import { getSession, requestJson } from '@/services/api.uts'

export type UserMessage = { id: string, type: string, category: string, icon: string, title: string, content: string, time: string, isRead: boolean }
export type MessagePage = { items: UserMessage[], snapshotId: string, nextBeforeId: string, unreadCount: number }
export type MessageDetail = { item: UserMessage, targetUrl: string, targetLabel: string, targetUnavailable: boolean }

const validId = (value: string): boolean => /^[1-9][0-9]{0,9}$/.test(value)
const count = (data: UTSJSONObject): number => {
    const value = data.getNumber('unreadCount')
    if (value == null || !Number.isInteger(value) || value < 0) throw new Error('未读数量格式无效')
    return value
}
function messageFrom(data: UTSJSONObject): UserMessage {
    const id = data.getString('id') ?? ''; const type = data.getString('type') ?? ''
    if (!validId(id) || !['system', 'service', 'activity'].includes(type)) throw new Error('消息格式无效')
    const categories: UTSJSONObject = { system: '系统通知', service: '服务通知', activity: '活动消息' }
    const icons: UTSJSONObject = { system: 'system-bell', service: 'approval', activity: 'gift' }
    const date = new Date((data.getString('createdAt') ?? '').replace(' ', 'T'))
    const now = new Date(); const pad = (n: number): string => n < 10 ? '0' + n.toString() : n.toString()
    let time = '未记录'
    if (!isNaN(date.getTime())) time = date.getFullYear() == now.getFullYear() && date.getMonth() == now.getMonth() && date.getDate() == now.getDate()
        ? pad(date.getHours()) + ':' + pad(date.getMinutes()) : date.getFullYear().toString() + '-' + pad(date.getMonth() + 1) + '-' + pad(date.getDate())
    return { id, type, category: categories.getString(type) ?? '', icon: icons.getString(type) ?? '', title: data.getString('title') ?? '',
        content: data.getString('content') ?? '', time, isRead: data.getBoolean('isRead') ?? false }
}
export async function fetchUnreadMessages(): Promise<number> {
    if (getSession() == null) return 0
    return count(await requestJson('/messages/unread-count', 'GET', {}))
}
export async function fetchMessages(type: string, beforeId: string = '', snapshotId: string = ''): Promise<MessagePage> {
    const params: UTSJSONObject = { type, limit: 20 }
    if (beforeId.length > 0) { params['beforeId'] = beforeId; params['snapshotId'] = snapshotId }
    const data = await requestJson('/messages', 'GET', params)
    const items = data['items'] as UTSJSONObject[]
    return { items: items.map((item: UTSJSONObject): UserMessage => messageFrom(item)), snapshotId: data.getString('snapshotId') ?? '',
        nextBeforeId: data.getString('nextBeforeId') ?? '', unreadCount: count(data) }
}
export async function fetchMessage(id: string): Promise<MessageDetail> {
    if (!validId(id)) throw new Error('消息编号无效')
    const data = await requestJson('/messages/' + id, 'GET', {})
    const target = data['target'] as UTSJSONObject | null
    let targetUrl = ''; let targetLabel = ''
    if (target != null) {
        const assessmentId = target.getString('assessmentId') ?? ''; const revisionId = target.getString('revisionId') ?? ''
        const type = target.getString('type') ?? ''; const kind = target.getString('kind') ?? ''
        if (!validId(assessmentId) || !validId(revisionId) || !['personal', 'enterprise'].includes(type)) throw new Error('关联评估格式无效')
        // 只构造白名单路由，通知不能下发任意链接；历史失败也只打开原提交版本。
        if (kind == 'report') { targetUrl = '/packages/finance/report/report?assessmentId=' + assessmentId + '&revisionId=' + revisionId; targetLabel = '查看报告' }
        else if (kind == 'revision') { targetUrl = '/packages/finance/archive/archive?assessmentId=' + assessmentId + '&revisionId=' + revisionId + '&type=' + type; targetLabel = '查看评估' }
        else throw new Error('关联评估格式无效')
    }
    return { item: messageFrom(data['item'] as UTSJSONObject), targetUrl, targetLabel, targetUnavailable: data.getBoolean('targetUnavailable') ?? false }
}
export async function readMessage(id: string): Promise<number> { return count(await requestJson('/messages/' + id + '/read', 'POST', {})) }
export async function readAllMessages(snapshotId: string): Promise<number> { return count(await requestJson('/messages/read-all', 'POST', { snapshotId })) }