import {
	Input,
	Markdown,
	matchesKey,
	truncateToWidth,
	visibleWidth,
	wrapTextWithAnsi,
} from "@earendil-works/pi-tui";
import { getMarkdownTheme } from "@earendil-works/pi-coding-agent";
import {
	findingText,
	guideEvidence,
	type Evidence,
	type Finding,
	type ReviewRecord,
} from "./review.ts";

export type ReviewView = {
	selected: string;
	screen: "reading" | "file" | "discussion" | "finding";
	file: string;
	target: string;
	pane: "contents" | "detail";
	offsets: Record<string, number>;
	drafts: Record<string, string>;
	row: number;
	scope?: string;
	returnTo?: {
		selected: string;
		screen: "reading" | "file" | "finding";
		file: string;
		target: string;
		row: number;
	};
};
export const newReviewView = (): ReviewView => ({
	selected: "overview",
	screen: "reading",
	file: "",
	target: "whole review",
	pane: "contents",
	offsets: {},
	drafts: {},
	row: 0,
});
export type ReviewControls = {
	ask(target: string, question: string): void;
	prepare(): void;
	regenerate(): void;
	retrySave(): void;
	stop(): void;
	close(): void;
	changed(): void;
	copy(text: string): void;
};
type Tui = { terminal: { rows: number; columns?: number }; requestRender(): void };
// Structural subset keeps normalized mouse support compatible with the pinned pre-mouse SDK.
type ReviewMouseEvent = { type: string; x: number; y: number; wheelDelta?: number };
type Theme = { fg: (name: any, text: string) => string; bold: (text: string) => string };
export const safeReviewText = (text: string): string =>
	text.replace(/[\x00-\x08\x0b-\x1f\x7f-\x9f]/g, "");
const label = (text: string) => safeReviewText(text).replace(/[\n\r\t]/g, " ");

/** The controller owns requests and saving; this component only owns interaction. */
export class ReviewModal {
	focused = true;
	busy = false;
	startedAt = 0;
	stage:
		| { step: "start" | "investigate" | "receive" | "check" | "save"; detail: string }
		| undefined;
	operation: "guide" | "answer" | "regenerate" = "guide";
	activeTurn: ReviewRecord["turns"][number] | undefined;
	notice = "";
	saveError = "";
	evidence = new Map<string, string>();
	evidenceErrors = new Map<string, string>();
	private input = new Input();
	private markdown = new Markdown("", 0, 0, getMarkdownTheme());
	private focus: "contents" | "body" | "actions" | "input";
	private action = 0;
	private maxOffset = 0;
	private tiny = false;
	private width = 100;
	private followAnswer = false;
	private fileDiffs: Map<string, string> | undefined;
	private contentsOffset: number | undefined;
	private manualListKey: string | undefined;
	private layout = {
		height: 0,
		bodyRows: 0,
		leftWidth: 0,
		navigationOnly: false,
		contentsStart: 0,
		bodyStart: 4,
	};
	readonly view: ReviewView;

	constructor(
		public record: ReviewRecord,
		public tui: Tui,
		private theme: Theme,
		private controls: ReviewControls,
	) {
		this.view = record.ui ??= newReviewView();
		this.focus =
			this.view.pane === "contents"
				? "contents"
				: this.view.screen === "discussion"
					? "input"
					: "body";
		this.syncGuideView();
	}
	private entries(): { id: string; title: string }[] {
		return [
			{ id: "overview", title: "Overview" },
			...(this.record.guide?.topics ?? []).map((topic, i) => ({
				id: topic.id,
				title: `${i + 1}. ${topic.title}`,
			})),
			...(this.record.guide?.assessment
				? [
						{ id: "findings", title: `Findings (${this.record.guide.assessment.findings.length})` },
						...(this.record.guide.assessment.findings.some((finding) => !finding.topicId)
							? [{ id: "across", title: "Across the change" }]
							: []),
						{ id: "coverage", title: "Coverage and limitations" },
					]
				: []),
			{ id: "files", title: `Changed files (${this.record.snapshot.files.length})` },
			{ id: "questions", title: `Your questions (${this.discussions.length})` },
			{ id: "close", title: this.busy ? "Stop and close" : "Close" },
		];
	}
	private get topic() {
		return this.record.guide?.topics.find((topic) => topic.id === this.view.selected);
	}
	private get finding() {
		return this.record.guide?.assessment?.findings.find(
			(finding) => finding.id === this.view.target,
		);
	}
	private get latestTurn() {
		return this.record.turns.filter((turn) => turn.target === this.view.target).at(-1);
	}
	private get stopLabel() {
		return this.operation === "answer"
			? "Stop response"
			: this.operation === "regenerate"
				? "Stop regeneration"
				: "Stop preparation";
	}
	private get findings() {
		const rank = { high: 0, medium: 1, low: 2 };
		return [...(this.record.guide?.assessment?.findings ?? [])]
			.filter(
				(finding) =>
					(this.view.selected !== "across" || !finding.topicId) &&
					(!this.view.scope || finding.topicId === this.view.scope),
			)
			.sort(
				(a, b) =>
					Number(a.kind === "question") - Number(b.kind === "question") ||
					rank[a.severity] - rank[b.severity],
			);
	}
	private get isList() {
		return (
			this.view.screen === "reading" &&
			["files", "questions", "findings", "across"].includes(this.view.selected)
		);
	}
	private get discussions() {
		return [
			...this.record.turns.map((turn) => ({
				target: turn.target,
				text: turn.question,
				draft: false,
			})),
			...Object.entries(this.view.drafts)
				.filter(([, text]) => text)
				.map(([target, text]) => ({ target, text, draft: true })),
		];
	}
	private get listLength() {
		return this.view.selected === "files"
			? this.record.snapshot.files.length
			: this.view.selected === "questions"
				? this.discussions.length
				: this.findings.length;
	}
	private get key() {
		return `${this.view.selected}:${this.view.screen}:${["discussion", "finding"].includes(this.view.screen) ? this.view.target : this.view.screen === "file" ? this.view.file : ""}${this.view.scope ? `:topic:${this.view.scope}` : ""}`;
	}
	private targetLabel(target: string): string {
		if (target === "whole review") return "whole review";
		if (target.startsWith("file:")) return target.slice(5);
		return (
			this.record.guide?.topics.find((topic) => topic.id === target)?.title ??
			this.record.guide?.assessment?.findings.find((finding) => finding.id === target)?.title ??
