import { useEffect, useMemo, useRef, useState } from 'react';
import { Box, Button, Dialog, DialogContent, DialogTitle, IconButton, Typography,
         ToggleButton, ToggleButtonGroup } from '@mui/material';
import { DataGrid } from '@mui/x-data-grid';
import EditRoundedIcon from '@mui/icons-material/EditRounded';
import DeleteRoundedIcon from '@mui/icons-material/DeleteRounded';
import AddOrEditCategoryForm from './AddOrEditCategoryForm';
import CategoriesApi from '../../api/CategoriesApi';
import { useAuth } from '../../context/AuthContext';

export default function Categories() {
  const { user } = useAuth();
  const token = user?.thalosToken || localStorage.getItem('thalosToken');
  const api = useMemo(() => new CategoriesApi(token), [token]);

  const [rows, setRows] = useState([]);
  const [statusFilter, setStatusFilter] = useState('All'); // <- por defecto All
  const [open, setOpen] = useState(false);
  const [editingCategory, setEditingCategory] = useState(null);
  const [confirmOpen, setConfirmOpen] = useState(false);
  const [rowToDelete, setRowToDelete] = useState(null);
  const hasLoaded = useRef(false);

  const pageSize = 100; // Número de filas por página

  useEffect(() => {
    if (!hasLoaded.current) {
      loadData();
      hasLoaded.current = true;
    }
  }, []);

  const loadData = async () => {
    try {
      const data = await api.getAll();
      const list = Array.isArray(data) ? data : [];

      // Build a map of parentId -> array of child tagNames
      const parentToChildren = {};
      for (const item of list) {
        const parents = Array.isArray(item?.parentTagId) ? item.parentTagId : [];
        for (const pid of parents) {
          if (!parentToChildren[pid]) parentToChildren[pid] = [];
          if (item?.tagName) parentToChildren[pid].push(item.tagName);
        }
      }

      // Enrich each row with `material` (children whose parentTagId includes this _id)
      const enriched = list.map((r) => ({
        ...r,
        material: Array.isArray(parentToChildren[r?._id]) ? parentToChildren[r._id].join(', ') : '',
      }));

      setRows(enriched);
    } catch (e) {
      console.error('Failed to load categories:', e);
      setRows([]);
    }
  };

  const handleAddClick = () => {
    setEditingCategory(null);
    setOpen(true);
  };

  const handleEditClick = (params) => {
    const r = params?.row;
    if (!r) return;
    setEditingCategory({
      _Id: r._id || r._Id || '',
      id: r.id || r.Id || '',
      tagName: r.tagName || r.name || '',
      typeId: r.typeId || '',
      parentTagId: Array.isArray(r.parentTagId) ? r.parentTagId : [],
      slug: r.slug || '',
      displayOrder: Number(r.displayOrder ?? 0),
      icon: r.icon || '',
      status: r.status ?? 'Active',
    });
    setOpen(true);
  };

  const handleDeleteClick = (row) => {
    if (!row) return;
    setRowToDelete(row);
    setConfirmOpen(true);
  };

  const pickHexId = (r) =>
    [r?._id, r?._Id, r?.id, r?.Id]
      .filter(Boolean)
      .find((x) => typeof x === 'string' && /^[0-9a-f]{24}$/i.test(x)) || null;

  const confirmDelete = async () => {
    try {
      if (!rowToDelete) return;
      const hexId = pickHexId(rowToDelete);
      if (!hexId) {
        alert('No se encontró _id (24-hex) para ChangeStatus en esta fila.');
        return;
      }
      await api.changeStatus({ id: hexId, status: 'Inactive' });
      await loadData();
    } catch (e) {
      console.error('Delete failed:', e);
      alert('Delete failed. Revisa la consola para más detalles.');
    } finally {
      setConfirmOpen(false);
      setRowToDelete(null);
    }
  };

  const handleFormDone = async () => {
    await loadData();
    setOpen(false);
    setEditingCategory(null);
  };

