"use client";

import {
  Activity,
  BarChart3,
  Building2,
  Check,
  Copy,
  Database,
  LogOut,
  MoreVertical,
  Plus,
  Search,
  Settings,
  Shield,
  User,
  Users,
} from "lucide-react";
import { useRouter } from "next/navigation";
import { useCallback, useEffect, useId, useState } from "react";
import { Badge } from "@/components/ui/badge";
import { Button } from "@/components/ui/button";
import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogFooter,
  DialogHeader,
  DialogTitle,
  DialogTrigger,
} from "@/components/ui/dialog";
import {
  DropdownMenu,
  DropdownMenuContent,
  DropdownMenuItem,
  DropdownMenuLabel,
  DropdownMenuSeparator,
  DropdownMenuTrigger,
} from "@/components/ui/dropdown-menu";
import { Input } from "@/components/ui/input";
import { Label } from "@/components/ui/label";
import { ThemeToggle } from "@/components/ui/theme-toggle";
import { useToast } from "@/hooks/use-toast";

interface Company {
  id: string;
  name: string;
  status: string;
  createdAt: string;
  _count: {
    users: number;
    sessions: number;
    imports: number;
  };
}

interface DashboardData {
  companies: Company[];
  pagination: {
    total: number;
    pages: number;
  };
}

interface PlatformSession {
  user: {
    id: string;
    email: string;
    name?: string;
    isPlatformUser: boolean;
    platformRole: string;
  };
}

interface NewCompanyData {
  name: string;
  csvUrl: string;
  csvUsername: string;
  csvPassword: string;
  adminEmail: string;
  adminName: string;
  adminPassword: string;
  maxUsers: number;
}

interface FormIds {
  companyNameId: string;
  csvUrlId: string;
  csvUsernameId: string;
  csvPasswordId: string;
  adminEmailId: string;
  adminNameId: string;
  adminPasswordId: string;
  maxUsersId: string;
}

// Custom hook for platform session
function usePlatformSession() {
  const [session, setSession] = useState<PlatformSession | null>(null);
  const [status, setStatus] = useState<
    "loading" | "authenticated" | "unauthenticated"
  >("loading");

  useEffect(() => {
    const fetchSession = async () => {
      try {
        const response = await fetch("/api/platform/auth/session");
        const sessionData = await response.json();

        if (sessionData?.user?.isPlatformUser) {
          setSession(sessionData);
          setStatus("authenticated");
        } else {
          setSession(null);
          setStatus("unauthenticated");
        }
      } catch (error) {
        console.error("Platform session fetch error:", error);
        setSession(null);
        setStatus("unauthenticated");
      }
    };

    fetchSession();
  }, []);

  return { data: session, status };
}

/**
 * Custom hook for managing platform dashboard state
 */
function usePlatformDashboardState() {
  const [dashboardData, setDashboardData] = useState<DashboardData | null>(
    null
  );
  const [isLoading, setIsLoading] = useState(true);
  const [showAddCompany, setShowAddCompany] = useState(false);
  const [isCreating, setIsCreating] = useState(false);
  const [copiedEmail, setCopiedEmail] = useState(false);
  const [copiedPassword, setCopiedPassword] = useState(false);
  const [searchTerm, setSearchTerm] = useState("");
  const [newCompanyData, setNewCompanyData] = useState({
    name: "",
    csvUrl: "",
    csvUsername: "",
    csvPassword: "",
    adminEmail: "",
    adminName: "",
    adminPassword: "",
    maxUsers: 10,
  });

  return {
    dashboardData,
    setDashboardData,
    isLoading,
    setIsLoading,
    showAddCompany,
    setShowAddCompany,
    isCreating,
    setIsCreating,
    copiedEmail,
    setCopiedEmail,
    copiedPassword,
    setCopiedPassword,
    searchTerm,
    setSearchTerm,
    newCompanyData,
    setNewCompanyData,
  };
}