			`Earlier · ${this.record.targetContexts?.[target]?.title ?? target}`
		);
	}
	syncGuideView(): void {
		if (!this.record.guide?.topics.some((topic) => topic.id === this.view.scope))
			delete this.view.scope;
		const origin = this.view.returnTo;
		if (
			origin &&
			(typeof origin !== "object" ||
				!["reading", "file", "finding"].includes(origin.screen) ||
				typeof origin.file !== "string" ||
				typeof origin.target !== "string" ||
				!Number.isInteger(origin.row) ||
				origin.row < 0 ||
				!this.entries().some((entry) => entry.id === origin.selected) ||
				(origin.screen === "finding" &&
					!this.record.guide?.assessment?.findings.some(
						(finding) => finding.id === origin.target,
					)) ||
				(origin.screen === "file" &&
					!this.record.snapshot.files.some((file) => file.path === origin.file)))
		)
			delete this.view.returnTo;
		this.focus =
			this.view.pane === "contents"
				? "contents"
				: this.view.screen === "discussion"
					? "input"
					: "body";
		this.input.setValue(this.view.drafts[this.view.target] ?? "");
		this.contentsOffset = undefined;
		this.manualListKey = undefined;
		this.followAnswer = false;
		this.action = 0;
	}
	private actions(): string[] {
		const recovery = this.saveError && this.view.selected !== "close" ? ["Retry saving"] : [];
		if (this.view.selected === "close") return [];
		if (this.view.screen === "discussion")
			return [
				...recovery,
				this.busy ? this.stopLabel : "Send question",
				...(!this.busy && this.latestTurn && this.latestTurn.status !== "complete"
					? ["Edit and resend"]
					: []),
				"Back",
			];
		const stop = this.busy ? [this.stopLabel] : [];
		const ask = this.busy
			? []
			: [
					this.view.screen === "finding"
						? "Ask about this finding"
						: this.view.screen === "file"
							? "Ask about this file"
							: this.topic
								? "Ask a question"
								: "Ask about this review",
				];
		if (this.view.screen === "finding")
			return [...recovery, ...ask, "Copy finding", "Back", ...stop];
		if (this.view.screen === "file") return [...recovery, ...ask, "Back to files", ...stop];
		if (this.isList || this.view.selected === "coverage") return [...recovery, ...stop];
		if (this.topic)
			return [
				...recovery,
				...(this.record.guide?.assessment?.findings.some(
					(finding) => finding.topicId === this.topic!.id,
				)
					? ["View topic findings"]
					: []),
				...ask,
				...stop,
			];
		return [
			...recovery,
			...(!this.record.guide && !this.busy ? ["Prepare guide"] : []),
			...ask,
			...(this.busy ? stop : this.record.guide ? ["Regenerate guide"] : []),
		];
	}
	private changed() {
		this.view.pane = this.focus === "contents" ? "contents" : "detail";
		this.controls.changed();
		this.tui.requestRender();
	}
	private select(id: string) {
		this.contentsOffset = undefined;
		this.manualListKey = undefined;
		if (id !== this.view.selected) this.view.row = 0;
		delete this.view.scope;
		delete this.view.returnTo;
		this.notice = "";
		this.view.selected = id;
		this.view.screen = "reading";
		this.action = 0;
		this.maxOffset = 0;
	}
	openDiscussion(target: string) {
		if (this.view.screen !== "discussion")
			this.view.returnTo = {
				selected: this.view.selected,
				screen: this.view.screen,
				file: this.view.file,
				target: this.view.target,
				row: this.view.row,
			};
		this.notice = "";
		this.view.target = target;
		this.followAnswer = false;
		this.view.screen = "discussion";
		this.focus = "input";
		this.input.setValue(this.view.drafts[target] ?? "");
		this.action = 0;
	}
	private back() {
		this.notice = "";
		if (this.view.screen === "discussion" && this.view.returnTo) {
			Object.assign(this.view, this.view.returnTo);
			delete this.view.returnTo;
			this.focus = "body";
		} else if (this.view.screen === "discussion") {
			this.view.screen = this.finding
				? "finding"
				: this.view.target.startsWith("file:")
					? "file"
					: "reading";
			if (this.view.screen === "file") {
				this.view.file = this.view.target.slice(5);
				this.view.selected = "files";
			} else
				this.view.selected = this.finding
					? "findings"
					: this.view.target === "whole review"
						? "overview"
						: this.record.guide?.topics.some((topic) => topic.id === this.view.target)
							? this.view.target
							: "questions";
			if (this.finding)
				this.view.row = Math.max(
					0,
					this.findings.findIndex((finding) => finding.id === this.view.target),
				);
			this.focus = "body";
		} else if (this.view.screen === "file" || this.view.screen === "finding") {
			this.view.screen = "reading";
			this.focus = "body";
		} else if (this.view.scope) {
			const topic = this.view.scope;
			this.select(topic);
			this.focus = "body";
		} else {
			this.focus = "contents";
		}
		this.action = 0;
	}
	private ask() {
		if (this.busy) {
			this.notice = `${this.operation === "answer" ? "An answer" : "Preparation"} is running. Your draft is kept; stop it before sending.`;
			return;
		}
		const question = this.input.getValue().trim();
		if (!question) {
			this.focus = "input";
			return;
		}
		this.input.setValue("");
		this.view.drafts[this.view.target] = "";
		this.followAnswer = true;
		this.controls.ask(this.view.target, question);
	}
	private activate() {
		const action = this.actions()[this.action];
		if (action?.startsWith("Ask"))
			this.openDiscussion(
				this.view.screen === "file"
