import React, { useState, useEffect } from 'react';
import { useTranslation } from 'react-i18next';
import type { SetupStepProps } from '../SetupWizard';
import { useQualityTemplates, useCreateQualityTemplate } from '../../../../api/hooks/qualityTemplates';
import { useCurrentTenant } from '../../../../stores/tenant.store';
import { useAuthUser } from '../../../../stores/auth.store';
import { QualityCheckType, ProcessStage } from '../../../../api/types/qualityTemplates';
import type { QualityCheckTemplateCreate } from '../../../../api/types/qualityTemplates';

export const QualitySetupStep: React.FC<SetupStepProps> = ({ onUpdate }) => {
  const { t } = useTranslation();

  // Get tenant ID and user
  const currentTenant = useCurrentTenant();
  const user = useAuthUser();
  const tenantId = currentTenant?.id || user?.tenant_id || '';
  const userId = user?.id || '';

  // Fetch quality templates
  const { data: templatesData, isLoading } = useQualityTemplates(tenantId);
  const templates = templatesData?.templates || [];

  // Mutations
  const createTemplateMutation = useCreateQualityTemplate(tenantId);

  // Form state
  const [isAdding, setIsAdding] = useState(false);
  const [formData, setFormData] = useState({
    name: '',
    check_type: QualityCheckType.VISUAL,
    description: '',
    applicable_stages: [] as ProcessStage[],
    is_required: false,
    is_critical: false,
  });
  const [errors, setErrors] = useState<Record<string, string>>({});

  // Notify parent when count changes
  useEffect(() => {
    const count = templates.length;
    onUpdate?.({
      itemsCount: count,
      canContinue: true, // Always allow continuing since this step is optional
    });
  }, [templates.length, onUpdate]);

  // Validation
  const validateForm = (): boolean => {
    const newErrors: Record<string, string> = {};

    if (!formData.name.trim()) {
      newErrors.name = t('setup_wizard:quality.errors.name_required', 'Name is required');
    }

    if (formData.applicable_stages.length === 0) {
      newErrors.stages = t('setup_wizard:quality.errors.stages_required', 'At least one stage is required');
    }

    setErrors(newErrors);
    return Object.keys(newErrors).length === 0;
  };

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

    if (!validateForm()) return;

    try {
      const templateData: QualityCheckTemplateCreate = {
        name: formData.name,
        check_type: formData.check_type,
        description: formData.description || undefined,
        applicable_stages: formData.applicable_stages,
        is_required: formData.is_required,
        is_critical: formData.is_critical,
        is_active: true,
        weight: formData.is_critical ? 10 : 5,
        created_by: userId,
      };

      await createTemplateMutation.mutateAsync(templateData);

      // Reset form
      resetForm();
    } catch (error) {
      console.error('Error saving quality template:', error);
    }
  };

  const resetForm = () => {
    setFormData({
      name: '',
      check_type: QualityCheckType.VISUAL,
      description: '',
      applicable_stages: [],
      is_required: false,
      is_critical: false,
    });
    setErrors({});
    setIsAdding(false);
  };

  const toggleStage = (stage: ProcessStage) => {
    const stages = formData.applicable_stages.includes(stage)
      ? formData.applicable_stages.filter((s) => s !== stage)
      : [...formData.applicable_stages, stage];
    setFormData({ ...formData, applicable_stages: stages });
  };

  const checkTypeOptions = [
    { value: QualityCheckType.VISUAL, label: t('quality:type.visual', 'Visual Inspection'), icon: '👁️' },
    { value: QualityCheckType.MEASUREMENT, label: t('quality:type.measurement', 'Measurement'), icon: '📏' },
    { value: QualityCheckType.TEMPERATURE, label: t('quality:type.temperature', 'Temperature'), icon: '🌡️' },
    { value: QualityCheckType.WEIGHT, label: t('quality:type.weight', 'Weight'), icon: '⚖️' },
    { value: QualityCheckType.TIMING, label: t('quality:type.timing', 'Timing'), icon: '⏱️' },
    { value: QualityCheckType.CHECKLIST, label: t('quality:type.checklist', 'Checklist'), icon: '✅' },
  ];

