// InvitationsModal.jsx — v0.16.0 / roadmap item #12.
//
// The RFC owner's surface for issuing per-RFC invitations and watching
// who has accepted. Opens from the RFC view's header strip when the
// viewer is the RFC's owner (or a platform admin/owner). Non-owner
// viewers never see the trigger.
//
// The modal shows two stacked sections:
//
//   1. "Invite someone" — email input + role picker
//      (contributor | discussant) + Send. The send goes through the
//      backend's POST /api/rfcs/<slug>/invitations, which both writes
//      the row and dispatches the email to the invitee. Success
//      refreshes the list below and clears the input.
//
//   2. "Existing invitations" — every invitation (pending +
//      accepted + revoked + expired) on this RFC, with revoke
//      buttons on the pending ones. The status of each row is the
//      effective status (the backend recomputes expired-from-pending
//      at read time so an unattended cron isn't required).
//
// No custom-message field — that belongs to item #16's platform-
// level surface, not here. No bulk-invite — one email at a time
// keeps the gesture deliberate.

import { useEffect, useState } from 'react'
import {
  createRFCInvitation,
  listRFCInvitations,
  revokeRFCInvitation,
} from '../api'
import { EVENTS, track } from '../lib/analytics'

const ROLE_OPTIONS = [
  { value: 'contributor', label: 'Contributor — can open PRs and join discussion' },
  { value: 'discussant', label: 'Discussant — can join discussion only' },
]

export default function InvitationsModal({ slug, rfcTitle, onClose }) {
  const [invitations, setInvitations] = useState(null)
  const [loadError, setLoadError] = useState(null)
  const [inviteeEmail, setInviteeEmail] = useState('')
  const [roleInRFC, setRoleInRFC] = useState('contributor')
  const [submitting, setSubmitting] = useState(false)
  const [submitError, setSubmitError] = useState(null)
  const [submitSuccess, setSubmitSuccess] = useState(null)
  const [revokingId, setRevokingId] = useState(null)

  async function refresh() {
    setLoadError(null)
    try {
      const r = await listRFCInvitations(slug)
      setInvitations(r.items || [])
    } catch (e) {
      setLoadError(e.message)
    }
  }

  useEffect(() => { refresh() /* eslint-disable-line react-hooks/exhaustive-deps */ }, [slug])

  async function handleSend(e) {
    e.preventDefault()
    const email = inviteeEmail.trim()
    if (!email) return
    setSubmitting(true)
    setSubmitError(null)
    setSubmitSuccess(null)
    try {
      await createRFCInvitation(slug, { inviteeEmail: email, roleInRFC })
      // v0.16.0 + #21 Part C — Amplitude wiring. No PII (the email
      // is the inviter's input, not the invitee's identity in our
      // analytics; we record the rfc_slug + role_in_rfc so a future
      // invite→accept correlation has both halves).
      track(EVENTS.INVITATION_SENT, { rfc_slug: slug, role_in_rfc: roleInRFC })
      setSubmitSuccess(`Invitation sent to ${email}.`)
      setInviteeEmail('')
      await refresh()
    } catch (err) {
      setSubmitError(err.message || 'Failed to send invitation.')
    } finally {
      setSubmitting(false)
    }
  }

  async function handleRevoke(invitationId) {
    setRevokingId(invitationId)
    try {
      await revokeRFCInvitation(slug, invitationId)
      await refresh()
    } catch (err) {
      setSubmitError(err.message || 'Failed to revoke invitation.')
    } finally {
      setRevokingId(null)
    }
  }

  return (
    <div className="modal-overlay" onClick={e => { if (e.target === e.currentTarget) onClose() }}>
      <div className="modal" style={{ maxWidth: 640 }}>
        <div className="modal-header">
          <h2>Invitations — {rfcTitle || slug}</h2>
          <button className="modal-close" onClick={onClose}>×</button>
        </div>
        <div className="modal-body">
          <p style={{ marginTop: 0, color: '#666' }}>
            Invite people by email to contribute PRs against this RFC or to
            join its discussion. Anyone with the link can read this RFC;
            this surface controls who can <em>write</em>.
          </p>

          <form onSubmit={handleSend} className="invitations-form" style={{ marginTop: 16 }}>
            <label htmlFor="invitee-email">Invitee email</label>
            <input
              id="invitee-email"
              type="email"
              value={inviteeEmail}
              onChange={e => setInviteeEmail(e.target.value)}
              placeholder="someone@example.com"
              autoFocus
              required
            />
            <label htmlFor="invitee-role" style={{ marginTop: 10 }}>Role on this RFC</label>
            <select
              id="invitee-role"
              value={roleInRFC}
              onChange={e => setRoleInRFC(e.target.value)}
            >
              {ROLE_OPTIONS.map(opt => (
                <option key={opt.value} value={opt.value}>{opt.label}</option>
              ))}
            </select>
            <div style={{ marginTop: 12, display: 'flex', gap: 8, alignItems: 'center' }}>
              <button type="submit" className="btn-primary" disabled={submitting}>
                {submitting ? 'Sending…' : 'Send invitation'}
              </button>
              {submitError && <span style={{ color: '#c33' }}>{submitError}</span>}
              {submitSuccess && <span style={{ color: '#383' }}>{submitSuccess}</span>}
            </div>
          </form>

          <hr style={{ margin: '20px 0' }} />

          <h3 style={{ margin: '0 0 8px' }}>Existing invitations</h3>
          {loadError && <div className="error-banner">{loadError}</div>}
          {invitations === null && <div>Loading…</div>}
          {invitations !== null && invitations.length === 0 && (
            <div style={{ color: '#666' }}>No invitations have been sent yet.</div>
          )}
          {invitations !== null && invitations.length > 0 && (
            <table style={{ width: '100%', borderCollapse: 'collapse' }}>
              <thead>
                <tr>
                  <th style={{ textAlign: 'left', padding: 4 }}>Email</th>
                  <th style={{ textAlign: 'left', padding: 4 }}>Role</th>
                  <th style={{ textAlign: 'left', padding: 4 }}>Status</th>
                  <th style={{ textAlign: 'left', padding: 4 }}>Sent</th>
                  <th style={{ padding: 4 }}></th>
                </tr>
              </thead>
              <tbody>
                {invitations.map(inv => (
                  <tr key={inv.id} style={{ borderTop: '1px solid #eee' }}>
                    <td style={{ padding: 4 }}>{inv.invitee_email}</td>
                    <td style={{ padding: 4 }}>{inv.role_in_rfc}</td>
                    <td style={{ padding: 4 }}>
                      <span className={`invitation-status status-${inv.status}`}>
                        {inv.status}
                      </span>
                      {inv.status === 'accepted' && inv.accepted_by_display && (
                        <span style={{ color: '#666', marginLeft: 6 }}>
                          by {inv.accepted_by_display}
                        </span>
                      )}
                    </td>
                    <td style={{ padding: 4, color: '#666' }}>
                      {inv.created_at?.slice(0, 10) || ''}
                    </td>
                    <td style={{ padding: 4, textAlign: 'right' }}>
                      {inv.status === 'pending' && (
                        <button
                          type="button"
                          className="btn-link"
                          onClick={() => handleRevoke(inv.id)}
                          disabled={revokingId === inv.id}
                        >
                          {revokingId === inv.id ? 'Revoking…' : 'Revoke'}
                        </button>
                      )}
                    </td>
                  </tr>
                ))}
              </tbody>
            </table>
          )}
        </div>
        <div className="modal-footer">
          <button type="button" className="btn-link" onClick={onClose}>Close</button>
        </div>
      </div>
    </div>
  )
}