"use client";

import {
  archiveClientRecord,
  createClientRecord,
  updateClientRecord,
  updateClientPipelineStage,
} from "@/app/(dashboard)/clients/actions";
import { Badge, Button, Card, CardContent, Input, Label, Textarea } from "poyraz-ui/atoms";
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogFooter,
  DialogHeader,
  DialogTitle,
  DialogTrigger,
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
  Tabs,
  TabsContent,
  TabsList,
  TabsTrigger,
} from "poyraz-ui/molecules";
import {
  Archive,
  ExternalLink,
  Mail,
  PauseCircle,
  Pencil,
  Phone,
  Plus,
  UserCheck,
  Users,
  Wallet,
  Clock,
  ArrowRight,
  type LucideIcon,
} from "lucide-react";
import Link from "next/link";
import { useState } from "react";
import { format, isPast, isToday } from "date-fns";
import { tr } from "date-fns/locale";
import {
  DndContext,
  DragEndEvent,
  DragOverlay,
  DragStartEvent,
  PointerSensor,
  useSensor,
  useSensors,
  closestCorners,
  useDroppable,
  useDraggable,
} from "@dnd-kit/core";
import { CSS } from "@dnd-kit/utilities";
import { useEffect } from "react";
import { cn } from "@/lib/utils";

export type ClientListItem = {
  id: string;
  name: string;
  company_name: string | null;
  email: string | null;
  phone: string | null;
  website: string | null;
  status: "active" | "paused" | "archived";
  notes: string | null;
  created_at: string;
  projectCount: number;
  revenueTotal: number;
  // CRM fields
  pipeline_stage: "lead" | "contacted" | "proposal_sent" | "won" | "lost";
  next_follow_up_date: string | null;
  last_contact_date: string | null;
  client_value_score: number;
};

const statusLabels = {
  active: "Aktif",
  paused: "Duraklatıldı",
  archived: "Arşivlendi",
};

const statusClasses = {
  active: "border-emerald-200 bg-emerald-50 text-emerald-700",
  paused: "border-amber-200 bg-amber-50 text-amber-700",
  archived: "border-zinc-200 bg-zinc-50 text-zinc-600",
};

const pipelineStages = [
  { id: "lead", label: "Potansiyel (Lead)", color: "border-slate-200 bg-slate-50 text-slate-700" },
  { id: "contacted", label: "İletişime Geçildi", color: "border-blue-200 bg-blue-50 text-blue-700" },
  { id: "proposal_sent", label: "Teklif İletildi", color: "border-amber-200 bg-amber-50 text-amber-700" },
  { id: "won", label: "Kazanıldı (Won)", color: "border-emerald-200 bg-emerald-50 text-emerald-700" },
  { id: "lost", label: "Kaybedildi (Lost)", color: "border-rose-200 bg-rose-50 text-rose-700" },
];

type ClientsClientProps = {
  clients: ClientListItem[];
  totalRevenue: number;
  activeCount: number;
  pausedCount: number;
  archivedCount: number;
};

export function ClientsClient({
  clients,
  totalRevenue,
  activeCount,
  pausedCount,
  archivedCount,
}: ClientsClientProps) {
  const [query, setQuery] = useState("");
  const normalizedQuery = query.trim().toLowerCase();
  
  const [activeDragClient, setActiveDragClient] = useState<ClientListItem | null>(null);
  const [localClients, setLocalClients] = useState(clients);

  useEffect(() => {
    setLocalClients(clients);
  }, [clients]);

  const sensors = useSensors(
    useSensor(PointerSensor, {
      activationConstraint: {
        distance: 5,
      },
    })
  );

  function handleDragStart(event: DragStartEvent) {
    const { active } = event;
    const client = localClients.find(c => c.id === active.id);
    if (client) setActiveDragClient(client);
  }

  async function handleDragEnd(event: DragEndEvent) {
    const { active, over } = event;
    setActiveDragClient(null);

    if (!over) return;

    const clientId = active.id as string;
    const newStage = over.id as string;