  const stageOptions = [
    { value: ProcessStage.MIXING, label: t('quality:stage.mixing', 'Mixing') },
    { value: ProcessStage.PROOFING, label: t('quality:stage.proofing', 'Proofing') },
    { value: ProcessStage.SHAPING, label: t('quality:stage.shaping', 'Shaping') },
    { value: ProcessStage.BAKING, label: t('quality:stage.baking', 'Baking') },
    { value: ProcessStage.COOLING, label: t('quality:stage.cooling', 'Cooling') },
    { value: ProcessStage.FINISHING, label: t('quality:stage.finishing', 'Finishing') },
    { value: ProcessStage.PACKAGING, label: t('quality:stage.packaging', 'Packaging') },
  ];

  return (
    <div className="space-y-6">
      {/* Why This Matters */}
      <div className="bg-[var(--color-info)]/10 border border-[var(--color-info)]/20 rounded-lg p-4">
        <h3 className="font-semibold text-[var(--text-primary)] mb-2 flex items-center gap-2">
          <svg className="w-5 h-5 text-[var(--color-info)]" fill="none" stroke="currentColor" viewBox="0 0 24 24">
            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M13 16h-1v-4h-1m1-4h.01M21 12a9 9 0 11-18 0 9 9 0 0118 0z" />
          </svg>
          {t('setup_wizard:why_this_matters', 'Why This Matters')}
        </h3>
        <p className="text-sm text-[var(--text-secondary)]">
          {t('setup_wizard:quality.why', 'Quality checks ensure consistent output and help you identify issues early. Define what "good" looks like for each stage of production.')}
        </p>
      </div>

      {/* Optional badge */}
      <div className="flex items-center gap-2 text-sm">
        <span className="px-2 py-1 bg-[var(--bg-secondary)] text-[var(--text-secondary)] rounded-full border border-[var(--border-secondary)]">
          {t('setup_wizard:optional', 'Optional')}
        </span>
        <span className="text-[var(--text-tertiary)]">
          {t('setup_wizard:quality.optional_note', 'You can skip this and configure quality checks later')}
        </span>
      </div>

      {/* Progress indicator */}
      <div className="flex items-center justify-between p-3 bg-[var(--bg-secondary)] rounded-lg">
        <div className="flex items-center gap-2">
          <svg className="w-5 h-5 text-[var(--text-secondary)]" fill="none" stroke="currentColor" viewBox="0 0 24 24">
            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M9 12l2 2 4-4m6 2a9 9 0 11-18 0 9 9 0 0118 0z" />
          </svg>
          <span className="text-sm font-medium text-[var(--text-primary)]">
            {t('setup_wizard:quality.added_count', { count: templates.length, defaultValue: '{{count}} quality check added' })}
          </span>
        </div>
        {templates.length >= 2 ? (
          <div className="flex items-center gap-1 text-xs text-[var(--color-success)]">
            <svg className="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M5 13l4 4L19 7" />
            </svg>
            {t('setup_wizard:quality.recommended_met', 'Recommended amount met')}
          </div>
        ) : (
          <div className="text-xs text-[var(--text-tertiary)]">
            {t('setup_wizard:quality.recommended', '2+ recommended (optional)')}
          </div>
        )}
      </div>

      {/* Templates list */}
      {templates.length > 0 && (
        <div className="space-y-2">
          <h4 className="text-sm font-medium text-[var(--text-secondary)]">
            {t('setup_wizard:quality.your_checks', 'Your Quality Checks')}
          </h4>
          <div className="space-y-2 max-h-80 overflow-y-auto">
            {templates.map((template) => (
              <div
                key={template.id}
                className="flex items-center justify-between p-3 bg-[var(--bg-secondary)] border border-[var(--border-secondary)] rounded-lg hover:border-[var(--border-primary)] transition-colors"
              >
                <div className="flex-1 min-w-0">
                  <div className="flex items-center gap-2">
                    <h5 className="font-medium text-[var(--text-primary)] truncate">{template.name}</h5>
                    {template.is_critical && (
                      <span className="text-xs px-2 py-0.5 bg-[var(--color-error)]/10 text-[var(--color-error)] rounded-full">
                        {t('quality:critical', 'Critical')}
                      </span>
                    )}
                    {template.is_required && (
                      <span className="text-xs px-2 py-0.5 bg-[var(--color-warning)]/10 text-[var(--color-warning)] rounded-full">
                        {t('quality:required', 'Required')}
                      </span>
                    )}
                  </div>
                  <div className="flex items-center gap-3 mt-1 text-xs text-[var(--text-secondary)]">
                    <span className="px-2 py-0.5 bg-[var(--bg-primary)] rounded-full">
                      {checkTypeOptions.find(opt => opt.value === template.check_type)?.label || template.check_type}
                    </span>
                    {template.applicable_stages && template.applicable_stages.length > 0 && (
                      <span>
                        {template.applicable_stages.length} {t('quality:stages', 'stage(s)')}
                      </span>
                    )}
                  </div>
                </div>
              </div>
            ))}
          </div>
        </div>
      )}

