/**
 * pi-dumb — Context Rot Indicator
 *
 * Shows actual token count with color-coded warning based on "context rot" research.
 *
 * Research shows LLM quality degrades based on ABSOLUTE token count, not percentage:
 * - Chroma (2025): All 18 frontier models degrade as context grows
 * - Liu et al. (Stanford): 30%+ accuracy drop from "lost-in-the-middle" effect
 * - Attention dilution is quadratic: 100k tokens = 10B pairwise relationships
 *
 * Thresholds (based on research):
 *   🧠  0–30k   "fresh" — Dex Horthy/Chroma's "sweet spot," peak reliability
 *   🟡  30–60k  "warm"  — past recommended reset point
 *   🔥  60–100k "hot"   — community consensus danger zone for coding
 *   💀  100k+   "rot"   — broadly degraded (Huntley sees issues by ~150k)
 *
 * These thresholds apply regardless of context window size (200k or 1M).
 */

import type { ExtensionAPI } from "@mariozechner/pi-coding-agent";

const THRESHOLDS = {
	fresh: 30_000,
	warm: 60_000,
	hot: 100_000,
};

export default function (pi: ExtensionAPI) {
	function fmt(n: number): string {
		if (n < 1000) return `${n}`;
		if (n < 10_000) return `${(n / 1000).toFixed(1)}k`;
		if (n < 1_000_000) return `${Math.round(n / 1000)}k`;
		return `${(n / 1_000_000).toFixed(1)}M`;
	}

	function updateStatus(ctx: Parameters<Parameters<typeof pi.on>[1]>[1]) {
		const usage = ctx.getContextUsage();
		if (!usage) return;

		const theme = ctx.ui.theme;
		const tokens = usage.tokens;

		let label: string;
		if (tokens < THRESHOLDS.fresh) {
			label = "🧠";
		} else if (tokens < THRESHOLDS.warm) {
			label = "🟡";
		} else if (tokens < THRESHOLDS.hot) {
			label = "🔥";
		} else {
			label = "💀";
		}

		const text = theme.fg("dim", `${label} ${fmt(tokens)}`);
		ctx.ui.setStatus("context-rot", text);
	}

	pi.on("turn_end", async (_event, ctx) => updateStatus(ctx));
	pi.on("session_start", async (_event, ctx) => updateStatus(ctx));
	pi.on("session_switch", async (_event, ctx) => updateStatus(ctx));
	pi.on("session_compact", async (_event, ctx) => {
		setTimeout(() => updateStatus(ctx), 500);
	});
}