"use client";

import {
	AlertCircle,
	CheckCircle2,
	ClipboardList,
	ExternalLink,
	Loader2,
	SearchX,
} 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 AuditIssue {
	type: string;
	severity: "error" | "warning" | "info";
	classname?: string;
	itemId?: number;
	catalogId?: number;
	message: string;
	sourceName?: string;
}

interface MissingFromSource {
	sourceName: string;
	sourceId: string;
	classname: string;
	itemName: string;
}

interface AuditSummary {
	totalItemsBase: number;
	totalCatalogItems: number;
	missingCatalog: number;
	orphanedCatalog: number;
	missingNitro: number;
	missingIcon: number;
	duplicates: number;
	missingFromSourcesTotal: number;
}

interface AuditEvent {
	type: string;
	message?: string;
	current?: number;
	total?: number;
	section?: string;
	issues?: AuditIssue[];
	missingFromSources?: MissingFromSource[];
	summary?: AuditSummary;
}

const TYPE_LABELS: Record<string, string> = {
	missing_catalog: "No catalog entry",
	orphaned_catalog: "Orphaned catalog reference",
	missing_nitro: "Missing .nitro file",
	missing_icon: "Missing icon file",
	duplicate_classname: "Duplicate classname",
	source_fetch_failed: "Source fetch failed",
};

export function AuditClient() {
	const [loading, setLoading] = useState(false);
	const [progress, setProgress] = useState("");
	const [activeTab, setActiveTab] = useState<"issues" | "sources">("issues");

	const [issues, setIssues] = useState<AuditIssue[]>([]);
	const [missingFromSources, setMissingFromSources] = useState<
		MissingFromSource[]
	>([]);
	const [summary, setSummary] = useState<AuditSummary | null>(null);

	const [checkProgress, setCheckProgress] = useState<{
		section: string;
		current: number;
		total: number;
	} | null>(null);

	const abortRef = useRef<AbortController | null>(null);

	const runAudit = useCallback(async () => {
		setLoading(true);
		setProgress("Starting audit…");
		setIssues([]);
		setMissingFromSources([]);
		setSummary(null);
		setCheckProgress(null);
		setActiveTab("issues");

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

		try {
			const res = await adminFetch("/api/admin/import/audit", {
				method: "POST",
				signal: abort.signal,
			});

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

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

			while (true) {
				const { value, done } = await reader.read();
				if (done) 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 AuditEvent;

						if (evt.type === "progress") {
							setProgress(evt.message ?? "");
						}

						if (evt.type === "items_loaded") {
							setProgress(`Loaded ${evt.total} items_base entries`);
						}

						if (evt.type === "catalog_loaded") {
							setProgress(`Loaded ${evt.total} catalog_items entries`);
						}

						if (evt.type === "checking") {
							setProgress(`Checking ${evt.section}…`);
							if (evt.total) {
								setCheckProgress({
									section: evt.section ?? "",
									current: evt.current ?? 0,
									total: evt.total,
								});
							}
						}

						if (evt.type === "batch_complete") {
							setIssues(evt.issues ?? []);
							setMissingFromSources(evt.missingFromSources ?? []);
							if (evt.summary) setSummary(evt.summary);
							setCheckProgress(null);
							setProgress("Done");
							if (
								evt.issues &&
								evt.issues.filter((i) => i.severity === "error").length > 0
							) {
								toast.error(
									`${evt.issues.filter((i) => i.severity === "error").length} error(s) found`,
								);
							} else if (
								evt.issues &&
								evt.issues.filter((i) => i.severity === "warning").length > 0
							) {
								toast.warning("Warnings found");
							} else {
								toast.success("No issues found");
							}
						}

						if (evt.type === "error") {
							setProgress(`ERROR: ${evt.message ?? ""}`);
							toast.error(evt.message ?? "Audit failed");
						}
					} catch {
						// skip parse errors
					}
				}
			}
		} catch (err) {
			if ((err as Error).name !== "AbortError") {
				toast.error("Audit request failed");
			}
		} finally {
			setLoading(false);
			abortRef.current = null;
		}
	}, []);

	const errors = issues.filter((i) => i.severity === "error");
	const warnings = issues.filter((i) => i.severity === "warning");

	return (
		<div className="space-y-6">
			{!summary && (
				<Button onClick={runAudit} disabled={loading} size="lg">
					{loading ? (
						<Loader2 className="w-4 h-4 animate-spin mr-2" />
					) : (
						<ClipboardList className="w-4 h-4 mr-2" />
					)}
					{loading ? progress || "Running…" : "Run Full Catalog Audit"}
				</Button>
			)}

