import { useEffect, type FC } from 'react'
import { useFormik } from 'formik'
import { p as P, Dropdown, pInput as PInput, Checkbox } from 'web-components'
import ProductsSelector from './ProductsSelector'
import DateInput from './DateInput'
import { trpc } from '@/lib/trpc-client'
import type { VendorSnippetForm as VendorSnippetFormType } from '@/types/vendor-snippets'

interface VendorSnippetFormProps {
  snippet?: VendorSnippetFormType | null
  onClose: () => void
  onSuccess: () => void
  showIsPermanentCheckbox?: boolean
}

const VendorSnippetForm: FC<VendorSnippetFormProps> = ({
  snippet,
  onClose,
  onSuccess,
  showIsPermanentCheckbox = false,
}) => {

  // Fetch slots
  const { data: slotsData } = trpc.user.slots.getSlots.useQuery()

  const createSnippet = trpc.admin.vendorSnippets.create.useMutation()
  const updateSnippet = trpc.admin.vendorSnippets.update.useMutation()

  const isEditing = !!snippet

  const formik = useFormik({
    initialValues: {
      snippetCode: snippet?.snippetCode || '',
      slotId: snippet?.slotId?.toString() || '',
      isPermanent: snippet?.isPermanent || false,
      skuIds: snippet?.skuIds?.map(id => id.toString()) || [],
      validTill: snippet?.validTill ? new Date(snippet.validTill) : null,
    },
    validate: (values) => {
      const errors: {[key: string]: string} = {}

      if (!values.snippetCode.trim()) {
        errors.snippetCode = 'Snippet code is required'
      }

      // Validate snippet code only contains alphanumeric characters and underscore
      const snippetCodeRegex = /^[a-zA-Z0-9_]+$/
      if (values.snippetCode && !snippetCodeRegex.test(values.snippetCode)) {
        errors.snippetCode = 'Snippet code can only contain letters, numbers, and underscores'
      }

      // Only require slotId if isPermanent is false
      if (!values.isPermanent && !values.slotId) {
        errors.slotId = 'Slot selection is required'
      }

      if (values.skuIds.length === 0) {
        errors.skuIds = 'At least one product must be selected'
      }

      return errors
    },
    onSubmit: async (values) => {
      try {

        const submitData = {
          snippetCode: values.snippetCode,
          slotId: values.isPermanent ? undefined : parseInt(values.slotId || '0'),
          isPermanent: values.isPermanent,
          skuIds: values.skuIds.map(id => parseInt(id)),
          validTill: values.validTill ? values.validTill.toISOString() : undefined,
        }

        if (isEditing && snippet) {
          await updateSnippet.mutateAsync({
            id: snippet.id,
            updates: submitData,
          })
          window.alert('Success: Vendor snippet updated successfully')
        } else {
          await createSnippet.mutateAsync(submitData)
          window.alert('Success: Vendor snippet created successfully')
        }

        onSuccess()
        onClose()
      } catch (error: any) {
        window.alert(`Error: ${error.message || 'Failed to save vendor snippet'}`)
      }
    },
  })

  // Generate unique snippet code if creating new (only on mount)
  useEffect(() => {
    if (!isEditing && !formik.values.snippetCode) {
      const timestamp = Date.now()
      const random = Math.random().toString(36).substring(2, 8)
      formik.setFieldValue('snippetCode', `VS_${timestamp}_${random}`)
    }
  }, [isEditing]) // Removed formik.values.snippetCode from deps

  const slotOptions = slotsData?.slots.map(slot => ({
    label: new Date(slot.deliveryTime).toLocaleString(),
    value: slot.id.toString(),
  })) || []

  return (
    <div className="flex-1 bg-white">
      <div className="px-6 py-4 border-b border-gray-200">
        <div className="flex flex-row justify-between items-center">
          <P className="text-xl font-bold text-gray-800">
            {isEditing ? 'Edit Vendor Snippet' : 'Create Vendor Snippet'}
          </P>
          <button
            type="button"
            onClick={onClose}
            className="p-2 text-gray-500 text-lg"
            aria-label="Close"
          >
            ✕
          </button>
        </div>
      </div>

      <div className="flex-1 overflow-auto px-6">
        <div className="py-6 space-y-6">
          {/* Snippet Code */}
          <div>
            <PInput
              topLabel="Snippet Code"
              value={formik.values.snippetCode}
              onChange={formik.handleChange('snippetCode')}
              placeholder="Enter snippet code"
              error={!!formik.errors.snippetCode && !!formik.touched.snippetCode}
            />
            {formik.errors.snippetCode && formik.touched.snippetCode && (
              <P className="text-red-500 text-sm mt-1">{formik.errors.snippetCode}</P>
            )}
          </div>

          {/* Is Permanent Checkbox */}
          <div>
            <button
              type="button"
              onClick={() => formik.setFieldValue('isPermanent', !formik.values.isPermanent)}
              className="flex flex-row items-center mb-2"
            >
              <Checkbox
                checked={formik.values.isPermanent}
                onPress={() => formik.setFieldValue('isPermanent', !formik.values.isPermanent)}
              />
              <P className="text-gray-700 font-medium ml-3">Is Permanent?</P>
            </button>
            <P className="text-sm text-gray-500 block">
              Check if this snippet is permanent and not tied to a specific delivery slot
            </P>
          </div>

          {/* Slot Selection - Only show if not permanent */}
          {!formik.values.isPermanent && (
            <div>
              <P className="text-gray-700 font-medium mb-2 block">Delivery Slot</P>
              <Dropdown
                label="Select Slot"
                value={formik.values.slotId}
                options={slotOptions}
                onValueChange={(value) => formik.setFieldValue('slotId', String(value))}
                className="w-full"
              />
              {formik.errors.slotId && formik.touched.slotId && (
                <P className="text-red-500 text-sm mt-1">{formik.errors.slotId}</P>
              )}
            </div>
          )}

          {/* Product Selection */}
          <div>
            <ProductsSelector
              value={formik.values.skuIds.map(id => parseInt(id))}
              onChange={(selectedProductIds) => formik.setFieldValue('skuIds', (selectedProductIds as number[]).map(id => id.toString()))}
              multiple={true}
              label="Select Products"
              placeholder="Select products"
              labelFormat={(product) => product.label}
            />
            {formik.errors.skuIds && formik.touched.skuIds && (
              <P className="text-red-500 text-sm mt-1">{formik.errors.skuIds}</P>
            )}
          </div>

          {/* Valid Till Date */}
          <div>
            <P className="text-gray-700 font-medium mb-2 block">Valid Till (Optional)</P>
            <DateInput
              value={formik.values.validTill}
              setValue={(date) => formik.setFieldValue('validTill', date)}
              placeholder="Select expiry date"
              showLabel={false}
            />
            <P className="text-sm text-gray-500 mt-1 block">
              Leave empty for no expiry
            </P>
          </div>
        </div>
      </div>

      {/* Submit Button */}
      <div className="px-6 py-4 border-t border-gray-200">
        <button
          type="button"
          onClick={() => formik.handleSubmit()}
          disabled={formik.isSubmitting}
          className={`bg-blue-500 py-3 rounded-lg w-full text-white text-center font-semibold disabled:opacity-50 ${formik.isSubmitting ? 'opacity-50' : ''}`}
        >
          {formik.isSubmitting
            ? 'Saving...'
            : isEditing ? 'Update Snippet' : 'Create Snippet'
          }
        </button>
      </div>
    </div>
  )
}

export default VendorSnippetForm