import React, { useEffect, useState } from 'react';
import { useNavigate, useParams } from 'react-router-dom';
import { ArrowLeft, CheckCircle } from 'lucide-react';
import { MainLayout } from '@/components/layout/MainLayout.tsx';
import PageHeader from '@/components/layout/PageHeader.tsx';
import Button from '@/components/ui/Button.tsx';
import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/Card.tsx';
import Input from '@/components/ui/Input.tsx';
import { Container, Flex, Stack } from '@/components/ui/layout';
import Select from '@/components/ui/Select.tsx';
import Spinner from '@/components/ui/Spinner.tsx';
import Textarea from '@/components/ui/Textarea.tsx';
import { useDynamicSectors } from '@/hooks/useDynamicSectors.ts';
import { useAuth } from '@/contexts/AuthContext.tsx';
import { useCreateOrganization, useOrganization } from '@/hooks/api/useOrganizationsAPI.ts';
import { useTranslation } from '@/hooks/useI18n.tsx';
import { useNavigation } from '@/hooks/useNavigation.tsx';
import { isValidEmail, sanitizeInput, validateInput } from '@/lib/api-client.ts';
import { getTranslatedSectorName } from '@/lib/sector-mapper.ts';
import { getOrganizationSubtypeLabel } from '@/schemas/organizationSubtype.ts';

const OrganizationEditPage = () => {
  const { id } = useParams<{ id: string }>();
  const navigate = useNavigate();
  const { t } = useTranslation();
  const { handleBackNavigation, handleFooterNavigate } = useNavigation();
  const { user, isAuthenticated } = useAuth();

  const isEditing = Boolean(id);
  const pageTitle = isEditing
    ? t('organizationEdit.editTitle')
    : t('organizationEdit.createTitle');
  const pageSubtitle = isEditing
    ? t('organizationEdit.editSubtitle')
    : t('organizationEdit.createSubtitle');

  // Data fetching
  const { data: existingOrganization, isLoading: isLoadingOrg, error: orgError } = useOrganization(id || '');
  const { sectors: availableSectors } = useDynamicSectors(50); // Get all sectors for editing

  // Mutations
  const createOrgMutation = useCreateOrganization();

  // Form state
  const [formData, setFormData] = useState({
    name: '',
    sector: '',
    description: '',
    subtype: '',
    website: '',
    address: '',
  });
  const [error, setError] = useState<string | null>(null);
  const [isSubmitting, setIsSubmitting] = useState(false);

  // Redirect to login if not authenticated
  useEffect(() => {
    if (!isAuthenticated) {
      navigate('/login');
    }
  }, [isAuthenticated, navigate]);

  // Initialize form with existing data when editing
  useEffect(() => {
    if (isEditing && existingOrganization) {
      setFormData({
        name: existingOrganization.Name || '',
        sector: existingOrganization.Sector || '',
        description: existingOrganization.Description || '',
        subtype: existingOrganization.Subtype || '',
        website: existingOrganization.Website || '',
        address: existingOrganization.Address || '',
      });
    }
  }, [isEditing, existingOrganization]);

  const handleInputChange = (field: string, value: string) => {
    setFormData(prev => ({ ...prev, [field]: value }));
  };

  const handleSubmit = async (e: React.FormEvent) => {
    e.preventDefault();

    if (!user) return;

    try {
      setError(null);
      setIsSubmitting(true);

      // Input validation and sanitization
      const sanitizedName = sanitizeInput(formData.name.trim());
      const sanitizedDescription = sanitizeInput(formData.description.trim());
      const sanitizedWebsite = formData.website.trim();
      const sanitizedAddress = sanitizeInput(formData.address.trim());

      // Validate organization name
      const nameValidation = validateInput(sanitizedName, {
        minLength: 2,
        maxLength: 100,
        allowSpecialChars: true,
        allowNumbers: true
      });
      if (!nameValidation.isValid) {
        throw new Error(`Organization name: ${nameValidation.error}`);
      }

      // Validate sector selection
      if (!formData.sector) {
        throw new Error('Please select an organization sector');
      }