					? `file:${this.view.file}`
					: this.view.screen === "finding"
						? this.view.target
						: (this.topic?.id ?? "whole review"),
			);
		else if (action === "Copy finding" && this.finding)
			this.controls.copy(findingText(this.finding));
		else if (action === "View topic findings") {
			const id = this.topic!.id;
			this.select("findings");
			this.view.scope = id;
			this.view.row = 0;
			this.focus = "body";
		} else if (action === "Send question") this.ask();
		else if (action === "Edit and resend") {
			if (this.view.drafts[this.view.target])
				this.notice =
					"Your current draft is kept. Edit it or clear it before restoring the earlier question.";
			else {
				const question = this.latestTurn?.question ?? "";
				this.input.setValue(question);
				this.view.drafts[this.view.target] = question;
			}
			this.focus = "input";
		} else if (action === this.stopLabel) this.controls.stop();
		else if (action === "Prepare guide") this.controls.prepare();
		else if (action === "Regenerate guide") this.controls.regenerate();
		else if (action === "Retry saving") this.controls.retrySave();
		else if (action === "Back" || action === "Back to files") this.back();
		this.action = 0;
	}
	handleMouse(event: ReviewMouseEvent): { handled: boolean; render: boolean } | undefined {
		if (event.type !== "wheel") return;
		if (
			this.tiny ||
			event.x < 0 ||
			event.x >= this.width ||
			event.y < 0 ||
			event.y >= this.layout.height
		)
			return { handled: true, render: false };
		const { bodyRows, leftWidth, navigationOnly, contentsStart, bodyStart } = this.layout;
		const start = 4;
		const rows = bodyRows + bodyStart - 4;
		if (event.y < start || event.y >= start + rows || event.x === 0 || event.x === this.width - 1)
			return { handled: true, render: false };
		const delta = Math.trunc(event.wheelDelta ?? 0);
		if (!delta) return { handled: true, render: false };
		if (navigationOnly || (leftWidth && event.x <= leftWidth)) {
			this.contentsOffset = Math.max(
				0,
				Math.min(
					Math.max(0, this.entries().length - bodyRows),
					(this.contentsOffset ?? contentsStart) + delta,
				),
			);
		} else {
			if (leftWidth && event.x < leftWidth + 4) return { handled: true, render: false };
			this.scroll(delta);
			this.manualListKey = this.key;
			this.controls.changed();
		}
		this.tui.requestRender();
		return { handled: true, render: true };
	}
	private scroll(delta: number) {
		const offset = Math.max(
			0,
			Math.min(this.maxOffset, (this.view.offsets[this.key] ?? 0) + delta),
		);
		this.view.offsets[this.key] = offset;
		this.followAnswer =
			this.busy &&
			this.activeTurn?.target === this.view.target &&
			this.view.screen === "discussion" &&
			delta > 0 &&
			offset === this.maxOffset;
	}
	handleInput(data: string): void {
		// Pi 0.84 forwards raw wheel input to focused overlays; newer hosts use handleMouse.
		const mouse = /^\u001b\[<(\d+);(\d+);(\d+)([Mm])$/.exec(data);
		if (mouse) {
			const button = Number(mouse[1]);
			if (button & 64 && (button & 3) < 2 && mouse[4] === "M") {
				const columns = this.tui.terminal.columns;
				if (columns !== undefined)
					this.handleMouse({
						type: "wheel",
						x: Number(mouse[2]) - 1 - Math.floor((columns - this.width) / 2),
						y: Number(mouse[3]) - 1 - Math.floor((this.tui.terminal.rows - this.layout.height) / 2),
						wheelDelta: button & 1 ? 3 : -3,
					});
			}
			return;
		}
		if (this.tiny) {
			if (matchesKey(data, "escape")) this.controls.close();
			return;
		}
		if (matchesKey(data, "escape")) {
			if (this.focus === "contents") {
				this.controls.close();
				return;
			}
			this.back();
			this.changed();
			return;
		}
		if (matchesKey(data, "tab") || matchesKey(data, "shift+tab")) {
			const order: (typeof this.focus)[] = [
				"contents",
				"body",
				...(this.view.screen === "discussion" ? ["input" as const] : []),
				...(this.actions().length ? ["actions" as const] : []),
			];
			this.focus =
				order[
					(order.indexOf(this.focus) + (matchesKey(data, "tab") ? 1 : order.length - 1)) %
						order.length
				]!;
		} else if (matchesKey(data, "pageDown") || matchesKey(data, "pageUp")) {
			this.render(this.width);
			const delta = (matchesKey(data, "pageDown") ? 1 : -1) * Math.max(1, this.layout.bodyRows - 1);
			if (this.focus === "contents") {
				const entries = this.entries(),
					index = entries.findIndex((entry) => entry.id === this.view.selected);
				this.select(entries[Math.max(0, Math.min(entries.length - 1, index + delta))]!.id);
			} else if (this.isList && this.focus === "body") {
				this.manualListKey = undefined;
				this.view.row = Math.max(
					0,
					Math.min(Math.max(0, this.listLength - 1), this.view.row + delta),
				);
			} else this.scroll(delta);
		} else if (this.focus === "input") {
			if (matchesKey(data, "return")) this.ask();
			else {
				this.input.handleInput(data);
				this.view.drafts[this.view.target] = this.input.getValue();
			}
		} else if (matchesKey(data, "up") || matchesKey(data, "down")) {
			const delta = matchesKey(data, "down") ? 1 : -1;
			if (this.focus === "contents") {
				const entries = this.entries();
				const index = entries.findIndex((entry) => entry.id === this.view.selected);
				this.select(entries[Math.max(0, Math.min(entries.length - 1, index + delta))]!.id);
			} else if (this.focus === "actions")
