'use client';

import { useState } from 'react';
import {
  Button, Card, CardContent, CardHeader, CardTitle, Input, Label,
  Dialog, DialogContent, DialogHeader, DialogTitle, DialogFooter,
  Select, SelectContent, SelectItem, SelectTrigger, SelectValue,
  cn,
} from '@horux/shared-ui';
import { useQueryClient } from '@tanstack/react-query';
import {
  FolderOpen, Plus, Trash2, ChevronDown, ChevronUp, X,
  Users, Building2, FolderPlus, UserCog,
} from 'lucide-react';
import {
  useCarteras, useCreateCartera, useDeleteCartera,
  useCarteraEntidades, useSubcarteras, useCreateSubcartera,
  useSupervisores,
} from '@/lib/hooks/use-carteras';
import {
  addEntidadToCartera, removeEntidadFromCartera,
} from '@/lib/api/carteras';
import { useContribuyentes } from '@/lib/hooks/use-contribuyentes';
import { useUsuarios } from '@/lib/hooks/use-usuarios';
import { useAuthStore } from '@/stores/auth-store';
import { DashboardShell } from '@/components/layouts/dashboard-shell';
import type { Cartera } from '@/lib/api/carteras';

/* ------------------------------------------------------------------ */
/* SubcarteraCard                                                      */
/* ------------------------------------------------------------------ */
function SubcarteraCard({ sub, usuarios, contribuyentes, onDelete }: {
  sub: Cartera;
  usuarios: any[];
  contribuyentes: any[];
  onDelete: () => void;
}) {
  const [expanded, setExpanded] = useState(false);
  const qc = useQueryClient();
  const { data: entidadIds, isLoading } = useCarteraEntidades(expanded ? sub.id : null);
  const [addingEntidad, setAddingEntidad] = useState(false);
  const [selectedEntidadId, setSelectedEntidadId] = useState('');
  const [busy, setBusy] = useState(false);

  const entidadMap = Object.fromEntries(
    (contribuyentes ?? []).map((c: any) => [c.id, { rfc: c.rfc, nombre: c.nombre }])
  );

  const available = (contribuyentes ?? []).filter(
    (c: any) => !(entidadIds ?? []).includes(c.id)
  );

  const auxiliarUser = usuarios?.find((u: any) => u.id === sub.auxiliarUserId);

  const invalidate = () => {
    qc.invalidateQueries({ queryKey: ['cartera-entidades', sub.id] });
    qc.invalidateQueries({ queryKey: ['subcarteras'] });
    qc.invalidateQueries({ queryKey: ['carteras'] });
  };

  const handleAddEntidad = async () => {
    if (!selectedEntidadId) return;
    setBusy(true);
    try {
      await addEntidadToCartera(sub.id, selectedEntidadId);
      setSelectedEntidadId('');
      setAddingEntidad(false);
      invalidate();
    } finally { setBusy(false); }
  };

  const handleRemoveEntidad = async (entidadId: string) => {
    setBusy(true);
    try {
      await removeEntidadFromCartera(sub.id, entidadId);
      invalidate();
    } finally { setBusy(false); }
  };

  return (
    <div className="border rounded-lg p-3 bg-muted/20">
      <div className="flex items-center justify-between">
        <button onClick={() => setExpanded(!expanded)} className="flex items-center gap-2 flex-1 text-left">
          <UserCog className="h-4 w-4 text-muted-foreground" />
          <div>
            <span className="font-medium text-sm">{sub.nombre}</span>
            {auxiliarUser && (
              <span className="text-xs text-muted-foreground ml-2">({auxiliarUser.nombre})</span>
            )}
          </div>
          <span className="text-xs text-muted-foreground ml-auto mr-2">{sub.entidadesCount} RFCs</span>
          {expanded ? <ChevronUp className="h-3 w-3" /> : <ChevronDown className="h-3 w-3" />}
        </button>
        <button onClick={onDelete} className="text-muted-foreground hover:text-destructive p-1">
          <Trash2 className="h-3.5 w-3.5" />
        </button>
      </div>