			{loading && checkProgress && (
				<div className="text-sm text-muted-foreground">
					{checkProgress.section}: {checkProgress.current} /{" "}
					{checkProgress.total}
				</div>
			)}

			{summary && (
				<>
					{/* Summary cards */}
					<div className="grid gap-3 sm:grid-cols-2 lg:grid-cols-4">
						<div className="rounded-xl border bg-card p-4 space-y-1">
							<div className="text-2xl font-bold">{summary.totalItemsBase}</div>
							<div className="text-xs text-muted-foreground">
								items_base entries
							</div>
						</div>
						<div className="rounded-xl border bg-card p-4 space-y-1">
							<div className="text-2xl font-bold">
								{summary.totalCatalogItems}
							</div>
							<div className="text-xs text-muted-foreground">
								catalog_items entries
							</div>
						</div>
						<div
							className={`rounded-xl border p-4 space-y-1 ${errors.length > 0 ? "border-[var(--admin-error-border)] bg-[var(--admin-error-subtle)]" : "bg-card"}`}
						>
							<div
								className={`text-2xl font-bold ${errors.length > 0 ? "text-[var(--admin-error)]" : ""}`}
							>
								{errors.length}
							</div>
							<div className="text-xs text-muted-foreground">Errors</div>
						</div>
						<div
							className={`rounded-xl border p-4 space-y-1 ${warnings.length > 0 ? "border-[var(--admin-warning-border)] bg-[var(--admin-warning-subtle)]" : "bg-card"}`}
						>
							<div
								className={`text-2xl font-bold ${warnings.length > 0 ? "text-[var(--admin-warning)]" : ""}`}
							>
								{warnings.length}
							</div>
							<div className="text-xs text-muted-foreground">Warnings</div>
						</div>
					</div>

					{/* Quick stats */}
					<div className="grid gap-2 sm:grid-cols-3 text-sm">
						<div className="flex items-center gap-2">
							{summary.missingCatalog > 0 ? (
								<AlertCircle className="w-4 h-4 text-[var(--admin-warning)]" />
							) : (
								<CheckCircle2 className="w-4 h-4 text-[var(--admin-success)]" />
							)}
							<span>{summary.missingCatalog} items without catalog entry</span>
						</div>
						<div className="flex items-center gap-2">
							{summary.orphanedCatalog > 0 ? (
								<AlertCircle className="w-4 h-4 text-[var(--admin-error)]" />
							) : (
								<CheckCircle2 className="w-4 h-4 text-[var(--admin-success)]" />
							)}
							<span>{summary.orphanedCatalog} orphaned catalog references</span>
						</div>
						<div className="flex items-center gap-2">
							{summary.missingNitro > 0 ? (
								<AlertCircle className="w-4 h-4 text-[var(--admin-error)]" />
							) : (
								<CheckCircle2 className="w-4 h-4 text-[var(--admin-success)]" />
							)}
							<span>{summary.missingNitro} items without .nitro</span>
						</div>
						<div className="flex items-center gap-2">
							{summary.missingIcon > 0 ? (
								<AlertCircle className="w-4 h-4 text-[var(--admin-warning)]" />
							) : (
								<CheckCircle2 className="w-4 h-4 text-[var(--admin-success)]" />
							)}
							<span>{summary.missingIcon} items without icon</span>
						</div>
						<div className="flex items-center gap-2">
							{summary.duplicates > 0 ? (
								<AlertCircle className="w-4 h-4 text-[var(--admin-error)]" />
							) : (
								<CheckCircle2 className="w-4 h-4 text-[var(--admin-success)]" />
							)}
							<span>{summary.duplicates} duplicate classnames</span>
						</div>
						<div className="flex items-center gap-2">
							{summary.missingFromSourcesTotal > 0 ? (
								<AlertCircle className="w-4 h-4 text-[var(--admin-warning)]" />
							) : (
								<CheckCircle2 className="w-4 h-4 text-[var(--admin-success)]" />
							)}
							<span>
								{summary.missingFromSourcesTotal} items missing from clone
								sources
							</span>
						</div>
					</div>