      // Validate description (optional but if provided, check length)
      if (sanitizedDescription && sanitizedDescription.length > 0) {
        const descValidation = validateInput(sanitizedDescription, {
          minLength: 0,
          maxLength: 500,
          allowSpecialChars: true,
          allowNumbers: true
        });
        if (!descValidation.isValid) {
          throw new Error(`Description: ${descValidation.error}`);
        }
      }

      // Validate website URL if provided
      if (sanitizedWebsite && !isValidEmail(sanitizedWebsite) && !sanitizedWebsite.startsWith('http')) {
        // If it looks like an email, validate as email
        if (sanitizedWebsite.includes('@')) {
          if (!isValidEmail(sanitizedWebsite)) {
            throw new Error('Please enter a valid email address or website URL');
          }
        } else {
          throw new Error('Please enter a valid website URL (starting with http:// or https://)');
        }
      }

      // Validate address if provided
      if (sanitizedAddress && sanitizedAddress.length > 0) {
        const addressValidation = validateInput(sanitizedAddress, {
          minLength: 0,
          maxLength: 200,
          allowSpecialChars: true,
          allowNumbers: true
        });
        if (!addressValidation.isValid) {
          throw new Error(`Address: ${addressValidation.error}`);
        }
      }

      // Create organization with sanitized data
      const orgPayload = {
        name: sanitizedName,
        sector: formData.sector,
        description: sanitizedDescription,
        subtype: formData.subtype || 'commercial',
        website: sanitizedWebsite,
        address: sanitizedAddress,
      };

      const newOrg = await createOrgMutation.mutateAsync(orgPayload);

      // Navigate to the organization page
      navigate(`/organization/${newOrg.ID}`);
    } catch (err) {
      console.error('Error saving organization:', err);
      setError(err instanceof Error ? err.message : 'Failed to save organization');
    } finally {
      setIsSubmitting(false);
    }
  };

  const handleCancel = () => {
    if (isEditing) {
      navigate(`/organization/${id}`);
    } else {
      navigate('/organizations');
    }
  };

  // Sector options
  const sectorOptions = availableSectors.map(sector => ({
    value: sector.backendName,
    label: t(sector.nameKey),
  }));

  // Subtype options (simplified)
  const subtypeOptions = [
    { value: 'commercial', label: getOrganizationSubtypeLabel('commercial') },
    { value: 'government', label: getOrganizationSubtypeLabel('government') },
    { value: 'other', label: getOrganizationSubtypeLabel('other') },
  ];

  if (isLoadingOrg && isEditing) {
    return (
      <MainLayout onNavigate={handleFooterNavigate} className="bg-muted/30">
        <Container size="2xl" className="py-8 sm:py-12">
          <div className="flex items-center justify-center min-h-96">
            <div className="text-center">
              <Spinner className="h-8 w-8 mx-auto mb-4" />
              <p className="text-muted-foreground">{t('organizationEdit.loading')}</p>
            </div>
          </div>
        </Container>
      </MainLayout>
    );
  }

  if (orgError && isEditing) {
    return (
      <MainLayout onNavigate={handleFooterNavigate} className="bg-muted/30">
        <Container size="2xl" className="py-8 sm:py-12">
          <PageHeader
            title={t('organizationEdit.errorTitle')}
            subtitle={t('organizationEdit.errorSubtitle')}
            onBack={handleBackNavigation}
          />
          <Card>
            <CardContent className="py-12">
              <div className="text-center">
                <p className="text-destructive mb-4">{orgError.message}</p>
                <Button onClick={handleBackNavigation}>
                  <ArrowLeft className="h-4 mr-2 text-current w-4" />
                  {t('common.back')}
                </Button>
              </div>
            </CardContent>
          </Card>
        </Container>
      </MainLayout>
    );
  }

  return (
    <MainLayout onNavigate={handleFooterNavigate} className="bg-muted/30">
      <Container size="2xl" className="py-8 sm:py-12">
        <PageHeader
          title={pageTitle}
          subtitle={pageSubtitle}
          onBack={handleBackNavigation}
        />

        <Stack spacing="2xl">
          {/* Action Bar */}
          <Flex align="center" justify="between" className="flex-wrap gap-4">
            <Button variant="outline" onClick={handleCancel}>
              <ArrowLeft className="h-4 mr-2 text-current w-4" />
              {t('common.cancel')}
            </Button>

