import { useEffect, useState } from 'react'
import { useNavigate } from 'react-router-dom'
import { Button, Field, Icon, Modal, SelectInput } from '../../components/ui'
import ActivityFields from '../../components/activity/ActivityFields'
import {
  ASSET_FIELDS,
  ASSET_INIT_ACTIVITY_ID,
  createAsset,
  fetchAssignableEmployees,
  uploadAssetFile,
} from '../../api/assets'
import { emptyValues, validateActivity } from '../../api/activityForm'
import { useAuth } from '../../store/AuthContext'

// Asset Brand and Asset Location come first, as on the Edit form; the rest
// keep the builder's order.
const FIRST_FIELDS = ['field_59', 'field_61']
const FORM_FIELDS = [
  ...FIRST_FIELDS.map((id) => ASSET_FIELDS.find((f) => f.id === id)),
  ...ASSET_FIELDS.filter((f) => !FIRST_FIELDS.includes(f.id)),
]

// Asset Owner sits after Condition, as in the builder.
const OWNER_AFTER = FORM_FIELDS.findIndex((f) => f.id === 'field_47') + 1
const FIELDS_BEFORE_OWNER = FORM_FIELDS.slice(0, OWNER_AFTER)
const FIELDS_AFTER_OWNER = FORM_FIELDS.slice(OWNER_AFTER)

const upload = (fieldId, file) => uploadAssetFile(ASSET_INIT_ACTIVITY_ID, fieldId, file)

/**
 * "Add Asset" dialog. Fields are rendered straight from the Zino builder
 * definition in api/assets.js, so the form always matches the activity.
 * "Asset Owner" is a lookup, so it is picked from a list of active employees.
 */
export default function AddAssetModal({ open, onClose, onCreated }) {
  const navigate = useNavigate()
  const { logout } = useAuth()

  const [values, setValues] = useState(() => emptyValues(ASSET_FIELDS))
  const [employees, setEmployees] = useState([])
  const [loadingEmployees, setLoadingEmployees] = useState(false)
  const [ownerId, setOwnerId] = useState('')
  const [errors, setErrors] = useState({})
  const [serverError, setServerError] = useState('')
  const [submitting, setSubmitting] = useState(false)

  // A fresh employee list each time the dialog opens.
  useEffect(() => {
    if (!open) return undefined
    let cancelled = false
    setLoadingEmployees(true)
    fetchAssignableEmployees()
      .then((list) => !cancelled && setEmployees(list))
      .catch((err) => {
        if (cancelled) return
        if (err?.status === 401) {
          logout()
          navigate('/login', { replace: true })
          return
        }
        setServerError(err?.message || 'Could not load the employee list.')
      })
      .finally(() => !cancelled && setLoadingEmployees(false))
    return () => {
      cancelled = true
    }
  }, [open, logout, navigate])

  function reset() {
    setValues(emptyValues(ASSET_FIELDS))
    setOwnerId('')
    setErrors({})
    setServerError('')
    setSubmitting(false)
  }

  function close() {
    if (submitting) return
    reset()
    onClose?.()
  }

  function handleChange(id, value) {
    setValues((v) => ({ ...v, [id]: value }))
    if (errors[id]) setErrors((er) => ({ ...er, [id]: undefined }))
    if (serverError) setServerError('')
  }

  async function handleSubmit(e) {
    e.preventDefault()
    const nextErrors = validateActivity(ASSET_FIELDS, values)
    setErrors(nextErrors)
    if (Object.keys(nextErrors).length) return

    setSubmitting(true)
    setServerError('')
    try {
      const owner = employees.find((emp) => String(emp.id) === ownerId) ?? null
      const response = await createAsset(values, owner)
      onCreated?.(values, response)
      reset()
      onClose?.()
    } catch (err) {
      if (err?.status === 401) {
        logout()
        navigate('/login', { replace: true })
        return
      }
      setServerError(err?.message || 'Could not create the asset. Please try again.')
      setSubmitting(false)
    }
  }

  return (
    <Modal
      open={open}
      onClose={close}
      title="Add Asset"
      subtitle="Starts the asset onboarding workflow."
      size="lg"
      footer={
        <>
          <Button onClick={close} disabled={submitting}>
            Cancel
          </Button>
          <Button
            type="submit"
            form="add-asset-form"
            variant="primary"
            icon={submitting ? undefined : 'plus'}
            disabled={submitting}
          >
            {submitting ? 'Creating…' : 'Create Asset'}
          </Button>
        </>
      }
    >
      {serverError && (
        <div className="auth__alert" role="alert">
          <Icon name="alert" size={15} />
          <span>{serverError}</span>
        </div>
      )}

      <form id="add-asset-form" className="form__grid" onSubmit={handleSubmit} noValidate>
        <ActivityFields
          fields={FIELDS_BEFORE_OWNER}
          values={values}
          errors={errors}
          onChange={handleChange}
          disabled={submitting}
          upload={upload}
        />
        <Field label="Asset Owner">
          {(id) => (
            <SelectInput
              id={id}
              value={ownerId}
              onChange={(e) => {
                setOwnerId(e.target.value)
                if (serverError) setServerError('')
              }}
              options={employees.map((emp) => ({
                value: String(emp.id),
                label: emp.code ? `${emp.name} (${emp.code})` : emp.name,
              }))}
              placeholder={loadingEmployees ? 'Loading employees…' : 'Select employee'}
              disabled={submitting || loadingEmployees}
            />
          )}
        </Field>
        <ActivityFields
          fields={FIELDS_AFTER_OWNER}
          values={values}
          errors={errors}
          onChange={handleChange}
          disabled={submitting}
          upload={upload}
        />
      </form>
    </Modal>
  )
}