      {expanded && (
        <div className="mt-3 space-y-2">
          {!addingEntidad && (
            <Button variant="ghost" size="sm" onClick={() => setAddingEntidad(true)} className="h-7 gap-1 text-xs">
              <Plus className="h-3 w-3" /> Asignar RFC
            </Button>
          )}
          {addingEntidad && (
            <div className="flex items-center gap-2">
              <select className="flex-1 rounded-md border bg-background px-2 py-1 text-sm" value={selectedEntidadId} onChange={e => setSelectedEntidadId(e.target.value)}>
                <option value="">-- Seleccionar RFC --</option>
                {available.map((c: any) => <option key={c.id} value={c.id}>{c.rfc} — {c.nombre}</option>)}
              </select>
              <Button size="sm" onClick={handleAddEntidad} disabled={!selectedEntidadId || busy}>Agregar</Button>
              <Button size="sm" variant="ghost" onClick={() => { setAddingEntidad(false); setSelectedEntidadId(''); }}>Cancelar</Button>
            </div>
          )}
          {isLoading ? (
            <p className="text-xs text-muted-foreground">Cargando...</p>
          ) : !entidadIds || entidadIds.length === 0 ? (
            <p className="text-xs text-muted-foreground">Sin RFCs asignados a esta subcartera.</p>
          ) : (
            <ul className="space-y-1">
              {entidadIds.map(id => {
                const info = entidadMap[id];
                return (
                  <li key={id} className="flex items-center justify-between bg-background rounded px-2 py-1 text-sm">
                    <span>{info ? <><span className="font-mono text-xs">{info.rfc}</span> <span className="text-muted-foreground">{info.nombre}</span></> : id}</span>
                    <button onClick={() => handleRemoveEntidad(id)} disabled={busy} className="text-muted-foreground hover:text-destructive"><X className="h-3 w-3" /></button>
                  </li>
                );
              })}
            </ul>
          )}
        </div>
      )}
    </div>
  );
}

/* ------------------------------------------------------------------ */
/* CarteraDetail                                                       */
/* ------------------------------------------------------------------ */
function CarteraDetail({ cartera, canEdit = true, canManageSubcarteras = true }: { cartera: Cartera; canEdit?: boolean; canManageSubcarteras?: boolean }) {
  const qc = useQueryClient();
  const { data: contribuyentes } = useContribuyentes();
  const { data: usuarios } = useUsuarios();
  const { data: entidadIds, isLoading: loadingEntidades } = useCarteraEntidades(cartera.id);
  const { data: subcarteras, isLoading: loadingSubs } = useSubcarteras(cartera.id);
  const createSub = useCreateSubcartera();

  const [addingEntidad, setAddingEntidad] = useState(false);
  const [selectedEntidadId, setSelectedEntidadId] = useState('');
  const [showCreateSub, setShowCreateSub] = useState(false);
  const [subForm, setSubForm] = useState({ nombre: '', auxiliarUserId: '' });
  const [busy, setBusy] = useState(false);

  const entidadMap = Object.fromEntries(
    (contribuyentes ?? []).map((c) => [c.id, { rfc: c.rfc, nombre: c.nombre }])
  );

  const available = (contribuyentes ?? []).filter(
    (c) => !(entidadIds ?? []).includes(c.id)
  );

