import { useState, useEffect } from 'react';
import { useForm } from 'react-hook-form';
import { zodResolver } from '@hookform/resolvers/zod';
import { z } from 'zod';
import { useAuthStore } from '@/features/auth/store/authStore';
import { useTranslation } from '@/hooks/useTranslation';
import { apiClient } from '@/services/api/client';
import { Button } from '@/components/ui/button';
import { Input } from '@/components/ui/input';
import { Textarea } from '@/components/ui/textarea';
import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card';
import { Progress } from '@/components/ui/progress';
import { useToast } from '@/hooks/useToast';
import { usernameSchema, emailSchema } from '@/schemas/validation';
import {
  calculateProfileCompletion,
  type ProfileCompletion,
  type UpdateProfileRequest,
} from '@/features/profile/services/profileService';
import {
  Twitter,
  Instagram,
  Facebook,
  Youtube,
  Link as LinkIcon,
  AlertCircle,
  CheckCircle2,
} from 'lucide-react';
import { Alert, AlertDescription } from '@/components/ui/alert';
import { logger } from '@/utils/logger';
import { parseApiError } from '@/utils/apiErrorHandler';
import { ErrorDisplay } from '@/components/ui/ErrorDisplay';
import { applyApiValidationErrors } from '@/utils/formValidation';

// FE-PAGE-003: Complete Profile page implementation

// Define schema with social links
const profileSchema = z.object({
  username: usernameSchema,
  email: emailSchema,
  first_name: z.string().optional(),
  last_name: z.string().optional(),
  bio: z.string().max(500, 'Bio must be less than 500 characters').optional(),
  location: z.string().max(100).optional(),
  social_links: z
    .object({
      twitter: z.string().url('Invalid Twitter URL').optional().or(z.literal('')),
      instagram: z.string().url('Invalid Instagram URL').optional().or(z.literal('')),
      facebook: z.string().url('Invalid Facebook URL').optional().or(z.literal('')),
      youtube: z.string().url('Invalid YouTube URL').optional().or(z.literal('')),
      website: z.string().url('Invalid website URL').optional().or(z.literal('')),
    })
    .optional(),
});

type ProfileFormData = z.infer<typeof profileSchema>;

export function ProfileForm() {
  const { user, refreshUser } = useAuthStore();
  const { t } = useTranslation();
  const toast = useToast();
  const [isEditing, setIsEditing] = useState(false);
  const [isLoading, setIsLoading] = useState(false);
  const [completion, setCompletion] = useState<ProfileCompletion | null>(null);
  const [mutationError, setMutationError] = useState<Error | null>(null);

  // FE-PAGE-003: Load profile completion
  useEffect(() => {
    if (user?.id) {
      calculateProfileCompletion(user.id)
        .then(setCompletion)
        .catch((err) => {
          logger.error('Failed to load profile completion:', err);
        });
    }
  }, [user?.id]);

  // FE-PAGE-003: Initialize form with social links
  const form = useForm<ProfileFormData>({
    resolver: zodResolver(profileSchema),
    defaultValues: {
      username: user?.username || '',
      email: user?.email || '',
      first_name: user?.first_name || '',
      last_name: user?.last_name || '',
      bio: user?.bio || '',
      location: user?.location || '',
      social_links: {
        twitter: (user as any)?.social_links?.twitter || '',
        instagram: (user as any)?.social_links?.instagram || '',
        facebook: (user as any)?.social_links?.facebook || '',
        youtube: (user as any)?.social_links?.youtube || '',
        website: (user as any)?.social_links?.website || '',
      },
    },
    mode: 'onBlur',
  });

  const {
    register,
    handleSubmit,
    reset,
    watch,
    setError,
    formState: { errors },
  } = form;

  // FE-PAGE-003: Watch form values to update completion
  const watchedValues = watch();

  useEffect(() => {
    if (user?.id && !isEditing) {
      // Reset form when user changes
      reset({
        username: user?.username || '',
        email: user?.email || '',
        first_name: user?.first_name || '',
        last_name: user?.last_name || '',
        bio: user?.bio || '',
        location: user?.location || '',
        social_links: {
          twitter: (user as any)?.social_links?.twitter || '',
          instagram: (user as any)?.social_links?.instagram || '',
          facebook: (user as any)?.social_links?.facebook || '',
          youtube: (user as any)?.social_links?.youtube || '',
          website: (user as any)?.social_links?.website || '',
        },
      });
    }
  }, [user, reset, isEditing]);

  const onSubmit = async (data: ProfileFormData) => {
    if (!user) return;
    setIsLoading(true);
    try {
      const userId = user.id;