      {/* Add form */}
      {isAdding ? (
        <form onSubmit={handleSubmit} className="space-y-4 p-4 border-2 border-[var(--color-primary)] rounded-lg bg-[var(--bg-secondary)]">
          <div className="flex items-center justify-between mb-2">
            <h4 className="font-medium text-[var(--text-primary)]">
              {t('setup_wizard:quality.add_check', 'Add Quality Check')}
            </h4>
            <button
              type="button"
              onClick={resetForm}
              className="text-sm text-[var(--text-secondary)] hover:text-[var(--text-primary)]"
            >
              {t('common:cancel', 'Cancel')}
            </button>
          </div>

          <div className="space-y-4">
            {/* Name */}
            <div>
              <label htmlFor="check-name" className="block text-sm font-medium text-[var(--text-primary)] mb-1">
                {t('setup_wizard:quality.fields.name', 'Check Name')} <span className="text-[var(--color-error)]">*</span>
              </label>
              <input
                id="check-name"
                type="text"
                value={formData.name}
                onChange={(e) => setFormData({ ...formData, name: e.target.value })}
                className={`w-full px-3 py-2 bg-[var(--bg-primary)] border ${errors.name ? 'border-[var(--color-error)]' : 'border-[var(--border-secondary)]'} rounded-lg focus:outline-none focus:ring-2 focus:ring-[var(--color-primary)] text-[var(--text-primary)]`}
                placeholder={t('setup_wizard:quality.placeholders.name', 'e.g., Crust color check, Dough temperature')}
              />
              {errors.name && <p className="mt-1 text-xs text-[var(--color-error)]">{errors.name}</p>}
            </div>

            {/* Check Type */}
            <div>
              <label className="block text-sm font-medium text-[var(--text-primary)] mb-2">
                {t('setup_wizard:quality.fields.check_type', 'Check Type')} <span className="text-[var(--color-error)]">*</span>
              </label>
              <div className="grid grid-cols-2 md:grid-cols-3 gap-2">
                {checkTypeOptions.map((option) => (
                  <button
                    key={option.value}
                    type="button"
                    onClick={() => setFormData({ ...formData, check_type: option.value })}
                    className={`p-3 text-left border rounded-lg transition-colors ${
                      formData.check_type === option.value
                        ? 'border-[var(--color-primary)] bg-[var(--color-primary)]/10'
                        : 'border-[var(--border-secondary)] hover:border-[var(--border-primary)]'
                    }`}
                  >
                    <div className="text-lg mb-1">{option.icon}</div>
                    <div className="text-xs font-medium text-[var(--text-primary)]">{option.label}</div>
                  </button>
                ))}
              </div>
            </div>

            {/* Description */}
            <div>
              <label htmlFor="description" className="block text-sm font-medium text-[var(--text-primary)] mb-1">
                {t('setup_wizard:quality.fields.description', 'Description')}
              </label>
              <textarea
                id="description"
                value={formData.description}
                onChange={(e) => setFormData({ ...formData, description: e.target.value })}
                rows={2}
                className="w-full px-3 py-2 bg-[var(--bg-primary)] border border-[var(--border-secondary)] rounded-lg focus:outline-none focus:ring-2 focus:ring-[var(--color-primary)] text-[var(--text-primary)] resize-none"
                placeholder={t('setup_wizard:quality.placeholders.description', 'What should be checked and why...')}
              />
            </div>