  // --- FILTRO DE ESTADO ---
  const filteredRows = useMemo(() => {
    if (statusFilter === 'All') return rows;
    const want = String(statusFilter).toLowerCase();
    return rows.filter((r) => String(r?.status ?? 'Active').toLowerCase() === want);
  }, [rows, statusFilter]);

  const columns = [
    {
      field: 'actions',
      headerName: '',
      width: 130,
      sortable: false,
      filterable: false,
      disableExport: true,
      renderCell: (params) => (
        <Box display="flex" alignItems="center" justifyContent="flex-start" height="100%" gap={1}>
          <IconButton
            size="small"
            sx={{
              backgroundColor: '#DFCCBC',
              color: '#26201A',
              '&:hover': { backgroundColor: '#C2B2A4' },
              borderRadius: 2,
              p: 1,
            }}
            onClick={() => handleEditClick(params)}
          >
            <EditRoundedIcon fontSize="small" />
          </IconButton>
          <IconButton
            size="small"
            sx={{
              backgroundColor: '#FBE9E7',
              color: '#C62828',
              '&:hover': { backgroundColor: '#EF9A9A' },
              borderRadius: 2,
              p: 1,
            }}
            onClick={() => handleDeleteClick(params?.row)}
          >
            <DeleteRoundedIcon fontSize="small" />
          </IconButton>
        </Box>
      ),
    },
    { field: 'tagName', headerName: 'Name', flex: 1.2, minWidth: 180 },
    { field: 'slug', headerName: 'Slug', flex: 1.0, minWidth: 160 },
    { field: 'icon', headerName: 'Icon', flex: 0.7, minWidth: 120 },
    // New computed column
    { field: 'material', headerName: 'Material', flex: 1.2, minWidth: 200 },
    // Hidden audit columns
    {
      field: 'createdAt',
      headerName: 'Created Date',
      flex: 1.0,
      minWidth: 180,
      hide: true,
      valueFormatter: (p) => {
        const v = p?.value;
        return v ? new Date(v).toLocaleString() : '—';
      },
    },
    { field: 'createdBy', headerName: 'Created By', flex: 0.9, minWidth: 160, hide: true },
    {
      field: 'updatedAt',
      headerName: 'Updated Date',
      flex: 1.0,
      minWidth: 180,
      hide: true,
      valueFormatter: (p) => {
        const v = p?.value;
        return v ? new Date(v).toLocaleString() : '—';
      },
    },
    { field: 'updatedBy', headerName: 'Updated By', flex: 0.9, minWidth: 160, hide: true },
    { field: 'status', headerName: 'Status', flex: 0.7, minWidth: 120 },
  ];

  return (
    <Box
      sx={{
        height: 'calc(100vh - 64px - 64px)',
        display: 'flex',
        flexDirection: 'column',
        gap: 2,
      }}
    >
      <Box sx={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center', gap: 2, flexWrap: 'wrap' }}>
        <Typography variant="h6">Categories</Typography>

        <Box sx={{ display: 'flex', alignItems: 'center', gap: 2 }}>
          <ToggleButtonGroup
            value={statusFilter}
            exclusive
            onChange={(_, v) => v && setStatusFilter(v)}
            size="small"
          >
            <ToggleButton value="Active">Active</ToggleButton>
            <ToggleButton value="All">All</ToggleButton>
            <ToggleButton value="Inactive">Inactive</ToggleButton>
          </ToggleButtonGroup>

          <Button variant="contained" onClick={handleAddClick} className="button-gold">
            Add Category
          </Button>
        </Box>
      </Box>

      <Box sx={{ flex: 1, minHeight: 0 }}>
        <DataGrid
          rows={filteredRows}
          columns={columns}
          initialState={{ pagination: { paginationModel: { pageSize: pageSize } } }}
          pageSizeOptions={[pageSize]}
          disableColumnMenu
          getRowId={(r) => r?._id || r?.id}
          sx={{
            height: '100%',
            '& .MuiDataGrid-cell, & .MuiDataGrid-columnHeader': {
              display: 'flex',
              alignItems: 'center',
            },
            '& .MuiDataGrid-filler': {
              display: 'none',
            },
          }}
          slots={{
            noRowsOverlay: () => (
              <Box sx={{ p: 2 }}>No categories found. Try switching the status filter to "All".</Box>
            ),
          }}
        />
      </Box>

      <Dialog open={open} onClose={() => { setOpen(false); setEditingCategory(null); }} fullWidth>
        <DialogTitle>{editingCategory ? 'Edit Category' : 'Add Category'}</DialogTitle>
        <DialogContent>
          <AddOrEditCategoryForm
            initialData={editingCategory}
            onAdd={handleFormDone}
            onCancel={() => { setOpen(false); setEditingCategory(null); }}
          />
        </DialogContent>
      </Dialog>

      <Dialog open={confirmOpen} onClose={() => setConfirmOpen(false)}>
        <DialogTitle>Delete Category</DialogTitle>
        <DialogContent>
          <Box sx={{ display: 'flex', gap: 1, mt: 2, mb: 1 }}>
            <Button onClick={() => setConfirmOpen(false)}>Cancel</Button>
            <Button color="error" variant="contained" onClick={confirmDelete}>Delete</Button>
          </Box>
        </DialogContent>
      </Dialog>
    </Box>
  );
}