import { useAuth } from "@/_core/hooks/useAuth";
import { Avatar, AvatarFallback } from "@/components/ui/avatar";
import {
  DropdownMenu,
  DropdownMenuContent,
  DropdownMenuItem,
  DropdownMenuTrigger,
} from "@/components/ui/dropdown-menu";
import {
  Sidebar,
  SidebarContent,
  SidebarFooter,
  SidebarHeader,
  SidebarInset,
  SidebarMenu,
  SidebarMenuButton,
  SidebarMenuItem,
  SidebarProvider,
  SidebarTrigger,
  useSidebar,
} from "@/components/ui/sidebar";
import { APP_LOGO, APP_TITLE, getLoginUrl } from "@/const";
import { useIsMobile } from "@/hooks/useMobile";
import { LayoutDashboard, LogOut, PanelLeft, Users, GraduationCap, Calendar, CalendarDays, Bell, BarChart3, UserCog, Mail, Settings, TrendingUp, Building2, FileSpreadsheet, ClipboardList, ChevronDown, User, FileText } from "lucide-react";
import { CSSProperties, useEffect, useRef, useState } from "react";
import { useLocation } from "wouter";
import { DashboardLayoutSkeleton } from './DashboardLayoutSkeleton';
import { Button } from "./ui/button";

const menuSections = [
  {
    title: "Tableau de bord",
    items: [
      { icon: LayoutDashboard, label: "Tableau de bord", path: "/admin" },
    ]
  },
  {
    title: "Gestion",
    items: [
      { icon: GraduationCap, label: "Formations", path: "/admin/formations" },
      { icon: Calendar, label: "Séquences", path: "/admin/sequences" },
      { icon: CalendarDays, label: "Calendrier", path: "/admin/calendrier" },
      { icon: Users, label: "Apprenants", path: "/admin/apprenants" },
    ]
  },
  {
    title: "Configuration",
    items: [
      { icon: UserCog, label: "Utilisateurs", path: "/admin/users" },
      { icon: User, label: "Formateurs", path: "/admin/formateurs" },
      { icon: FileSpreadsheet, label: "Import Excel", path: "/admin/import-excel" },
      { icon: Bell, label: "Rappels", path: "/admin/rappels" },
      { icon: ClipboardList, label: "Questionnaires", path: "/admin/questionnaires" },
      { icon: Mail, label: "Templates d'emails", path: "/admin/email-templates" },
      { icon: Settings, label: "Configuration SMTP", path: "/admin/email-config" },
      { icon: FileText, label: "Attestations de formation", path: "/admin/attestations" },
    ]
  },
  {
    title: "Traçabilité",
    items: [
      { icon: Building2, label: "Établissements", path: "/admin/etablissements" },
      { icon: Mail, label: "Notifications", path: "/admin/notifications" },
      { icon: TrendingUp, label: "Suivi Questionnaires", path: "/admin/questionnaires/suivi" },
      { icon: Bell, label: "Rappels", path: "/admin/rappels/historique" },
    ]
  },
  {
    title: "Analyses",
    items: [
      { icon: TrendingUp, label: "Tableau de bord analytique", path: "/admin/analytics" },
      { icon: BarChart3, label: "Rapport Public Cible", path: "/admin/rapport-public-cible" },
      { icon: BarChart3, label: "Statistiques des rappels", path: "/admin/rappels/statistiques" },
    ]
  },
];

const SIDEBAR_WIDTH_KEY = "sidebar-width";
const DEFAULT_WIDTH = 280;
const MIN_WIDTH = 200;
const MAX_WIDTH = 480;

export default function DashboardLayout({
  children,
}: {
  children: React.ReactNode;
}) {
  const [sidebarWidth, setSidebarWidth] = useState(() => {
    const saved = localStorage.getItem(SIDEBAR_WIDTH_KEY);
    return saved ? parseInt(saved, 10) : DEFAULT_WIDTH;
  });
  const { loading, user } = useAuth();

