/**
 * GM-facing orchestration: the End Session flow and the bulk
 * snapshot push it depends on. Imported by main.js and exposed on
 * `globalThis.seitimeBridge` for use from Foundry macros.
 *
 * Recommended macro body (Script type, no arguments):
 *   seitimeBridge.endSession();
 */

import { MODULE_ID } from "./constants.js";
import {
	completeSession,
	listScheduledSessions,
	pushSnapshot,
} from "./api.js";

function escapeHtml(s) {
	return String(s ?? "").replace(
		/[&<>"']/g,
		(c) => ({ "&": "&amp;", "<": "&lt;", ">": "&gt;", '"': "&quot;", "'": "&#39;" })[c],
	);
}

/**
 * Push snapshots for every PC in the world, in parallel. Returns a summary
 * with successful/failed counts and the names of any failures so the caller
 * can surface them.
 */
export async function pushAllSnapshots() {
	const pcs = game.actors.filter((a) => a.type === "character");
	const results = await Promise.allSettled(pcs.map((a) => pushSnapshot(a)));
	const failed = results
		.map((r, i) => (r.status === "rejected" ? { name: pcs[i].name, error: r.reason?.message ?? String(r.reason) } : null))
		.filter(Boolean);
	return {
		total: pcs.length,
		successful: pcs.length - failed.length,
		failed,
	};
}

/**
 * Show the appropriate dialog for the number of candidates and resolve to
 * the chosen session_id, or null if the user cancels.
 */
async function pickSession(sessions) {
	if (sessions.length === 1) {
		const s = sessions[0];
		const confirmed = await Dialog.confirm({
			title: "End Session",
			content: `
				<p>End <b>${escapeHtml(s.session_title)}</b>?</p>
				<p>This will mark it Completed, schedule the next session, and push snapshots for all PCs.</p>
			`,
			yes: () => true,
			no: () => false,
			defaultYes: true,
		});
		return confirmed ? s.session_id : null;
	}

	const options = sessions
		.map(
			(s) =>
				`<option value="${escapeHtml(s.session_id)}">${escapeHtml(s.session_title)}${s.session_start ? ` — ${escapeHtml(s.session_start)}` : ""}</option>`,
		)
		.join("");

	return new Promise((resolve) => {
		new Dialog({
			title: "End Session",
			content: `
				<p>Multiple scheduled sessions match this Foundry world. Pick one to end:</p>
				<select id="seitime-session-pick" style="width:100%; margin-bottom:0.5em;">
					${options}
				</select>
			`,
			buttons: {
				cancel: { label: "Cancel", callback: () => resolve(null) },
				end: {
					label: "End Session",
					callback: (html) => {
						const value = html.find("#seitime-session-pick").val();
						resolve(value || null);
					},
				},
			},
			default: "end",
			close: () => resolve(null),
		}).render(true);
	});
}

function buildSummaryHtml(completion, snapshotResult) {
	const parts = [
		`<h3>Session Complete</h3>`,
		`<p><b>${escapeHtml(completion.completed_session)}</b> marked Completed.</p>`,
	];
	if (completion.next_session) {
		parts.push(
			`<p>Next session scheduled: <b>${escapeHtml(completion.next_session)}</b> (#${escapeHtml(completion.next_session_number)}).</p>`,
		);
	}
	parts.push(
		`<p>Snapshots pushed: ${snapshotResult.successful} of ${snapshotResult.total}.</p>`,
	);
	if (snapshotResult.failed.length) {
		const items = snapshotResult.failed
			.map((f) => `<li>${escapeHtml(f.name)}: ${escapeHtml(f.error)}</li>`)
			.join("");
		parts.push(`<p style="color:#a00"><b>Failed pushes:</b></p><ul>${items}</ul>`);
	}
	return parts.join("");
}

/**
 * Full end-of-session flow. Invoked from a Foundry macro by the GM.
 */
export async function endSession() {
	if (!game.user.isGM) {
		ui.notifications.warn("End Session is GM-only.");
		return;
	}

	let sessions;
	try {
		sessions = await listScheduledSessions();
	} catch (err) {
		console.error(`[${MODULE_ID}]`, err);
		ui.notifications.error(`Could not fetch scheduled sessions: ${err.message}`);
		return;
	}

	if (!sessions.length) {
		ui.notifications.warn(
			"No scheduled sessions found for this Foundry world. Check that the world ID matches a Game in Frappe.",
		);
		return;
	}

	const sessionId = await pickSession(sessions);
	if (!sessionId) return;

	let completion;
	try {
		completion = await completeSession(sessionId);
	} catch (err) {
		console.error(`[${MODULE_ID}]`, err);
		ui.notifications.error(`Could not complete session: ${err.message}`);
		return;
	}

	const snapshotResult = await pushAllSnapshots();

	await ChatMessage.create({
		content: buildSummaryHtml(completion, snapshotResult),
		speaker: { alias: "Seitime Bridge" },
		whisper: ChatMessage.getWhisperRecipients("GM").map((u) => u.id),
	});

	const failureNote = snapshotResult.failed.length ? ` (${snapshotResult.failed.length} snapshot push(es) failed — see chat)` : "";
	ui.notifications.info(`Session ended. ${snapshotResult.successful}/${snapshotResult.total} snapshots pushed${failureNote}.`);
}