import { useEffect, useMemo, useState } from 'react';
import { useParams } from 'react-router-dom';
import { Alert, Card, Collapse, Descriptions, Image, Spin, Table, Tag, Typography } from 'antd';
import type { CollectionItemInspection } from '@atlas/contracts';
import { collectionApi } from '@/services/collection';
import { apiErrorMessage } from '@/services/api';
import { mediaApi } from '@/services/media';

/** Temporary parser inspection surface. This is deliberately read-only: it lets
 * product and parser work be checked before these values become editor fields. */
export default function CollectionInspectionPage() {
    const { id } = useParams<{ id: string }>();
    const [record, setRecord] = useState<CollectionItemInspection>();
    const [error, setError] = useState<string>();
    const [previewUrls, setPreviewUrls] = useState<Record<string, string>>({});

    useEffect(() => {
        if (!id) return;
        void collectionApi
            .inspection(id)
            .then(setRecord)
            .catch((reason) => setError(apiErrorMessage(reason)));
    }, [id]);

    const assetIds = useMemo(
        () => [
            ...new Set(
                (record?.asset_transfers ?? [])
                    .filter((transfer) => transfer.status === 'succeeded' && !!transfer.asset_id)
                    .map((transfer) => transfer.asset_id as string)
            ),
        ],
        [record]
    );

    useEffect(() => {
        let disposed = false;
        setPreviewUrls({});
        if (!assetIds.length) return;
        void loadPreviewUrls(assetIds).then((urls) => {
            if (!disposed) setPreviewUrls(urls);
        });
        return () => {
            disposed = true;
        };
    }, [assetIds]);

    const variantsById = useMemo(
        () => new Map((record?.variants ?? []).map((variant) => [variant.id, variant])),
        [record]
    );

    if (error)
        return <Alert type="error" message="无法读取采集数据" description={error} showIcon />;
    if (!record)
        return (
            <div style={{ padding: 64, textAlign: 'center' }}>
                <Spin size="large" />
            </div>
        );

    return (
        <Card title="采集数据测试页" extra={<Tag color="blue">只读测试</Tag>}>
            <Alert
                type="info"
                showIcon
                style={{ marginBottom: 16 }}
                message="这里展示扩展实际提交、服务端实际保存的数据，不代表已确认的商品编辑字段。"
            />
            <Descriptions
                bordered
                size="small"
                column={2}
                items={[
                    { key: 'title', label: '商品标题', children: record.title ?? '未命名' },
                    {
                        key: 'source',
                        label: '采集来源',
                        children: `${record.source.platform_code ?? '手动'} · ${record.source.url ?? '—'}`,
                    },
                    { key: 'status', label: '采集状态', children: record.collection_status },
                    { key: 'parser', label: '解析器版本', children: record.parser_version ?? '—' },
                    { key: 'sku', label: '已创建 SKU', children: record.variants.length },
                    { key: 'assets', label: '素材任务', children: record.asset_transfers.length },
                ]}
            />
            <Typography.Title level={5} style={{ marginTop: 24 }}>
                SKU 草稿
            </Typography.Title>
            <Table
                size="small"
                pagination={false}
                rowKey="id"
                dataSource={record.variants}
                columns={[
                    {
                        title: '来源 SKU ID',
                        dataIndex: 'source_variant_key',
                        render: (value) => value ?? '默认 SKU（待确认）',
                    },
                    {
                        title: '来源货号',
                        dataIndex: 'source_sku',
                        render: (value) => value ?? '—',
                    },
                    {
                        title: '名称',
                        dataIndex: 'display_name',
                        render: (value) => value ?? '—',
                    },
                ]}
            />
            <Typography.Title level={5} style={{ marginTop: 24 }}>
                素材转存任务
            </Typography.Title>
            <Table
                size="small"
                pagination={false}
                rowKey="id"
                dataSource={record.asset_transfers}
                columns={[
                    {
                        title: '素材预览',
                        width: 108,
                        render: (_, transfer) => {
                            const url = transfer.asset_id
                                ? previewUrls[transfer.asset_id]
                                : undefined;
                            if (url)
                                return (
                                    <Image
                                        width={72}
                                        height={72}
                                        src={url}
                                        alt="已转存采集素材"
                                        style={{ objectFit: 'cover' }}
                                    />
                                );
                            return (
                                <Typography.Text type="secondary">
                                    {transfer.status === 'succeeded' ? '预览加载中…' : '待转存'}
                                </Typography.Text>
                            );
                        },
                    },
                    { title: '类型', dataIndex: 'role' },
                    {
                        title: '关联 SKU',
                        render: (_, transfer) => {
                            const variant = transfer.source_variant_id
                                ? variantsById.get(transfer.source_variant_id)
                                : undefined;
                            return variant?.source_sku ?? variant?.source_variant_key ?? '商品级';
                        },
                    },
                    { title: '状态', dataIndex: 'status' },
                    {
                        title: '来源 URL',
                        dataIndex: 'source_url',
                        ellipsis: true,
                        render: (value) => (
                            <Typography.Link href={value} target="_blank">
                                查看来源
                            </Typography.Link>
                        ),
                    },
                    {
                        title: '错误',
                        dataIndex: 'error_payload',
                        render: (value) =>
                            value ? (
                                <Typography.Text type="danger">
                                    {JSON.stringify(value)}
                                </Typography.Text>
                            ) : (
                                '—'
                            ),
                    },
                ]}
            />
            <Collapse
                style={{ marginTop: 24 }}
                items={[
                    {
                        key: 'normalized',
                        label: '规范化采集载荷（normalized_payload）',
                        children: <Json value={record.normalized_payload} />,
                    },
                    {
                        key: 'evidence',
                        label: '原始证据（raw_evidence）',
                        children: <Json value={record.raw_evidence} />,
                    },
                ]}
            />
        </Card>
    );
}

async function loadPreviewUrls(assetIds: string[]) {
    const urls: Record<string, string> = {};
    let cursor = 0;
    const worker = async () => {
        while (cursor < assetIds.length) {
            const assetId = assetIds[cursor++];
            try {
                urls[assetId] = (await mediaApi.createPreviewUrl(assetId)).url;
            } catch {
                // The task row remains inspectable through its source URL and error state.
            }
        }
    };
    await Promise.all(Array.from({ length: Math.min(4, assetIds.length) }, () => worker()));
    return urls;
}

function Json({ value }: { value: unknown }) {
    return (
        <pre
            style={{
                margin: 0,
                overflow: 'auto',
                whiteSpace: 'pre-wrap',
                wordBreak: 'break-word',
                fontSize: 12,
            }}
        >
            {JSON.stringify(value, null, 2)}
        </pre>
    );
}