  useEffect(() => {
    localStorage.setItem(SIDEBAR_WIDTH_KEY, sidebarWidth.toString());
  }, [sidebarWidth]);

  if (loading) {
    return <DashboardLayoutSkeleton />
  }

  if (!user) {
    return (
      <div className="flex items-center justify-center min-h-screen">
        <div className="flex flex-col items-center gap-8 p-8 max-w-md w-full">
          <div className="flex flex-col items-center gap-6">
            <div className="relative group">
              <div className="relative">
                <img
                  src={APP_LOGO}
                  alt={APP_TITLE}
                  className="h-20 w-20 rounded-xl object-cover shadow"
                />
              </div>
            </div>
            <div className="text-center space-y-2">
              <h1 className="text-2xl font-bold tracking-tight">{APP_TITLE}</h1>
              <p className="text-sm text-muted-foreground">
                Veuillez vous connecter pour continuer
              </p>
            </div>
          </div>
          <Button
            onClick={() => {
              window.location.href = getLoginUrl();
            }}
            size="lg"
            className="w-full shadow-lg hover:shadow-xl transition-all"
          >
            Se connecter
          </Button>
        </div>
      </div>
    );
  }

  return (
    <SidebarProvider
      style={
        {
          "--sidebar-width": `${sidebarWidth}px`,
        } as CSSProperties
      }
    >
      <DashboardLayoutContent setSidebarWidth={setSidebarWidth}>
        {children}
      </DashboardLayoutContent>
    </SidebarProvider>
  );
}

type DashboardLayoutContentProps = {
  children: React.ReactNode;
  setSidebarWidth: (width: number) => void;
};

function DashboardLayoutContent({
  children,
  setSidebarWidth,
}: DashboardLayoutContentProps) {
  const { user, logout } = useAuth();
  const [location, setLocation] = useLocation();
  const { state, toggleSidebar } = useSidebar();
  const isCollapsed = state === "collapsed";
  const [isResizing, setIsResizing] = useState(false);
  const sidebarRef = useRef<HTMLDivElement>(null);
  const activeMenuItem = menuSections.flatMap(section => section.items).find(item => item.path === location);
  const isMobile = useIsMobile();
  
  // État pour gérer les sections ouvertes/fermées (persisté dans localStorage)
  const [openSections, setOpenSections] = useState<Record<string, boolean>>(() => {
    // Version du système de menu (incrémenter pour forcer la réinitialisation)
    const MENU_VERSION = 2;
    const savedVersion = localStorage.getItem('menuVersion');
    
    // Si la version a changé, ignorer le localStorage existant
    if (savedVersion && parseInt(savedVersion) === MENU_VERSION) {
      const saved = localStorage.getItem('menuSectionsState');
      if (saved) {
        try {
          return JSON.parse(saved);
        } catch {
          // En cas d'erreur, utiliser les valeurs par défaut
        }
      }
    }
    
    // Valeurs par défaut : seule la section TABLEAU DE BORD est ouverte
    const initial: Record<string, boolean> = {};
    menuSections.forEach(section => {
      // Ouvrir uniquement "Tableau de bord", fermer les autres
      initial[section.title] = section.title === "Tableau de bord";
    });
    
    // Sauvegarder la version et l'état initial
    localStorage.setItem('menuVersion', MENU_VERSION.toString());
    localStorage.setItem('menuSectionsState', JSON.stringify(initial));
    
    return initial;
  });
  
