import { useState } from 'react'
import { api } from '../../api/client.js'

// Shown when a user tries to trust a device but is already at the trusted-device
// cap. Styled like the TOTP entry flow (centered card on a dim overlay). The user
// MUST revoke at least one existing device before they can continue — there is no
// silent pruning — or they can cancel and leave the device untrusted.
//
// Props:
//   devices    — the existing trusted devices (from the 409 / trustLimitReached payload)
//   onTrusted  — called after the current device is successfully trusted (post-revoke)
//   onCancel   — called when the user backs out without trusting this device
export default function TrustLimitModal({ devices: initialDevices, onTrusted, onCancel }) {
  const [devices, setDevices] = useState(initialDevices || [])
  const [revokedAny, setRevokedAny] = useState(false)
  const [busy, setBusy] = useState(false)
  const [error, setError] = useState('')

  async function revoke(id) {
    setBusy(true)
    setError('')
    try {
      await api.revokeTrustedDevice(id)
      setDevices((list) => list.filter((d) => d.id !== id))
      setRevokedAny(true)
    } catch {
      setError('Could not revoke that device. Please try again.')
    } finally {
      setBusy(false)
    }
  }

  async function trustNow() {
    setBusy(true)
    setError('')
    try {
      await api.trustThisDevice()
      onTrusted?.()
    } catch (err) {
      // Still at the cap somehow (a race) — surface it and let them revoke more.
      if (err.status === 409 && err.body?.devices) {
        setDevices(err.body.devices)
        setError('Still at the limit — revoke another device.')
      } else {
        setError('Could not trust this device. Please try again.')
      }
    } finally {
      setBusy(false)
    }
  }

  return (
    <div style={overlay} role="dialog" aria-modal="true" aria-label="Trusted-device limit reached">
      <div style={card}>
        <h2 className="display" style={{ margin: '0 0 8px', fontSize: '1.15rem', color: 'var(--head)' }}>
          Trusted-device limit reached
        </h2>
        <p className="sans" style={{ margin: '0 0 16px', color: 'var(--muted)', fontSize: '0.88rem', lineHeight: 1.6 }}>
          You can trust up to {Math.max(devices.length, 1)} devices. Revoke one below to make room, then
          continue — or cancel to leave this device untrusted.
        </p>

        <div style={{ display: 'flex', flexDirection: 'column', gap: 8, marginBottom: 16, maxHeight: 240, overflowY: 'auto' }}>
          {devices.map((d) => (
            <div key={d.id} style={row}>
              <div style={{ flex: 1, minWidth: 0 }}>
                <div className="sans" style={{ color: 'var(--head)', fontSize: '0.88rem' }}>
                  {d.deviceName || d.platform || 'Device'}
                </div>
                <div className="sans dim" style={{ fontSize: '0.74rem', overflow: 'hidden', textOverflow: 'ellipsis', whiteSpace: 'nowrap' }}>
                  {d.userAgent || '—'}
                </div>
              </div>
              <button onClick={() => revoke(d.id)} disabled={busy} className="pill" style={{ color: '#d98b84', borderColor: '#d98b84' }}>
                Revoke
              </button>
            </div>
          ))}
          {devices.length === 0 && (
            <p className="sans dim" style={{ fontSize: '0.84rem', margin: 0 }}>All devices revoked. You can trust this one now.</p>
          )}
        </div>

        {error && <p className="sans" style={{ margin: '0 0 12px', color: '#d98b84', fontSize: '0.84rem' }}>{error}</p>}

        <div style={{ display: 'flex', gap: 10, alignItems: 'center' }}>
          <button onClick={trustNow} disabled={busy || !revokedAny} className="btn btn-primary btn-sq">
            {busy ? 'Working…' : 'Trust this device'}
          </button>
          <button onClick={onCancel} disabled={busy} className="pill">
            Cancel
          </button>
        </div>
      </div>
    </div>
  )
}

const overlay = {
  position: 'fixed',
  inset: 0,
  background: 'rgba(0,0,0,0.6)',
  display: 'flex',
  alignItems: 'center',
  justifyContent: 'center',
  padding: 16,
  zIndex: 1000,
}
const card = {
  width: '100%',
  maxWidth: 460,
  background: 'var(--panel, #1a1a1f)',
  border: '1px solid var(--line)',
  borderRadius: 12,
  padding: 24,
}
const row = {
  display: 'flex',
  alignItems: 'center',
  gap: 12,
  padding: '10px 14px',
  border: '1px solid var(--line)',
  borderRadius: 8,
}