					{/* Tabs */}
					{issues.length > 0 || missingFromSources.length > 0 ? (
						<div className="border-b border-border">
							<div className="flex gap-4">
								<button
									type="button"
									onClick={() => setActiveTab("issues")}
									className={`pb-2 text-sm font-medium border-b-2 transition-colors ${
										activeTab === "issues"
											? "border-primary text-foreground"
											: "border-transparent text-muted-foreground hover:text-foreground"
									}`}
								>
									Issues ({issues.length})
								</button>
								<button
									type="button"
									onClick={() => setActiveTab("sources")}
									className={`pb-2 text-sm font-medium border-b-2 transition-colors ${
										activeTab === "sources"
											? "border-primary text-foreground"
											: "border-transparent text-muted-foreground hover:text-foreground"
									}`}
								>
									Missing from sources ({missingFromSources.length})
								</button>
							</div>
						</div>
					) : null}

					{/* Issues list */}
					{activeTab === "issues" && issues.length > 0 && (
						<div className="space-y-2">
							{issues.map((issue) => (
								<div
									key={issue.message}
									className={`rounded-xl border p-4 text-sm ${
										issue.severity === "error"
											? "border-[var(--admin-error-border)] bg-[var(--admin-error-subtle)]"
											: issue.severity === "warning"
												? "border-[var(--admin-warning-border)] bg-[var(--admin-warning-subtle)]"
												: "bg-card"
									}`}
								>
									<div className="flex items-start gap-2">
										<AlertCircle
											className={`w-4 h-4 mt-0.5 shrink-0 ${
												issue.severity === "error"
													? "text-[var(--admin-error)]"
													: issue.severity === "warning"
														? "text-[var(--admin-warning)]"
														: "text-[var(--admin-text-muted)]"
											}`}
										/>
										<div className="space-y-0.5 min-w-0">
											<div className="flex items-center gap-2 flex-wrap">
												<span
													className={`font-medium ${
														issue.severity === "error"
															? "text-[var(--admin-error)]"
															: issue.severity === "warning"
																? "text-[var(--admin-warning)]"
																: "text-[var(--admin-text-muted)]"
													}`}
												>
													{TYPE_LABELS[issue.type] || issue.type}
												</span>
												{issue.classname && (
													<code className="text-xs bg-background/50 px-1.5 py-0.5 rounded font-mono">
														{issue.classname}
													</code>
												)}
												{issue.sourceName && (
													<span className="text-xs text-muted-foreground">
														source: {issue.sourceName}
													</span>
												)}
											</div>
											<p className="text-muted-foreground">{issue.message}</p>
										</div>
									</div>
								</div>
							))}
						</div>
					)}

					{/* Missing from sources list */}
					{activeTab === "sources" && missingFromSources.length > 0 && (
						<div className="space-y-2">
							{missingFromSources.map((item) => (
								<div
									key={`${item.sourceId}-${item.classname}`}
									className="rounded-xl border bg-card p-3 text-sm flex items-center gap-2"
								>
									<ExternalLink className="w-3.5 h-3.5 text-muted-foreground shrink-0" />
									<code className="font-mono text-xs">{item.classname}</code>
									<span className="text-xs text-muted-foreground">
										— {item.itemName}
									</span>
									<span className="text-xs text-muted-foreground ml-auto">
										in {item.sourceName}
									</span>
								</div>
							))}
						</div>
					)}

					{activeTab === "issues" &&
						issues.length === 0 &&
						missingFromSources.length === 0 && (
							<div className="rounded-xl border bg-card p-12 text-center text-muted-foreground">
								<CheckCircle2 className="w-12 h-12 mx-auto mb-3 text-[var(--admin-success)]" />
								<p className="text-lg font-medium">No issues found</p>
								<p className="text-sm">Your catalog is clean!</p>
							</div>
						)}

					<Button
						variant="outline"
						onClick={() => {
							setSummary(null);
							setIssues([]);
							setMissingFromSources([]);
							setProgress("");
							setCheckProgress(null);
						}}
					>
						Run Again
					</Button>
				</>
			)}

			{!loading && !summary && (
				<div className="rounded-xl border bg-card p-12 text-center text-muted-foreground">
					<SearchX className="w-12 h-12 mx-auto mb-3 opacity-40" />
					<p>
						Run a full audit to check for missing catalog entries, broken
						references, missing files, and items available from clone sources.
					</p>
				</div>
			)}
		</div>
	);
}