    const client = localClients.find(c => c.id === clientId);
    if (!client || client.pipeline_stage === newStage) return;

    setLocalClients(prev => 
      prev.map(c => c.id === clientId ? { ...c, pipeline_stage: newStage as any } : c)
    );

    try {
      await updateClientPipelineStage(clientId, newStage);
    } catch (error) {
      setLocalClients(clients);
    }
  }

  const filteredClients = normalizedQuery
    ? localClients.filter((client) =>
        [
          client.name,
          client.company_name,
          client.email,
          client.phone,
          client.website,
          client.notes,
        ]
          .filter(Boolean)
          .some((value) => value!.toLowerCase().includes(normalizedQuery)),
      )
    : localClients;

  return (
    <div className="mx-auto flex max-w-7xl flex-col gap-6 animate-in fade-in slide-in-from-bottom-4 duration-500">
      <div className="flex flex-col gap-4 border-b border-border pb-5 lg:flex-row lg:items-end lg:justify-between">
        <div className="space-y-2">
          <div className="flex items-center gap-2 text-sm text-muted-foreground">
            <Users className="h-4 w-4" />
            CRM & Operasyon
          </div>
          <div>
            <h1 className="text-3xl font-semibold tracking-normal text-foreground">
              CRM & Müşteriler
            </h1>
            <p className="mt-1 max-w-2xl text-sm text-muted-foreground">
              Potansiyel müşterilerini pipeline üzerinden takip et ve müşteri ilişkilerini yönet.
            </p>
          </div>
        </div>

        <ClientDialog mode="create" />
      </div>

      <div className="grid gap-3 md:grid-cols-4">
        <StatCard
          label="Potansiyel (Lead)"
          value={clients.filter(c => c.pipeline_stage === 'lead' || c.pipeline_stage === 'contacted').length.toString()}
          icon={Users}
          iconClassName="bg-blue-50 text-blue-700"
        />
        <StatCard
          label="Aktif Müşteri"
          value={activeCount.toString()}
          icon={UserCheck}
          iconClassName="bg-emerald-50 text-emerald-700"
        />
        <StatCard
          label="Bekleyen Follow-up"
          value={clients.filter(c => c.next_follow_up_date && (isPast(new Date(c.next_follow_up_date)) || isToday(new Date(c.next_follow_up_date)))).length.toString()}
          icon={Clock}
          iconClassName="bg-rose-50 text-rose-700"
        />
        <StatCard
          label="Kayıtlı Gelir"
          value={formatCurrency(totalRevenue)}
          description="Ödenmiş gelir işlemleri"
          icon={Wallet}
          iconClassName="bg-primary/10 text-primary"
        />
      </div>

      <Tabs defaultValue="pipeline" className="w-full">
        <div className="flex flex-col sm:flex-row sm:items-center justify-between gap-4 mb-4">
          <TabsList>
            <TabsTrigger value="pipeline">Pipeline (Kanban)</TabsTrigger>
            <TabsTrigger value="list">Müşteri Listesi</TabsTrigger>
          </TabsList>
          
          <Input
            value={query}
            onChange={(event) => setQuery(event.target.value)}
            placeholder="Müşteri, firma, e-posta veya not ara"
            className="md:max-w-sm"
          />
        </div>

        <TabsContent value="pipeline" className="mt-0">
          <DndContext 
            sensors={sensors} 
            collisionDetection={closestCorners} 
            onDragStart={handleDragStart} 
            onDragEnd={handleDragEnd}
          >
            <div className="flex gap-4 overflow-x-auto pb-4 snap-x">
              {pipelineStages.map(stage => {
                const stageClients = filteredClients.filter(c => c.pipeline_stage === stage.id && c.status !== 'archived');
                return (
                  <DroppableColumn 
                    key={stage.id} 
                    id={stage.id} 
                    title={stage.label} 
                    count={stageClients.length} 
                    color={stage.color.split(' ')[1]}
                  >
                    {stageClients.map(client => (
                      <DraggableClientCard key={client.id} client={client} />
                    ))}
                    {stageClients.length === 0 && (
                      <div className="h-24 flex items-center justify-center border-2 border-dashed border-border rounded-md text-xs text-muted-foreground">
                        Boş
                      </div>
                    )}
                  </DroppableColumn>
                );
              })}
            </div>
            <DragOverlay>
              {activeDragClient ? (
                <DraggableClientCard client={activeDragClient} isOverlay />
              ) : null}
            </DragOverlay>
          </DndContext>
        </TabsContent>

