import type { FleetRow } from "./fleet-read-model.ts";
import { moveSelection, type Selection } from "./fleet-selection.ts";
import { confirmFleetAction, type FleetConfirmation } from "./fleet-dashboard-ops.ts";
import { safeTerminalText, treePrefix, type TextMetrics } from "./fleet-strip-view.ts";

export interface ThemeLike { fg(color: string, text: string): string; bold(text: string): string; bg?(color: string, text: string): string; }
export const FLEET_CHROME_ROWS = 4;
export interface FleetViewModel {
	rows: readonly FleetRow[];
	selection: Selection;
	summary: { running: number; done: number; failed: number; totalTokens: number; intervals: Array<[number, number]>; wallMs: number };
	filterQuery?: string;
	showFinished: boolean;
	scrollOffset?: number;
	confirmation?: string;
	comsLines?: readonly string[];
}

const fit = (text: string, width: number, metrics: TextMetrics) => metrics.truncateToWidth(text, Math.max(0, width));
const padCells = (text: string, width: number, metrics: TextMetrics) => text + " ".repeat(Math.max(0, width - metrics.visibleWidth(text)));
const duration = (ms: number) => ms < 60_000 ? `${Math.round(ms / 1000)}s` : `${Math.floor(ms / 60_000)}:${String(Math.round(ms / 1000) % 60).padStart(2, "0")}`;
const tokens = (n: number | null) => n == null ? "—" : n >= 1000 ? `${Math.round(n / 1000)}k` : String(n);
const glyph = (row: FleetRow) => row.status === "running" ? "●" : row.status === "done" ? "✓" : row.status === "error" ? "✗" : row.status === "pending" ? "◌" : row.status === "stale" ? "○" : "▪";
const context = (pct: number | null) => pct == null ? "[automatic]  —" : `[${"#".repeat(Math.max(0, Math.min(10, Math.round(pct / 10))))}${"·".repeat(Math.max(0, 10 - Math.round(pct / 10)))}] ${Math.round(pct)}%`;

/** Render a constant-height, width-bounded fleet list without pi runtime dependencies. */
export function renderFleetDashboard(vm: FleetViewModel, width: number, bodyHeight: number, theme: ThemeLike, metrics: TextMetrics): string[] {
	const w = Math.max(1, width), body = Math.max(0, bodyHeight);
	const summary = `${vm.summary.running} running · ${vm.summary.done} done${vm.summary.failed ? ` · ${vm.summary.failed} failed` : ""} · ${duration(vm.summary.wallMs)} · ${tokens(vm.summary.totalTokens)} tok`;
	const title = ` Fleet ${vm.filterQuery ? `· filter: ${safeTerminalText(vm.filterQuery)}` : ""}`;
	const header = fit(title, Math.max(1, w - metrics.visibleWidth(summary) - 1), metrics);
	const lines: string[] = [fit(theme.bold(header) + " " + theme.fg("dim", summary), w, metrics), theme.fg("dim", "╭" + "─".repeat(Math.max(0, w - 2)) + "╮")];
	if (vm.rows.length === 0) {
		const message = "no agents dispatched yet";
		lines.push(...Array.from({ length: body }, (_, i) => i === Math.floor(body / 2) ? fit(theme.fg("dim", " ".repeat(Math.max(0, Math.floor((w - metrics.visibleWidth(message)) / 2))) + message), w, metrics) : ""));
	} else {
		const offset = Math.max(0, Math.min(vm.scrollOffset ?? 0, Math.max(0, vm.rows.length - body)));
		for (let i = 0; i < body; i++) {
			const row = vm.rows[offset + i];
			if (!row) { lines.push(""); continue; }
			const selected = offset + i === vm.selection.index;
			const indent = treePrefix(row.lastAtDepth, row.depth);
			const name = `${selected ? "❯" : " "} ${indent}${glyph(row)} ${safeTerminalText(row.name)}`;
			const parts = [name, row.kind, `${row.backend === "coms" ? "⇄ " : ""}${safeTerminalText(row.model)}`, context(row.contextPct), tokens(row.contextTokens), duration(row.elapsed), row.toolCount == null ? "—" : String(row.toolCount), safeTerminalText(row.lastWork)];
			const count = w < 80 ? 4 : w < 105 ? 6 : 8;
			const line = fit(parts.slice(0, count).join("  "), w, metrics);
			lines.push(selected && theme.bg ? theme.bg("selectedBg", padCells(line, w, metrics)) : line);
		}
	}
	lines.push(theme.fg("dim", "╰" + "─".repeat(Math.max(0, w - 2)) + "╯"));
	lines.push(fit(theme.fg("dim", vm.confirmation ?? "↑↓ select · Enter open · h history · m substitute · x kill · r restart · f filter · a all · q close"), w, metrics));
	const coms = vm.comsLines ?? [];
	lines.push(...coms);
	const total = body + FLEET_CHROME_ROWS + coms.length;
	return lines.slice(0, total).concat(Array(Math.max(0, total - lines.length)).fill(""));
}

