import type {
	AccountUsage,
	ProviderName,
	Theme,
	UiContext,
	UsageWindow,
} from "./types.js";

const PROVIDER_LABELS: Record<ProviderName, string> = {
	claude: "Claude",
	codex: "Codex",
	grok: "Grok",
};
const CLAUDE_ORANGE = "\u001b[38;5;208m";

function accountLabel(label: string): string {
	return label;
}

export function usageBar(used: number, width = 10): string {
	const percent = Math.max(0, Math.min(100, used));
	const filled = Math.round((percent / 100) * width);
	return "━".repeat(filled) + "─".repeat(width - filled);
}

export function formatCompact(items: AccountUsage[]): string {
	return items
		.map((item) => {
			if (item.error) {
				return `${PROVIDER_LABELS[item.provider]} ${accountLabel(item.label)}: ! ${item.error}`;
			}
			const windows = [
				item.session &&
					`S ${usageBar(item.session.used)} ${Math.round(item.session.used)}%`,
				item.weekly &&
					`W ${usageBar(item.weekly.used)} ${Math.round(item.weekly.used)}%`,
			].filter(Boolean);
			return `${PROVIDER_LABELS[item.provider]} ${accountLabel(item.label)}  ${windows.join("  ") || "–"}`;
		})
		.join("\n");
}

export function formatDetails(items: AccountUsage[]): string {
	if (!items.length) return "No enabled CLIProxyAPI accounts found.";
	return items
		.map((item) => {
			if (item.error) return `${item.provider}/${item.label}: ${item.error}`;
			const windows = [
				item.session && `Session ${item.session.used.toFixed(0)}% used`,
				item.weekly && `Weekly ${item.weekly.used.toFixed(0)}% used`,
			].filter(Boolean);
			return `${item.provider}/${item.label}: ${windows.join(" · ") || "No usage window"}`;
		})
		.join("\n");
}

function truncateAnsi(text: string, width: number): string {
	let visible = 0;
	let result = "";
	for (let index = 0; index < text.length && visible < width; ) {
		if (text[index] === "\u001b") {
			const match = text.slice(index).match(/^\u001b\[[0-?]*[ -/]*[@-~]/);
			if (match) {
				result += match[0];
				index += match[0].length;
				continue;
			}
		}
		const point = text.codePointAt(index);
		if (point === undefined) break;
		result += String.fromCodePoint(point);
		index += point > 0xffff ? 2 : 1;
		visible++;
	}
	return `${result}\u001b[0m`;
}

export function clearUsage(ctx: UiContext): void {
	ctx.ui.setStatus("cliproxy-usage", undefined);
	ctx.ui.setWidget("cliproxy-usage", undefined);
}

export function renderUsage(
	ctx: UiContext,
	items: AccountUsage[],
	maxVisibleAccounts: number,
): void {
	ctx.ui.setStatus("cliproxy-usage", undefined);
	if (!items.length) {
		ctx.ui.setWidget("cliproxy-usage", undefined);
		return;
	}
	const visibleItems = items
		.map((item, index) => ({
			item,
			index,
			priority: item.error
				? Number.POSITIVE_INFINITY
				: Math.max(item.session?.used ?? -1, item.weekly?.used ?? -1),
		}))
		.sort(
			(left, right) =>
				right.priority - left.priority || left.index - right.index,
		)
		.slice(0, maxVisibleAccounts)
		.map(({ item }) => item);
	const hiddenCount = items.length - visibleItems.length;
	const providerWidth = Math.max(
		...visibleItems.map((item) => PROVIDER_LABELS[item.provider].length),
	);
	const accountWidth = Math.max(
		...visibleItems.map((item) => accountLabel(item.label).length),
	);
	ctx.ui.setWidget(
		"cliproxy-usage",
		(_tui: unknown, theme: Theme) => ({
			invalidate() {},
			render(width: number): string[] {
				const lines = visibleItems.map((item) => {
					const providerText =
						PROVIDER_LABELS[item.provider].padEnd(providerWidth);
					const providerLabel =
						item.provider === "claude"
							? `${CLAUDE_ORANGE}${providerText}\u001b[0m`
							: theme.fg("text", providerText);
					const separator = theme.fg("dim", " │ ");
					const prefix =
						providerLabel +
						separator +
						theme.fg("muted", accountLabel(item.label).padEnd(accountWidth)) +
						separator;
					if (item.error) {
						return truncateAnsi(
							`${prefix}${theme.fg("error", `! ${item.error}`)}`,
							width,
						);
					}
					const meter = (name: string, usage: UsageWindow) => {
						const used = Math.max(0, Math.min(100, usage.used));
						const color =
							used >= 90 ? "error" : used >= 70 ? "warning" : "text";
						const filled = usageBar(used).replace(/─+$/, "");
						const empty = "─".repeat(10 - filled.length);
						return `${theme.fg("muted", name)} ${theme.fg(color, filled)}${theme.fg("dim", empty)} ${theme.fg(color, `${Math.round(used)}%`)}`;
					};
					const windows = [
						item.session && meter("S", item.session),
						item.weekly && meter("W", item.weekly),
					].filter(Boolean);
					return truncateAnsi(
						`${prefix}${windows.join(theme.fg("dim", "  │  "))}`,
						width,
					);
				});
				if (hiddenCount) {
					lines.push(
						truncateAnsi(
							theme.fg(
								"dim",
								`… ${hiddenCount} more account${hiddenCount === 1 ? "" : "s"} · /cliproxy-usage for details`,
							),
							width,
						),
					);
				}
				return lines;
			},
		}),
		{ placement: "belowEditor" },
	);
}