        <TabsContent value="list" className="mt-0">
          {filteredClients.length > 0 ? (
            <div className="overflow-hidden rounded-sm border border-border">
              <div className="hidden grid-cols-[1.5fr_1fr_1fr_1fr_0.8fr_0.8fr] gap-4 border-b border-border bg-muted/40 px-4 py-3 text-xs font-medium uppercase text-muted-foreground lg:grid">
                <span>Müşteri</span>
                <span>İletişim</span>
                <span>Aşama</span>
                <span>Follow-up</span>
                <span>Projeler</span>
                <span className="text-right">İşlem</span>
              </div>
              <div className="divide-y divide-border">
                {filteredClients.map((client) => (
                  <ClientRow key={client.id} client={client} />
                ))}
              </div>
            </div>
          ) : (
            <EmptyState hasQuery={Boolean(normalizedQuery)} />
          )}
        </TabsContent>
      </Tabs>
    </div>
  );
}

function DroppableColumn({ id, title, count, color, children }: { id: string, title: string, count: number, color: string, children: React.ReactNode }) {
  const { isOver, setNodeRef } = useDroppable({ id });
  return (
    <div
      ref={setNodeRef}
      className={cn(
        "flex-shrink-0 w-[340px] px-2 flex flex-col h-[calc(100vh-320px)] min-h-[500px] transition-colors rounded-lg",
        isOver ? "bg-muted/30" : ""
      )}
    >
      <div className="flex items-center justify-between mb-3 px-1">
        <h3 className="font-semibold text-sm text-foreground flex items-center gap-2">
          <span className={`w-2 h-2 rounded-full ${color}`}></span>
          {title}
        </h3>
        <Badge variant="secondary" className="text-xs">{count}</Badge>
      </div>
      <div className="flex-1 overflow-y-auto space-y-3 pr-1 tiny-scrollbar">
        {children}
      </div>
    </div>
  );
}

function DraggableClientCard({ client, isOverlay }: { client: ClientListItem, isOverlay?: boolean }) {
  const { attributes, listeners, setNodeRef, transform, isDragging } = useDraggable({
    id: client.id,
    data: client,
  });

  const style = {
    transform: CSS.Translate.toString(transform),
    opacity: isDragging && !isOverlay ? 0.3 : 1,
    zIndex: isDragging ? 999 : "auto",
  };

  return (
    <div ref={setNodeRef} style={style} {...listeners} {...attributes} className={cn("touch-none cursor-grab active:cursor-grabbing", isOverlay && "rotate-2 scale-105 shadow-xl")}>
      <Card className="hover:border-primary/50 transition-colors">
        <CardContent className="p-3">
          <div className="flex justify-between items-start mb-2">
            <Link href={`/clients/${client.id}`} className="font-medium text-foreground hover:underline" onPointerDown={(e) => e.stopPropagation()}>
              {client.name}
            </Link>
            <div onPointerDown={(e) => e.stopPropagation()}>
              <ClientDialog mode="edit" client={client} trigger={<Button variant="ghost" className="h-6 w-6 p-0"><Pencil className="h-3 w-3" /></Button>} />
            </div>
          </div>
          {client.company_name && <p className="text-xs text-muted-foreground mb-2 pointer-events-none">{client.company_name}</p>}
          
