"use client";

import { Check, CloudDownload, Loader2 } from "lucide-react";
import { useCallback, useRef, useState } from "react";
import { toast } from "sonner";
import { Button } from "@/components/ui/button";
import { adminFetch } from "@/lib/admin-fetch";

interface SyncEvent {
	type: string;
	classname?: string;
	status?: string;
	succeeded?: number;
	failed?: number;
}

export function SyncAllClient() {
	const [syncing, setSyncing] = useState(false);
	const [progress, setProgress] = useState<{
		done: number;
		total: number;
	} | null>(null);
	const [log, setLog] = useState<string[]>([]);
	const [result, setResult] = useState<{
		succeeded: number;
		failed: number;
		sources: number;
	} | null>(null);
	const abortRef = useRef<AbortController | null>(null);

	const startSync = useCallback(async () => {
		setSyncing(true);
		setProgress(null);
		setLog([]);
		setResult(null);

		const abort = new AbortController();
		abortRef.current = abort;

		try {
			const res = await adminFetch("/api/admin/import/clone/sync-all", {
				method: "POST",
				headers: { "Content-Type": "application/json" },
				body: JSON.stringify({}),
				signal: abort.signal,
			});

			if (!res.body) {
				toast.error("No response stream");
				setSyncing(false);
				return;
			}

			if (!res.headers.get("content-type")?.includes("text/event-stream")) {
				let errMsg = "Sync failed";
				try {
					const json = await res.json();
					errMsg = json.error || errMsg;
				} catch {
					// ignore
				}
				toast.error(errMsg);
				setSyncing(false);
				return;
			}

			const reader = res.body.getReader();
			const decoder = new TextDecoder();
			let buf = "";
			let succeeded = 0;
			let failed = 0;
			let totalItems = 0;

			while (true) {
				const { value, done: streamDone } = await reader.read();
				if (streamDone) break;
				buf += decoder.decode(value, { stream: true });
				const parts = buf.split("\n\n");
				buf = parts.pop() ?? "";
				for (const part of parts) {
					if (!part.startsWith("data: ")) continue;
					try {
						const evt = JSON.parse(part.slice(6)) as SyncEvent;
						if (
							evt.type === "item_progress" &&
							(evt.status === "done" || evt.status === "failed")
						) {
							totalItems++;
							if (evt.status === "done") succeeded++;
							else failed++;
							setProgress({ done: succeeded + failed, total: totalItems });
							setLog((prev) => [
								...prev,
								`${evt.status === "done" ? "✓" : "✗"} ${evt.classname ?? ""}`,
							]);
						}
						if (evt.type === "batch_complete") {
							succeeded = evt.succeeded ?? succeeded;
							failed = evt.failed ?? failed;
						}
					} catch {
						// skip parse errors
					}
				}
			}

			// Check for skipped state (all up to date)
			try {
				const parsed = JSON.parse(
					buf.includes("data:") ? (buf.split("data:").pop() ?? "{}") : "{}",
				);
				if (parsed.skipped) {
					toast.info(parsed.message || "All sources are up to date");
					setResult({ succeeded: 0, failed: 0, sources: 0 });
					setSyncing(false);
					return;
				}
			} catch {
				// not a skipped response
			}

			setResult({ succeeded, failed, sources: 1 });
			if (succeeded > 0) toast.success(`${succeeded} items synced`);
			if (failed > 0) toast.error(`${failed} items failed`);
		} catch (err) {
			if ((err as Error).name === "AbortError") {
				toast.info("Sync cancelled");
			} else {
				toast.error("Sync request failed");
			}
		} finally {
			setSyncing(false);
			abortRef.current = null;
		}
	}, []);

	return (
		<div className="space-y-4">
			{!result && (
				<div className="flex items-center gap-2 flex-wrap">
					<Button onClick={startSync} disabled={syncing} size="lg">
						{syncing ? (
							<Loader2 className="w-4 h-4 animate-spin mr-2" />
						) : (
							<CloudDownload className="w-4 h-4 mr-2" />
						)}
						{syncing
							? `Syncing… ${progress ? `${progress.done}/${progress.total}` : ""}`
							: "Start Sync All Sources"}
					</Button>
					{syncing && (
						<Button
							variant="outline"
							size="lg"
							onClick={() => abortRef.current?.abort()}
						>
							Cancel
						</Button>
					)}
				</div>
			)}

			{progress && (
				<div className="text-sm text-muted-foreground">
					Processed {progress.done} items
					{progress.total > 0 ? ` out of ${progress.total}` : ""}
				</div>
			)}

			{log.length > 0 && (
				<div className="rounded-xl border bg-card p-4 max-h-80 overflow-x-auto overflow-y-auto space-y-0.5">
					{log.map((line) => (
						<div
							key={line}
							className="text-xs font-mono text-muted-foreground whitespace-nowrap"
						>
							{line}
						</div>
					))}
				</div>
			)}

			{result && result.sources > 0 && (
				<div className="rounded-xl border bg-card p-5 space-y-3">
					<div className="flex items-center gap-2">
						<Check className="w-5 h-5 text-[var(--admin-success)]" />
						<span className="text-lg font-semibold">Sync Complete</span>
					</div>
					<div className="text-sm space-y-1">
						<p>
							<span className="text-muted-foreground">Succeeded:</span>{" "}
							{result.succeeded}
						</p>
						<p>
							<span className="text-muted-foreground">Failed:</span>{" "}
							{result.failed}
						</p>
					</div>
				</div>
			)}

			{!syncing && !result && (
				<div className="rounded-xl border bg-card p-6 text-center text-muted-foreground text-sm">
					<CloudDownload className="w-10 h-10 mx-auto mb-3 opacity-40" />
					<p>
						Click the button above to scan all clone sources for missing
						furniture and import it automatically.
					</p>
				</div>
			)}
		</div>
	);
}