// Shared compact single-line rendering for flow-owned tools.
//
// The call renderer owns the row while a tool is running. Once the result
// arrives, the call renderer becomes empty and the result renderer redraws the
// name and arguments on the same row, optionally followed by expanded detail.

import { quietStatusMark } from "./quiet-state.ts";
import type { Theme } from "@earendil-works/pi-coding-agent";
import type { Component } from "@earendil-works/pi-tui";
import { truncateToWidth } from "@earendil-works/pi-tui";

// A structural subset of pi's Theme so both the real Theme and the MCP renderer's
// local RenderTheme (string-keyed fg) satisfy it without contravariance errors.
export type QuietTheme = Pick<Theme, "fg"> & Partial<Pick<Theme, "bold">>;

interface ResultLike {
	content: Array<{ type: string; text?: string }>;
}

function lineComponent(text: string): Component {
	return {
		render(width: number): string[] {
			const safeWidth = Math.max(1, width);
			return text.split("\n").map((line) => truncateToWidth(line, safeWidth, "…"));
		},
		invalidate(): void {},
	};
}

export function toolCallLine(theme: QuietTheme, name: string, arg = ""): Component {
	const bold = theme.bold ?? ((text: string) => text);
	return lineComponent(
		`  ${theme.fg("warning", quietStatusMark("running"))} ${theme.fg("toolTitle", bold(name))}${arg ? ` ${theme.fg("accent", arg)}` : ""}`,
	);
}

export function toolResultLine(
	theme: QuietTheme,
	o: {
		name: string;
		mark?: string;
		ok?: boolean;
		arg?: string;
		summary?: string;
		detail?: string;
		expanded?: boolean;
	},
): Component {
	const bold = theme.bold ?? ((text: string) => text);
	const mark = o.mark ?? (o.ok === false
		? theme.fg("error", quietStatusMark("failure"))
		: theme.fg("success", quietStatusMark("success")));
	let line = `  ${mark} ${theme.fg("toolTitle", bold(o.name))}${o.arg ? ` ${theme.fg("accent", o.arg)}` : ""}${o.summary ? ` ${theme.fg("dim", `· ${o.summary}`)}` : ""}`;
	if (o.expanded && o.detail && o.detail.trim()) line += `\n${theme.fg("dim", o.detail)}`;
	return lineComponent(line);
}

/** First non-empty line of a tool result's text content, truncated to maxLen. */
export function resultFirstLine(result: ResultLike, maxLen = 60): string {
	const text = result.content.find((c) => c.type === "text" && c.text)?.text ?? "";
	const line = (text.split("\n").find((l) => l.trim()) ?? "").trim();
	return line.length > maxLen ? `${line.slice(0, maxLen - 1)}…` : line;
}

/** Count of non-empty lines in a tool result's text content. */
export function resultLineCount(result: ResultLike): number {
	const text = result.content.find((c) => c.type === "text" && c.text)?.text ?? "";
	return text.split("\n").filter((l) => l.trim()).length;
}

/**
 * Generic result summary: a short first line, falling back to a line count.
 * Keeps any tool's quiet result line meaningful without per-tool logic.
 */
export function resultSummary(result: ResultLike, maxLen = 60): string {
	const first = resultFirstLine(result, maxLen);
	if (first) return first;
	const n = resultLineCount(result);
	return n > 0 ? `${n} lines` : "done";
}

/** One-line compact JSON of a value, whitespace-collapsed and truncated. For quiet call args. */
export function compactJson(value: unknown, maxLen = 50): string {
	let s: string;
	try {
		s = typeof value === "string" ? value : JSON.stringify(value);
	} catch {
		s = String(value);
	}
	if (s === undefined || s === "null") return "";
	s = s.replace(/\s+/g, " ").trim();
	return s.length > maxLen ? `${s.slice(0, maxLen - 1)}…` : s;
}