				this.action = Math.max(0, Math.min(this.actions().length - 1, this.action + delta));
			else if (this.isList) {
				this.manualListKey = undefined;
				this.view.row = Math.max(
					0,
					Math.min(Math.max(0, this.listLength - 1), this.view.row + delta),
				);
			} else {
				this.render(this.width);
				this.scroll(delta);
			}
		} else if (matchesKey(data, "return")) {
			if (this.focus === "contents") {
				if (this.view.selected === "close") {
					this.controls.close();
					return;
				}
				this.focus = "body";
			} else if (this.view.selected === "close") {
				this.controls.close();
				return;
			} else if (this.focus === "actions") this.activate();
			else if (this.isList) {
				if (this.view.selected === "files") {
					const file = this.record.snapshot.files[this.view.row];
					if (file) {
						this.view.file = file.path;
						this.view.screen = "file";
					}
				} else if (this.view.selected === "findings" || this.view.selected === "across") {
					const finding = this.findings[this.view.row];
					if (finding) {
						this.view.target = finding.id;
						this.view.screen = "finding";
					}
				} else {
					const discussion = this.discussions[this.view.row];
					if (discussion) this.openDiscussion(discussion.target);
				}
			} else if (this.actions().length) this.focus = "actions";
		}
		this.changed();
	}
	private section(title: string, width: number, color = "accent"): string {
		const text = `── ${label(title)} `;
		return this.theme.fg(
			color,
			truncateToWidth(text + "─".repeat(Math.max(0, width - visibleWidth(text))), width, "…"),
		);
	}
	private codeLine(text: string, gutter: string, width: number, color = "text"): string[] {
		const prefix = `${gutter} │ `;
		const available = Math.max(1, width - visibleWidth(prefix));
		return wrapTextWithAnsi(safeReviewText(text).replace(/\t/g, "    "), available).map(
			(part, index) =>
				this.theme.fg("dim", index ? " ".repeat(visibleWidth(gutter)) + " │ " : prefix) +
				this.theme.fg(color, part),
		);
	}
	private diffLines(section: string, width: number): string[] {
		const source = section.split("\n");
		const digits = Math.max(
			1,
			...Array.from(section.matchAll(/^@@ -(\d+)(?:,(\d+))? \+(\d+)(?:,(\d+))? @@/gm), (match) =>
				Math.max(
					String(Number(match[1]) + Number(match[2] ?? 1)).length,
					String(Number(match[3]) + Number(match[4] ?? 1)).length,
				),
			),
		);
		let old = 0,
			next = 0,
			inHunk = false;
		const output: string[] = [];
		for (const line of source) {
			if (line.startsWith("diff --git ")) {
				inHunk = false;
				continue;
			}
			const hunk = /^@@ -(\d+)(?:,\d+)? \+(\d+)(?:,\d+)? @@/.exec(line);
			if (hunk) {
				old = Number(hunk[1]);
				next = Number(hunk[2]);
				inHunk = true;
				output.push(this.section(line, width));
				continue;
			}
			if (!inHunk) {
				if (!/^(diff --git |index |--- |\+\+\+ )/.test(line) && line)
					output.push(...wrapTextWithAnsi(safeReviewText(line), width));
				continue;
			}
			if (!/^[ +\-]/.test(line)) {
				if (line) output.push(...wrapTextWithAnsi(safeReviewText(line), width));
				continue;
			}
			const added = line.startsWith("+"),
				removed = line.startsWith("-");
			const gutter = `${added ? " ".repeat(digits) : String(old++).padStart(digits)} ${removed ? " ".repeat(digits) : String(next++).padStart(digits)}`;
			output.push(
				...this.codeLine(line, gutter, width, added ? "success" : removed ? "error" : "text"),
			);
		}
		return output;
	}
	private findingBadge(finding: Finding): string {
		return this.theme.bold(
			this.theme.fg(
				finding.kind === "question"
					? "accent"
					: finding.severity === "high"
						? "error"
						: finding.severity === "medium"
							? "warning"
							: "accent",
				`▌ ${finding.severity.toUpperCase()} · ${finding.kind}`,
			),
		);
	}
	private findingCard(finding: Finding, width: number): string[] {
		const rail = this.theme.fg("border", "│ ");
		return [
			this.findingBadge(finding),
			...wrapTextWithAnsi(
				this.theme.bold(label(finding.title)),
				Math.max(1, Math.min(width, 72) - 2),
			).map((line) => rail + line),
			"",
		];
	}
	private middle(text: string, width: number): string {
		text = label(text);
		if (visibleWidth(text) <= width) return text;
		const tail = Array.from(text);
		let suffix = "";
		while (tail.length && visibleWidth(suffix + tail.at(-1)!) <= Math.max(1, width - 4))
			suffix = tail.pop()! + suffix;
		return truncateToWidth(text, Math.max(1, width - visibleWidth(suffix) - 1), "") + "…" + suffix;
	}
	private listRow(text: string, index: number, width: number): string[] {
		const selected = index === this.view.row;
		const prefix = selected ? "› " : "  ";
		const lines = selected
			? wrapTextWithAnsi(text, Math.max(1, width - 2)).slice(0, 3)
			: [truncateToWidth(text, width - 2, "…")];
		return lines.map(
			(line, i) =>
				(i ? "  " : prefix) +
				(selected && this.focus === "body" ? this.theme.fg("accent", line) : line),
		);
	}
	private content(width: number): string[] {
		const prose = (text: string) =>
			wrapTextWithAnsi(safeReviewText(text), Math.max(1, Math.min(width, 72)));
		const quiet = (text: string) => prose(text).map((line) => this.theme.fg("dim", line));
		const markdown = (text: string, size = Math.min(width, 72)) => {
			this.markdown.setText(safeReviewText(text));
			const lines = [...this.markdown.render(size)];
			while (lines.length && !visibleWidth(lines[0]!)) lines.shift();
