import { useEffect, useState } from 'react'
import { X, Thermometer, History } from 'lucide-react'
import type { ZoneStatus, ActivityEntry, HvacDefaults } from '../types'
import { ROOM_STATE_LABELS, DEFAULT_HVAC_TEMPLATE, MHI_MODES, MHI_FAN_SPEEDS, can } from '../types'
import { useAuth } from './AuthGate'
import { updateZone, overrideZone, fetchActivity, fetchConfig } from '../api'
import MhiControlPanel from './MhiControlPanel'

// The 12 fields a room can individually override — each is `null` on the zone when
// inheriting the matching field from the global hvac_defaults template (Settings page),
// or an explicit value when overridden. Mirrors the OVERRIDABLE_FIELDS list in
// backend/src/routes/zones.js.
type OverridableField =
  | 'occupied_temp' | 'vacant_temp' | 'heating_offset_min' | 'cooling_offset_min'
  | 'ac_occupied_power' | 'ac_occupied_mode' | 'ac_occupied_setpoint' | 'ac_occupied_fan_speed'
  | 'ac_vacant_power' | 'ac_vacant_mode' | 'ac_vacant_setpoint' | 'ac_vacant_fan_speed'

function defaultFor(field: OverridableField, d: HvacDefaults): string | number {
  switch (field) {
    case 'occupied_temp': return d.trv_occupied_temp
    case 'vacant_temp': return d.trv_vacant_temp
    case 'heating_offset_min': return d.arrival_prep_offset_min
    case 'cooling_offset_min': return d.departure_prep_offset_min
    case 'ac_occupied_power': return d.ac_occupied.power
    case 'ac_occupied_mode': return d.ac_occupied.mode
    case 'ac_occupied_setpoint': return d.ac_occupied.setpoint
    case 'ac_occupied_fan_speed': return d.ac_occupied.fan_speed
    case 'ac_vacant_power': return d.ac_vacant.power
    case 'ac_vacant_mode': return d.ac_vacant.mode
    case 'ac_vacant_setpoint': return d.ac_vacant.setpoint
    case 'ac_vacant_fan_speed': return d.ac_vacant.fan_speed
  }
}

// Checkbox + either the override input (children) or the inherited default value,
// depending on whether this field is currently overridden.
function OverrideCell({ checked, defaultLabel, onToggle, children }: {
  checked: boolean
  defaultLabel: string
  onToggle: (checked: boolean) => void
  children: React.ReactNode
}) {
  return (
    <div>
      <label style={{ display: 'flex', alignItems: 'center', gap: 4, fontSize: 11, color: 'var(--text-mid)', marginBottom: 4, cursor: 'pointer' }}>
        <input type="checkbox" checked={checked} onChange={e => onToggle(e.target.checked)} style={{ width: 13, height: 13 }} />
        Override
      </label>
      {checked ? children : <span className="muted" style={{ fontSize: 13 }}>{defaultLabel}</span>}
    </div>
  )
}

export default function ZoneDetailModal({ zone, onClose, onSaved }: {
  zone: ZoneStatus
  onClose: () => void
  onSaved: () => void
}) {
  const { user } = useAuth()
  const canEdit = can(user, 'schedule_edit')
  const canControl = can(user, 'control')

  const [hvacDefaults, setHvacDefaults] = useState<HvacDefaults>(DEFAULT_HVAC_TEMPLATE)
  const [overrides, setOverrides] = useState<Record<OverridableField, string | number | null>>({
    occupied_temp: zone.occupied_temp,
    vacant_temp: zone.vacant_temp,
    heating_offset_min: zone.heating_offset_min,
    cooling_offset_min: zone.cooling_offset_min,
    ac_occupied_power: zone.ac_occupied_power,
    ac_occupied_mode: zone.ac_occupied_mode,
    ac_occupied_setpoint: zone.ac_occupied_setpoint,
    ac_occupied_fan_speed: zone.ac_occupied_fan_speed,
    ac_vacant_power: zone.ac_vacant_power,
    ac_vacant_mode: zone.ac_vacant_mode,
    ac_vacant_setpoint: zone.ac_vacant_setpoint,
    ac_vacant_fan_speed: zone.ac_vacant_fan_speed,
  })
  const [autoMode, setAutoMode] = useState(zone.auto_mode)
  const [syncValves, setSyncValves] = useState(zone.sync_valves)
  const [excludeBathroom, setExcludeBathroom] = useState(zone.exclude_bathroom)
  const [overrideTemp, setOverrideTemp] = useState(zone.occupied_temp ?? String(hvacDefaults.trv_occupied_temp))
  const [saving, setSaving] = useState(false)
  const [error, setError] = useState('')
  const [msg, setMsg] = useState('')
  const [activity, setActivity] = useState<ActivityEntry[]>([])

  useEffect(() => {
    fetchActivity(zone.id, 20).then(setActivity).catch(() => {})
    fetchConfig().then(cfg => setHvacDefaults(cfg.hvac_defaults ?? DEFAULT_HVAC_TEMPLATE)).catch(() => {})
  }, [zone.id])