/**
 * Custom hook for form IDs
 */
function useFormIds() {
  const companyNameId = useId();
  const csvUrlId = useId();
  const csvUsernameId = useId();
  const csvPasswordId = useId();
  const adminEmailId = useId();
  const adminNameId = useId();
  const adminPasswordId = useId();
  const maxUsersId = useId();

  return {
    companyNameId,
    csvUrlId,
    csvUsernameId,
    csvPasswordId,
    adminEmailId,
    adminNameId,
    adminPasswordId,
    maxUsersId,
  };
}

/**
 * Render company form fields
 */
function renderCompanyFormFields(
  newCompanyData: NewCompanyData,
  setNewCompanyData: (
    updater: (prev: NewCompanyData) => NewCompanyData
  ) => void,
  formIds: FormIds
) {
  return (
    <div className="grid gap-4 py-4">
      <div className="space-y-2">
        <Label htmlFor={formIds.companyNameId}>Company Name *</Label>
        <Input
          id={formIds.companyNameId}
          value={newCompanyData.name}
          onChange={(e) =>
            setNewCompanyData((prev: NewCompanyData) => ({
              ...prev,
              name: e.target.value,
            }))
          }
          placeholder="Acme Corporation"
        />
      </div>
      <div className="space-y-2">
        <Label htmlFor={formIds.csvUrlId}>CSV Data URL *</Label>
        <Input
          id={formIds.csvUrlId}
          value={newCompanyData.csvUrl}
          onChange={(e) =>
            setNewCompanyData((prev: NewCompanyData) => ({
              ...prev,
              csvUrl: e.target.value,
            }))
          }
          placeholder="https://api.company.com/sessions.csv"
        />
      </div>
      <div className="space-y-2">
        <Label htmlFor={formIds.csvUsernameId}>CSV Auth Username</Label>
        <Input
          id={formIds.csvUsernameId}
          value={newCompanyData.csvUsername}
          onChange={(e) =>
            setNewCompanyData((prev: NewCompanyData) => ({
              ...prev,
              csvUsername: e.target.value,
            }))
          }
          placeholder="Optional HTTP auth username"
        />
      </div>
      <div className="space-y-2">
        <Label htmlFor={formIds.csvPasswordId}>CSV Auth Password</Label>
        <Input
          id={formIds.csvPasswordId}
          type="password"
          value={newCompanyData.csvPassword}
          onChange={(e) =>
            setNewCompanyData((prev: NewCompanyData) => ({
              ...prev,
              csvPassword: e.target.value,
            }))
          }
          placeholder="Optional HTTP auth password"
        />
      </div>
      <div className="space-y-2">
        <Label htmlFor={formIds.adminNameId}>Admin Name *</Label>
        <Input
          id={formIds.adminNameId}
          value={newCompanyData.adminName}
          onChange={(e) =>
            setNewCompanyData((prev: NewCompanyData) => ({
              ...prev,
              adminName: e.target.value,
            }))
          }
          placeholder="John Doe"
        />
      </div>
      <div className="space-y-2">
        <Label htmlFor={formIds.adminEmailId}>Admin Email *</Label>
        <Input
          id={formIds.adminEmailId}
          type="email"
          value={newCompanyData.adminEmail}
          onChange={(e) =>
            setNewCompanyData((prev: NewCompanyData) => ({
              ...prev,
              adminEmail: e.target.value,
            }))
          }
          placeholder="admin@acme.com"
        />
      </div>
      <div className="space-y-2">
        <Label htmlFor={formIds.adminPasswordId}>Admin Password</Label>
        <Input
          id={formIds.adminPasswordId}
          type="password"
          value={newCompanyData.adminPassword}
          onChange={(e) =>
            setNewCompanyData((prev: NewCompanyData) => ({
              ...prev,
              adminPassword: e.target.value,
            }))
          }
          placeholder="Leave empty to auto-generate"
        />
      </div>
      <div className="space-y-2">
        <Label htmlFor={formIds.maxUsersId}>Max Users</Label>
        <Input
          id={formIds.maxUsersId}
          type="number"
          value={newCompanyData.maxUsers}
          onChange={(e) =>
            setNewCompanyData((prev: NewCompanyData) => ({
              ...prev,
              maxUsers: Number.parseInt(e.target.value) || 10,
            }))
          }
          min="1"
          max="1000"
        />
      </div>
    </div>
  );
}

