"use client"

import Link from "next/link"
import { useRouter, useSearchParams } from "next/navigation"
import { Suspense, type ReactNode } from "react"
import { User, Palette, Lock, Bell, Sparkles } from "lucide-react"
import { signOut } from "next-auth/react"

import { ThemePreferencesCard } from "@/modules/settings/components/theme-preferences-card"
import { ProfileSettingsForm } from "@/modules/settings/components/profile-settings-form"
import { PasswordChangeForm } from "@/modules/settings/components/password-change-form"
import { NotificationPreferencesForm } from "@/modules/settings/components/notification-preferences-form"
import { AiProviderSettingsCard } from "@/modules/settings/components/ai-provider-settings-card"
import { Button } from "@/shared/components/ui/button"
import { Card, CardContent, CardDescription, CardHeader, CardTitle } from "@/shared/components/ui/card"
import { Tabs, TabsContent, TabsList, TabsTrigger } from "@/shared/components/ui/tabs"
import {
  AlertDialog,
  AlertDialogAction,
  AlertDialogCancel,
  AlertDialogContent,
  AlertDialogDescription,
  AlertDialogFooter,
  AlertDialogHeader,
  AlertDialogTitle,
  AlertDialogTrigger,
} from "@/shared/components/ui/alert-dialog"
import { UserProfile } from "@/modules/users/data-access"
import type { NotificationPreferences } from "@/modules/notifications/types"
import { usePermission } from "@/shared/hooks/use-permission"
import { Permissions } from "@/shared/types/permissions"

interface SettingsViewProps {
  /** 页面副标题描述 */
  description: string
  /** 返回仪表盘的链接 */
  backHref: string
  /** 当前用户 */
  user: UserProfile
  /** 通知偏好 */
  notificationPreferences: NotificationPreferences
  /** General 标签页中 ProfileSettingsForm 下方的内容（角色专属快捷链接/组织信息等） */
  generalExtra?: ReactNode
}

const VALID_TABS = ["general", "notifications", "appearance", "security", "ai"] as const
type TabValue = (typeof VALID_TABS)[number]

function isTabValue(value: string | null): value is TabValue {
  return value !== null && (VALID_TABS as readonly string[]).includes(value)
}

/**
 * 统一设置页视图
 *
 * 消除 admin / teacher / student / parent 四个设置视图的重复布局：
 * - 相同的页面头部（标题 + 描述 + 返回按钮）
 * - 相同的标签页（General / Notifications / Appearance / Security / AI）
 * - 相同的 Notifications / Appearance / Security 标签页内容
 * - 相同的 Session 卡片（登出）
 *
 * 角色差异通过 `description`、`backHref` 和 `generalExtra` 三个 props 注入。
 * 当前激活的标签页通过 URL `?tab=` 参数持久化。
 */
function SettingsViewInner({
  description,
  backHref,
  user,
  notificationPreferences,
  generalExtra,
}: SettingsViewProps) {
  const router = useRouter()
  const searchParams = useSearchParams()
  const { hasPermission } = usePermission()

  const tabParam = searchParams.get("tab")
  const activeTab: TabValue = isTabValue(tabParam) ? tabParam : "general"

  const handleTabChange = (value: string) => {
    const params = new URLSearchParams(searchParams.toString())
    if (value === "general") {
      params.delete("tab")
    } else {
      params.set("tab", value)
    }
    const query = params.toString()
    router.push(query ? `?${query}` : "?", { scroll: false })
  }

  const canConfigureAi = hasPermission(Permissions.AI_CONFIGURE)

  return (
    <div className="flex h-full flex-col gap-8 p-8">
      <div className="flex flex-col justify-between gap-4 md:flex-row md:items-center">
        <div className="space-y-1">
          <h1 className="text-3xl font-bold tracking-tight">Settings</h1>
          <div className="text-sm text-muted-foreground">{description}</div>
        </div>
        <div className="flex items-center gap-2">
          <Button asChild variant="outline">
            <Link href={backHref}>Back to dashboard</Link>
          </Button>
        </div>
      </div>

      <Tabs value={activeTab} onValueChange={handleTabChange} className="w-full">
        <TabsList className="w-full justify-start">
          <TabsTrigger value="general" className="gap-2">
            <User className="h-4 w-4" />
            General
          </TabsTrigger>
          <TabsTrigger value="notifications" className="gap-2">
            <Bell className="h-4 w-4" />
            Notifications
          </TabsTrigger>
          <TabsTrigger value="appearance" className="gap-2">
            <Palette className="h-4 w-4" />
            Appearance
          </TabsTrigger>
          <TabsTrigger value="security" className="gap-2">
            <Lock className="h-4 w-4" />
            Security
          </TabsTrigger>
          {canConfigureAi ? (
            <TabsTrigger value="ai" className="gap-2">
              <Sparkles className="h-4 w-4" />
              AI
            </TabsTrigger>
          ) : null}
        </TabsList>

        <TabsContent value="general" className="mt-6 space-y-6">
          <ProfileSettingsForm user={user} />
          {generalExtra}
        </TabsContent>

        <TabsContent value="notifications" className="mt-6 space-y-6">
          <NotificationPreferencesForm preferences={notificationPreferences} />
        </TabsContent>

        <TabsContent value="appearance" className="mt-6 space-y-6">
          <ThemePreferencesCard />
        </TabsContent>

        <TabsContent value="security" className="mt-6 space-y-6">
          <PasswordChangeForm />
          <Card>
            <CardHeader>
              <CardTitle>Session</CardTitle>
              <CardDescription>Account access and session controls.</CardDescription>
            </CardHeader>
            <CardContent className="flex flex-col gap-4 sm:flex-row sm:items-center sm:justify-between">
              <div className="space-y-1">
                <div className="text-sm font-medium">Sign out</div>
                <div className="text-sm text-muted-foreground">Return to the login screen.</div>
              </div>
              <AlertDialog>
                <AlertDialogTrigger asChild>
                  <Button variant="outline">Log out</Button>
                </AlertDialogTrigger>
                <AlertDialogContent>
                  <AlertDialogHeader>
                    <AlertDialogTitle>Confirm sign out</AlertDialogTitle>
                    <AlertDialogDescription>
                      Are you sure you want to sign out? You will be returned to the login screen.
                    </AlertDialogDescription>
                  </AlertDialogHeader>
                  <AlertDialogFooter>
                    <AlertDialogCancel>Cancel</AlertDialogCancel>
                    <AlertDialogAction onClick={() => signOut({ callbackUrl: "/login" })}>
                      Sign out
                    </AlertDialogAction>
                  </AlertDialogFooter>
                </AlertDialogContent>
              </AlertDialog>
            </CardContent>
          </Card>
        </TabsContent>

        {canConfigureAi ? (
          <TabsContent value="ai" className="mt-6 space-y-6">
            <AiProviderSettingsCard />
          </TabsContent>
        ) : null}
      </Tabs>
    </div>
  )
}

export function SettingsView(props: SettingsViewProps) {
  return (
    <Suspense fallback={null}>
      <SettingsViewInner {...props} />
    </Suspense>
  )
}