import { useState } from 'react';
import { useTranslation } from 'react-i18next';
import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
import {
  MapPin,
  Search,
  Plus,
  Pencil,
  Trash2,
  Check,
  X,
  ChevronLeft,
  ChevronRight,
} from 'lucide-react';
import { Input } from '@/components/ui/input';
import { Button } from '@/components/ui/button';
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from '@/components/ui/select';
import {
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableHeader,
  TableRow,
} from '@/components/ui/table';
import { cn } from '@/lib/utils';
import { api } from '@/services/api';
import { toast } from 'sonner';

interface BranchData {
  id: number;
  email: string;
  branch: string;
  active: boolean;
  updatedAt: string;
}

const BRANCH_COLORS = [
  'bg-blue-100 text-blue-600',
  'bg-indigo-100 text-indigo-600',
  'bg-purple-100 text-purple-600',
  'bg-teal-100 text-teal-600',
  'bg-amber-100 text-amber-600',
  'bg-pink-100 text-pink-600',
  'bg-emerald-100 text-emerald-600',
  'bg-cyan-100 text-cyan-600',
];

function getBranchColor(name: string): string {
  let hash = 0;
  for (let i = 0; i < name.length; i++) {
    hash = name.charCodeAt(i) + ((hash << 5) - hash);
  }
  return BRANCH_COLORS[Math.abs(hash) % BRANCH_COLORS.length];
}

const PER_PAGE = 100;

export default function BranchTable() {
  const { t } = useTranslation();
  const queryClient = useQueryClient();
  const [search, setSearch] = useState('');
  const [statusFilter, setStatusFilter] = useState('all');
  const [currentPage, setCurrentPage] = useState(1);

  // Add form state
  const [showAddForm, setShowAddForm] = useState(false);
  const [addEmail, setAddEmail] = useState('');
  const [addBranch, setAddBranch] = useState('');

  // Edit state
  const [editingId, setEditingId] = useState<number | null>(null);
  const [editEmail, setEditEmail] = useState('');
  const [editBranch, setEditBranch] = useState('');

  // Delete confirmation state
  const [deletingId, setDeletingId] = useState<number | null>(null);

  // Fetch branches
  const { data, isLoading, isError } = useQuery({
    queryKey: ['branches'],
    queryFn: () => api.get<{ branches: BranchData[] }>('/settings/branches'),
    retry: false,
  });

  const allBranches = data?.branches ?? [];

  // Filter branches
  const filtered = allBranches.filter((b) => {
    const matchesSearch =
      !search ||
      b.email.toLowerCase().includes(search.toLowerCase()) ||
      b.branch.toLowerCase().includes(search.toLowerCase());
    const matchesStatus =
      statusFilter === 'all' ||
      (statusFilter === 'active' && b.active) ||
      (statusFilter === 'inactive' && !b.active);
    return matchesSearch && matchesStatus;
  });

  const totalPages = Math.ceil(filtered.length / PER_PAGE);
  const paginated = filtered.slice(
    (currentPage - 1) * PER_PAGE,
    currentPage * PER_PAGE
  );
  const startItem = filtered.length > 0 ? (currentPage - 1) * PER_PAGE + 1 : 0;
  const endItem = Math.min(currentPage * PER_PAGE, filtered.length);

  // Mutations
  const addMutation = useMutation({
    mutationFn: (data: { email: string; branch: string }) =>
      api.post('/settings/branches', data),
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['branches'] });
      setShowAddForm(false);
      setAddEmail('');
      setAddBranch('');
      toast.success('Succursale ajoutée');
    },
    onError: (err: Error) => {
      toast.error(err.message);
    },
  });

  const updateMutation = useMutation({
    mutationFn: ({ id, ...data }: { id: number; email?: string; branch?: string; active?: boolean }) =>
      api.put(`/settings/branches/${id}`, data),
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['branches'] });
      setEditingId(null);
      toast.success('Succursale mise à jour');
    },
    onError: (err: Error) => {
      toast.error(err.message);
    },
  });

  const deleteMutation = useMutation({
    mutationFn: (id: number) => api.delete(`/settings/branches/${id}`),
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['branches'] });
      setDeletingId(null);
      toast.success('Succursale supprimée');
    },
    onError: (err: Error) => {
      toast.error(err.message);
    },
  });