/**
 * Render company list item
 */
function renderCompanyListItem(
  company: Company,
  getStatusBadgeVariant: (status: string) => string,
  router: { push: (url: string) => void }
) {
  return (
    <div
      key={company.id}
      className="flex items-center justify-between p-4 border rounded-lg hover:bg-gray-50 dark:hover:bg-gray-800 transition-colors"
    >
      <div className="flex-1">
        <div className="flex items-center gap-3 mb-2">
          <h3 className="font-semibold">{company.name}</h3>
          <Badge
            variant={
              getStatusBadgeVariant(company.status) as
                | "default"
                | "destructive"
                | "outline"
                | "secondary"
            }
          >
            {company.status}
          </Badge>
        </div>
        <div className="flex items-center gap-6 text-sm text-muted-foreground">
          <span>{company._count.users} users</span>
          <span>{company._count.sessions} sessions</span>
          <span>{company._count.imports} imports</span>
          <span>
            Created {new Date(company.createdAt).toLocaleDateString()}
          </span>
        </div>
      </div>
      <div className="flex gap-2">
        <Button variant="outline" size="sm">
          <BarChart3 className="w-4 h-4 mr-2" />
          Analytics
        </Button>
        <Button
          variant="outline"
          size="sm"
          onClick={() => router.push(`/platform/companies/${company.id}`)}
        >
          <Settings className="w-4 h-4 mr-2" />
          Manage
        </Button>
      </div>
    </div>
  );
}

/**
 * Render dashboard header with user info and actions
 */
function renderDashboardHeader(
  session: PlatformSession,
  searchTerm: string,
  setSearchTerm: (term: string) => void,
  router: { push: (url: string) => void }
) {
  return (
    <div className="border-b bg-white dark:bg-gray-800">
      <div className="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8">
        <div className="flex justify-between items-center py-6">
          <div>
            <h1 className="text-2xl font-bold text-gray-900 dark:text-white">
              Platform Dashboard
            </h1>
            <p className="text-sm text-gray-500 dark:text-gray-400">
              Welcome back, {session.user.name || session.user.email}
            </p>
          </div>
          <div className="flex gap-4 items-center">
            <Button
              variant="outline"
              size="sm"
              onClick={() => router.push("/platform/security")}
            >
              <Shield className="w-4 h-4 mr-2" />
              Security Monitoring
            </Button>

            <ThemeToggle />

            <div className="relative">
              <Search className="absolute left-3 top-1/2 transform -translate-y-1/2 text-gray-400 w-4 h-4" />
              <Input
                placeholder="Search companies..."
                value={searchTerm}
                onChange={(e) => setSearchTerm(e.target.value)}
                className="pl-10 w-64"
              />
            </div>
            <DropdownMenu>
              <DropdownMenuTrigger asChild>
                <Button variant="outline" size="sm">
                  <MoreVertical className="w-4 h-4" />
                </Button>
              </DropdownMenuTrigger>
              <DropdownMenuContent align="end" className="w-56">
                <DropdownMenuLabel>
                  <div className="flex flex-col space-y-1">
                    <p className="text-sm font-medium">
                      {session.user.name || session.user.email}
                    </p>
                    <p className="text-xs text-muted-foreground">
                      {session.user.platformRole || "Platform User"}
                    </p>
                  </div>
                </DropdownMenuLabel>
                <DropdownMenuSeparator />
                <DropdownMenuItem
                  onClick={() => router.push("/platform/settings")}
                >
                  <User className="w-4 h-4 mr-2" />
                  Account Settings
                </DropdownMenuItem>
                <DropdownMenuSeparator />
                <DropdownMenuItem
                  onClick={async () => {
                    await fetch("/api/platform/auth/logout", {
                      method: "POST",
                    });
                    router.push("/platform/login");
                  }}
                  className="text-red-600"
                >
                  <LogOut className="w-4 h-4 mr-2" />
                  Sign Out
                </DropdownMenuItem>
              </DropdownMenuContent>
            </DropdownMenu>
          </div>
        </div>
      </div>
    </div>
  );
}