      // FE-PAGE-003: Prepare update request with social links
      const updateData: UpdateProfileRequest & { social_links?: Record<string, string> } = {
        username: data.username,
        first_name: data.first_name || undefined,
        last_name: data.last_name || undefined,
        bio: data.bio || undefined,
        location: data.location || undefined,
      };

      // Add social links if provided
      if (data.social_links) {
        const socialLinks: Record<string, string> = {};
        if (data.social_links.twitter) socialLinks.twitter = data.social_links.twitter;
        if (data.social_links.instagram) socialLinks.instagram = data.social_links.instagram;
        if (data.social_links.facebook) socialLinks.facebook = data.social_links.facebook;
        if (data.social_links.youtube) socialLinks.youtube = data.social_links.youtube;
        if (data.social_links.website) socialLinks.website = data.social_links.website;

        if (Object.keys(socialLinks).length > 0) {
          updateData.social_links = socialLinks;
        }
      }

      await apiClient.put(`/users/${userId}`, updateData);
      await refreshUser();

      // Refresh completion
      if (user.id) {
        const newCompletion = await calculateProfileCompletion(user.id);
        setCompletion(newCompletion);
      }

      toast.success(t('profile.success') || 'Profile updated successfully');
      setIsEditing(false);
      setMutationError(null);
    } catch (err: unknown) {
      const apiError = parseApiError(err);
      
      // Action 3.2.1.3: Apply validation errors to form fields
      const validationErrorsApplied = applyApiValidationErrors(apiError, setError);
      
      // Only show mutation error banner if validation errors weren't applied
      // (validation errors are shown inline on fields)
      if (!validationErrorsApplied) {
        setMutationError(new Error(apiError.message || t('profile.error') || 'Failed to update profile'));
      } else {
        setMutationError(null);
      }
    } finally {
      setIsLoading(false);
    }
  };

  const handleCancel = () => {
    reset({
      username: user?.username || '',
      email: user?.email || '',
      first_name: user?.first_name || '',
      last_name: user?.last_name || '',
      bio: user?.bio || '',
      location: user?.location || '',
      social_links: {
        twitter: (user as any)?.social_links?.twitter || '',
        instagram: (user as any)?.social_links?.instagram || '',
        facebook: (user as any)?.social_links?.facebook || '',
        youtube: (user as any)?.social_links?.youtube || '',
        website: (user as any)?.social_links?.website || '',
      },
    });
    setIsEditing(false);
  };

  if (!user) {
    return (
      <Card>
        <CardContent className="pt-6">
          <div className="text-center text-muted-foreground">
            <p>Chargement du profil...</p>
          </div>
        </CardContent>
      </Card>
    );
  }

  return (
    <div className="space-y-6">
      {mutationError && (
        <ErrorDisplay
          error={mutationError}
          variant="banner"
          severity="error"
          context={{
            action: 'updating profile',
            resource: 'profile',
          }}
          onDismiss={() => setMutationError(null)}
        />
      )}
      {/* FE-PAGE-003: Profile Completion Indicator */}
      {completion && (
        <Card>
          <CardHeader>
            <CardTitle className="flex items-center gap-2">
              {completion.percentage === 100 ? (
                <CheckCircle2 className="h-5 w-5 text-green-600" />
              ) : (
                <AlertCircle className="h-5 w-5 text-yellow-600" />
              )}
              Profile Completion
            </CardTitle>
          </CardHeader>
          <CardContent className="space-y-4">
            <div className="space-y-2">
              <div className="flex items-center justify-between text-sm">
                <span className="text-muted-foreground">
                  {completion.percentage}% Complete
                </span>
                <span className="font-medium">
                  {completion.percentage === 100
                    ? 'Profile Complete!'
                    : `${completion.missing.length} field(s) missing`}
                </span>
              </div>
              <Progress value={completion.percentage} className="h-2" />
            </div>
            {completion.missing.length > 0 && (
              <Alert>
                <AlertCircle className="h-4 w-4" />
                <AlertDescription>
                  <p className="font-medium mb-1">Complete your profile:</p>
                  <ul className="list-disc list-inside text-sm space-y-1">
                    {completion.missing.map((field, index) => (
                      <li key={index}>{field}</li>
                    ))}
                  </ul>
                </AlertDescription>
              </Alert>
            )}
          </CardContent>
        </Card>
      )}

