// rocie - An enterprise grocery management system - Web app
//
// Copyright (C) 2026 Benedikt Peetz <benedikt.peetz@b-peetz.de>
// SPDX-License-Identifier: GPL-3.0-or-later
//
// This file is part of Rocie.
//
// You should have received a copy of the License along with this program.
// If not, see <https://www.gnu.org/licenses/gpl-3.0.txt>.

use leptos::{
    IntoView, component,
    prelude::{ElementExt, Get, Show, WriteSignal, signal},
    task::spawn_local,
    view,
};
use leptos_router::{NavigateOptions, hooks::use_navigate};
use rocie_client::models::{Barcode, BarcodeId, Product, Unit, UnitAmount, UnitId};
use rocie_macros::Form;
use uuid::Uuid;

use crate::{
    api::{
        associate_barcode_external_wrapped, get_config, product_by_id_wrapped,
        product_by_name_404_wrapped, product_by_name_external_wrapped,
        product_suggestion_by_name_wrapped, unit_by_id_wrapped, unit_property_by_id_wrapped,
    },
    components::{
        async_fetch::AsyncResource, banner::Banner, catch_errors::CatchErrors,
        login_wall::LoginWall, site_header::SiteHeader,
    },
};

#[component]
pub fn AssociateBarcode() -> impl IntoView {
    let (errors, errors_set) = signal(None);

    let (show_units, show_units_set) = signal(false);

    view! {
        <CatchErrors>
            <LoginWall back=move || "/associate-barcode-product".to_owned()>
                <SiteHeader logo=icondata_io::IoPricetag back_location="/" name="Buy" />

                <Show when=move || errors.get().is_some()>
                    <Banner text=move || errors.get().expect("Was some") />
                </Show>

                {
                    let product_name_signal;
                    Form! {
                        on_submit = |barcode_id, product_name, amount, unit_id| {
                            let config = get_config!();
                            let navigate = use_navigate();

                            spawn_local(async move {
                                let output = async {
                                    let product = product_by_name_external_wrapped(&config, product_name.trim()).await?;

                                    associate_barcode_external_wrapped(&config, product.id, Barcode {
                                        amount:UnitAmount {
                                            unit: UnitId { value: unit_id },
                                            value: u32::from(amount),
                                        },
                                        id: BarcodeId { value: barcode_id },
                                    }).await?;

                                    Ok::<_, leptos::error::Error>(())
                                };

                                match output.await {
                                    Ok(()) => {
                                        navigate("/associate-barcode-product", NavigateOptions::default());
                                    },
                                    Err(err) => {
                                        errors_set.set(
                                            Some(
                                                format!("Could not associate barcode: {err}")
                                            )
                                        );
                                    },
                                }
                        });
                };

                <Input
                    name=barcode_id,
                    rust_type=u32,
                    html_type="number",
                    label="Barcode number",
                />

                <Input
                    name=product_name,
                    rust_type=String,
                    html_type="text",
                    label="Product Name",
                    reactive=product_name_signal
                    auto_complete=generate_suggest_products
                />

                <Show
                    when=move || show_units.get(),
                >
                    <Select
                        name=unit_id,
                        rust_type=Uuid,
                        label="Unit",
                        options=AsyncResource! {
                            (
                                product_name: Option<String> = product_name_signal(),
                                show_units_set: WriteSignal<bool> = show_units_set
                            ) -> Result<Vec<(String, String)>, leptos::error::Error> {
                                let units = product_unit_fetcher(product_name).await?;

                                show_units_set.set(units.is_some());
                                if let Some(units) = units {
                                    Ok(
                                        units
                                            .into_iter()
                                            .map(|unit| (unit.full_name_singular, unit.id.to_string()))
                                            .collect()
                                    )
                                } else {
                                    Ok(vec![])
                                }
                            }
                        },
                    />
                </Show>

                <Input
                    name=amount,
                    rust_type=u16,
                    html_type="number",
                    label="Amount"
                />
                    }
                }
            </LoginWall>
        </CatchErrors>
    }
}

async fn generate_suggest_products(
    optional_product_name: Option<String>,
) -> Result<Option<Vec<String>>, leptos::error::Error> {
    if let Some(product_name) = optional_product_name
        && !product_name.is_empty()
    {
        let products = product_suggestion_by_name_wrapped(&product_name).await?;
        Ok(Some(products.into_iter().map(|prod| prod.name).collect()))
    } else {
        Ok(None)
    }
}

async fn product_unit_fetcher(
    optinal_product_name: Option<String>,
) -> Result<Option<Vec<Unit>>, leptos::error::Error> {
    if let Some(product_name) = optinal_product_name
        && !product_name.is_empty()
    {
        let maybe_product: Option<Product> = product_by_name_404_wrapped(&product_name).await?;

        if let Some(product) = maybe_product {
            let unit_property =
                unit_property_by_id_wrapped(product_by_id_wrapped(product.id).await?.unit_property)
                    .await?;

            let mut units = Vec::with_capacity(unit_property.units.len());
            for unit_id in unit_property.units {
                units.push(unit_by_id_wrapped(unit_id).await?);
            }

            Ok(Some(units))
        } else {
            Ok(None)
        }
    } else {
        Ok(None)
    }
}