/**
 * Render dashboard statistics cards
 */
function renderDashboardStats(
  totalCompanies: number,
  totalUsers: number,
  totalSessions: number,
  activeCompanies: number
) {
  return (
    <div className="grid grid-cols-1 md:grid-cols-4 gap-6 mb-8">
      <Card>
        <CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
          <CardTitle className="text-sm font-medium">Total Companies</CardTitle>
          <Building2 className="h-4 w-4 text-muted-foreground" />
        </CardHeader>
        <CardContent>
          <div className="text-2xl font-bold">{totalCompanies}</div>
        </CardContent>
      </Card>

      <Card>
        <CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
          <CardTitle className="text-sm font-medium">Total Users</CardTitle>
          <Users className="h-4 w-4 text-muted-foreground" />
        </CardHeader>
        <CardContent>
          <div className="text-2xl font-bold">{totalUsers}</div>
        </CardContent>
      </Card>

      <Card>
        <CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
          <CardTitle className="text-sm font-medium">Total Sessions</CardTitle>
          <Database className="h-4 w-4 text-muted-foreground" />
        </CardHeader>
        <CardContent>
          <div className="text-2xl font-bold">{totalSessions}</div>
        </CardContent>
      </Card>

      <Card>
        <CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
          <CardTitle className="text-sm font-medium">
            Active Companies
          </CardTitle>
          <Activity className="h-4 w-4 text-muted-foreground" />
        </CardHeader>
        <CardContent>
          <div className="text-2xl font-bold">{activeCompanies}</div>
        </CardContent>
      </Card>
    </div>
  );
}

export default function PlatformDashboard() {
  const { data: session, status } = usePlatformSession();
  const router = useRouter();
  const { toast } = useToast();

  const {
    dashboardData,
    setDashboardData,
    isLoading,
    setIsLoading,
    showAddCompany,
    setShowAddCompany,
    isCreating,
    setIsCreating,
    copiedEmail,
    setCopiedEmail,
    copiedPassword,
    setCopiedPassword,
    searchTerm,
    setSearchTerm,
    newCompanyData,
    setNewCompanyData,
  } = usePlatformDashboardState();

  const {
    companyNameId,
    csvUrlId,
    csvUsernameId,
    csvPasswordId,
    adminEmailId,
    adminNameId,
    adminPasswordId,
    maxUsersId,
  } = useFormIds();

  const fetchDashboardData = useCallback(async () => {
    try {
      const response = await fetch("/api/platform/companies");
      if (response.ok) {
        const data = await response.json();
        setDashboardData(data);
      }
    } catch (error) {
      console.error("Failed to fetch dashboard data:", error);
    } finally {
      setIsLoading(false);
    }
  }, [setDashboardData, setIsLoading]);

  useEffect(() => {
    if (status === "loading") return;

    if (status === "unauthenticated" || !session?.user?.isPlatformUser) {
      router.push("/platform/login");
      return;
    }

    fetchDashboardData();
  }, [session, status, router, fetchDashboardData]);

  const copyToClipboard = async (text: string, type: "email" | "password") => {
    try {
      await navigator.clipboard.writeText(text);
      if (type === "email") {
        setCopiedEmail(true);
        setTimeout(() => setCopiedEmail(false), 2000);
      } else {
        setCopiedPassword(true);
        setTimeout(() => setCopiedPassword(false), 2000);
      }
    } catch (err) {
      console.error("Failed to copy: ", err);
    }
  };

  const getFilteredCompanies = () => {
    if (!dashboardData?.companies) return [];

    return dashboardData.companies.filter((company) =>
      company.name.toLowerCase().includes(searchTerm.toLowerCase())
    );
  };

  const validateCompanyData = () => {
    return !!(
      newCompanyData.name &&
      newCompanyData.csvUrl &&
      newCompanyData.adminEmail &&
      newCompanyData.adminName
    );
  };