            <Button
              onClick={handleSubmit}
              disabled={isSubmitting}
            >
              {isSubmitting ? (
                <>
                  <Spinner className="h-4 w-4 mr-2" />
                  {t('organizationEdit.saving')}
                </>
              ) : (
                <>
                  <CheckCircle className="h-4 mr-2 text-current w-4" />
                  {isEditing ? t('organizationEdit.saveChanges') : t('organizationEdit.createOrganization')}
                </>
              )}
            </Button>
          </Flex>

          {/* Error Message */}
          {error && (
            <Card className="border-destructive">
              <CardContent className="pt-6">
                <p className="text-destructive">{error}</p>
              </CardContent>
            </Card>
          )}

          {/* Organization Form */}
          <form onSubmit={handleSubmit}>
            <Stack spacing="lg">
              {/* Basic Information */}
              <Card>
                <CardHeader>
                  <CardTitle>{t('organizationEdit.basicInfo')}</CardTitle>
                </CardHeader>
                <CardContent>
                  <Stack spacing="md">
                    <div>
                      <label className="block text-sm font-medium mb-2">
                        {t('organizationEdit.organizationName')} *
                      </label>
                      <Input
                        value={formData.name}
                        onChange={(e) => handleInputChange('name', e.target.value)}
                        placeholder={t('organizationEdit.namePlaceholder')}
                        required
                      />
                    </div>

                    <div>
                      <label className="block text-sm font-medium mb-2">
                        {t('organizationEdit.sector')} *
                      </label>
                      <Select
                        value={formData.sector}
                        onValueChange={(value) => handleInputChange('sector', value)}
                        options={sectorOptions}
                        placeholder={t('organizationEdit.selectSector')}
                        required
                      />
                    </div>

                    <div>
                      <label className="block text-sm font-medium mb-2">
                        {t('organizationEdit.subtype')}
                      </label>
                      <Select
                        value={formData.subtype}
                        onValueChange={(value) => handleInputChange('subtype', value)}
                        options={subtypeOptions}
                        placeholder={t('organizationEdit.selectSubtype')}
                      />
                    </div>

                    <div>
                      <label className="block text-sm font-medium mb-2">
                        {t('organizationEdit.description')}
                      </label>
                      <Textarea
                        value={formData.description}
                        onChange={(e) => handleInputChange('description', e.target.value)}
                        placeholder={t('organizationEdit.descriptionPlaceholder')}
                        rows={4}
                      />
                    </div>
                  </Stack>
                </CardContent>
              </Card>

              {/* Contact Information */}
              <Card>
                <CardHeader>
                  <CardTitle>{t('organizationEdit.contactInfo')}</CardTitle>
                </CardHeader>
                <CardContent>
                  <Stack spacing="md">
                    <div>
                      <label className="block text-sm font-medium mb-2">
                        {t('organizationEdit.website')}
                      </label>
                      <Input
                        type="url"
                        value={formData.website}
                        onChange={(e) => handleInputChange('website', e.target.value)}
                        placeholder={t('organizationEdit.websitePlaceholder')}
                      />
                    </div>

                    <div>
                      <label className="block text-sm font-medium mb-2">
                        {t('organizationEdit.address')}
                      </label>
                      <Textarea
                        value={formData.address}
                        onChange={(e) => handleInputChange('address', e.target.value)}
                        placeholder={t('organizationEdit.addressPlaceholder')}
                        rows={3}
                      />
                    </div>
                  </Stack>
                </CardContent>
              </Card>

              {/* Form Actions */}
              <Card>
                <CardContent className="pt-6">
                  <Flex align="center" justify="center" gap="md">
                    <Button type="button" variant="outline" onClick={handleCancel}>
                      {t('common.cancel')}
                    </Button>
                    <Button type="submit" disabled={isSubmitting}>
                      {isEditing ? t('organizationEdit.saveChanges') : t('organizationEdit.createOrganization')}
                    </Button>
                  </Flex>
                </CardContent>
              </Card>
            </Stack>
          </form>
        </Stack>
      </Container>
    </MainLayout>
  );
};

export default OrganizationEditPage;