import { getMarkdownTheme } from "@bastani/atomic";
import { Container, Markdown, Spacer, Text } from "@earendil-works/pi-tui";
import { type DisplayItem, formatToolCall, formatUsageStats, getDisplayItems, getFinalOutput } from "./display.js";
import type { SingleResult, SubagentDetails } from "./types.js";

const COLLAPSED_ITEM_COUNT = 10;

type TextContent = { type: "text"; text: string };
type ToolResult = { content: TextContent[]; details?: SubagentDetails };
type RenderState = { expanded: boolean };
type RenderTheme = {
	fg(color: string, text: string): string;
	bold(text: string): string;
};

export function renderSubagentResult(result: ToolResult, { expanded }: RenderState, theme: RenderTheme) {
	const details = result.details as SubagentDetails | undefined;
	if (!details || details.results.length === 0) {
		const text = result.content[0];
		return new Text(text?.type === "text" ? text.text : "(no output)", 0, 0);
	}

	const mdTheme = getMarkdownTheme();

	const renderDisplayItems = (items: DisplayItem[], limit?: number) => {
		const toShow = limit ? items.slice(-limit) : items;
		const skipped = limit && items.length > limit ? items.length - limit : 0;
		let text = "";
		if (skipped > 0) text += theme.fg("muted", `... ${skipped} earlier items\n`);
		for (const item of toShow) {
			if (item.type === "text") {
				const preview = expanded ? item.text : item.text.split("\n").slice(0, 3).join("\n");
				text += `${theme.fg("toolOutput", preview)}\n`;
			} else {
				text += `${theme.fg("muted", "→ ") + formatToolCall(item.name, item.args, theme.fg.bind(theme))}\n`;
			}
		}
		return text.trimEnd();
	};

	if (details.mode === "single" && details.results.length === 1) {
		const r = details.results[0];
		const isError = r.exitCode !== 0 || r.stopReason === "error" || r.stopReason === "aborted";
		const icon = isError ? theme.fg("error", "✗") : theme.fg("success", "✓");
		const displayItems = getDisplayItems(r.messages);
		const finalOutput = getFinalOutput(r.messages);

		if (expanded) {
			const container = new Container();
			let header = `${icon} ${theme.fg("toolTitle", theme.bold(r.agent))}${theme.fg("muted", ` (${r.agentSource})`)}`;
			if (isError && r.stopReason) header += ` ${theme.fg("error", `[${r.stopReason}]`)}`;
			container.addChild(new Text(header, 0, 0));
			if (isError && r.errorMessage)
				container.addChild(new Text(theme.fg("error", `Error: ${r.errorMessage}`), 0, 0));
			container.addChild(new Spacer(1));
			container.addChild(new Text(theme.fg("muted", "─── Task ───"), 0, 0));
			container.addChild(new Text(theme.fg("dim", r.task), 0, 0));
			container.addChild(new Spacer(1));
			container.addChild(new Text(theme.fg("muted", "─── Output ───"), 0, 0));
			if (displayItems.length === 0 && !finalOutput) {
				container.addChild(new Text(theme.fg("muted", "(no output)"), 0, 0));
			} else {
				for (const item of displayItems) {
					if (item.type === "toolCall")
						container.addChild(
							new Text(
								theme.fg("muted", "→ ") + formatToolCall(item.name, item.args, theme.fg.bind(theme)),
								0,
								0,
							),
						);
				}
				if (finalOutput) {
					container.addChild(new Spacer(1));
					container.addChild(new Markdown(finalOutput.trim(), 0, 0, mdTheme));
				}
			}
			const usageStr = formatUsageStats(r.usage, r.model);
			if (usageStr) {
				container.addChild(new Spacer(1));
				container.addChild(new Text(theme.fg("dim", usageStr), 0, 0));
			}
			return container;
		}

		let text = `${icon} ${theme.fg("toolTitle", theme.bold(r.agent))}${theme.fg("muted", ` (${r.agentSource})`)}`;
		if (isError && r.stopReason) text += ` ${theme.fg("error", `[${r.stopReason}]`)}`;
		if (isError && r.errorMessage) text += `\n${theme.fg("error", `Error: ${r.errorMessage}`)}`;
		else if (displayItems.length === 0) text += `\n${theme.fg("muted", "(no output)")}`;
		else {
			text += `\n${renderDisplayItems(displayItems, COLLAPSED_ITEM_COUNT)}`;
			if (displayItems.length > COLLAPSED_ITEM_COUNT) text += `\n${theme.fg("muted", "(ctrl+o to expand)")}`;
		}
		const usageStr = formatUsageStats(r.usage, r.model);
		if (usageStr) text += `\n${theme.fg("dim", usageStr)}`;
		return new Text(text, 0, 0);
	}