  // Auxiliares available for subcarteras (those assigned to this supervisor)
  const auxiliares = (usuarios ?? []).filter((u: any) => u.role === 'auxiliar');

  const supervisorUser = usuarios?.find((u: any) => u.id === cartera.supervisorUserId);

  const invalidate = () => {
    qc.invalidateQueries({ queryKey: ['cartera-entidades', cartera.id] });
    qc.invalidateQueries({ queryKey: ['subcarteras', cartera.id] });
    qc.invalidateQueries({ queryKey: ['carteras'] });
  };

  const handleAddEntidad = async () => {
    if (!selectedEntidadId) return;
    setBusy(true);
    try {
      await addEntidadToCartera(cartera.id, selectedEntidadId);
      setSelectedEntidadId('');
      setAddingEntidad(false);
      invalidate();
    } finally { setBusy(false); }
  };

  const handleRemoveEntidad = async (entidadId: string) => {
    setBusy(true);
    try {
      await removeEntidadFromCartera(cartera.id, entidadId);
      invalidate();
    } finally { setBusy(false); }
  };

  const handleCreateSubcartera = async () => {
    if (!subForm.nombre.trim() || !subForm.auxiliarUserId) return;
    try {
      await createSub.mutateAsync({
        carteraId: cartera.id,
        nombre: subForm.nombre.trim(),
        auxiliarUserId: subForm.auxiliarUserId,
      });
      setSubForm({ nombre: '', auxiliarUserId: '' });
      setShowCreateSub(false);
    } catch (err: any) {
      alert(err.response?.data?.message || 'Error al crear subcartera');
    }
  };

  const handleDeleteSubcartera = async (subId: string) => {
    if (!confirm('¿Eliminar esta subcartera?')) return;
    try {
      const { deleteCartera } = await import('@/lib/api/carteras');
      await deleteCartera(subId);
      invalidate();
    } catch (err: any) {
      alert(err.response?.data?.message || 'Error al eliminar');
    }
  };

  return (
    <div className="border-t mt-4 pt-4 space-y-6">
      {/* Supervisor info */}
      {supervisorUser && (
        <div className="flex items-center gap-2 text-xs text-muted-foreground">
          <UserCog className="h-3.5 w-3.5" />
          Supervisor: <span className="font-medium text-foreground">{supervisorUser.nombre}</span> ({supervisorUser.email})
        </div>
      )}

      {/* ---- Contribuyentes ---- */}
      <div>
        <div className="flex items-center justify-between mb-2">
          <h3 className="text-sm font-semibold flex items-center gap-1.5">
            <Building2 className="h-4 w-4 text-muted-foreground" />
            Contribuyentes ({entidadIds?.length || 0})
          </h3>
          {canEdit && !addingEntidad && (
            <Button variant="ghost" size="sm" onClick={() => setAddingEntidad(true)} className="h-7 gap-1 text-xs">
              <Plus className="h-3 w-3" /> Agregar
            </Button>
          )}
        </div>

        {canEdit && addingEntidad && (
          <div className="flex items-center gap-2 mb-3">
            <select className="flex-1 rounded-md border bg-background px-3 py-1.5 text-sm" value={selectedEntidadId} onChange={e => setSelectedEntidadId(e.target.value)}>
              <option value="">-- Seleccionar RFC --</option>
              {available.map(c => <option key={c.id} value={c.id}>{c.rfc} — {c.nombre}</option>)}
            </select>
            <Button size="sm" onClick={handleAddEntidad} disabled={!selectedEntidadId || busy}>Agregar</Button>
            <Button size="sm" variant="ghost" onClick={() => { setAddingEntidad(false); setSelectedEntidadId(''); }}>Cancelar</Button>
          </div>
        )}

        {loadingEntidades ? (
          <p className="text-xs text-muted-foreground">Cargando...</p>
        ) : !entidadIds || entidadIds.length === 0 ? (
          <p className="text-xs text-muted-foreground">Sin contribuyentes asignados.</p>
        ) : (
          <ul className="space-y-1">
            {entidadIds.map(id => {
              const info = entidadMap[id];
              return (
                <li key={id} className="flex items-center justify-between rounded-md bg-muted/40 px-3 py-1.5 text-sm">
                  <span>{info ? <><span className="font-mono text-xs">{info.rfc}</span> <span className="text-muted-foreground ml-2">{info.nombre}</span></> : <span className="font-mono text-xs">{id}</span>}</span>
                  {canEdit && <button onClick={() => handleRemoveEntidad(id)} disabled={busy} className="text-muted-foreground hover:text-destructive ml-2"><X className="h-3.5 w-3.5" /></button>}
                </li>
              );
            })}
          </ul>
        )}
      </div>