			while (lines.length && !visibleWidth(lines.at(-1)!)) lines.pop();
			return lines;
		};
		if (this.view.screen === "discussion")
			return [
				...prose(`Your question · ${this.targetLabel(this.view.target)}`),
				...(this.record.targetContexts?.[this.view.target]
					? [
							this.section("ORIGINAL DISCUSSION CONTEXT", width),
							...markdown(this.record.targetContexts[this.view.target]!.text),
							"",
						]
					: []),
				...this.record.turns
					.filter((turn) => turn.target === this.view.target)
					.flatMap((turn) => [
						this.section("YOU", width),
						...prose(turn.question),
						this.section("BRO · ANSWER", width),
						...markdown(
							turn.answer ||
								(this.busy && turn === this.activeTurn ? "Working…" : "No answer received."),
						),
						...(turn.error
							? [this.theme.fg("warning", "Request failed"), ...prose(turn.error)]
							: []),
						...(turn.status !== "complete"
							? [
									this.busy && turn === this.activeTurn
										? "Answering…"
										: turn.status === "failed"
											? "Failed · partial answer kept"
											: "Stopped · partial answer kept",
								]
							: []),
						"",
					]),
				...(this.record.turns.some((turn) => turn.target === this.view.target)
					? []
					: ["Ask a question below. Nothing is posted to GitHub."]),
			];
		if (this.view.screen === "file") {
			if (!this.fileDiffs) {
				// Capture disables renames; type changes can have two adjacent sections with the same header.
				const sections: string[] = [];
				let previousHeader = "";
				for (const section of this.record.snapshot.diff
					.split(/(?=^diff --git )/m)
					.filter(Boolean)) {
					if (!section.startsWith("diff --git ")) continue;
					const header = section.split("\n", 1)[0]!;
					if (header === previousHeader) sections[sections.length - 1] += section;
					else {
						sections.push(section);
						previousHeader = header;
					}
				}
				this.fileDiffs = new Map(
					sections.length === this.record.snapshot.files.length
						? this.record.snapshot.files.map((file, index) => [file.path, sections[index]!])
						: [],
				);
			}
			const section = this.fileDiffs.get(this.view.file);
			return [
				this.section("CHANGES", width),
				...prose(this.view.file),
				this.theme.fg("dim", "old / new line numbers"),
				...(section
					? this.diffLines(section, width)
					: ["Diff inventory mismatch; captured changes cannot be mapped safely."]),
			];
		}
		if (this.view.screen === "finding") {
			const finding = this.finding;
			if (!finding) return ["Finding no longer available in this guide."];
			const block = (title: string, text: string, color = "accent") => [
				this.theme.bold(this.theme.fg(color, title)),
				"",
				...markdown(text, Math.max(1, Math.min(width, 64) - 2)).map((line) => "  " + line),
				"",
			];
			return [
				...wrapTextWithAnsi(
					`${this.findingBadge(finding)}  ${this.theme.bold(label(finding.title))}`,
					width,
				),
				"",
				...block("What happens", finding.scenario),
				...block("Why it matters", finding.impact),
				...block("Suggested fix", finding.fix, "success"),
				...block("How to check", finding.check, "success"),
				...block("Reasoning", finding.reasoning),
				...(finding.uncertainty
					? block("Uncertainty", finding.uncertainty)
					: quiet("Review note: source assessment only; not independently verified.")),
				"",
				...(finding.evidence.length
					? this.evidenceLines(finding.evidence, width)
					: quiet("No resolved source references cited.")),
				"",
				...quiet(
					"Suggestions are not applied or independently verified. Suggested checks have not been executed by this review.",
				),
				...(!finding.evidence.some((ref) => ref.valid)
					? quiet("No resolved source evidence; treat this finding as unverified.")
					: []),
			];
		}
		if (this.view.selected === "findings" || this.view.selected === "across")
			return [
				this.section(
					this.view.scope
						? `Findings · ${this.targetLabel(this.view.scope)}`
						: this.view.selected === "across"
							? "ACROSS THE CHANGE"
							: "FINDINGS TO EXAMINE",
					width,
					"warning",
				),
				...(this.findings.length
					? this.findings.flatMap((finding, index) =>
							this.listRow(
								`${this.findingBadge(finding)}  ${this.theme.bold(label(finding.title))}`,
								index,
								width,
							),
						)
					: ["No issues reported in covered material. This is not approval."]),
			];
		if (this.view.selected === "coverage") {
			const assessment = this.record.guide?.assessment;
			if (!assessment) return ["Quality assessment not performed."];
			const cited = new Set(
				guideEvidence(this.record.guide)
					.filter((ref) => ref.valid)
					.map((ref) => ref.path),
			);
			const list = (title: string, items: string[], empty: string) => [
				this.theme.bold(this.theme.fg("accent", title)),
				"",
				...(items.length
					? items.flatMap((item) =>
							wrapTextWithAnsi(safeReviewText(item), Math.max(1, Math.min(width, 64) - 2)).map(
								(line, index) => (index ? "  " : "• ") + line,
							),
						)
					: quiet(empty)),
				"",
			];
			return [
				this.section("COVERAGE", width),
				"",
				...prose(
					this.record.snapshot.diff.length > 100_000
						? "Diff: first 100,000 characters supplied. Full captured diff remains available."
