import React, { useState, useEffect } from "react";
import { Plus, Edit, Trash, CalendarDays } from "lucide-react";
import { format, parseISO } from "date-fns";
import { useQueryClient, useQuery, useMutation } from "@tanstack/react-query";
import { Button } from "@/components/ui/button";
import { Label } from "@/components/ui/label";
import { Input } from "@/components/ui/input";
import { Textarea } from "@/components/ui/textarea";
import { Calendar } from "@/components/ui/calendar";
import { Popover, PopoverContent, PopoverTrigger } from "@/components/ui/popover";
import { 
  Table, 
  TableBody, 
  TableCell, 
  TableHead, 
  TableHeader, 
  TableRow 
} from "@/components/ui/table";
import { toast } from "@/lib/custom-toast";
import { cn } from "@/lib/utils";
import { 
  MaintenanceAmcDate, 
  MaintenanceAmcDateCreateRequest, 
  MaintenanceAmcDateUpdateRequest 
} from "@/types";
import { maintenanceAmcDateService } from "@/lib/api";
import CustomDialog from "@/components/CustomDialog";

interface MaintenanceAmcDatesSectionProps {
  projectId: number;
}

export default function MaintenanceAmcDatesSection({ projectId }: MaintenanceAmcDatesSectionProps) {
  const queryClient = useQueryClient();
  const [open, setOpen] = useState(false);
  const [editMode, setEditMode] = useState(false);
  const [formData, setFormData] = useState<MaintenanceAmcDateCreateRequest>({
    projectId: projectId,
    maintenanceType: '',
    startDate: new Date().toISOString(),
    endDate: new Date().toISOString(),
    notes: ''
  });
  const [selectedId, setSelectedId] = useState<number | null>(null);
  const [startDateOpen, setStartDateOpen] = useState(false);
  const [endDateOpen, setEndDateOpen] = useState(false);

  // Fetch maintenance AMC dates for the project
  const { data: maintenanceAmcDates = [], isLoading } = useQuery({
    queryKey: ['maintenanceAmcDates', projectId],
    queryFn: () => maintenanceAmcDateService.getByProjectId(projectId),
    enabled: !!projectId
  });

  // Create mutation
  const createMutation = useMutation({
    mutationFn: (data: MaintenanceAmcDateCreateRequest) => maintenanceAmcDateService.create(data),
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['maintenanceAmcDates', projectId] });
      toast.success('Maintenance/AMC date added successfully');
      resetForm();
      setOpen(false);
    },
    onError: (error) => {
      console.error('Error creating maintenance AMC date:', error);
      toast.error('Failed to add maintenance/AMC date');
    }
  });

  // Update mutation
  const updateMutation = useMutation({
    mutationFn: (data: MaintenanceAmcDateUpdateRequest) => maintenanceAmcDateService.update(data),
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['maintenanceAmcDates', projectId] });
      toast.success('Maintenance/AMC date updated successfully');
      resetForm();
      setOpen(false);
    },
    onError: (error) => {
      console.error('Error updating maintenance AMC date:', error);
      toast.error('Failed to update maintenance/AMC date');
    }
  });

  // Delete mutation
  const deleteMutation = useMutation({
    mutationFn: (id: number) => maintenanceAmcDateService.delete(id),
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['maintenanceAmcDates', projectId] });
      toast.success('Maintenance/AMC date deleted successfully');
    },
    onError: (error) => {
      console.error('Error deleting maintenance AMC date:', error);
      toast.error('Failed to delete maintenance/AMC date');
    }
  });

  // Reset form data
  const resetForm = () => {
    setFormData({
      projectId: projectId,
      maintenanceType: '',
      startDate: new Date().toISOString(),
      endDate: new Date().toISOString(),
      notes: ''
    });
    setEditMode(false);
    setSelectedId(null);
  };

  // Handle submit
  const handleSubmit = (e: React.FormEvent) => {
    e.preventDefault();
    
    if (!formData.maintenanceType.trim()) {
      toast.error('Maintenance Type is required');
      return;
    }

    if (editMode && selectedId) {
      updateMutation.mutate({
        ...formData,
        maintenanceId: selectedId
      } as MaintenanceAmcDateUpdateRequest);
    } else {
      createMutation.mutate(formData);
    }
  };

  // Handle edit button click
  const handleEdit = (item: MaintenanceAmcDate) => {
    setEditMode(true);
    setSelectedId(item.maintenanceId);
    setFormData({
      projectId: item.projectId,
      maintenanceType: item.maintenanceType,
      startDate: item.startDate,
      endDate: item.endDate,
      notes: item.notes
    });
    setOpen(true);
  };

  // Handle delete button click
  const handleDelete = (id: number) => {
    if (confirm('Are you sure you want to delete this maintenance/AMC date?')) {
      deleteMutation.mutate(id);
    }
  };

  // Handle form input changes
  const handleInputChange = (e: React.ChangeEvent<HTMLInputElement | HTMLTextAreaElement>) => {
    const { name, value } = e.target;
    setFormData(prev => ({ ...prev, [name]: value }));
  };

  // Handle date changes
  const handleStartDateChange = (date: Date | undefined) => {
    if (date) {
      setFormData(prev => ({ ...prev, startDate: date.toISOString() }));
    }
  };

  const handleEndDateChange = (date: Date | undefined) => {
    if (date) {
      setFormData(prev => ({ ...prev, endDate: date.toISOString() }));
    }
  };