          {client.next_follow_up_date && (
            <div className="mt-3 flex items-center gap-1.5 text-xs pointer-events-none">
              <Clock className={`h-3 w-3 ${isPast(new Date(client.next_follow_up_date)) ? 'text-rose-500' : 'text-muted-foreground'}`} />
              <span className={isPast(new Date(client.next_follow_up_date)) ? 'text-rose-500 font-medium' : 'text-muted-foreground'}>
                {format(new Date(client.next_follow_up_date), 'd MMM yyyy', { locale: tr })}
              </span>
            </div>
          )}
        </CardContent>
      </Card>
    </div>
  );
}

function ClientRow({ client }: { client: ClientListItem }) {
  const isFollowUpOverdue = client.next_follow_up_date && (isPast(new Date(client.next_follow_up_date)) || isToday(new Date(client.next_follow_up_date)));
  const stage = pipelineStages.find(s => s.id === client.pipeline_stage) || pipelineStages[0];

  return (
    <div className="grid gap-4 px-4 py-4 lg:grid-cols-[1.5fr_1fr_1fr_1fr_0.8fr_0.8fr] lg:items-center">
      <div className="min-w-0">
        <div className="flex items-center gap-3">
          <div className="flex h-10 w-10 shrink-0 items-center justify-center rounded-sm bg-primary/10 text-sm font-semibold text-primary">
            {getInitials(client.name)}
          </div>
          <div className="min-w-0">
            <Link href={`/clients/${client.id}`} className="truncate font-medium text-foreground hover:underline block">{client.name}</Link>
            <div className="truncate text-sm text-muted-foreground">
              {client.company_name || "Firma bilgisi yok"}
            </div>
          </div>
        </div>
      </div>

      <div className="space-y-1 text-sm text-muted-foreground">
        {client.email ? (
          <Link href={`mailto:${client.email}`} className="flex items-center gap-2 hover:text-primary">
            <Mail className="h-3.5 w-3.5" />
            <span className="truncate">{client.email}</span>
          </Link>
        ) : null}
        {client.phone ? (
          <Link href={`tel:${client.phone}`} className="flex items-center gap-2 hover:text-primary">
            <Phone className="h-3.5 w-3.5" />
            <span className="truncate">{client.phone}</span>
          </Link>
        ) : null}
        {!client.email && !client.phone && !client.website ? (
          <span>İletişim bilgisi yok</span>
        ) : null}
      </div>

      <div>
        <Badge className={stage.color}>
          {stage.label}
        </Badge>
      </div>

      <div className="text-sm">
        {client.next_follow_up_date ? (
          <div className={`flex items-center gap-1.5 ${isFollowUpOverdue ? 'text-rose-600 font-medium' : 'text-muted-foreground'}`}>
            <Clock className="h-3.5 w-3.5" />
            {format(new Date(client.next_follow_up_date), 'd MMM yyyy', { locale: tr })}
          </div>
        ) : (
          <span className="text-muted-foreground opacity-50">-</span>
        )}
      </div>

      <div className="text-sm">
        <div className="font-medium text-foreground">{client.projectCount} Proje</div>
        <div className="text-muted-foreground">{formatCurrency(client.revenueTotal)}</div>
      </div>

      <div className="flex justify-start gap-2 lg:justify-end">
        <Link href={`/clients/${client.id}`}>
          <Button variant="ghost" className="h-9 w-9 p-0">
            <ArrowRight className="h-4 w-4" />
          </Button>
        </Link>
        <ClientDialog mode="edit" client={client} trigger={<Button variant="outline" className="h-9 min-w-20 gap-2 px-3"><Pencil className="h-4 w-4" /> Düzenle</Button>} />
      </div>
    </div>
  );
}

function ClientDialog({
  mode,
  client,
  trigger
}: {
  mode: "create" | "edit";
  client?: ClientListItem;
  trigger?: React.ReactNode;
}) {
  const [open, setOpen] = useState(false);
  const [isSubmitting, setIsSubmitting] = useState(false);
  const action = mode === "create" ? createClientRecord : updateClientRecord;

  async function handleSubmit(formData: FormData) {
    setIsSubmitting(true);