      <Card>
        <CardHeader className="flex flex-row items-center justify-between">
          <CardTitle>{t('profile.title') || 'Profile'}</CardTitle>
          {!isEditing && (
            <Button onClick={() => setIsEditing(true)} variant="outline">
              {t('profile.edit') || 'Edit'}
            </Button>
          )}
        </CardHeader>
        <CardContent>
          <h3 className="text-lg font-medium mb-4">
            {t('profile.personalInfo') || 'Personal Information'}
          </h3>

          <form onSubmit={handleSubmit(onSubmit)} className="space-y-4">
            {/* Avatar Section */}
            {isEditing && (
              <div className="mb-4">
                <Button type="button" variant="ghost">
                  {t('profile.avatar.changePhoto') || 'Change Photo'}
                </Button>
              </div>
            )}

            <div className="grid gap-2">
              <label className="text-sm font-medium" htmlFor="username">
                Username
              </label>
              <Input
                id="username"
                {...register('username')}
                disabled={!isEditing}
              />
              {errors.username && (
                <p className="text-sm text-red-500">{errors.username.message}</p>
              )}
            </div>

            <div className="grid gap-2">
              <label className="text-sm font-medium" htmlFor="email">
                Email
              </label>
              <Input
                id="email"
                type="email"
                {...register('email')}
                disabled={!isEditing}
              />
              {errors.email && (
                <p className="text-sm text-red-500">{errors.email.message}</p>
              )}
            </div>

            <div className="grid grid-cols-2 gap-4">
              <div className="grid gap-2">
                <label className="text-sm font-medium" htmlFor="first_name">
                  First Name
                </label>
                <Input
                  id="first_name"
                  {...register('first_name')}
                  disabled={!isEditing}
                />
                {errors.first_name && (
                  <p className="text-sm text-red-500">
                    {errors.first_name.message}
                  </p>
                )}
              </div>
              <div className="grid gap-2">
                <label className="text-sm font-medium" htmlFor="last_name">
                  Last Name
                </label>
                <Input
                  id="last_name"
                  {...register('last_name')}
                  disabled={!isEditing}
                />
                {errors.last_name && (
                  <p className="text-sm text-red-500">
                    {errors.last_name.message}
                  </p>
                )}
              </div>
            </div>

            <div className="grid gap-2">
              <label className="text-sm font-medium" htmlFor="location">
                Location
              </label>
              <Input
                id="location"
                {...register('location')}
                disabled={!isEditing}
                placeholder="City, Country"
              />
              {errors.location && (
                <p className="text-sm text-red-500">{errors.location.message}</p>
              )}
            </div>

            {/* FE-PAGE-003: Bio with Textarea */}
            <div className="grid gap-2">
              <label className="text-sm font-medium" htmlFor="bio">
                Bio
              </label>
              <Textarea
                id="bio"
                {...register('bio')}
                disabled={!isEditing}
                placeholder="Tell us about yourself..."
                rows={4}
                maxLength={500}
              />
              <div className="flex justify-between text-xs text-muted-foreground">
                {errors.bio && (
                  <p className="text-red-500">{errors.bio.message}</p>
                )}
                <span className="ml-auto">
                  {watchedValues.bio?.length || 0}/500 characters
                </span>
              </div>
            </div>

            {/* FE-PAGE-003: Social Links Section */}
            {isEditing && (
              <div className="space-y-4 pt-4 border-t">
                <h4 className="text-md font-medium">Social Links</h4>
                <div className="grid gap-4">
                  <div className="grid gap-2">
                    <label
                      className="text-sm font-medium flex items-center gap-2"
                      htmlFor="twitter"
                    >
                      <Twitter className="h-4 w-4" />
                      Twitter
                    </label>
                    <Input
                      id="twitter"
                      type="url"
                      placeholder="https://twitter.com/username"
                      {...register('social_links.twitter')}
                    />
                    {errors.social_links?.twitter && (
                      <p className="text-sm text-red-500">
                        {errors.social_links.twitter.message}
                      </p>
                    )}
                  </div>

                  <div className="grid gap-2">
                    <label
                      className="text-sm font-medium flex items-center gap-2"
                      htmlFor="instagram"
                    >
                      <Instagram className="h-4 w-4" />
                      Instagram
                    </label>
                    <Input
                      id="instagram"
                      type="url"
                      placeholder="https://instagram.com/username"
                      {...register('social_links.instagram')}
                    />
                    {errors.social_links?.instagram && (
                      <p className="text-sm text-red-500">
                        {errors.social_links.instagram.message}
                      </p>
                    )}
                  </div>

