("get_items_by_barcode.sql", {
        "item_barcode": item["item_barcode"],
        "location_id": item["location"]
    }).fetchall()

    return render_template("inventory/read_item.html", **{
        "item": item,
        "snacks": snacks,
        "same_barcode_items": same_barcode_items
    })


@bp.post("/item/<item_id>/deactivate")
def deactivate_item(item_id: int):
    item = db.run_query("get_item_by_id.sql", {
        "item_id": item_id
    }).fetchone()

    if item["units_left"] != 0:
        return "Only items without stock can be deactivated", 400

    db.run_query("deactivate_item.sql", {
        "item_id": item_id
    })
    db.get_db().commit()

    return redirect(request.referrer)


@bp.post("/correction")
def create_correction():
    try:
        item_id = int(request.form.get("item_id"))
        correction_delta = int(request.form.get("correction_delta"))
        correction_comment = request.form.get("correction_comment")
    except:
        return "Incomplete or mistyped form", 400

    if correction_delta == 0:
        return "Correction delta may not be 0", 400

    if correction_comment == "":
        return "Correction comment may not be empty", 400

    db.run_query("create_correction.sql", {
        "item_id": item_id,
        "correction_delta": correction_delta,
        "correction_comment": correction_comment
    })
    db.get_db().commit()

    return redirect(request.referrer)


@bp.post("/transfer")
def transfer_items():
    try:
        from_item_id = int(request.form.get("from_item_id"))
        to_item_id = int(request.form.get("to_item_id"))
        amount = int(request.form.get("amount"))
    except:
        return "Incomplete or mistyped form", 400

    if amount == 0:
        return "Amount may not be 0", 400

    if from_item_id == to_item_id:
        return "Transfers must be between different items", 400

    db.run_query("transfer_items.sql", {
        "from_item_id": from_item_id,
        "to_item_id": to_item_id,
        "amount": amount
    })
    db.get_db().commit()

    return redirect(request.referrer)