// modules/admin/pages/assets/ViewDocumentAsset.jsx

import { useParams, useNavigate } from "react-router-dom";
import { ArrowLeft, Lock, Globe, FileText, Download } from "lucide-react";
import { useDateFormat } from "@/hooks/useDateFormat";

import { useAssetFetchState } from "@/hooks/useAssetFetchState";
import { useAssetPreviewSrc } from "@/hooks/useAssetPreviewSrc";
import { downloadAsset } from "@/utils/media.util";
import { Spinner }   from "@/components/ui/spinner";
import { Badge }     from "@/components/ui/badge";
import { Button }    from "@/components/ui/button";
import { Separator } from "@/components/ui/separator";
import { MediaFallback } from "@/components/generic/MediaFallback";
import AssetPageLoader from "@/components/generic/AssetLoader";

function MetaRow({ label, value }) {
    if (!value && value !== 0) return null;
    return (
        <div className="flex items-start gap-3 py-2">
            <span className="text-muted-foreground text-sm w-36 shrink-0">{label}</span>
            <span className="text-sm font-medium break-all">{String(value)}</span>
        </div>
    );
}

const PREVIEWABLE = ["pdf", "txt", "html", "htm", "csv", "md"];

export default function ViewDocumentAsset() {
    const { assetId } = useParams();
    const navigate    = useNavigate();
    const { fmtDateTime } = useDateFormat();

    const { asset: selectedAsset, loading, notFound } = useAssetFetchState(assetId);
    const { src: streamUrl } = useAssetPreviewSrc(selectedAsset, { scope: "admin" });

    if (loading) {
        return <AssetPageLoader />;
    }

    if (notFound) {
        return (
            <div className="flex flex-col items-center justify-center h-96 gap-3 text-muted-foreground">
                <p>Asset not found.</p>
                <Button variant="outline" onClick={() => navigate(-1)}>Go Back</Button>
            </div>
        );
    }

    const a = selectedAsset;
    const canPreview = PREVIEWABLE.includes((a.extension ?? "").toLowerCase());

    return (
        <div className="max-w-7xl mx-auto px-4 py-6 space-y-6">

            {/* ── Header ── */}
            <div className="flex items-center gap-3">
                <Button variant="ghost" size="icon" onClick={() => navigate(-1)}>
                    <ArrowLeft className="h-4 w-4" />
                </Button>
                <div className="flex-1 min-w-0">
                    <h1 className="text-xl font-semibold truncate">{a.display_name ?? a.original_name}</h1>
                    <p className="text-sm text-muted-foreground">{a.mime_type}</p>
                </div>
                <Button variant="outline" size="sm" onClick={() => downloadAsset(a, { scope: "admin" })}>
                    <Download className="h-4 w-4" /> Download
                </Button>
            </div>

            <div className="grid grid-cols-1 lg:grid-cols-5 gap-6">

                {/* ── Document preview ── */}
                <div className="lg:col-span-3">
                    {canPreview && streamUrl ? (
                        <div className="rounded-lg border overflow-hidden bg-white" style={{ height: 600 }}>
                            <iframe
                                src={streamUrl}
                                title={a.display_name ?? a.original_name}
                                className="w-full h-full"
                                // sandbox="allow-scripts allow-same-origin"
                            />
                        </div>
                    ) : (
                        <div className="rounded-lg border bg-muted/30 flex flex-col items-center justify-center gap-4 py-20">
                            <FileText className="h-16 w-16 text-muted-foreground/40" />
                            <p className="text-muted-foreground text-sm">
                                Preview not available for this file type.
                            </p>
                        </div>
                    )}
                </div>

                {/* ── Metadata panel ── */}
                <div className="lg:col-span-2 space-y-4">
                    <div className="rounded-lg border bg-card p-4 space-y-1">
                        <p className="text-xs font-semibold uppercase tracking-wide text-muted-foreground mb-2">File Info</p>
                        <MetaRow label="Original Name" value={a.original_name} />
                        <MetaRow label="Extension"     value={a.extension} />
                        <MetaRow label="File Size"     value={a.file_size ? `${(a.file_size / 1024).toFixed(1)} KB` : null} />
                        <MetaRow label="MIME Type"     value={a.mime_type} />
                        <Separator className="my-2" />
                        <p className="text-xs font-semibold uppercase tracking-wide text-muted-foreground mb-2">Storage</p>
                        <MetaRow label="Provider"      value={a.storage_provider} />
                        <MetaRow label="Bucket"        value={a.storage_bucket} />
                        <MetaRow label="Key"           value={a.storage_key} />
                        <Separator className="my-2" />
                        <p className="text-xs font-semibold uppercase tracking-wide text-muted-foreground mb-2">Access</p>
                        <div className="flex items-center gap-2 py-1">
                            {a.is_public
                                ? <><Globe className="h-3.5 w-3.5 text-green-500" /><Badge variant="outline" className="text-green-600 border-green-400">Public</Badge></>
                                : <><Lock  className="h-3.5 w-3.5 text-yellow-500" /><Badge variant="outline" className="text-yellow-600 border-yellow-400">Private</Badge></>
                            }
                        </div>
                        <MetaRow label="Access Level"  value={a.access_level} />
                        <MetaRow label="Owner Type"    value={a.owner_type} />
                        <MetaRow label="Owner ID"      value={a.owner_id} />
                        <Separator className="my-2" />
                        <p className="text-xs font-semibold uppercase tracking-wide text-muted-foreground mb-2">Timestamps</p>
                        <MetaRow label="Created By"    value={a.createdBy} />
                        <MetaRow label="Created"       value={a.createdAt ? fmtDateTime(a.createdAt) : null} />
                        <MetaRow label="Modified"      value={a.updatedAt ? fmtDateTime(a.updatedAt) : null} />
                    </div>

                    {a.description && (
                        <div className="rounded-lg border bg-card p-4">
                            <p className="text-xs font-semibold uppercase tracking-wide text-muted-foreground mb-2">Description</p>
                            <p className="text-sm text-foreground">{a.description}</p>
                        </div>
                    )}
                </div>
            </div>
        </div>
    );
}