            {/* Applicable Stages */}
            <div>
              <label className="block text-sm font-medium text-[var(--text-primary)] mb-2">
                {t('setup_wizard:quality.fields.stages', 'Applicable Stages')} <span className="text-[var(--color-error)]">*</span>
              </label>
              {errors.stages && <p className="mb-2 text-xs text-[var(--color-error)]">{errors.stages}</p>}
              <div className="grid grid-cols-2 md:grid-cols-3 gap-2">
                {stageOptions.map((option) => (
                  <button
                    key={option.value}
                    type="button"
                    onClick={() => toggleStage(option.value)}
                    className={`p-2 text-sm text-left border rounded-lg transition-colors ${
                      formData.applicable_stages.includes(option.value)
                        ? 'border-[var(--color-primary)] bg-[var(--color-primary)]/10 text-[var(--color-primary)]'
                        : 'border-[var(--border-secondary)] text-[var(--text-secondary)] hover:border-[var(--border-primary)]'
                    }`}
                  >
                    {option.label}
                  </button>
                ))}
              </div>
            </div>

            {/* Flags */}
            <div className="space-y-2">
              <label className="flex items-center gap-2 cursor-pointer">
                <input
                  type="checkbox"
                  checked={formData.is_required}
                  onChange={(e) => setFormData({ ...formData, is_required: e.target.checked })}
                  className="w-4 h-4 text-[var(--color-primary)] rounded focus:ring-2 focus:ring-[var(--color-primary)]"
                />
                <span className="text-sm text-[var(--text-primary)]">
                  {t('setup_wizard:quality.fields.required', 'Required check (must be completed)')}
                </span>
              </label>
              <label className="flex items-center gap-2 cursor-pointer">
                <input
                  type="checkbox"
                  checked={formData.is_critical}
                  onChange={(e) => setFormData({ ...formData, is_critical: e.target.checked })}
                  className="w-4 h-4 text-[var(--color-error)] rounded focus:ring-2 focus:ring-[var(--color-error)]"
                />
                <span className="text-sm text-[var(--text-primary)]">
                  {t('setup_wizard:quality.fields.critical', 'Critical check (failure stops production)')}
                </span>
              </label>
            </div>
          </div>

          <div className="flex gap-2 pt-2">
            <button
              type="submit"
              disabled={createTemplateMutation.isPending}
              className="px-4 py-2 bg-[var(--color-primary)] text-white rounded-lg hover:bg-[var(--color-primary-dark)] disabled:opacity-50 disabled:cursor-not-allowed transition-colors font-medium"
            >
              {createTemplateMutation.isPending ? (
                <span className="flex items-center gap-2">
                  <svg className="animate-spin h-4 w-4" fill="none" viewBox="0 0 24 24">
                    <circle className="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" strokeWidth="4" />
                    <path className="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4zm2 5.291A7.962 7.962 0 014 12H0c0 3.042 1.135 5.824 3 7.938l3-2.647z" />
                  </svg>
                  {t('common:saving', 'Saving...')}
                </span>
              ) : (
                t('common:add', 'Add')
              )}
            </button>
            <button
              type="button"
              onClick={resetForm}
              className="px-4 py-2 text-[var(--text-secondary)] hover:text-[var(--text-primary)] hover:bg-[var(--bg-primary)] rounded-lg transition-colors"
            >
              {t('common:cancel', 'Cancel')}
            </button>
          </div>
        </form>
      ) : (
        <button
          type="button"
          onClick={() => setIsAdding(true)}
          className="w-full p-4 border-2 border-dashed border-[var(--border-secondary)] rounded-lg hover:border-[var(--color-primary)] hover:bg-[var(--bg-secondary)] transition-colors group"
        >
          <div className="flex items-center justify-center gap-2 text-[var(--text-secondary)] group-hover:text-[var(--color-primary)]">
            <svg className="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 6v6m0 0v6m0-6h6m-6 0H6" />
            </svg>
            <span className="font-medium">
              {templates.length === 0
                ? t('setup_wizard:quality.add_first', 'Add Your First Quality Check')
                : t('setup_wizard:quality.add_another', 'Add Another Quality Check')}
            </span>
          </div>
        </button>
      )}

      {/* Loading state */}
      {isLoading && templates.length === 0 && (
        <div className="text-center py-8">
          <svg className="animate-spin h-8 w-8 text-[var(--color-primary)] mx-auto" fill="none" viewBox="0 0 24 24">
            <circle className="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" strokeWidth="4" />
            <path className="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4zm2 5.291A7.962 7.962 0 014 12H0c0 3.042 1.135 5.824 3 7.938l3-2.647z" />
          </svg>
          <p className="mt-2 text-sm text-[var(--text-secondary)]">
            {t('common:loading', 'Loading...')}
          </p>
        </div>
      )}
    </div>
  );
};