      {/* ---- Subcarteras ---- */}
      <div>
        <div className="flex items-center justify-between mb-2">
          <h3 className="text-sm font-semibold flex items-center gap-1.5">
            <Users className="h-4 w-4 text-muted-foreground" />
            Subcarteras ({subcarteras?.length || 0})
          </h3>
          {canManageSubcarteras && !showCreateSub && (
            <Button variant="ghost" size="sm" onClick={() => setShowCreateSub(true)} className="h-7 gap-1 text-xs">
              <FolderPlus className="h-3 w-3" /> Nueva subcartera
            </Button>
          )}
        </div>

        {canManageSubcarteras && showCreateSub && (
          <div className="border rounded-lg p-3 mb-3 space-y-3 bg-muted/20">
            <div className="grid grid-cols-2 gap-3">
              <div>
                <Label className="text-xs">Nombre</Label>
                <Input value={subForm.nombre} onChange={e => setSubForm(p => ({ ...p, nombre: e.target.value }))} placeholder="Ej. Cartera de María" className="h-8 text-sm mt-1" />
              </div>
              <div>
                <Label className="text-xs">Auxiliar</Label>
                <select className="w-full h-8 rounded-md border bg-background px-2 text-sm mt-1" value={subForm.auxiliarUserId} onChange={e => setSubForm(p => ({ ...p, auxiliarUserId: e.target.value }))}>
                  <option value="">-- Seleccionar auxiliar --</option>
                  {auxiliares.map((u: any) => <option key={u.id} value={u.id}>{u.nombre} ({u.email})</option>)}
                </select>
              </div>
            </div>
            <div className="flex gap-2">
              <Button size="sm" onClick={handleCreateSubcartera} disabled={!subForm.nombre.trim() || !subForm.auxiliarUserId || createSub.isPending}>Crear</Button>
              <Button size="sm" variant="ghost" onClick={() => { setShowCreateSub(false); setSubForm({ nombre: '', auxiliarUserId: '' }); }}>Cancelar</Button>
            </div>
          </div>
        )}

        {loadingSubs ? (
          <p className="text-xs text-muted-foreground">Cargando...</p>
        ) : !subcarteras || subcarteras.length === 0 ? (
          <p className="text-xs text-muted-foreground">Sin subcarteras. Crea una para asignar RFCs a un auxiliar.</p>
        ) : (
          <div className="space-y-2">
            {subcarteras.map(sub => (
              <SubcarteraCard
                key={sub.id}
                sub={sub}
                usuarios={usuarios ?? []}
                contribuyentes={contribuyentes ?? []}
                onDelete={() => handleDeleteSubcartera(sub.id)}
              />
            ))}
          </div>
        )}
      </div>
    </div>
  );
}

