//! Certificate list, flat or as an issuer tree.
use std::collections::HashMap;

use sycamore::prelude::*;
use wasm_bindgen_futures::spawn_local;

use crate::api;
use crate::components::nav::{app_nav, spinner, whoami};
use crate::components::ui::{page_header, toast_error};
use crate::model::{fmt_date, fmt_fp, status_badge, CertificateSummary, Me};

pub fn CertificatesPage(vault_id: String) -> View {
    let id: &'static str = Box::leak(vault_id.clone().into_boxed_str());
    let me = create_signal(None::<Me>);
    let certificates = create_signal(Vec::<CertificateSummary>::new());
    let error = create_signal(None::<String>);
    let loading = create_signal(true);
    let filter = create_signal(String::new());
    let plain = create_signal(false);

    spawn_local(async move {
        match api::me().await {
            Ok(user) => {
                if me.is_alive() {
                    me.set(Some(user));
                }
                match api::certificates(id).await {
                    Ok(page) => {
                        if certificates.is_alive() {
                            certificates.set(page.results);
                        }
                    }
                    Err(message) if message != api::LOGIN_REQUIRED => {
                        if error.is_alive() {
                            error.set(Some(message));
                        }
                    }
                    _ => {}
                }
            }
            Err(message) if message == api::LOGIN_REQUIRED => {}
            Err(message) => {
                if error.is_alive() {
                    error.set(Some(message));
                }
            }
        }
        if loading.is_alive() {
            loading.set(false);
        }
    });

    let content = move || {
        if loading.get() {
            return spinner();
        }
        let rows = certificates.get_clone();
        let query = filter.get_clone().to_lowercase();
        let visible: Vec<CertificateSummary> = rows
            .into_iter()
            .filter(|cert| {
                query.is_empty()
                    || cert.name.to_lowercase().contains(&query)
                    || cert.subject.to_lowercase().contains(&query)
                    || cert.issuer_name.to_lowercase().contains(&query)
                    || cert.serial_hex.to_lowercase().contains(&query)
                    || cert.fingerprint_sha256.to_lowercase().contains(&query)
            })
            .collect();
        let html = if plain.get() {
            flat_html(&visible, id)
        } else {
            tree_html(&visible, id)
        };
        view! {
            (page_header(
                "Certificates",
                "The tree follows issuer links; use the plain view for a flat table.",
                view! {
                    a(class="btn btn-primary", href=format!("/vaults/{id}/certificates/new")) { "New certificate" }
                    a(class="btn btn-outline-light", href=format!("/vaults/{id}/import")) { "Import" }
                    button(class="btn btn-outline-light", on:click=move |_| plain.set(!plain.get())) {
                        (if plain.get() { "Tree view" } else { "Plain view" })
                    }
                },
            ))
            div(class="card mb-3") {
                div(class="card-body py-2") {
                    input(class="form-control", placeholder="Filter by name, subject, issuer, serial or fingerprint…",
                          bind:value=filter)
                }
            }
            div(class="card", dangerously_set_inner_html=html) {}
        }
    };

    let nav = move || match me.get_clone() {
        Some(user) => whoami(&user),
        None => view! {},
    };

    view! {
        (app_nav("/", Some(id), nav))
        main(class="container page-shell py-4") {
            (toast_error(error))
            (content)
        }
    }
}

fn flat_html(rows: &[CertificateSummary], vault_id: &str) -> String {
    if rows.is_empty() {
        return "<p class=\"empty-state\">No certificates match.</p>".to_string();
    }
    let mut body = String::new();
    for cert in rows {
        let (badge_class, badge_label) = status_badge(cert);
        body.push_str(&format!(
            "<tr><td><a href=\"/vaults/{}/{}\">{}</a><div class=\"item-sub\">{}</div></td><td>{}</td><td>{}</td><td class=\"fingerprint\">{}</td><td>{}</td><td><span class=\"badge {}\">{}</span>{}</td><td class=\"fingerprint\">{}</td></tr>",
            escape(vault_id),
            escape(&cert.id),
            escape(&cert.name),
            escape(&cert.subject),
            escape(&cert.issuer_name),
            if cert.is_ca { "CA" } else { "end entity" },
            escape(&cert.serial_hex),
            if cert.no_expiration { "No expiration".to_string() } else { fmt_date(&cert.not_after) },
            badge_class,
            badge_label,
            if cert.has_private_key { " <span class=\"badge badge-soft\">key</span>" } else { "" },
            fmt_fp(&cert.fingerprint_sha256),
        ));
    }
    format!(
        "<div class=\"table-responsive\"><table class=\"table table-hover align-middle mb-0\"><thead><tr><th>Name</th><th>Issuer</th><th>Type</th><th>Serial</th><th>Expires</th><th>Status</th><th>SHA-256</th></tr></thead><tbody>{body}</tbody></table></div>"
    )
}

fn tree_html(rows: &[CertificateSummary], vault_id: &str) -> String {
    if rows.is_empty() {
        return "<p class=\"empty-state\">No certificates match.</p>".to_string();
    }
    let mut children: HashMap<String, Vec<CertificateSummary>> = HashMap::new();
    let mut roots: Vec<CertificateSummary> = Vec::new();
    let ids: Vec<String> = rows.iter().map(|cert| cert.id.clone()).collect();
    for cert in rows {
        match &cert.issuer_id {
            Some(issuer) if ids.contains(issuer) && issuer != &cert.id => {
                children
                    .entry(issuer.clone())
                    .or_default()
                    .push(cert.clone());
            }
            _ => roots.push(cert.clone()),
        }
    }
    roots.sort_by(|a, b| a.name.to_lowercase().cmp(&b.name.to_lowercase()));
    let mut html = String::from("<div class=\"card-body\"><ul class=\"cert-tree\">");
    for root in &roots {
        html.push_str(&node_html(root, &children, vault_id));
    }
    html.push_str("</ul></div>");
    html
}

fn node_html(
    cert: &CertificateSummary,
    children: &HashMap<String, Vec<CertificateSummary>>,
    vault_id: &str,
) -> String {
    let (badge_class, badge_label) = status_badge(cert);
    let sub = if cert.subject == cert.issuer_name {
        "self-signed".to_string()
    } else {
        format!("issuer: {}", cert.issuer_name)
    };
    let mut row = format!(
        "<div class=\"cert-row\"><a class=\"item-name\" href=\"/vaults/{}/{}\">{}</a>{} <span class=\"badge {}\">{}</span><span class=\"item-sub\">{}</span><span class=\"item-sub\">expires {}</span><span class=\"item-sub fingerprint\">{}</span></div>",
        escape(vault_id),
        escape(&cert.id),
        escape(&cert.name),
        if cert.is_ca { " <span class=\"badge badge-ca\">CA</span>" } else { "" },
        badge_class,
        badge_label,
        escape(&sub),
        fmt_date(&cert.not_after),
        fmt_fp(&cert.fingerprint_sha256),
    );
    let kids = children.get(&cert.id);
    if let Some(kids) = kids {
        if !kids.is_empty() {
            row = format!(
                "<li><details class=\"cert-node\" open><summary>{row}</summary><ul class=\"cert-tree\">{}</ul></details></li>",
                kids.iter().map(|child| node_html(child, children, vault_id)).collect::<String>()
            );
        } else {
            row = format!("<li>{row}</li>");
        }
    } else {
        row = format!("<li>{row}</li>");
    }
    row
}

fn escape(value: &str) -> String {
    value
        .replace('&', "&amp;")
        .replace('<', "&lt;")
        .replace('>', "&gt;")
        .replace('"', "&quot;")
}