  const handleAdd = () => {
    if (!addEmail || !addBranch) return;
    addMutation.mutate({ email: addEmail, branch: addBranch });
  };

  const startEdit = (b: BranchData) => {
    setEditingId(b.id);
    setEditEmail(b.email);
    setEditBranch(b.branch);
  };

  const handleEdit = () => {
    if (editingId === null || !editEmail || !editBranch) return;
    updateMutation.mutate({ id: editingId, email: editEmail, branch: editBranch });
  };

  const toggleActive = (b: BranchData) => {
    updateMutation.mutate({ id: b.id, active: !b.active });
  };

  return (
    <div className="flex flex-col gap-6">
      {/* Search & Filters */}
      <div className="flex flex-col gap-4 rounded-xl bg-card p-4 shadow-sm sm:flex-row sm:items-center sm:justify-between border border-border">
        <div className="relative w-full max-w-md">
          <div className="pointer-events-none absolute inset-y-0 left-0 flex items-center pl-3">
            <Search className="h-4 w-4 text-muted-foreground" />
          </div>
          <Input
            className="pl-10 bg-slate-50 border-slate-300"
            placeholder={t('branches.searchPlaceholder')}
            value={search}
            onChange={(e) => {
              setSearch(e.target.value);
              setCurrentPage(1);
            }}
          />
        </div>
        <div className="flex items-center gap-3">
          <div className="flex items-center gap-2">
            <label className="text-sm font-medium text-slate-700" htmlFor="status-filter">
              {t('branches.statusLabel')}:
            </label>
            <Select value={statusFilter} onValueChange={(v) => { setStatusFilter(v); setCurrentPage(1); }}>
              <SelectTrigger className="w-[130px] bg-slate-50 border-slate-300">
                <SelectValue />
              </SelectTrigger>
              <SelectContent>
                <SelectItem value="all">{t('branches.statusAll')}</SelectItem>
                <SelectItem value="active">{t('branches.statusActive')}</SelectItem>
                <SelectItem value="inactive">{t('branches.statusInactive')}</SelectItem>
              </SelectContent>
            </Select>
          </div>
          <Button
            size="sm"
            className="gap-2"
            onClick={() => setShowAddForm(!showAddForm)}
          >
            <Plus className="h-4 w-4" />
            {t('branches.addBranch')}
          </Button>
        </div>
      </div>

      {/* Add form */}
      {showAddForm && (
        <div className="flex items-end gap-3 rounded-xl bg-blue-50 border border-blue-200 p-4">
          <div className="flex-1 space-y-1">
            <label className="text-xs font-semibold text-slate-600 uppercase tracking-wide">
              {t('branches.colEmail')}
            </label>
            <Input
              placeholder="email@iccameriques.org"
              value={addEmail}
              onChange={(e) => setAddEmail(e.target.value)}
              className="bg-white"
            />
          </div>
          <div className="flex-1 space-y-1">
            <label className="text-xs font-semibold text-slate-600 uppercase tracking-wide">
              {t('branches.colBranch')}
            </label>
            <Input
              placeholder="Ville"
              value={addBranch}
              onChange={(e) => setAddBranch(e.target.value)}
              className="bg-white"
            />
          </div>
          <Button onClick={handleAdd} disabled={addMutation.isPending} className="gap-2">
            <Check className="h-4 w-4" />
            {t('common.save')}
          </Button>
          <Button
            variant="outline"
            onClick={() => { setShowAddForm(false); setAddEmail(''); setAddBranch(''); }}
          >
            {t('common.cancel')}
          </Button>
        </div>
      )}