    try {
      await action(formData);
      setOpen(false);
    } finally {
      setIsSubmitting(false);
    }
  }

  return (
    <Dialog open={open} onOpenChange={setOpen}>
      <DialogTrigger asChild>
        {trigger || (
          <Button
            variant={mode === "create" ? "default" : "outline"}
            className="h-9 min-w-24 gap-2 px-3"
          >
            {mode === "create" ? <Plus className="h-4 w-4" /> : <Pencil className="h-4 w-4" />}
            {mode === "create" ? "Müşteri ekle" : "Düzenle"}
          </Button>
        )}
      </DialogTrigger>
      <DialogContent className="sm:max-w-xl max-h-[90vh] overflow-y-auto">
        <form action={handleSubmit} className="space-y-5">
          {client ? <input type="hidden" name="id" value={client.id} /> : null}
          <DialogHeader>
            <DialogTitle>
              {mode === "create" ? "Yeni müşteri" : "Müşteriyi düzenle"}
            </DialogTitle>
            <DialogDescription>
              Müşterinin iletişim ve CRM detaylarını girin.
            </DialogDescription>
          </DialogHeader>

          <ClientFormFields client={client} />

          <DialogFooter>
            <Button type="submit" disabled={isSubmitting} className="gap-2">
              {mode === "create" ? <Plus className="h-4 w-4" /> : <Pencil className="h-4 w-4" />}
              {isSubmitting
                ? "Kaydediliyor"
                : mode === "create"
                  ? "Müşteriyi ekle"
                  : "Değişiklikleri kaydet"}
            </Button>
          </DialogFooter>
        </form>
      </DialogContent>
    </Dialog>
  );
}

function ClientFormFields({ client }: { client?: ClientListItem }) {
  return (
    <div className="grid gap-4">
      <div className="grid gap-4 md:grid-cols-2">
        <div className="grid gap-2">
          <Label htmlFor={`name-${client?.id || "new"}`}>Müşteri adı</Label>
          <Input
            id={`name-${client?.id || "new"}`}
            name="name"
            defaultValue={client?.name || ""}
            required
            placeholder="Örn. Acme Corp"
          />
        </div>
        <div className="grid gap-2">
          <Label htmlFor={`company-${client?.id || "new"}`}>Firma / marka adı</Label>
          <Input
            id={`company-${client?.id || "new"}`}
            name="company_name"
            defaultValue={client?.company_name || ""}
            placeholder="Opsiyonel"
          />
        </div>
      </div>

      <div className="grid gap-4 md:grid-cols-2 border-t border-border pt-4 mt-2">
        <div className="grid gap-2">
          <Label>Satış Aşaması (Pipeline)</Label>
          <Select name="pipeline_stage" defaultValue={client?.pipeline_stage || "lead"}>
            <SelectTrigger>
              <SelectValue placeholder="Aşama seç" />
            </SelectTrigger>
            <SelectContent>
              {pipelineStages.map(stage => (
                <SelectItem key={stage.id} value={stage.id}>{stage.label}</SelectItem>
              ))}
            </SelectContent>
          </Select>
        </div>
        <div className="grid gap-2">
          <Label>Durum</Label>
          <Select name="status" defaultValue={client?.status || "active"}>
            <SelectTrigger>
              <SelectValue placeholder="Durum seç" />
            </SelectTrigger>
            <SelectContent>
              <SelectItem value="active">Aktif</SelectItem>
              <SelectItem value="paused">Duraklatıldı</SelectItem>
              <SelectItem value="archived">Arşivlendi</SelectItem>
            </SelectContent>
          </Select>
        </div>
      </div>

      <div className="grid gap-4 md:grid-cols-2">
        <div className="grid gap-2">
          <Label htmlFor={`followup-${client?.id || "new"}`}>Sonraki Follow-up Tarihi</Label>
          <Input
            id={`followup-${client?.id || "new"}`}
            name="next_follow_up_date"
            type="date"
            defaultValue={client?.next_follow_up_date ? new Date(client.next_follow_up_date).toISOString().slice(0, 10) : ""}
          />
        </div>
      </div>