export type DashboardConfirm = FleetConfirmation;
export interface DashboardControllerState {
	selection: Selection;
	scrollOffset: number;
	filtering: boolean;
	filterQuery: string;
	showFinished: boolean;
	confirm: DashboardConfirm;
}
export type DashboardIntent =
	| null
	| "close"
	| "substitute"
	| "history"
	| { open: string }
	| { kill: string }
	| { restart: string };

/** Pure keyboard transitions for the fleet list controller (mirrors detailTransition). */
export function dashboardTransition(
	input: string,
	state: DashboardControllerState,
	rows: readonly { key: string; runToken?: string }[],
	bodyHeight: number,
	now = Date.now(),
): DashboardIntent {
	if (state.filtering) {
		if (input === "\u001b") {
			state.filterQuery = "";
			state.filtering = false;
		} else if (input === "\r") {
			state.filtering = false;
		} else if (input === "\u007f" || input === "\b") {
			state.filterQuery = Array.from(state.filterQuery).slice(0, -1).join("");
		} else if (input.length === 1) {
			state.filterQuery += input;
		}
		return null;
	}
	const selected = rows[state.selection.index];
	if (input !== "x" && input !== "r") state.confirm = null;
	if (input === "\u001b[A" || input === "k" || input === "\u001b[B" || input === "j") {
		moveSelection(state.selection, rows, input === "\u001b[A" || input === "k" ? -1 : 1);
		const viewport = Math.max(1, bodyHeight);
		if (state.selection.index < state.scrollOffset) state.scrollOffset = state.selection.index;
		else if (state.selection.index >= state.scrollOffset + viewport) state.scrollOffset = state.selection.index - viewport + 1;
		state.scrollOffset = Math.max(0, Math.min(state.scrollOffset, Math.max(0, rows.length - viewport)));
		return null;
	}
	if (input === "\u001b[5~" || input === "\u001b[6~") {
		const viewport = Math.max(1, bodyHeight);
		moveSelection(state.selection, rows, (input === "\u001b[5~" ? -1 : 1) * viewport);
		state.scrollOffset = Math.max(0, Math.min(state.selection.index, Math.max(0, rows.length - viewport)));
		return null;
	}
	if (input === "f") {
		state.filtering = true;
		return null;
	}
	if (input === "a") {
		state.showFinished = !state.showFinished;
		return null;
	}
	if (input === "m" || input === "M") return "substitute";
	if (input === "h" || input === "H") return "history";
	if (input === "\r" && selected) return { open: selected.key };
	if (input === "x" || input === "r") {
		if (!selected) return null;
		const action = input === "x" ? "kill" : "restart";
		const result = confirmFleetAction(state.confirm, action, selected, now);
		state.confirm = result.confirmation;
		if (!result.confirmed) return null;
		return action === "kill" ? { kill: selected.key } : { restart: selected.key };
	}
	if (input === "\u001b" || input === "q") return "close";
	return null;
}