  // Fonction pour toggle une section
  const toggleSection = (sectionTitle: string) => {
    setOpenSections(prev => {
      const newState = {
        ...prev,
        [sectionTitle]: !prev[sectionTitle]
      };
      // Sauvegarder dans localStorage
      localStorage.setItem('menuSectionsState', JSON.stringify(newState));
      return newState;
    });
  };

  useEffect(() => {
    if (isCollapsed) {
      setIsResizing(false);
    }
  }, [isCollapsed]);

  useEffect(() => {
    const handleMouseMove = (e: MouseEvent) => {
      if (!isResizing) return;

      const sidebarLeft = sidebarRef.current?.getBoundingClientRect().left ?? 0;
      const newWidth = e.clientX - sidebarLeft;
      if (newWidth >= MIN_WIDTH && newWidth <= MAX_WIDTH) {
        setSidebarWidth(newWidth);
      }
    };

    const handleMouseUp = () => {
      setIsResizing(false);
    };

    if (isResizing) {
      document.addEventListener("mousemove", handleMouseMove);
      document.addEventListener("mouseup", handleMouseUp);
      document.body.style.cursor = "col-resize";
      document.body.style.userSelect = "none";
    }

    return () => {
      document.removeEventListener("mousemove", handleMouseMove);
      document.removeEventListener("mouseup", handleMouseUp);
      document.body.style.cursor = "";
      document.body.style.userSelect = "";
    };
  }, [isResizing, setSidebarWidth]);

  return (
    <>
      <div className="relative" ref={sidebarRef}>
        <Sidebar
          collapsible="icon"
          className="border-r-0"
          disableTransition={isResizing}
        >
          <SidebarHeader className="h-16 justify-center">
            <div className="flex items-center gap-3 pl-2 group-data-[collapsible=icon]:px-0 transition-all w-full">
              {isCollapsed ? (
                <div className="relative h-8 w-8 shrink-0 group">
                  <img
                    src={APP_LOGO}
                    className="h-8 w-8 rounded-md object-cover ring-1 ring-border"
                    alt="Logo"
                  />
                  <button
                    onClick={toggleSidebar}
                    className="absolute inset-0 flex items-center justify-center bg-accent rounded-md ring-1 ring-border opacity-0 group-hover:opacity-100 transition-opacity focus:outline-none focus-visible:ring-2 focus-visible:ring-ring"
                  >
                    <PanelLeft className="h-4 w-4 text-foreground" />
                  </button>
                </div>
              ) : (
                <>
                  <div className="flex items-center gap-3 min-w-0">
                    <img
                      src={APP_LOGO}
                      className="h-8 w-8 rounded-md object-cover ring-1 ring-border shrink-0"
                      alt="Logo"
                    />
                    <span className="font-semibold tracking-tight truncate">
                      {APP_TITLE}
                    </span>
                  </div>
                  <button
                    onClick={toggleSidebar}
                    className="ml-auto h-8 w-8 flex items-center justify-center hover:bg-accent rounded-lg transition-colors focus:outline-none focus-visible:ring-2 focus-visible:ring-ring shrink-0"
                  >
                    <PanelLeft className="h-4 w-4 text-muted-foreground" />
                  </button>
                </>
              )}
            </div>
          </SidebarHeader>