						: "Diff: complete captured diff supplied.",
				),
				...quiet("Execution: no project tests independently verified."),
				"",
				...list("Inspected · model-reported", assessment.inspected, "No inspected paths reported."),
				...list(
					"Not checked · model-reported",
					assessment.notExamined,
					"No gaps reported; this does not prove complete coverage.",
				),
				...list(
					"Changed files without citations",
					this.record.snapshot.files
						.filter((file) => !cited.has(file.path))
						.map((file) => file.path),
					"All changed files have cited evidence.",
				),
				...(assessment.warnings.length ? list("Assessment gaps", assessment.warnings, "") : []),
				this.theme.fg("dim", "Reading these results"),
				"",
				...quiet(
					"Citations show source locations, not proof of full inspection or a finding’s conclusion.",
				),
				"",
				...quiet(
					"Automatic preparation is instructed not to execute repository code. This is not an enforced sandbox. The assessment is not independently verified.",
				),
			];
		}
		if (this.topic) {
			const findings =
				this.record.guide?.assessment?.findings.filter(
					(finding) => finding.topicId === this.topic!.id,
				) ?? [];
			return [
				...prose(this.topic.title).map((line) => this.theme.bold(line)),
				"",
				this.section("EXPLANATION", width),
				...markdown(this.topic.explanation),
				"",
				...(findings.length
					? [
							this.section("FINDINGS TO EXAMINE", width, "warning"),
							"",
							...findings.flatMap((finding) => this.findingCard(finding, width)),
							...quiet("View topic findings for evidence, fixes and checks."),
							"",
						]
					: []),
				...this.evidenceLines(this.topic.evidence, width),
			];
		}
		if (this.view.selected === "files")
			return [
				"Changed files",
				...this.record.snapshot.files.flatMap((file, index) =>
					this.listRow(
						`${({ M: "Modified", A: "Added", D: "Deleted", T: "Type changed" } as Record<string, string>)[file.status] ?? file.status} · ${this.middle(file.path, Math.max(8, width - 14))}`,
						index,
						width,
					),
				),
			];
		if (this.view.selected === "questions")
			return [
				"Your questions and drafts",
				...(this.discussions.length
					? this.discussions.flatMap((discussion, index) =>
							this.listRow(
								`${discussion.draft ? "Draft · " : ""}${this.middle(this.targetLabel(discussion.target), Math.max(8, Math.floor(width / 2)))}: ${label(discussion.text)}`,
								index,
								width,
							),
						)
					: ["No questions yet. Ask from the overview, a topic, finding or file."]),
			];
		if (this.view.selected === "close")
			return [
				this.busy ? "Stop and close" : "Close",
				"",
				...prose(
					this.busy
						? `The active ${this.operation === "answer" ? "answer" : this.operation === "regenerate" ? "regeneration" : "preparation"} will stop. Partial work, drafts and reading position will be saved privately.`
						: "Your questions, drafts and reading position are saved privately. Nothing is posted to GitHub.",
				),
				"",
				"Enter to close.",
			];
		return [
			this.section("PURPOSE OF THIS CHANGE", width),
			"",
			...markdown(
				this.record.guide?.summary ??
					(this.busy
						? "Bro is reading the captured changes. You can browse files while it works."
						: "No guide yet. Prepare it below, or inspect the changed files."),
			),
			...(this.record.guide
				? this.record.guide.assessment
					? [
							"",
							this.section("FINDINGS TO EXAMINE", width, "warning"),
							"",
							...this.findings.slice(0, 3).flatMap((finding) => this.findingCard(finding, width)),
							...quiet(
								this.record.guide.assessment.warnings.length
									? "Assessment incomplete · See Coverage and limitations."
									: this.findings.length
										? `Open Findings for all ${this.findings.length} concerns, evidence, fixes and checks.`
										: "No issues reported in covered material. This is not approval.",
							),
							"",
							this.section("QUALITY ASSESSMENT", width),
							"",
							...markdown(this.record.guide.assessment.overview),
							"",
							...quiet(
								"Source assessment · execution not independently verified. See Coverage and limitations.",
							),
						]
					: [
							...prose(
								"Quality assessment not performed. Regenerate guide to assess this captured revision.",
							),
						]
				: []),
			...(!this.busy && this.record.guideAttempt
				? [
						"",
						...prose(
							this.record.guideAttempt.error ??
								(this.record.guide
									? "Regeneration was interrupted. Your current guide is unchanged; choose Regenerate guide to retry."
									: "Preparation was interrupted. Choose Prepare guide to try again."),
						),
					]
				: []),
			"",
			...quiet(
				`${this.record.snapshot.files.length} changed files · captured ${this.record.snapshot.target.head.slice(0, 8)}`,
			),
		];
	}
	private evidenceLines(evidence: Evidence[], width: number): string[] {
		const prose = (text: string) => wrapTextWithAnsi(safeReviewText(text), Math.max(1, width));
		return evidence.flatMap((ref) => {
			const key = `${ref.path}:${ref.side}:${ref.start}:${ref.end}`;
			const code = this.evidence.get(key),
				digits = String(ref.end).length;
			return [
				this.section("CAPTURED CODE", width),
				...prose(`${ref.path} · ${ref.side} lines ${ref.start}–${ref.end}`),
				...(!ref.valid
					? ["Evidence unavailable — unresolved reference"]
					: this.evidenceErrors.has(key)
						? prose(this.evidenceErrors.get(key)!)
