import { useState, type FormEvent } from 'react'
import { Modal } from '@/components/ui/Modal'
import { Alert } from '@/components/ui/Alert'
import { Button } from '@/components/ui/Button'
import { Select } from '@/components/ui/Select'
import { TextField } from '@/components/ui/TextField'
import { cn } from '@/lib/cn'
import { fieldControlClass } from '@/components/ui/field'
import { errorMessage } from '@/lib/api'
import type { Garden } from '@/lib/gardens'
import { useAddShare, useRemoveShare, useShares, useUpdateShareRole, type ShareRole } from '@/lib/shares'

const roleOptions = [
  { value: 'viewer', label: 'Viewer (read-only)' },
  { value: 'editor', label: 'Editor (can edit)' },
]

/**
 * Owner-only dialog to manage a garden's shares: invite an existing user by
 * email as viewer/editor, change a share's role, or remove it. Targets existing
 * accounts only (v1 has no invitation emails) — an unknown email surfaces a
 * friendly "no account with that email".
 */
export function ShareGardenModal({ garden, onClose }: { garden: Garden; onClose: () => void }) {
  const shares = useShares(garden.id)
  const add = useAddShare(garden.id)
  const updateRole = useUpdateShareRole(garden.id)
  const remove = useRemoveShare(garden.id)

  const [email, setEmail] = useState('')
  const [role, setRole] = useState<ShareRole>('viewer')
  const [error, setError] = useState<string | null>(null)

  async function onInvite(e: FormEvent) {
    e.preventDefault()
    setError(null)
    if (!email.trim()) {
      setError('Enter an email address.')
      return
    }
    try {
      await add.mutateAsync({ email: email.trim(), role })
      setEmail('')
    } catch (err) {
      setError(errorMessage(err, 'Could not share the garden.'))
    }
  }

  const onMutationError = (fallback: string) => (err: unknown) => setError(errorMessage(err, fallback))

  return (
    <Modal title="Share garden" onClose={onClose} busy={add.isPending || updateRole.isPending || remove.isPending}>
      <div className="flex flex-col gap-4">
        <form onSubmit={onInvite} className="flex flex-col gap-2">
          <TextField
            label="Invite by email"
            name="email"
            type="email"
            placeholder="person@example.com"
            value={email}
            onChange={(e) => setEmail(e.target.value)}
          />
          <div className="flex items-end gap-2">
            <Select
              label="Role"
              name="role"
              value={role}
              onChange={(e) => setRole(e.target.value as ShareRole)}
              options={roleOptions}
              className="flex-1"
            />
            <Button type="submit" disabled={add.isPending}>
              {add.isPending ? 'Sharing…' : 'Share'}
            </Button>
          </div>
          {error && <Alert>{error}</Alert>}
        </form>

        <div>
          <h3 className="mb-2 text-sm font-medium text-fg">Shared with</h3>
          {shares.isPending && <p className="text-sm text-muted">Loading…</p>}
          {shares.isError && <Alert>Could not load who this garden is shared with.</Alert>}
          {shares.isSuccess && shares.data.length === 0 && (
            <p className="text-sm text-muted">Not shared with anyone yet.</p>
          )}
          <ul className="flex flex-col gap-2">
            {shares.data?.map((sh) => (
              <li key={sh.userId} className="flex items-center gap-2">
                <div className="min-w-0 flex-1">
                  <p className="truncate text-sm font-medium text-fg">{sh.displayName}</p>
                  <p className="truncate text-xs text-muted">{sh.email}</p>
                </div>
                <select
                  value={sh.role}
                  onChange={(e) => {
                    setError(null)
                    updateRole.mutate(
                      { userId: sh.userId, role: e.target.value as ShareRole },
                      { onError: onMutationError('Could not change that role.') },
                    )
                  }}
                  aria-label={`Role for ${sh.displayName}`}
                  className={cn(fieldControlClass, 'w-auto px-2 py-1 text-sm')}
                >
                  <option value="viewer">Viewer</option>
                  <option value="editor">Editor</option>
                </select>
                <button
                  type="button"
                  onClick={() => {
                    setError(null)
                    remove.mutate(sh.userId, { onError: onMutationError('Could not remove that person.') })
                  }}
                  aria-label={`Remove ${sh.displayName}`}
                  className="rounded-md px-2 py-1 text-sm text-muted transition-colors hover:bg-red-500/10 hover:text-red-600 dark:hover:text-red-400"
                >
                  ✕
                </button>
              </li>
            ))}
          </ul>
        </div>

        <div className="flex justify-end">
          <Button variant="ghost" onClick={onClose}>
            Done
          </Button>
        </div>
      </div>
    </Modal>
  )
}