  function toggleOverride(field: OverridableField, checked: boolean) {
    setOverrides(o => ({ ...o, [field]: checked ? defaultFor(field, hvacDefaults) : null }))
  }
  function setOverrideValue(field: OverridableField, value: string | number) {
    setOverrides(o => ({ ...o, [field]: value }))
  }

  async function save() {
    setSaving(true); setError(''); setMsg('')
    try {
      await updateZone(zone.id, {
        occupied_temp: overrides.occupied_temp != null ? Number(overrides.occupied_temp) : null,
        vacant_temp: overrides.vacant_temp != null ? Number(overrides.vacant_temp) : null,
        heating_offset_min: overrides.heating_offset_min != null ? Number(overrides.heating_offset_min) : null,
        cooling_offset_min: overrides.cooling_offset_min != null ? Number(overrides.cooling_offset_min) : null,
        ac_occupied_power: overrides.ac_occupied_power || null,
        ac_occupied_mode: overrides.ac_occupied_mode || null,
        ac_occupied_setpoint: overrides.ac_occupied_setpoint != null ? Number(overrides.ac_occupied_setpoint) : null,
        ac_occupied_fan_speed: overrides.ac_occupied_fan_speed || null,
        ac_vacant_power: overrides.ac_vacant_power || null,
        ac_vacant_mode: overrides.ac_vacant_mode || null,
        ac_vacant_setpoint: overrides.ac_vacant_setpoint != null ? Number(overrides.ac_vacant_setpoint) : null,
        ac_vacant_fan_speed: overrides.ac_vacant_fan_speed || null,
        auto_mode: autoMode,
        sync_valves: syncValves,
        exclude_bathroom: excludeBathroom,
      })
      setMsg('Saved')
      onSaved()
    } catch (e) {
      setError(e instanceof Error ? e.message : 'Save failed')
    } finally {
      setSaving(false)
    }
  }

  async function forceTemp() {
    setSaving(true); setError(''); setMsg('')
    try {
      const res = await overrideZone(zone.id, Number(overrideTemp))
      if (res.ok) {
        setMsg(`Set to ${overrideTemp}°C (${res.successful}/${res.total} devices) — auto mode disabled`)
        setAutoMode(false)
        onSaved()
      } else {
        setError(res.error || 'Override failed')
      }
    } catch (e) {
      setError(e instanceof Error ? e.message : 'Override failed')
    } finally {
      setSaving(false)
    }
  }

  return (
    <div className="modal-overlay" onClick={onClose}>
      <div className="modal" onClick={e => e.stopPropagation()}>
        <div className="modal-header">
          <h2>{zone.name}</h2>
          <button className="modal-close" onClick={onClose}><X size={18} strokeWidth={1.75} /></button>
        </div>

        <div className={`badge badge-st-${zone.room_state}`} style={{ marginBottom: 10 }}>
          {ROOM_STATE_LABELS[zone.room_state]}
        </div>

        {error && <div className="error-banner">{error}</div>}
        {msg && <div className="ok-banner">{msg}</div>}

        <div className="section-title">Devices</div>
        {zone.devices.length === 0 && <p className="muted">No devices mapped to this zone yet — assign some on the Devices page.</p>}
        {zone.devices.map(d => (
          <div key={d.id} className="card">
            <div style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center' }}>
              <div>
                <div style={{ fontWeight: 600, fontSize: 13 }}>{d.location || d.discovered_name || d.external_ref}</div>
                <div className="muted" style={{ fontSize: 12 }}>
                  {d.current_target_temp != null ? `${Number(d.current_target_temp).toFixed(1)}°C` : '—'}
                  {d.battery_pct != null && ` · ${d.battery_pct}% battery`}
                </div>
              </div>
              <span className={`badge badge-health-${d.health_state}`}>{d.health_state.replace('_', ' ')}</span>
            </div>
            {(d.device_type === 'mhi_modbus' || d.device_type === 'mhi_mqtt') && <MhiControlPanel deviceId={d.id} canControl={canControl} />}
          </div>
        ))}

        {canControl && (
          <>
            <div className="section-title">Manual Override</div>
            <div className="field-row">
              <div className="field" style={{ flex: 'none', width: 120 }}>
                <input type="number" step="0.5" value={overrideTemp} onChange={e => setOverrideTemp(e.target.value)} />
              </div>
              <button className="btn" disabled={saving} onClick={forceTemp}>
                <Thermometer size={14} strokeWidth={1.75} /> Force temperature
              </button>
            </div>
            <p className="field-hint">Disables auto mode for this zone until re-enabled below.</p>
          </>
        )}

        {canEdit && (
          <>
            <div className="section-title">Schedule</div>
            <p className="field-hint" style={{ marginBottom: 10 }}>
              Every value below inherits the global default (Settings → Default Templates) unless overridden here.
            </p>