  const showValidationError = () => {
    toast({
      title: "Error",
      description: "Please fill in all required fields",
      variant: "destructive",
    });
  };

  const createCompanyRequest = async () => {
    const response = await fetch("/api/platform/companies", {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify(newCompanyData),
    });
    return response;
  };

  const showCreateSuccessToast = (
    result: {
      adminUser?: { name: string; email: string };
      csvImportScheduled?: boolean;
    },
    companyName: string
  ) => {
    toast({
      title: "Success",
      description: `${companyName} created successfully! 🎉`,
    });

    if (result.adminUser) {
      toast({
        title: "Admin User Created",
        description: `Admin user ${result.adminUser.name} (${result.adminUser.email}) has been created`,
      });
    }

    if (result.csvImportScheduled) {
      toast({
        title: "CSV Import Scheduled",
        description:
          "CSV import has been scheduled and will begin processing shortly",
      });
    }
  };

  const showCredentialsToast = (
    result: { adminUser: { email: string }; generatedPassword: string },
    companyName: string
  ) => {
    toast({
      title: "Company Created Successfully!",
      description: (
        <div className="space-y-3">
          <p className="font-medium">
            Company &quot;{companyName}&quot; has been created.
          </p>
          <div className="space-y-2">
            <div className="flex items-center justify-between bg-muted p-2 rounded">
              <div className="flex-1">
                <p className="text-xs text-muted-foreground">Admin Email:</p>
                <p className="font-mono text-sm">{result.adminUser.email}</p>
              </div>
              <Button
                size="sm"
                variant="ghost"
                onClick={() => copyToClipboard(result.adminUser.email, "email")}
                className="h-8 w-8 p-0"
              >
                {copiedEmail ? (
                  <Check className="h-3 w-3" />
                ) : (
                  <Copy className="h-3 w-3" />
                )}
              </Button>
            </div>
            <div className="flex items-center justify-between bg-muted p-2 rounded">
              <div className="flex-1">
                <p className="text-xs text-muted-foreground">Admin Password:</p>
                <p className="font-mono text-sm">{result.generatedPassword}</p>
              </div>
              <Button
                size="sm"
                variant="ghost"
                onClick={() =>
                  copyToClipboard(result.generatedPassword, "password")
                }
                className="h-8 w-8 p-0"
              >
                {copiedPassword ? (
                  <Check className="h-3 w-3" />
                ) : (
                  <Copy className="h-3 w-3" />
                )}
              </Button>
            </div>
          </div>
        </div>
      ),
      duration: 15000, // Longer duration for credentials
    });
  };

  const showCreateErrorToast = (errorData: { error?: string }) => {
    toast({
      title: "Error",
      description: errorData.error || "Failed to create company",
      variant: "destructive",
    });
  };

  const resetCreateForm = () => {
    setNewCompanyData({
      name: "",
      csvUrl: "",
      csvUsername: "",
      csvPassword: "",
      adminEmail: "",
      adminName: "",
      adminPassword: "",
      maxUsers: 10,
    });
    setShowAddCompany(false);
  };

  const handleCreateCompany = async () => {
    if (!validateCompanyData()) {
      showValidationError();
      return;
    }

    const companyName = newCompanyData.name; // Store before reset
    setIsCreating(true);
    try {
      const response = await createCompanyRequest();

      if (response.ok) {
        const result = await response.json();
        showCreateSuccessToast(result, companyName);
        resetCreateForm();
        await fetchDashboardData();

        if (result.generatedPassword) {
          showCredentialsToast(result, companyName);
        }
      } else {
        const errorData = await response.json();
        showCreateErrorToast(errorData);
      }
    } catch (error) {
      showCreateErrorToast({
        error:
          error instanceof Error ? error.message : "Failed to create company",
      });
    } finally {
      setIsCreating(false);
    }
  };