						: code === undefined
							? ["Loading captured code…"]
							: code
									.split("\n")
									.flatMap((line, index) =>
										this.codeLine(line, String(ref.start + index).padStart(digits), width),
									)),
			];
		});
	}
	private runningStatus(narrow: boolean): string {
		const spinner = ["⠋", "⠙", "⠹", "⠸", "⠼", "⠴", "⠦", "⠧", "⠇", "⠏"][
			Math.floor(Date.now() / 200) % 10
		];
		const elapsed = `${Math.max(0, Math.floor((Date.now() - this.startedAt) / 1000))}s`;
		if (this.stage) {
			if (this.operation === "answer") return `${spinner} ${this.stage.detail} · ${elapsed}`;
			const step = this.stage.step === "check" ? 1 : this.stage.step === "save" ? 2 : 0;
			const trail = [0, 1, 2]
				.map((index) => (index < step ? "●" : index === step ? spinner : "○"))
				.join(" ");
			return narrow
				? `${spinner} ${elapsed} · ${this.stage.detail}`
				: `${trail} ${this.operation === "regenerate" ? "↻ Regenerating" : "Preparing"} · ${this.stage.detail} · ${elapsed}`;
		}
		return `${spinner} ${this.operation === "guide" ? "Preparing review guide" : this.operation === "regenerate" ? "Regenerating guide" : "Answering question"} · ${elapsed}`;
	}
	render(width: number): string[] {
		this.width = width;
		const height = Math.max(1, Math.min(36, this.tui.terminal.rows - 2));
		const inner = Math.max(1, width - 2);
		const fit = (text: string, size: number) => {
			const line = truncateToWidth(text, size, "…");
			return line + " ".repeat(Math.max(0, size - visibleWidth(line)));
		};
		const border = (left: string, right: string) =>
			this.theme.fg("border", left + "─".repeat(Math.max(0, width - 2)) + right);
		const row = (text: string) =>
			this.theme.fg("border", "│") + fit(text, inner) + this.theme.fg("border", "│");
		this.tiny = width < 36 || height < 16;
		this.layout.height = height;
		if (this.tiny)
			return [
				border("╭", "╮"),
				row("Resize to at least 36×18"),
				row(this.busy ? "Esc: stop and close" : "Esc: close"),
				border("╰", "╯"),
			]
				.slice(0, height)
				.map((line) => truncateToWidth(line, width, ""));
		const narrow = width < 90;
		const navigationOnly = narrow && this.focus === "contents";
		const leftWidth = narrow ? 0 : Math.min(38, Math.floor(inner * 0.32));
		const detailWidth = inner - leftWidth - (leftWidth ? 3 : 0);
		const detailRow = (text: string) =>
			row((leftWidth ? " ".repeat(leftWidth) + this.theme.fg("border", " │ ") : "") + text);
		const composer = !navigationOnly && this.view.screen === "discussion";
		const actions = navigationOnly ? [] : this.actions();
		this.action = Math.max(0, Math.min(this.action, actions.length - 1));
		const short: Record<string, string> = {
			"Send question": "Send",
			"Ask about this finding": "Ask",
			"Ask about this file": "Ask",
			"Ask about this review": "Ask",
			"Ask a question": "Ask",
			"Copy finding": "Copy",
			"Back to files": "Back",
			"View topic findings": "Topic findings",
			"Edit and resend": "Edit and resend",
		};
		const buttons = actions.map((action, index) => {
			const focused = this.focus === "actions" && index === this.action;
			const text = `${focused ? "›" : ""}[${narrow ? (short[action] ?? action) : action}]`;
			return focused ? this.theme.bold(this.theme.fg("accent", text)) : text;
		});
		const actionRows = !buttons.length
			? []
			: narrow
				? wrapTextWithAnsi(buttons.join(" "), detailWidth)
				: buttons.map((button) => "  " + button);
		const availableRows = height - (narrow ? 7 : 8) - actionRows.length - (composer ? 1 : 0);
		const sticky =
			!navigationOnly &&
			this.view.screen === "finding" &&
			this.finding &&
			availableRows >= 4 &&
			(this.view.offsets[this.key] ?? 0) > 0
				? truncateToWidth(
						`${this.findingBadge(this.finding)}  ${this.theme.bold(label(this.finding.title))}`,
						detailWidth,
						"…",
					)
				: undefined;
		const actionGap = actionRows.length && availableRows >= 8 ? 1 : 0;
		const bodyRows = availableRows - (sticky ? 1 : 0) - actionGap;
		const bodyStart = 4 + (sticky ? 1 : 0);
		if (this.isList)
			this.view.row = Math.max(0, Math.min(Math.max(0, this.listLength - 1), this.view.row));
		const body = [
			...(this.saveError
				? [
						this.theme.fg("warning", "Not saved · Retry saving"),
						...wrapTextWithAnsi(label(this.saveError), detailWidth),
						"",
					]
				: []),
			...(this.notice && this.notice !== "Saved" && !this.busy
				? [
						...wrapTextWithAnsi(label(this.notice), detailWidth).map((line) =>
							this.theme.fg("accent", line),
						),
						"",
					]
				: []),
			...this.content(detailWidth),
		];
		this.maxOffset = Math.max(0, body.length - bodyRows);
		const listCursor = this.isList ? body.findIndex((line) => line.startsWith("› ")) : 0;
		const offset =
			this.view.screen === "discussion" && this.followAnswer
				? this.maxOffset
				: this.isList && this.manualListKey !== this.key
					? Math.max(0, Math.min(this.maxOffset, Math.max(0, listCursor) - bodyRows + 3))
					: Math.min(this.maxOffset, this.view.offsets[this.key] ?? 0);
		this.view.offsets[this.key] = offset;
		const entries = this.entries();
