import { formatHint } from "../rail.ts";
import type { RunUiSnapshot } from "../snapshot-types.ts";

/**
 * Transcript pane (pane 4). WP-8 (R8): per-attempt model transparency —
 * tasks that burned fallback attempts show which model each attempt used
 * (`requested ✓` / `failed ✗ → next`), newest first, capped to the pane
 * budget. Rendering stays uncolored (pane convention); status glyphs are
 * colorized by the shared colorizeStatusGlyphs pass.
 */

const ATTEMPT_SUMMARY_TASKS = 3;

function modelAttemptLines(snapshot: RunUiSnapshot): string[] {
	const withAttempts = snapshot.tasks
		.filter((task) => (task.modelAttempts?.length ?? 0) > 0)
		.slice(-ATTEMPT_SUMMARY_TASKS)
		.reverse();
	if (!withAttempts.length) return [];
	const lines = ["model attempts (newest first):"];
	for (const task of withAttempts) {
		const attempts = (task.modelAttempts ?? [])
			.map(
				(attempt) =>
					`${attempt.model ?? "?"} ${attempt.success ? "✓" : `✗${attempt.exitCode !== undefined ? `(${attempt.exitCode})` : ""}`}`,
			)
			.join(" → ");
		const resolved = task.modelRouting?.resolved ? ` · resolved ${task.modelRouting.resolved}` : "";
		lines.push(`  ${task.id ?? "?"} (${task.role ?? "?"})${resolved}: ${attempts}`);
	}
	return lines;
}

export function renderTranscriptPane(snapshot: RunUiSnapshot | undefined): string[] {
	if (!snapshot) return ["Output pane: snapshot unavailable"];
	const lines = snapshot.recentOutputLines ?? [];
	return [
		// Hint format owned by rail.ts (`formatHint`): keys `label` joined by ` · `.
		`Output pane: ${lines.length} recent lines · press ${formatHint([
			["v", "for transcript viewer"],
			["o", "for raw output"],
		])}`,
		...modelAttemptLines(snapshot),
		...lines.slice(-12).map((line) => `⎿ ${line}`),
		...(lines.length ? [] : ["No recent output"]),
	];
}