/* ------------------------------------------------------------------ */
/* CarteraCard                                                         */
/* ------------------------------------------------------------------ */
function CarteraCard({ cartera, expanded, onToggle, onDelete, usuarios, canEdit, canManageSubcarteras }: {
  cartera: Cartera;
  expanded: boolean;
  onToggle: () => void;
  onDelete: () => void;
  usuarios: any[];
  canEdit: boolean;
  canManageSubcarteras: boolean;
}) {
  const supervisorUser = usuarios?.find((u: any) => u.id === cartera.supervisorUserId);
  return (
    <Card className={cn('transition-shadow', expanded && 'ring-1 ring-primary/30 shadow-md')}>
      <CardHeader className="pb-2">
        <div className="flex items-start justify-between gap-4">
          <button onClick={onToggle} className="flex-1 text-left flex items-center gap-2 group">
            <FolderOpen className={cn('h-5 w-5 flex-shrink-0 transition-colors', expanded ? 'text-primary' : 'text-muted-foreground group-hover:text-foreground')} />
            <div>
              <CardTitle className="text-base">{cartera.nombre}</CardTitle>
              {cartera.descripcion && <p className="text-xs text-muted-foreground mt-0.5">{cartera.descripcion}</p>}
            </div>
            {expanded ? <ChevronUp className="h-4 w-4 text-muted-foreground ml-auto" /> : <ChevronDown className="h-4 w-4 text-muted-foreground ml-auto" />}
          </button>
          {canEdit && (
            <Button variant="ghost" size="sm" onClick={onDelete} className="text-destructive hover:text-destructive flex-shrink-0 h-8 w-8 p-0">
              <Trash2 className="h-4 w-4" />
            </Button>
          )}
        </div>
        <div className="flex gap-4 mt-1 pl-7">
          {supervisorUser && (
            <span className="text-xs text-muted-foreground">
              <UserCog className="inline h-3 w-3 mr-1" />
              {supervisorUser.nombre}
            </span>
          )}
          <span className="text-xs text-muted-foreground">
            <Building2 className="inline h-3 w-3 mr-1" />
            {cartera.entidadesCount} RFCs
          </span>
          <span className="text-xs text-muted-foreground">
            <Users className="inline h-3 w-3 mr-1" />
            {cartera.subcarterasCount} subcarteras
          </span>
        </div>
      </CardHeader>
      {expanded && (
        <CardContent className="pt-0">
          <CarteraDetail cartera={cartera} canEdit={canEdit} canManageSubcarteras={canManageSubcarteras} />
        </CardContent>
      )}
    </Card>
  );
}

/* ------------------------------------------------------------------ */
/* Page                                                                */
/* ------------------------------------------------------------------ */
export default function CarterasPage() {
  const { user } = useAuthStore();
  const userRole = user?.role || 'visor';
  const canCreate = userRole === 'owner'; // Create top-level carteras
  const canEditCartera = userRole === 'owner'; // Edit/delete top-level carteras + add/remove RFCs
  const canManageSubcarteras = userRole === 'owner' || userRole === 'supervisor'; // Create subcarteras
  const isAuxiliar = userRole === 'auxiliar';
  const { data: carteras, isLoading } = useCarteras();
  const { data: supervisores } = useSupervisores();
  const { data: usuarios } = useUsuarios();
  const createMut = useCreateCartera();
  const deleteMut = useDeleteCartera();

  const [expandedId, setExpandedId] = useState<string | null>(null);
  const [showCreate, setShowCreate] = useState(false);
  const [form, setForm] = useState({ nombre: '', descripcion: '', supervisorUserId: '' });

  const hasSupervisores = supervisores && supervisores.length > 0;

  const resetForm = () => {
    setForm({ nombre: '', descripcion: '', supervisorUserId: '' });
    setShowCreate(false);
  };

  const handleCreate = async () => {
    if (!form.nombre.trim()) return;
    try {
      const supervisorUserId = form.supervisorUserId && form.supervisorUserId !== '__self__'
        ? form.supervisorUserId : undefined;
      const cartera = await createMut.mutateAsync({
        nombre: form.nombre.trim(),
        descripcion: form.descripcion.trim() || undefined,
        supervisorUserId,
      });
      resetForm();
      setExpandedId(cartera.id);
    } catch (err: any) {
      alert(err.response?.data?.message || 'Error al crear cartera');
    }
  };

  const handleDelete = async (cartera: Cartera) => {
    if (!confirm(`¿Eliminar la cartera "${cartera.nombre}"? Se eliminarán también sus subcarteras.`)) return;
    try {
      await deleteMut.mutateAsync(cartera.id);
      if (expandedId === cartera.id) setExpandedId(null);
    } catch (err: any) {
      alert(err.response?.data?.message || 'Error al eliminar cartera');
    }
  };

  return (
    <DashboardShell title="Carteras">
      <div className="max-w-3xl mx-auto space-y-6">
        {/* Header */}
        <div className="flex items-center justify-between">
          <div>
            <p className="text-sm text-muted-foreground">
              {isAuxiliar ? 'Carteras asignadas a ti' : 'Organiza contribuyentes en carteras y asigna subcarteras a cada auxiliar'}
            </p>
          </div>
          {canCreate && (
            <Button onClick={() => setShowCreate(true)} className="flex items-center gap-2">
              <Plus className="h-4 w-4" /> Nueva cartera
            </Button>
          )}
        </div>

