function validRecordId(value: string): boolean { return /^[1-9][0-9]{0,9}$/.test(value) }

export function parseCompareIds(raw: string): string[] {
    if (raw.length == 0) return []
    const ids = raw.split(',')
    if (ids.length > 3) throw new Error('每次最多对比3个产品，请返回重新选择。')
    const seen: string[] = []
    ids.forEach((id: string) => {
        if (!validRecordId(id) || seen.includes(id)) throw new Error('对比产品编号无效或重复，请返回重新选择。')
        seen.push(id)
    })
    return ids
}

export function compareQuery(assessmentId: string, ids: string[], revisionId: string = ''): string {
    return '?assessmentId=' + encodeURIComponent(assessmentId) + '&productIds=' + ids.join(',') + (revisionId.length > 0 ? '&revisionId=' + revisionId : '')
}

// 主包共享的纯路由逻辑，账号分包登录时无需加载融资分包；不接受任意URL。
export function matchReturnPath(page: string, assessmentId: string, rawIds: string, revisionId: string, productId: string = '', group: string = 'eligible', tab: string = 'explanation', from: string = ''): string {
    if (!['matches','product','compare'].includes(page) || (revisionId.length > 0 && !validRecordId(revisionId))) return ''
    if (assessmentId.length > 0 ? !validRecordId(assessmentId) : page != 'product') return ''
    let ids: string[] = []
    try { ids = parseCompareIds(rawIds) } catch (err) { return '' }
    if (assessmentId.length == 0 && (revisionId.length > 0 || ids.length > 0)) return ''
    if (page == 'matches' && !['eligible','ineligible','unknown'].includes(group)) return ''
    if (page == 'product' && (!validRecordId(productId) || !['explanation','details','conditions'].includes(tab) || (assessmentId.length == 0 && tab == 'explanation') || !['','matches','product','compare','report','next-step','archive'].includes(from))) return ''
    const query = assessmentId.length > 0 ? compareQuery(assessmentId, ids, revisionId) : '?'
    if (page == 'matches') return '/packages/finance/matches/matches' + query + '&group=' + group
    if (page == 'compare') return '/packages/finance/compare/compare' + query
    return '/packages/finance/product/product' + query + (assessmentId.length > 0 ? '&' : '') + 'productId=' + productId + '&tab=' + tab + '&from=' + from
}