import { TRAVERSE_BEHAVOUR_ATTR, TRAVERSE_BEHAVOUR_IGNORE_MAGIC, traverse_text } from "@/utils/domtraverse";
import { SyncingExtensionConfig } from "@/utils/config";
import { ExtConsole } from "@/utils/logging";
import { sendMessage } from "@/utils/messaging";

const console = ExtConsole("contentscript::text_class");

const CONFIG = new SyncingExtensionConfig("ai_text");

const DOM_OBSERVATORY: { observer: MutationObserver; timer: ReturnType<typeof setTimeout> | null } = {
    observer: new MutationObserver((_) => {
        if (DOM_OBSERVATORY.timer) clearTimeout(DOM_OBSERVATORY.timer);
        DOM_OBSERVATORY.timer = setTimeout(() => {
            console.debug("observatory trigger");
            traverse();
        }, 1000);
    }),
    timer: null,
};

const VIEWPORT_OBSERVATORY: { observer: IntersectionObserver } = {
    observer: new IntersectionObserver((entries, observer) => {
        for (const entry of entries) {
            if (entry.isIntersecting) {
                const stack = STATE.stack.get(entry.target);
                if (stack) {
                    sendMessage("inference_aiText_classify", { text: stack.text })
                        .then((resp) => {
                            console.debug("received inf response", resp);
                            observer.unobserve(entry.target);
                            apply_class(entry.target, resp.prob_ai, resp.prob_human);
                        })
                        .catch((e) => {
                            console.warn("inference failed", e, "\nentry will be rescheduled by observer");
                        });
                } else {
                    console.warn("viewport_observatory triggered on node, but the stack is absent");
                    observer.unobserve(entry.target);
                }
            }
        }
    }),
};

const STATE: {
    stack: WeakMap<Element, { text: string }>;
    badge: WeakMap<Node, Element>;
} = {
    stack: new WeakMap(),
    badge: new WeakMap(),
};

export default function setup() {
    DOM_OBSERVATORY.observer.observe(document.body, {
        subtree: true,
        characterData: true,
    });
}

export function traverse() {
    CONFIG.sync.then(() => {
        if (!CONFIG.value.enabled) {
            console.debug("disabled");
            return;
        }

        console.debug("traverse start");
        for (const stack of traverse_text(600, 20)) {
            const target = stack.first_node.parentElement || stack.root.parentElement;
            if (target) {
                set_badge(target);
                STATE.stack.set(target, { text: stack.text });
                VIEWPORT_OBSERVATORY.observer.observe(target);
            } else {
                console.warn("Stack didn't have target");
            }
        }
    });
}

function apply_class(target: Node, prob_ai: number, prob_human: number) {
    CONFIG.sync.then(() => {
        if (CONFIG.value.show_ai && prob_ai >= CONFIG.value.threshold && prob_ai >= prob_human) {
            set_badge(target, { type: "ai", prob: prob_ai });
        } else if (CONFIG.value.show_human && prob_human >= CONFIG.value.threshold && prob_human >= prob_ai) {
            set_badge(target, { type: "human", prob: prob_human });
        } else {
            clear_badge(target);
        }
    });
}

function set_badge(target: Node, data?: { type: "ai" | "human"; prob: number }) {
    if (STATE.badge.has(target)) STATE.badge.delete(target);

    let badge = document.createElement("mark");
    badge.setAttribute(TRAVERSE_BEHAVOUR_ATTR, TRAVERSE_BEHAVOUR_IGNORE_MAGIC);
    badge.style.display = "inline";
    badge.style.borderRadius = "4px";
    badge.style.textAlign = "center";
    badge.style.fontFamily = "sans";
    badge.style.fontSize = "12px";
    badge.style.padding = "1px";
    badge.style.marginRight = "4px";
    if (data?.type === "ai") {
        badge.style.backgroundColor = "#ffc36d";
        badge.style.color = "#fff";
        badge.textContent = `🤖: ${Math.trunc(data.prob * 100)}%`;
    } else if (data?.type === "human") {
        badge.style.backgroundColor = "#8fe1a1";
        badge.style.color = "#fff";
        badge.textContent = `👨‍💼: ${Math.trunc(data.prob * 100)}%`;
    } else {
        badge.style.backgroundColor = "#ddd";
        badge.style.color = "#fff";
        badge.textContent = "🦊 •••• ";
    }

    badge = target.insertBefore(badge, target.firstChild);
    STATE.badge.set(target, badge);
}

function clear_badge(target: Node) {
    STATE.badge.delete(target);
}