		const selected = entries.findIndex((entry) => entry.id === this.view.selected);
		const start = Math.max(
			0,
			Math.min(
				this.contentsOffset ?? selected - Math.floor(bodyRows / 2),
				Math.max(0, entries.length - bodyRows),
			),
		);
		this.layout = { height, bodyRows, leftWidth, navigationOnly, contentsStart: start, bodyStart };
		const target = this.record.snapshot.target;
		const paneRule = (title: string, size: number, active: boolean) =>
			this.theme.fg(
				active ? "accent" : "border",
				truncateToWidth(`─ ${title} ` + "─".repeat(size), size, ""),
			);
		const divider = leftWidth
			? row(
					paneRule("Contents", leftWidth, this.focus === "contents") +
						this.theme.fg("border", " │ ") +
						paneRule(
							this.focus === "input"
								? "Your draft"
								: this.focus === "actions"
									? "Actions"
									: "Reading",
							detailWidth,
							this.focus !== "contents",
						),
				)
			: border("├", "┤");
		const lines = [
			border("╭", "╮"),
			row(this.theme.fg("accent", label(`Bro · Review · ${target.repository} #${target.number}`))),
			row(
				this.theme.bold(
					this.theme.fg(
						this.busy
							? "accent"
							: this.saveError
								? "warning"
								: this.record.guideAttempt
									? "warning"
									: this.record.guide
										? "success"
										: "muted",
						this.busy
							? this.runningStatus(narrow)
							: this.saveError
								? "Review not saved · retry saving"
								: this.record.guide && this.record.guideAttempt
									? `Regeneration ${this.record.guideAttempt.status === "failed" ? "failed" : "stopped"} · current guide kept`
									: this.record.guide
										? this.record.guide.assessment
											? this.record.guide.assessment.warnings.length
												? "Review ready · assessment incomplete"
												: `✓ Review ready · ${this.record.guide.assessment.findings.length} findings`
											: `✓ Guide ready · ${this.record.guide.topics.length} topic${this.record.guide.topics.length === 1 ? "" : "s"}`
										: this.record.guideAttempt
											? `Preparation ${this.record.guideAttempt.status === "failed" ? "failed" : "stopped"} · Prepare guide to retry`
											: "Captured changes ready",
					),
				),
			),
			divider,
		];
		for (let i = 0; i < bodyRows + (sticky ? 1 : 0); i++) {
			const entry = entries[start + i];
			let nav = entry ? `${entry.id === this.view.selected ? "›" : " "} ${label(entry.title)}` : "";
			if (entry?.id === this.view.selected)
				nav =
					this.focus === "contents"
						? this.theme.bold(this.theme.fg("accent", nav))
						: this.theme.fg("dim", nav);
			if (i === 0 && start > 0) nav = "▲ " + nav.slice(2);
			if (i === bodyRows + (sticky ? 1 : 0) - 1 && start + i + 1 < entries.length)
				nav = "▼ " + nav.slice(2);
			lines.push(
				row(
					navigationOnly
						? nav
						: leftWidth
							? fit(nav, leftWidth) +
								this.theme.fg("border", " │ ") +
								fit(
									sticky && i === 0 ? sticky : (body[offset + i - (sticky ? 1 : 0)] ?? ""),
									detailWidth,
								)
							: sticky && i === 0
								? sticky
								: (body[offset + i - (sticky ? 1 : 0)] ?? ""),
				),
			);
		}
		if (actionGap) lines.push(detailRow(this.theme.fg("dim", "─".repeat(detailWidth))));
		if (composer) {
			this.input.focused = this.focus === "input" && this.focused;
			lines.push(detailRow(this.input.render(detailWidth)[0] ?? ""));
		}
		for (const action of actionRows) lines.push(detailRow(action));
		const exit =
			this.focus === "contents" ? (this.busy ? "Esc stop/close" : "Esc close") : "Esc back";
		const primary =
			this.focus === "contents"
				? this.view.selected === "close"
					? "Enter close"
					: "Enter read"
				: this.focus === "input"
					? this.busy
						? "Typing draft"
						: "Enter send"
					: this.focus === "actions"
						? "Enter select"
						: this.view.selected === "close"
							? "Enter close"
							: this.isList && this.listLength
								? "Enter open"
								: actions.length
									? "Enter actions"
									: "↑↓ read";
		const hint = `${exit} · ${primary} · Tab${narrow ? "" : this.focus === "input" ? " actions" : " focus"}`;
		const more = navigationOnly ? start + bodyRows < entries.length : offset < this.maxOffset;
		const paused =
			this.busy &&
			this.view.screen === "discussion" &&
			!this.followAnswer &&
			this.activeTurn?.target === this.view.target &&
			offset < this.maxOffset;
		const status = this.saveError
			? "Not saved · Retry saving"
			: paused
				? "New output below"
				: this.notice || `Private · ${target.head.slice(0, 8)}`;
		lines.push(border("├", "┤"));
		if (!narrow)
			lines.push(
				row(
					`${this.focus === "contents" ? "Contents" : this.focus === "body" ? "Reading" : this.focus === "input" ? "Your draft" : "Actions"} · ${label(status)}${more ? " · ▼ more below" : ""}`,
				),
			);
		lines.push(
			row(hint + (narrow && more ? (paused ? " · ↓ new" : " · ▼") : "")),
			border("╰", "╯"),
		);
		return lines;
	}
	invalidate() {
		this.input.invalidate();
		this.markdown.invalidate();
	}
	dispose() {}
}