        {/* List */}
        {isLoading ? (
          <p className="text-muted-foreground">Cargando...</p>
        ) : !carteras || carteras.length === 0 ? (
          <Card>
            <CardContent className="flex flex-col items-center justify-center py-12 text-center">
              <FolderOpen className="h-12 w-12 text-muted-foreground mb-4" />
              <h3 className="text-lg font-semibold">Sin carteras</h3>
              <p className="text-sm text-muted-foreground mt-1 mb-4">
                Crea la primera cartera para organizar tus contribuyentes.
              </p>
              <Button onClick={() => setShowCreate(true)}>Crear primera cartera</Button>
            </CardContent>
          </Card>
        ) : (
          <div className="space-y-3">
            {carteras.map(cartera => (
              <CarteraCard
                key={cartera.id}
                cartera={cartera}
                expanded={expandedId === cartera.id}
                onToggle={() => setExpandedId(expandedId === cartera.id ? null : cartera.id)}
                onDelete={() => handleDelete(cartera)}
                usuarios={usuarios ?? []}
                canEdit={canEditCartera}
                canManageSubcarteras={canManageSubcarteras}
              />
            ))}
          </div>
        )}

        {/* Create dialog */}
        <Dialog open={showCreate} onOpenChange={open => { if (!open) resetForm(); }}>
          <DialogContent>
            <DialogHeader>
              <DialogTitle>Nueva cartera</DialogTitle>
            </DialogHeader>
            <div className="space-y-4 py-4">
              <div>
                <Label>Nombre *</Label>
                <Input value={form.nombre} onChange={e => setForm(p => ({ ...p, nombre: e.target.value }))} placeholder="Ej. Clientes CDMX" autoFocus />
              </div>
              <div>
                <Label>Descripcion (opcional)</Label>
                <Input value={form.descripcion} onChange={e => setForm(p => ({ ...p, descripcion: e.target.value }))} placeholder="Descripcion breve" />
              </div>
              {hasSupervisores ? (
                <div>
                  <Label>Asignar a supervisor</Label>
                  <Select value={form.supervisorUserId} onValueChange={v => setForm(p => ({ ...p, supervisorUserId: v }))}>
                    <SelectTrigger>
                      <SelectValue placeholder="Yo mismo (Owner)" />
                    </SelectTrigger>
                    <SelectContent>
                      <SelectItem value="__self__">Yo mismo (Owner)</SelectItem>
                      {supervisores!.map(s => (
                        <SelectItem key={s.userId} value={s.userId}>{s.nombre} ({s.email})</SelectItem>
                      ))}
                    </SelectContent>
                  </Select>
                  <p className="text-xs text-muted-foreground mt-1">Si no seleccionas, la cartera se asigna a ti.</p>
                </div>
              ) : (
                <p className="text-xs text-muted-foreground border rounded-md p-3 bg-muted/30">
                  No hay supervisores registrados. La cartera se asignará a ti como owner.
                </p>
              )}
            </div>
            <DialogFooter>
              <Button variant="outline" onClick={resetForm}>Cancelar</Button>
              <Button onClick={handleCreate} disabled={!form.nombre.trim() || createMut.isPending}>
                {createMut.isPending ? 'Creando...' : 'Crear'}
              </Button>
            </DialogFooter>
          </DialogContent>
        </Dialog>
      </div>
    </DashboardShell>
  );
}