	const aggregateUsage = (results: SingleResult[]) => {
		const total = {
			input: 0,
			output: 0,
			cacheRead: 0,
			cacheWrite: 0,
			cost: 0,
			turns: 0,
		};
		for (const r of results) {
			total.input += r.usage.input;
			total.output += r.usage.output;
			total.cacheRead += r.usage.cacheRead;
			total.cacheWrite += r.usage.cacheWrite;
			total.cost += r.usage.cost;
			total.turns += r.usage.turns;
		}
		return total;
	};

	if (details.mode === "parallel") {
		const running = details.results.filter((r) => r.exitCode === -1).length;
		const successCount = details.results.filter((r) => r.exitCode === 0).length;
		const failCount = details.results.filter((r) => r.exitCode > 0).length;
		const isRunning = running > 0;
		const icon = isRunning
			? theme.fg("warning", "⏳")
			: failCount > 0
				? theme.fg("warning", "◐")
				: theme.fg("success", "✓");
		const status = isRunning
			? `${successCount + failCount}/${details.results.length} done, ${running} running`
			: `${successCount}/${details.results.length} tasks`;

		if (expanded && !isRunning) {
			const container = new Container();
			container.addChild(
				new Text(`${icon} ${theme.fg("toolTitle", theme.bold("parallel "))}${theme.fg("accent", status)}`, 0, 0),
			);

			for (const r of details.results) {
				const rIcon = r.exitCode === 0 ? theme.fg("success", "✓") : theme.fg("error", "✗");
				const displayItems = getDisplayItems(r.messages);
				const finalOutput = getFinalOutput(r.messages);

				container.addChild(new Spacer(1));
				container.addChild(new Text(`${theme.fg("muted", "─── ") + theme.fg("accent", r.agent)} ${rIcon}`, 0, 0));
				container.addChild(new Text(theme.fg("muted", "Task: ") + theme.fg("dim", r.task), 0, 0));

				// Show tool calls
				for (const item of displayItems) {
					if (item.type === "toolCall") {
						container.addChild(
							new Text(
								theme.fg("muted", "→ ") + formatToolCall(item.name, item.args, theme.fg.bind(theme)),
								0,
								0,
							),
						);
					}
				}

				// Show final output as markdown
				if (finalOutput) {
					container.addChild(new Spacer(1));
					container.addChild(new Markdown(finalOutput.trim(), 0, 0, mdTheme));
				}

				const taskUsage = formatUsageStats(r.usage, r.model);
				if (taskUsage) container.addChild(new Text(theme.fg("dim", taskUsage), 0, 0));
			}

			const usageStr = formatUsageStats(aggregateUsage(details.results));
			if (usageStr) {
				container.addChild(new Spacer(1));
				container.addChild(new Text(theme.fg("dim", `Total: ${usageStr}`), 0, 0));
			}
			return container;
		}

		// Collapsed view (or still running)
		let text = `${icon} ${theme.fg("toolTitle", theme.bold("parallel "))}${theme.fg("accent", status)}`;
		for (const r of details.results) {
			const rIcon =
				r.exitCode === -1
					? theme.fg("warning", "⏳")
					: r.exitCode === 0
						? theme.fg("success", "✓")
						: theme.fg("error", "✗");
			const displayItems = getDisplayItems(r.messages);
			text += `\n\n${theme.fg("muted", "─── ")}${theme.fg("accent", r.agent)} ${rIcon}`;
			if (displayItems.length === 0)
				text += `\n${theme.fg("muted", r.exitCode === -1 ? "(running...)" : "(no output)")}`;
			else text += `\n${renderDisplayItems(displayItems, 5)}`;
		}
		if (!isRunning) {
			const usageStr = formatUsageStats(aggregateUsage(details.results));
			if (usageStr) text += `\n\n${theme.fg("dim", `Total: ${usageStr}`)}`;
		}
		if (!expanded) text += `\n${theme.fg("muted", "(ctrl+o to expand)")}`;
		return new Text(text, 0, 0);
	}

	const text = result.content[0];
	return new Text(text?.type === "text" ? text.text : "(no output)", 0, 0);
}