  // Format date for display
  const formatDate = (dateString: string) => {
    try {
      return format(parseISO(dateString), 'PPP');
    } catch (error) {
      console.error('Error formatting date:', error);
      return 'Invalid date';
    }
  };

  return (
    <div className="space-y-4">
      <div className="flex items-center justify-between">
        <h3 className="text-lg font-medium">Maintenance & AMC Dates</h3>
        <Button 
          size="sm" 
          onClick={() => {
            resetForm();
            setOpen(true);
          }}
        >
          <Plus className="h-4 w-4 mr-2" />
          Add New
        </Button>
      </div>
      
      <CustomDialog
        isOpen={open}
        onClose={() => setOpen(false)}
        title={`${editMode ? 'Edit' : 'Add'} Maintenance or AMC Date`}
      >
        <form onSubmit={handleSubmit} className="space-y-4">
          <div className="space-y-2">
            <Label htmlFor="maintenanceType">Maintenance Type</Label>
            <Input
              id="maintenanceType"
              name="maintenanceType"
              value={formData.maintenanceType}
              onChange={handleInputChange}
              placeholder="e.g. Regular Maintenance, AMC, Service"
              required
            />
          </div>
          
          <div className="grid grid-cols-2 gap-4">
            <div className="space-y-2">
              <Label htmlFor="startDate">Start Date</Label>
              <Popover open={startDateOpen} onOpenChange={setStartDateOpen}>
                <PopoverTrigger asChild>
                  <Button
                    variant="outline"
                    className={cn(
                      "w-full justify-start text-left font-normal",
                      !formData.startDate && "text-muted-foreground"
                    )}
                  >
                    <CalendarDays className="mr-2 h-4 w-4" />
                    {formData.startDate ? formatDate(formData.startDate) : <span>Select date</span>}
                  </Button>
                </PopoverTrigger>
                <PopoverContent className="w-auto p-0">
                  <Calendar
                    mode="single"
                    selected={formData.startDate ? parseISO(formData.startDate) : undefined}
                    onSelect={(date) => {
                      handleStartDateChange(date);
                      setStartDateOpen(false);
                    }}
                    initialFocus
                  />
                </PopoverContent>
              </Popover>
            </div>
            
            <div className="space-y-2">
              <Label htmlFor="endDate">End Date</Label>
              <Popover open={endDateOpen} onOpenChange={setEndDateOpen}>
                <PopoverTrigger asChild>
                  <Button
                    variant="outline"
                    className={cn(
                      "w-full justify-start text-left font-normal",
                      !formData.endDate && "text-muted-foreground"
                    )}
                  >
                    <CalendarDays className="mr-2 h-4 w-4" />
                    {formData.endDate ? formatDate(formData.endDate) : <span>Select date</span>}
                  </Button>
                </PopoverTrigger>
                <PopoverContent className="w-auto p-0">
                  <Calendar
                    mode="single"
                    selected={formData.endDate ? parseISO(formData.endDate) : undefined}
                    onSelect={(date) => {
                      handleEndDateChange(date);
                      setEndDateOpen(false);
                    }}
                    initialFocus
                  />
                </PopoverContent>
              </Popover>
            </div>
          </div>
          
          <div className="space-y-2">
            <Label htmlFor="notes">Notes</Label>
            <Textarea
              id="notes"
              name="notes"
              value={formData.notes}
              onChange={handleInputChange}
              placeholder="Additional details or notes"
              rows={3}
            />
          </div>
          
          <div className="flex justify-end gap-2 pt-2">
            <Button type="button" variant="outline" onClick={() => setOpen(false)}>
              Cancel
            </Button>
            <Button type="submit">
              {editMode ? 'Update' : 'Add'}
            </Button>
          </div>
        </form>
      </CustomDialog>
      
      {isLoading ? (
        <div className="text-center py-4">Loading...</div>
      ) : maintenanceAmcDates.length === 0 ? (
        <div className="text-center py-8 border rounded-md bg-muted/20">
          <CalendarDays className="h-8 w-8 mx-auto mb-2 text-muted-foreground" />
          <p className="text-muted-foreground">No maintenance or AMC dates have been added yet.</p>
        </div>
      ) : (
        <Table>
          <TableHeader>
            <TableRow>
              <TableHead>Type</TableHead>
              <TableHead>Start Date</TableHead>
              <TableHead>End Date</TableHead>
              <TableHead>Notes</TableHead>
              <TableHead className="text-right">Actions</TableHead>
            </TableRow>
          </TableHeader>
          <TableBody>
            {maintenanceAmcDates.map(item => (
              <TableRow key={item.maintenanceId}>
                <TableCell className="font-medium">{item.maintenanceType}</TableCell>
                <TableCell>{formatDate(item.startDate)}</TableCell>
                <TableCell>{formatDate(item.endDate)}</TableCell>
                <TableCell className="max-w-[200px] truncate">{item.notes}</TableCell>
                <TableCell className="text-right">
                  <div className="flex justify-end gap-2">
                    <Button 
                      size="icon" 
                      variant="ghost" 
                      onClick={() => handleEdit(item)}
                    >
                      <Edit className="h-4 w-4" />
                    </Button>
                    <Button 
                      size="icon" 
                      variant="ghost" 
                      className="text-destructive" 
                      onClick={() => handleDelete(item.maintenanceId)}
                    >
                      <Trash className="h-4 w-4" />
                    </Button>
                  </div>
                </TableCell>
              </TableRow>
            ))}
          </TableBody>
        </Table>
      )}
    </div>
  );
}