                  <div className="grid gap-2">
                    <label
                      className="text-sm font-medium flex items-center gap-2"
                      htmlFor="facebook"
                    >
                      <Facebook className="h-4 w-4" />
                      Facebook
                    </label>
                    <Input
                      id="facebook"
                      type="url"
                      placeholder="https://facebook.com/username"
                      {...register('social_links.facebook')}
                    />
                    {errors.social_links?.facebook && (
                      <p className="text-sm text-red-500">
                        {errors.social_links.facebook.message}
                      </p>
                    )}
                  </div>

                  <div className="grid gap-2">
                    <label
                      className="text-sm font-medium flex items-center gap-2"
                      htmlFor="youtube"
                    >
                      <Youtube className="h-4 w-4" />
                      YouTube
                    </label>
                    <Input
                      id="youtube"
                      type="url"
                      placeholder="https://youtube.com/@username"
                      {...register('social_links.youtube')}
                    />
                    {errors.social_links?.youtube && (
                      <p className="text-sm text-red-500">
                        {errors.social_links.youtube.message}
                      </p>
                    )}
                  </div>

                  <div className="grid gap-2">
                    <label
                      className="text-sm font-medium flex items-center gap-2"
                      htmlFor="website"
                    >
                      <LinkIcon className="h-4 w-4" />
                      Website
                    </label>
                    <Input
                      id="website"
                      type="url"
                      placeholder="https://example.com"
                      {...register('social_links.website')}
                    />
                    {errors.social_links?.website && (
                      <p className="text-sm text-red-500">
                        {errors.social_links.website.message}
                      </p>
                    )}
                  </div>
                </div>
              </div>
            )}

            {/* FE-PAGE-003: Display social links when not editing */}
            {!isEditing && watchedValues.social_links && (
              <div className="space-y-4 pt-4 border-t">
                <h4 className="text-md font-medium">Social Links</h4>
                <div className="flex flex-wrap gap-4">
                  {watchedValues.social_links.twitter && (
                    <a
                      href={watchedValues.social_links.twitter}
                      target="_blank"
                      rel="noopener noreferrer"
                      className="flex items-center gap-2 text-blue-500 hover:underline"
                    >
                      <Twitter className="h-4 w-4" />
                      Twitter
                    </a>
                  )}
                  {watchedValues.social_links.instagram && (
                    <a
                      href={watchedValues.social_links.instagram}
                      target="_blank"
                      rel="noopener noreferrer"
                      className="flex items-center gap-2 text-pink-500 hover:underline"
                    >
                      <Instagram className="h-4 w-4" />
                      Instagram
                    </a>
                  )}
                  {watchedValues.social_links.facebook && (
                    <a
                      href={watchedValues.social_links.facebook}
                      target="_blank"
                      rel="noopener noreferrer"
                      className="flex items-center gap-2 text-blue-600 hover:underline"
                    >
                      <Facebook className="h-4 w-4" />
                      Facebook
                    </a>
                  )}
                  {watchedValues.social_links.youtube && (
                    <a
                      href={watchedValues.social_links.youtube}
                      target="_blank"
                      rel="noopener noreferrer"
                      className="flex items-center gap-2 text-red-500 hover:underline"
                    >
                      <Youtube className="h-4 w-4" />
                      YouTube
                    </a>
                  )}
                  {watchedValues.social_links.website && (
                    <a
                      href={watchedValues.social_links.website}
                      target="_blank"
                      rel="noopener noreferrer"
                      className="flex items-center gap-2 text-muted-foreground hover:underline"
                    >
                      <LinkIcon className="h-4 w-4" />
                      Website
                    </a>
                  )}
                  {!watchedValues.social_links.twitter &&
                    !watchedValues.social_links.instagram &&
                    !watchedValues.social_links.facebook &&
                    !watchedValues.social_links.youtube &&
                    !watchedValues.social_links.website && (
                      <p className="text-sm text-muted-foreground">
                        No social links added
                      </p>
                    )}
                </div>
              </div>
            )}

            {isEditing && (
              <div className="flex justify-end gap-2 mt-4">
                <Button type="button" variant="secondary" onClick={handleCancel}>
                  {t('profile.cancel') || 'Cancel'}
                </Button>
                <Button type="submit" disabled={isLoading}>
                  {isLoading
                    ? 'Saving...'
                    : t('profile.save') || 'Save'}
                </Button>
              </div>
            )}
          </form>
        </CardContent>
      </Card>
    </div>
  );
}