      <div className="grid gap-4 md:grid-cols-2 border-t border-border pt-4 mt-2">
        <div className="grid gap-2">
          <Label htmlFor={`email-${client?.id || "new"}`}>E-posta</Label>
          <Input
            id={`email-${client?.id || "new"}`}
            name="email"
            type="email"
            defaultValue={client?.email || ""}
            placeholder="musteri@example.com"
          />
        </div>
        <div className="grid gap-2">
          <Label htmlFor={`phone-${client?.id || "new"}`}>Telefon</Label>
          <PhoneInput
            id={`phone-${client?.id || "new"}`}
            name="phone"
            defaultValue={client?.phone || ""}
          />
        </div>
      </div>

      <div className="grid gap-2">
        <Label htmlFor={`notes-${client?.id || "new"}`}>Genel Notlar</Label>
        <Textarea
          id={`notes-${client?.id || "new"}`}
          name="notes"
          defaultValue={client?.notes || ""}
          placeholder="İletişim notları, beklentiler, özel bilgiler..."
          rows={3}
        />
      </div>
    </div>
  );
}

function PhoneInput({ id, name, defaultValue }: { id: string; name: string; defaultValue: string; }) {
  const [value, setValue] = useState(defaultValue);
  return (
    <Input
      id={id}
      name={name}
      value={value}
      inputMode="tel"
      placeholder="+90 (5xx) xxx xx xx"
      onChange={(event) => setValue(formatPhone(event.target.value))}
    />
  );
}

function StatCard({ label, value, description, icon: Icon, iconClassName }: { label: string; value: string; description?: string; icon: LucideIcon; iconClassName: string; }) {
  return (
    <Card>
      <CardContent className="p-4">
        <div className="flex items-center justify-between gap-3">
          <div>
            <p className="text-sm text-muted-foreground">{label}</p>
            <p className="mt-1 text-2xl font-semibold text-foreground">{value}</p>
            {description ? <p className="mt-1 text-xs text-muted-foreground">{description}</p> : null}
          </div>
          <div className={`flex h-10 w-10 items-center justify-center rounded-sm ${iconClassName}`}>
            <Icon className="h-5 w-5" />
          </div>
        </div>
      </CardContent>
    </Card>
  );
}

function EmptyState({ hasQuery }: { hasQuery: boolean }) {
  return (
    <div className="flex min-h-72 flex-col items-center justify-center rounded-sm border border-dashed border-border bg-muted/20 p-8 text-center">
      <Users className="h-10 w-10 text-muted-foreground" />
      <h3 className="mt-4 text-lg font-semibold text-foreground">
        {hasQuery ? "Aramana uygun müşteri yok" : "Henüz müşteri eklenmedi"}
      </h3>
      <p className="mt-2 max-w-md text-sm text-muted-foreground">
        İlk müşterini ekleyerek potansiyel satışlarını takip etmeye başla.
      </p>
    </div>
  );
}

function getInitials(name: string) {
  return name.split(" ").filter(Boolean).slice(0, 2).map((part) => part[0]?.toUpperCase()).join("");
}

function formatPhone(input: string) {
  const digits = input.replace(/\D/g, "");
  if (!digits) return "";
  const local = digits.startsWith("90") ? digits.slice(2, 12) : digits.startsWith("0") ? digits.slice(1, 11) : digits.slice(0, 10);
  const area = local.slice(0, 3);
  const first = local.slice(3, 6);
  const second = local.slice(6, 8);
  const third = local.slice(8, 10);
  let formatted = "+90";
  if (area) formatted += ` (${area}`;
  if (area.length === 3) formatted += ")";
  if (first) formatted += ` ${first}`;
  if (second) formatted += ` ${second}`;
  if (third) formatted += ` ${third}`;
  return formatted;
}

function formatCurrency(value: number) {
  return new Intl.NumberFormat("tr-TR", { style: "currency", currency: "USD", maximumFractionDigits: 0 }).format(value);
}