  const getStatusBadgeVariant = (status: string) => {
    switch (status) {
      case "ACTIVE":
        return "default";
      case "TRIAL":
        return "secondary";
      case "SUSPENDED":
        return "destructive";
      case "ARCHIVED":
        return "outline";
      default:
        return "default";
    }
  };

  if (status === "loading" || isLoading) {
    return (
      <div className="flex items-center justify-center min-h-screen">
        <div className="text-center">Loading platform dashboard...</div>
      </div>
    );
  }

  if (status === "unauthenticated" || !session?.user?.isPlatformUser) {
    return null;
  }

  const filteredCompanies = getFilteredCompanies();
  const totalCompanies = dashboardData?.pagination?.total || 0;
  const totalUsers =
    dashboardData?.companies?.reduce(
      (sum, company) => sum + company._count.users,
      0
    ) || 0;
  const totalSessions =
    dashboardData?.companies?.reduce(
      (sum, company) => sum + company._count.sessions,
      0
    ) || 0;

  return (
    <div className="min-h-screen bg-gray-50 dark:bg-gray-900">
      {renderDashboardHeader(session, searchTerm, setSearchTerm, router)}

      <div className="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8 py-8">
        {/* Stats Overview */}
        {renderDashboardStats(
          totalCompanies,
          totalUsers,
          totalSessions,
          dashboardData?.companies?.filter((c) => c.status === "ACTIVE")
            .length || 0
        )}

        {/* Companies List */}
        <Card>
          <CardHeader>
            <CardTitle className="flex items-center justify-between">
              <div className="flex items-center gap-2">
                <Building2 className="w-5 h-5" />
                Companies
                {searchTerm && (
                  <Badge variant="secondary" className="ml-2">
                    {filteredCompanies.length} of {totalCompanies} shown
                  </Badge>
                )}
              </div>
              <div className="flex items-center gap-2">
                {searchTerm && (
                  <Badge variant="outline" className="text-xs">
                    Search: &quot;{searchTerm}&quot;
                  </Badge>
                )}
                <Dialog open={showAddCompany} onOpenChange={setShowAddCompany}>
                  <DialogTrigger asChild>
                    <Button size="sm">
                      <Plus className="w-4 h-4 mr-2" />
                      Add Company
                    </Button>
                  </DialogTrigger>
                  <DialogContent className="sm:max-w-[425px]">
                    <DialogHeader>
                      <DialogTitle>Add New Company</DialogTitle>
                      <DialogDescription>
                        Create a new company and invite the first administrator.
                      </DialogDescription>
                    </DialogHeader>
                    {renderCompanyFormFields(
                      newCompanyData,
                      setNewCompanyData,
                      {
                        companyNameId,
                        csvUrlId,
                        csvUsernameId,
                        csvPasswordId,
                        adminEmailId,
                        adminNameId,
                        adminPasswordId,
                        maxUsersId,
                      }
                    )}
                    <DialogFooter>
                      <Button
                        variant="outline"
                        onClick={() => setShowAddCompany(false)}
                      >
                        Cancel
                      </Button>
                      <Button
                        onClick={handleCreateCompany}
                        disabled={isCreating}
                      >
                        {isCreating ? "Creating..." : "Create Company"}
                      </Button>
                    </DialogFooter>
                  </DialogContent>
                </Dialog>
              </div>
            </CardTitle>
          </CardHeader>
          <CardContent>
            <div className="space-y-4">
              {filteredCompanies.map((company) =>
                renderCompanyListItem(company, getStatusBadgeVariant, router)
              )}

              {!filteredCompanies.length && (
                <div className="text-center py-8 text-muted-foreground">
                  {searchTerm ? (
                    <div className="space-y-2">
                      <p>No companies match &quot;{searchTerm}&quot;.</p>
                      <Button
                        variant="link"
                        onClick={() => setSearchTerm("")}
                        className="text-sm"
                      >
                        Clear search to see all companies
                      </Button>
                    </div>
                  ) : (
                    "No companies found. Create your first company to get started."
                  )}
                </div>
              )}
            </div>
          </CardContent>
        </Card>
      </div>
    </div>
  );
}