// Interpolate color between three theme colors over 0-100 range.
// 0-50 => start (success.light), 50-75 => mid (warning.light), 75-100 => end (error.light)
export const getResponseColor = (
	ms: number,
	colors: {
		start: string | undefined;
		mid: string | undefined;
		end: string | undefined;
	}
): string => {
	// New ranges with open high end:
	// 0–300ms: interpolate start (good) -> mid (warning)
	// 300–600ms: interpolate mid (warning) -> end (error)
	// >600ms: solid end (error)
	// MUI default success/warning/error.main values, used only when the caller
	// fails to pass theme colors (defensive — keeps the gradient meaningful).
	const safe = { ...colors };
	if (!safe.start) safe.start = "#4caf50";
	if (!safe.mid) safe.mid = "#ff9800";
	if (!safe.end) safe.end = "#f44336";

	const toHex = (c: number) => c.toString(16).padStart(2, "0");
	const clamp = (n: number) => Math.min(255, Math.max(0, Math.round(n)));
	const rgbToHex = (r: number, g: number, b: number) =>
		`#${toHex(clamp(r))}${toHex(clamp(g))}${toHex(clamp(b))}`;

	const normalizeToHex = (value: string) => {
		const v = value.trim();
		if (v.startsWith("#")) {
			const h = v.slice(1);
			const full =
				h.length === 3
					? h
							.split("")
							.map((c) => c + c)
							.join("")
					: h.substring(0, 6);
			return `#${full.toLowerCase()}`;
		}
		const m = v
			.replace(/\s+/g, "")
			.match(/^rgba?\((\d{1,3}),(\d{1,3}),(\d{1,3})(?:,(0|0?\.\d+|1))?\)$/i);
		if (m) {
			const r = parseInt(m[1], 10);
			const g = parseInt(m[2], 10);
			const b = parseInt(m[3], 10);
			return rgbToHex(r, g, b);
		}
		// Fallback neutral
		return "#7f7f7f";
	};

	const parseHex = (hex: string) => {
		const h = hex.replace("#", "");
		const full =
			h.length === 3
				? h
						.split("")
						.map((c) => c + c)
						.join("")
				: h;
		const n = parseInt(full, 16);
		return { r: (n >> 16) & 255, g: (n >> 8) & 255, b: n & 255 };
	};
	const mix = (a: number, b: number, t: number) => Math.round(a + (b - a) * t);

	const v = Math.max(0, ms);
	if (v <= 300) {
		const t = v / 300; // 0..1 from start->mid
		const s = parseHex(normalizeToHex(safe.start));
		const m = parseHex(normalizeToHex(safe.mid));
		const r = mix(s.r, m.r, t);
		const g = mix(s.g, m.g, t);
		const b = mix(s.b, m.b, t);
		return `#${toHex(r)}${toHex(g)}${toHex(b)}`;
	}
	if (v <= 600) {
		const t = (v - 300) / 300; // 0..1 from mid->end
		const m = parseHex(normalizeToHex(safe.mid));
		const e = parseHex(normalizeToHex(safe.end));
		const r = mix(m.r, e.r, t);
		const g = mix(m.g, e.g, t);
		const b = mix(m.b, e.b, t);
		return `#${toHex(r)}${toHex(g)}${toHex(b)}`;
	}
	return normalizeToHex(safe.end);
};

export const MIN_HEIGHT_PCT = 8;
const CAP_PERCENTILE = 95;

const percentile = (sortedValues: number[], p: number): number => {
	const index = (p / 100) * (sortedValues.length - 1);
	const lower = Math.floor(index);
	const upper = lower + 1;
	const weight = index % 1;
	if (upper >= sortedValues.length) return sortedValues[lower];
	return sortedValues[lower] * (1 - weight) + sortedValues[upper] * weight;
};

export const computeBarHeights = (
	checks: { responseTime?: number | null }[]
): number[] => {
	const values = checks.map((check) => {
		return typeof check.responseTime === "number" && Number.isFinite(check.responseTime)
			? Math.max(0, check.responseTime)
			: 0;
	});

	const sorted = values.slice().sort((a, b) => a - b);
	const cap = percentile(sorted, CAP_PERCENTILE);
	if (cap <= 0) return values.map(() => MIN_HEIGHT_PCT);
	return values.map((value) => {
		return Math.max(MIN_HEIGHT_PCT, Math.min(100, (value / cap) * 100));
	});
};

export const computeDayBarHeights = (
	buckets: { date: string; avgResponseTime: number | null }[]
): Map<string, number> => {
	const values = buckets.map((bucket) =>
		typeof bucket.avgResponseTime === "number" && Number.isFinite(bucket.avgResponseTime)
			? Math.max(0, bucket.avgResponseTime)
			: 0
	);

	const sorted = values.slice().sort((a, b) => a - b);
	const cap = percentile(sorted, CAP_PERCENTILE);
	return new Map(
		buckets.map((bucket, i) => [
			bucket.date,
			cap <= 0
				? MIN_HEIGHT_PCT
				: Math.max(MIN_HEIGHT_PCT, Math.min(100, (values[i] / cap) * 100)),
		])
	);
};