//! Browse page — paginated quote list with author and tag filter controls.

use crate::api;
use crate::components::error::ErrorDisplay;
use crate::components::pagination::Pagination;
use crate::components::quote_card::QuoteCard;
use quotesdb::Quote;
use wasm_bindgen_futures::spawn_local;
use web_sys::HtmlInputElement;
use yew::prelude::*;

/// Browse page component.
///
/// Displays a paginated list of quotes. Supports filtering by author name
/// and tag. Fetches from the API whenever page, author, or tag state changes.
#[function_component(BrowsePage)]
pub fn browse_page() -> Html {
    let page = use_state(|| 1u32);
    let total_pages = use_state(|| 1u32);
    let author_filter = use_state(String::new);
    let tag_filter = use_state(String::new);
    let quotes: UseStateHandle<Vec<Quote>> = use_state(Vec::new);
    let error: UseStateHandle<Option<String>> = use_state(|| None);
    let loading = use_state(|| true);

    // Fetch quotes whenever page, author, or tag changes
    {
        let page = page.clone();
        let total_pages = total_pages.clone();
        let author_filter = author_filter.clone();
        let tag_filter = tag_filter.clone();
        let quotes = quotes.clone();
        let error = error.clone();
        let loading = loading.clone();
        let page_val = *page;
        let author_val = (*author_filter).clone();
        let tag_val = (*tag_filter).clone();
        use_effect_with((page_val, author_val.clone(), tag_val.clone()), move |_| {
            loading.set(true);
            error.set(None);
            let author = if author_val.is_empty() {
                None
            } else {
                Some(author_val.clone())
            };
            let tag = if tag_val.is_empty() {
                None
            } else {
                Some(tag_val.clone())
            };
            spawn_local(async move {
                match api::list_quotes(page_val, author.as_deref(), tag.as_deref()).await {
                    Ok(resp) => {
                        quotes.set(resp.quotes);
                        total_pages.set(resp.total_pages.max(1));
                        loading.set(false);
                    }
                    Err(e) => {
                        error.set(Some(e.to_string()));
                        loading.set(false);
                    }
                }
            });
        });
    }

    let on_page = {
        let page = page.clone();
        Callback::from(move |p: u32| page.set(p))
    };

    let on_author_input = {
        let author_filter = author_filter.clone();
        let page = page.clone();
        Callback::from(move |e: InputEvent| {
            let input: HtmlInputElement = e.target_unchecked_into();
            author_filter.set(input.value());
            page.set(1);
        })
    };

    let on_tag_input = {
        let tag_filter = tag_filter.clone();
        let page = page.clone();
        Callback::from(move |e: InputEvent| {
            let input: HtmlInputElement = e.target_unchecked_into();
            tag_filter.set(input.value());
            page.set(1);
        })
    };

    html! {
        <div class="page-browse">
            <h1 class="page-browse__title">{ "Browse Quotes" }</h1>

            <div class="page-browse__filters">
                <input
                    class="page-browse__filter-input"
                    type="text"
                    placeholder="Filter by author..."
                    value={(*author_filter).clone()}
                    oninput={on_author_input}
                />
                <input
                    class="page-browse__filter-input"
                    type="text"
                    placeholder="Filter by tag..."
                    value={(*tag_filter).clone()}
                    oninput={on_tag_input}
                />
            </div>

            if *loading {
                <p class="page-browse__loading">{ "Loading..." }</p>
            } else if let Some(err) = (*error).clone() {
                <ErrorDisplay message={err} />
            } else if quotes.is_empty() {
                <p class="page-browse__empty">{ "No quotes found." }</p>
            } else {
                <div class="page-browse__list">
                    { for (*quotes).iter().map(|q| html! {
                        <QuoteCard quote={q.clone()} />
                    }) }
                </div>
                <Pagination
                    page={*page}
                    total_pages={*total_pages}
                    on_page={on_page}
                />
            }
        </div>
    }
}