          <SidebarContent className="gap-0">
            {menuSections.map((section, sectionIndex) => {
              const isOpen = openSections[section.title] ?? false;
              return (
                <div key={section.title}>
                  {sectionIndex > 0 && (
                    <div className="border-t border-border my-2" />
                  )}
                  <button
                    onClick={() => toggleSection(section.title)}
                    className="w-full px-4 py-2 flex items-center justify-between hover:bg-accent/50 transition-colors rounded-md mx-2 focus:outline-none focus-visible:ring-2 focus-visible:ring-ring"
                  >
                    <h3 className="text-xs font-semibold text-blue-600 uppercase tracking-wider">
                      {section.title}
                    </h3>
                    <ChevronDown 
                      className={`h-3 w-3 text-blue-600 transition-transform duration-200 ${
                        isOpen ? 'rotate-180' : ''
                      }`}
                    />
                  </button>
                  {isOpen && (
                    <SidebarMenu className="px-2 py-1">
                      {section.items.map(item => {
                        const isActive = location === item.path;
                        const hasSubItems = 'subItems' in item && item.subItems && item.subItems.length > 0;
                        const isSubItemActive = hasSubItems && item.subItems.some((sub: any) => location === sub.path);
                        return (
                          <div key={item.path}>
                            <SidebarMenuItem>
                              <SidebarMenuButton
                                isActive={isActive || isSubItemActive}
                                onClick={() => setLocation(item.path)}
                                tooltip={item.label}
                                className={`h-10 transition-all font-normal`}
                              >
                                <item.icon
                                  className={`h-4 w-4 ${isActive || isSubItemActive ? "text-primary" : ""}`}
                                />
                                <span>{item.label}</span>
                              </SidebarMenuButton>
                            </SidebarMenuItem>
                            {hasSubItems && (
                              <div className="ml-6 mt-1 space-y-1">
                                {item.subItems.map((subItem: any) => {
                                  const isSubActive = location === subItem.path;
                                  return (
                                    <SidebarMenuItem key={subItem.path}>
                                      <SidebarMenuButton
                                        isActive={isSubActive}
                                        onClick={() => setLocation(subItem.path)}
                                        tooltip={subItem.label}
                                        className="h-9 text-sm font-normal"
                                      >
                                        <span className="ml-2">{subItem.label}</span>
                                      </SidebarMenuButton>
                                    </SidebarMenuItem>
                                  );
                                })}
                              </div>
                            )}
                          </div>
                        );
                      })}
                    </SidebarMenu>
                  )}
                </div>
              );
            })}
          </SidebarContent>

          <SidebarFooter className="p-3">
            <DropdownMenu>
              <DropdownMenuTrigger asChild>
                <button className="flex items-center gap-3 rounded-lg px-1 py-1 hover:bg-accent/50 transition-colors w-full text-left group-data-[collapsible=icon]:justify-center focus:outline-none focus-visible:ring-2 focus-visible:ring-ring">
                  <Avatar className="h-9 w-9 border shrink-0">
                    <AvatarFallback className="text-xs font-medium">
                      {user?.name?.charAt(0).toUpperCase()}
                    </AvatarFallback>
                  </Avatar>
                  <div className="flex-1 min-w-0 group-data-[collapsible=icon]:hidden">
                    <p className="text-sm font-medium truncate leading-none">
                      {user?.name || "-"}
                    </p>
                    <p className="text-xs text-muted-foreground truncate mt-1.5">
                      {user?.email || "-"}
                    </p>
                  </div>
                </button>
              </DropdownMenuTrigger>
              <DropdownMenuContent align="end" className="w-48">
                <DropdownMenuItem
                  onClick={async () => {
                    await logout();
                    setLocation('/');
                  }}
                  className="cursor-pointer text-destructive focus:text-destructive"
                >
                  <LogOut className="mr-2 h-4 w-4" />
                  <span>Déconnexion</span>
                </DropdownMenuItem>
              </DropdownMenuContent>
            </DropdownMenu>
          </SidebarFooter>
        </Sidebar>
        <div
          className={`absolute top-0 right-0 w-1 h-full cursor-col-resize hover:bg-primary/20 transition-colors ${isCollapsed ? "hidden" : ""}`}
          onMouseDown={() => {
            if (isCollapsed) return;
            setIsResizing(true);
          }}
          style={{ zIndex: 50 }}
        />
      </div>

      <SidebarInset>
        {isMobile && (
          <div className="flex border-b h-14 items-center justify-between bg-background/95 px-2 backdrop-blur supports-[backdrop-filter]:backdrop-blur sticky top-0 z-40">
            <div className="flex items-center gap-2">
              <SidebarTrigger className="h-9 w-9 rounded-lg bg-background" />
              <div className="flex items-center gap-3">
                <div className="flex flex-col gap-1">
                  <span className="tracking-tight text-foreground">
                    {activeMenuItem?.label ?? APP_TITLE}
                  </span>
                </div>
              </div>
            </div>
          </div>
        )}
        <main className="flex-1 p-4">{children}</main>
      </SidebarInset>
    </>
  );
}