      {/* Table */}
      <div className="overflow-hidden rounded-xl border border-border bg-card shadow-sm">
        <div className="overflow-x-auto">
          <Table>
            <TableHeader>
              <TableRow className="bg-slate-50">
                <TableHead className="font-semibold text-xs uppercase text-slate-700">
                  {t('branches.colEmail')}
                </TableHead>
                <TableHead className="font-semibold text-xs uppercase text-slate-700">
                  {t('branches.colBranch')}
                </TableHead>
                <TableHead className="font-semibold text-xs uppercase text-slate-700">
                  {t('branches.colStatus')}
                </TableHead>
                <TableHead className="font-semibold text-xs uppercase text-slate-700 text-right">
                  {t('branches.colActions')}
                </TableHead>
              </TableRow>
            </TableHeader>
            <TableBody>
              {isLoading ? (
                Array.from({ length: 5 }).map((_, i) => (
                  <TableRow key={i} className="animate-pulse">
                    {Array.from({ length: 4 }).map((_, j) => (
                      <TableCell key={j} className="py-4">
                        <div className="h-4 bg-slate-100 rounded w-32" />
                      </TableCell>
                    ))}
                  </TableRow>
                ))
              ) : isError ? (
                <TableRow>
                  <TableCell colSpan={4} className="py-12 text-center text-red-500">
                    Veuillez vous connecter pour voir les succursales.
                  </TableCell>
                </TableRow>
              ) : paginated.length === 0 ? (
                <TableRow>
                  <TableCell colSpan={4} className="py-16 text-center">
                    <div className="flex flex-col items-center gap-3">
                      <div className="h-12 w-12 rounded-xl bg-slate-100 flex items-center justify-center">
                        <MapPin className="h-6 w-6 text-slate-400" />
                      </div>
                      <div>
                        <p className="text-sm font-medium text-slate-700">
                          {search ? t('transactions.noResults') : t('branches.emptyTitle', 'No branches configured yet')}
                        </p>
                        <p className="text-xs text-slate-500 mt-1">
                          {search ? '' : t('branches.emptyDesc', 'Add a branch to map recipient emails to branch names')}
                        </p>
                      </div>
                      {!search && !showAddForm && (
                        <Button size="sm" className="gap-2 mt-2" onClick={() => setShowAddForm(true)}>
                          <Plus className="h-4 w-4" />
                          {t('branches.addBranch')}
                        </Button>
                      )}
                    </div>
                  </TableCell>
                </TableRow>
              ) : (
                paginated.map((branch) => (
                  <TableRow
                    key={branch.id}
                    className="bg-white hover:bg-slate-50 transition-colors"
                  >
                    {editingId === branch.id ? (
                      <>
                        <TableCell>
                          <Input
                            value={editEmail}
                            onChange={(e) => setEditEmail(e.target.value)}
                            className="h-8 text-sm"
                          />
                        </TableCell>
                        <TableCell>
                          <Input
                            value={editBranch}
                            onChange={(e) => setEditBranch(e.target.value)}
                            className="h-8 text-sm"
                          />
                        </TableCell>
                        <TableCell>
                          <button
                            onClick={() => toggleActive(branch)}
                            className="cursor-pointer"
                          >
                            {branch.active ? (
                              <span className="inline-flex items-center rounded-full bg-emerald-100 px-2.5 py-0.5 text-xs font-medium text-emerald-800">
                                <span className="mr-1.5 h-1.5 w-1.5 rounded-full bg-emerald-500" />
                                {t('branches.statusActive')}
                              </span>
                            ) : (
                              <span className="inline-flex items-center rounded-full bg-slate-100 px-2.5 py-0.5 text-xs font-medium text-slate-600">
                                <span className="mr-1.5 h-1.5 w-1.5 rounded-full bg-slate-400" />
                                {t('branches.statusInactive')}
                              </span>
                            )}
                          </button>
                        </TableCell>
                        <TableCell className="text-right">
                          <button
                            onClick={handleEdit}
                            className="rounded-lg p-2 text-emerald-600 hover:bg-emerald-50 transition-colors"
                          >
                            <Check className="h-4 w-4" />
                          </button>
                          <button
                            onClick={() => setEditingId(null)}
                            className="rounded-lg p-2 text-slate-500 hover:bg-slate-100 transition-colors"
                          >
                            <X className="h-4 w-4" />
                          </button>
                        </TableCell>
                      </>
                    ) : (
                      <>
                        <TableCell className="font-medium text-slate-900 whitespace-nowrap">
                          {branch.email}
                        </TableCell>
                        <TableCell>
                          <div className="flex items-center gap-2">
                            <div
                              className={cn(
                                'flex h-8 w-8 items-center justify-center rounded-full',
                                getBranchColor(branch.branch)
                              )}
                            >
                              <MapPin className="h-3.5 w-3.5" />
                            </div>
                            <span className="text-slate-600">{branch.branch}</span>
                          </div>
                        </TableCell>
                        <TableCell>
                          <button
                            onClick={() => toggleActive(branch)}
                            className="cursor-pointer"
                          >
                            {branch.active ? (
                              <span className="inline-flex items-center rounded-full bg-emerald-100 px-2.5 py-0.5 text-xs font-medium text-emerald-800 hover:bg-emerald-200 transition-colors">
                                <span className="mr-1.5 h-1.5 w-1.5 rounded-full bg-emerald-500" />
                                {t('branches.statusActive')}
                              </span>
                            ) : (
                              <span className="inline-flex items-center rounded-full bg-slate-100 px-2.5 py-0.5 text-xs font-medium text-slate-600 hover:bg-slate-200 transition-colors">
                                <span className="mr-1.5 h-1.5 w-1.5 rounded-full bg-slate-400" />
                                {t('branches.statusInactive')}
                              </span>
                            )}
                          </button>
                        </TableCell>
                        <TableCell className="text-right">
                          {deletingId === branch.id ? (
                            <>
                              <Button
                                size="sm"
                                variant="outline"
                                className="h-8 text-xs border-red-300 text-red-700 hover:bg-red-50 mr-1"
                                onClick={() => deleteMutation.mutate(branch.id)}
                                disabled={deleteMutation.isPending}
                              >
                                Confirmer
                              </Button>
                              <Button
                                size="sm"
                                variant="outline"
                                className="h-8 text-xs"
                                onClick={() => setDeletingId(null)}
                              >
                                {t('common.cancel')}
                              </Button>
                            </>
                          ) : (
                            <>
                              <button
                                onClick={() => startEdit(branch)}
                                className="rounded-lg p-2 text-slate-500 hover:bg-slate-100 hover:text-primary transition-colors"
                              >
                                <Pencil className="h-4 w-4" />
                              </button>
                              <button
                                onClick={() => setDeletingId(branch.id)}
                                className="rounded-lg p-2 text-slate-500 hover:bg-slate-100 hover:text-red-600 transition-colors"
                              >
                                <Trash2 className="h-4 w-4" />
                              </button>
                            </>
                          )}
                        </TableCell>
                      </>
                    )}
                  </TableRow>
                ))
              )}
            </TableBody>
          </Table>
        </div>

