import { Alert, Button, Progress, Skeleton } from 'antd'
import { ArrowRightOutlined, ReloadOutlined } from '@ant-design/icons'
import { useQuery } from '@tanstack/react-query'
import http from '../api/http'
import { useAuthStore } from '../stores/auth'
import StudentDashboardPage from './dashboard/StudentDashboardPage'
import TeacherDashboardPage from './dashboard/TeacherDashboardPage'
import './dashboard/role-dashboard.css'

interface DashboardData {
  audience: {
    level: string
    title: string
    scopeName: string
    description: string
  }
  currentTerm?: {
    id: string
    name: string
    startDate: string
    endDate: string
  }
  counts: {
    students: number
    teachers: number
    courses: number
    teachingTasks: number
    publishedTeachingTasks: number
    scheduledTeachingTasks: number
    courseEnrollments: number
    gradeSheets: number
    publishedGradeSheets: number
    submittedGradeSheets: number
    openCourseSelectionRounds: number
  }
  pending: Record<string, number>
  greeting: {
    title: string
    subtitle: string
    narrative: string
  }
}

const number = new Intl.NumberFormat('zh-CN')

function percent(value: number, total: number) {
  return total > 0 ? Math.min(100, Math.round(value / total * 100)) : 0
}

function formatDate(value?: string) {
  if (!value) return '待设置'
  const date = new Date(`${value.slice(0, 10)}T00:00:00`)
  return new Intl.DateTimeFormat('zh-CN', { month: 'long', day: 'numeric' }).format(date)
}

function AdminDashboardPage() {
  const query = useQuery({
    queryKey: ['dashboard'],
    queryFn: async () => (await http.get<DashboardData>('/dashboard')).data,
  })

  if (query.isLoading) return <div className="page-container"><Skeleton active paragraph={{ rows: 10 }} /></div>
  if (query.isError || !query.data) {
    return (
      <div className="page-container">
        <Alert
          type="error"
          showIcon
          message="教务总览暂时无法加载"
          description="请确认后端服务已经启动，然后重新加载。"
          action={<Button icon={<ReloadOutlined />} onClick={() => void query.refetch()}>重新加载</Button>}
        />
      </div>
    )
  }

  const data = query.data
  const metrics = [
    { label: '在籍学生', value: data.counts.students, hint: `${data.audience.scopeName}当前有效学籍` },
    { label: '教师档案', value: data.counts.teachers, hint: '当前数据范围内的教师' },
    { label: '本学期教学班', value: data.counts.teachingTasks, hint: `${data.counts.publishedTeachingTasks} 个已发布` },
    { label: '有效选课', value: data.counts.courseEnrollments, hint: `${data.counts.openCourseSelectionRounds} 个批次开放中` },
  ]
  const readiness = [
    { label: '任务发布', value: data.counts.publishedTeachingTasks, total: data.counts.teachingTasks },
    { label: '课表覆盖', value: data.counts.scheduledTeachingTasks, total: data.counts.publishedTeachingTasks },
    { label: '成绩发布', value: data.counts.publishedGradeSheets, total: data.counts.gradeSheets },
  ]
  const pending = Object.entries(data.pending).filter(([, value]) => value > 0)

  return (
    <main className="page-container">
      <div className="migration-banner"><b>React 迁移预览</b><span>当前页面直接读取现有 `/api/dashboard`，业务数据未使用模拟值。</span></div>
      <header className="page-heading">
        <div>
          <span className="page-heading__kicker">{data.audience.title}</span>
          <h1>{data.greeting.title}</h1>
          <p>{data.greeting.narrative || data.audience.description}</p>
        </div>
        <div className="term-status">
          <span>ACADEMIC TERM</span>
          <strong>{data.currentTerm?.name ?? '尚未设置当前学期'} · {formatDate(data.currentTerm?.startDate)}—{formatDate(data.currentTerm?.endDate)}</strong>
        </div>
      </header>
      <section className="metric-grid" aria-label="教务指标">
        {metrics.map((metric) => (
          <article className="metric-card" key={metric.label}>
            <span>{metric.label}</span><strong>{number.format(metric.value)}</strong><small>{metric.hint}</small>
          </article>
        ))}
      </section>
      <section className="dashboard-grid">
        <article className="content-panel">
          <header className="content-panel__header"><h2>教学运行准备度</h2><Button type="link" icon={<ArrowRightOutlined />}>查看明细</Button></header>
          <div className="content-panel__body readiness-list">
            {readiness.map((item) => {
              const value = percent(item.value, item.total)
              return (
                <div className="readiness-row" key={item.label}>
                  <span>{item.label}</span><Progress percent={value} strokeColor="#087f73" trailColor="#e9edf2" showInfo={false} /><strong>{value}%</strong>
                </div>
              )
            })}
          </div>
        </article>
        <article className="content-panel">
          <header className="content-panel__header"><h2>等待处理</h2><span>{pending.reduce((sum, [, value]) => sum + value, 0)} 项</span></header>
          <div className="content-panel__body pending-list">
            {pending.length === 0 ? <Alert type="success" showIcon message="当前没有待处理事项" /> : pending.slice(0, 6).map(([key, value]) => (
              <div className="pending-item" key={key}><span>{key}</span><strong>{value}</strong></div>
            ))}
          </div>
        </article>
      </section>
    </main>
  )
}

export default function DashboardPage() {
  const roles = useAuthStore((state) => state.user?.roles ?? [])
  const isStudent = roles.includes('Student') &&
    !roles.some((role) => ['SuperAdmin', 'AcademicAdmin', 'CollegeAdmin', 'Counselor'].includes(role))
  const isTeacher = roles.includes('Teacher') &&
    !roles.some((role) => ['SuperAdmin', 'AcademicAdmin', 'CollegeAdmin', 'Counselor', 'Student'].includes(role))

  if (isStudent) return <StudentDashboardPage />
  if (isTeacher) return <TeacherDashboardPage />
  return <AdminDashboardPage />
}