/// <reference lib="dom" />

interface Bangs { [key: string]: string }
let bangs: Bangs = {}
let status_el: HTMLElement

globalThis.addEventListener("hashchange", () => process_url())
globalThis.addEventListener("load", async () => {
    const bangs_res = await fetch("/bangs.json")
    if (!bangs_res.ok) document.writeln("error: could not download bangs.json")
    bangs = await bangs_res.json()
    process_url()
})

function setup_page(engine?: string) {
    const section = document.createElement("section")

    if (engine) {
        document.head.innerHTML += `<link rel="search" type="application/opensearchdescription+xml" title="laufente" href="todo" />`

        const heading = document.createElement("h1")
        heading.textContent = engine

        const input = document.createElement("input")
        input.type = "input"
        input.addEventListener("keydown", ev => {
            if (ev.code == "Enter") process_query(engine, input.value ?? "")
        })

        const submit = document.createElement("button")
        submit.textContent = "Search"
        submit.addEventListener("click", () => {
            process_query(engine, input.value ?? "")
        })

        const info = document.createElement("p")
        info.textContent = `To install this as the default search engine, select "Add <name>" in the context-menu of the URL-bar.`

        section.append(heading, input, submit, info)
    } else {
        const info = document.createElement("p")
        info.textContent = `todo`
        section.append(info)
    }

    status_el = document.createElement("p")
    section.append(status_el)
    document.body.append(section)
}


function status(text: string, color?: string) {
    status_el.textContent = text
    if (color) status_el.style.color = color
}

function process_url() {
    if (document.location.hash.length != 0) {
        const input = document.location.hash.substring(1)
        const [default_engine, query_encoded] = input.split("#")
        if (!query_encoded) return setup_page(default_engine)
        const query = decodeURIComponent(query_encoded)
        process_query(default_engine, query)
    } else {
        setup_page()
    }
}

function process_query(default_engine: string, query: string) {
    const bang_prefix = "!"
    let url = ""
    if (query.startsWith(bang_prefix)) {
        const [engine, ...query_parts] = query.substring(bang_prefix.length).split(" ")
        url = search_url(engine, query_parts.join(" "))
    } else {
        url = search_url(default_engine, query)
    }

    status(`Forwarding to ${url}`, "green")
    setTimeout(() => document.location.href = url, 0)
}

function search_url(engine: string, query: string) {
    return bangs[engine].replace("{{{s}}}", encodeURIComponent(query).replaceAll("%20", "+"))
}