        {/* Pagination */}
        {filtered.length > 0 && (
          <div className="flex items-center justify-between border-t border-border bg-white px-4 py-3 sm:px-6">
            <div className="hidden sm:flex sm:flex-1 sm:items-center sm:justify-between">
              <p className="text-sm text-slate-700">
                {t('transactions.showing')}{' '}
                <span className="font-medium text-slate-900">{startItem}</span>{' '}
                {t('transactions.to')}{' '}
                <span className="font-medium text-slate-900">{endItem}</span>{' '}
                {t('transactions.of')}{' '}
                <span className="font-medium text-slate-900">{filtered.length}</span>{' '}
                {t('transactions.results')}
              </p>
              {totalPages > 1 && (
                <nav className="isolate inline-flex -space-x-px rounded-md shadow-sm">
                  <button
                    className="relative inline-flex items-center rounded-l-md px-2 py-2 text-slate-400 ring-1 ring-inset ring-slate-300 hover:bg-slate-50 disabled:opacity-50"
                    disabled={currentPage === 1}
                    onClick={() => setCurrentPage((p) => Math.max(1, p - 1))}
                  >
                    <ChevronLeft className="h-4 w-4" />
                  </button>
                  {Array.from({ length: totalPages }, (_, i) => i + 1).map((page) => (
                    <button
                      key={page}
                      className={cn(
                        'relative inline-flex items-center px-4 py-2 text-sm font-semibold',
                        page === currentPage
                          ? 'z-10 bg-primary text-white'
                          : 'text-slate-900 ring-1 ring-inset ring-slate-300 hover:bg-slate-50'
                      )}
                      onClick={() => setCurrentPage(page)}
                    >
                      {page}
                    </button>
                  ))}
                  <button
                    className="relative inline-flex items-center rounded-r-md px-2 py-2 text-slate-400 ring-1 ring-inset ring-slate-300 hover:bg-slate-50 disabled:opacity-50"
                    disabled={currentPage === totalPages}
                    onClick={() => setCurrentPage((p) => Math.min(totalPages, p + 1))}
                  >
                    <ChevronRight className="h-4 w-4" />
                  </button>
                </nav>
              )}
            </div>
          </div>
        )}
      </div>
    </div>
  );
}