            <div className="field-row">
              <div className="field">
                <label>Heating offset (mins before arrival)</label>
                <OverrideCell
                  checked={overrides.heating_offset_min != null}
                  defaultLabel={`Default: ${hvacDefaults.arrival_prep_offset_min} mins`}
                  onToggle={c => toggleOverride('heating_offset_min', c)}
                >
                  <input
                    type="number" value={overrides.heating_offset_min ?? 0}
                    onChange={e => setOverrideValue('heating_offset_min', parseInt(e.target.value) || 0)}
                  />
                </OverrideCell>
              </div>
              <div className="field">
                <label>Cooling offset (mins after departure)</label>
                <OverrideCell
                  checked={overrides.cooling_offset_min != null}
                  defaultLabel={`Default: ${hvacDefaults.departure_prep_offset_min} mins`}
                  onToggle={c => toggleOverride('cooling_offset_min', c)}
                >
                  <input
                    type="number" value={overrides.cooling_offset_min ?? 0}
                    onChange={e => setOverrideValue('cooling_offset_min', parseInt(e.target.value) || 0)}
                  />
                </OverrideCell>
              </div>
            </div>

            <div style={{ fontWeight: 600, fontSize: 13, margin: '10px 0 6px' }}>Aircon</div>
            <div className="table-wrap" style={{ marginBottom: 16 }}>
              <table className="data">
                <thead><tr><th></th><th>Occupied</th><th>Vacant</th></tr></thead>
                <tbody>
                  <tr>
                    <td>On/Off</td>
                    <td>
                      <OverrideCell
                        checked={overrides.ac_occupied_power != null}
                        defaultLabel={hvacDefaults.ac_occupied.power === 'on' ? 'Default: On' : 'Default: Off'}
                        onToggle={c => toggleOverride('ac_occupied_power', c)}
                      >
                        <select value={overrides.ac_occupied_power ?? 'on'} onChange={e => setOverrideValue('ac_occupied_power', e.target.value)}>
                          <option value="on">On</option><option value="off">Off</option>
                        </select>
                      </OverrideCell>
                    </td>
                    <td>
                      <OverrideCell
                        checked={overrides.ac_vacant_power != null}
                        defaultLabel={hvacDefaults.ac_vacant.power === 'on' ? 'Default: On' : 'Default: Off'}
                        onToggle={c => toggleOverride('ac_vacant_power', c)}
                      >
                        <select value={overrides.ac_vacant_power ?? 'off'} onChange={e => setOverrideValue('ac_vacant_power', e.target.value)}>
                          <option value="on">On</option><option value="off">Off</option>
                        </select>
                      </OverrideCell>
                    </td>
                  </tr>
                  <tr>
                    <td>Mode</td>
                    <td>
                      <OverrideCell
                        checked={overrides.ac_occupied_mode != null}
                        defaultLabel={`Default: ${hvacDefaults.ac_occupied.mode}`}
                        onToggle={c => toggleOverride('ac_occupied_mode', c)}
                      >
                        <select value={overrides.ac_occupied_mode ?? 'cool'} onChange={e => setOverrideValue('ac_occupied_mode', e.target.value)}>
                          {MHI_MODES.map(m => <option key={m} value={m}>{m[0].toUpperCase() + m.slice(1)}</option>)}
                        </select>
                      </OverrideCell>
                    </td>
                    <td>
                      <OverrideCell
                        checked={overrides.ac_vacant_mode != null}
                        defaultLabel={`Default: ${hvacDefaults.ac_vacant.mode}`}
                        onToggle={c => toggleOverride('ac_vacant_mode', c)}
                      >
                        <select value={overrides.ac_vacant_mode ?? 'cool'} onChange={e => setOverrideValue('ac_vacant_mode', e.target.value)}>
                          {MHI_MODES.map(m => <option key={m} value={m}>{m[0].toUpperCase() + m.slice(1)}</option>)}
                        </select>
                      </OverrideCell>
                    </td>
                  </tr>
                  <tr>
                    <td>Setpoint (°C)</td>
                    <td>
                      <OverrideCell
                        checked={overrides.ac_occupied_setpoint != null}
                        defaultLabel={`Default: ${hvacDefaults.ac_occupied.setpoint}°C`}
                        onToggle={c => toggleOverride('ac_occupied_setpoint', c)}
                      >
                        <input
                          type="number" step="0.5" style={{ width: 90 }}
                          value={overrides.ac_occupied_setpoint ?? 0}
                          onChange={e => setOverrideValue('ac_occupied_setpoint', parseFloat(e.target.value) || 0)}
                        />
                      </OverrideCell>
                    </td>
                    <td>
                      <OverrideCell
                        checked={overrides.ac_vacant_setpoint != null}
                        defaultLabel={`Default: ${hvacDefaults.ac_vacant.setpoint}°C`}
                        onToggle={c => toggleOverride('ac_vacant_setpoint', c)}
                      >
                        <input
                          type="number" step="0.5" style={{ width: 90 }}
                          value={overrides.ac_vacant_setpoint ?? 0}
                          onChange={e => setOverrideValue('ac_vacant_setpoint', parseFloat(e.target.value) || 0)}
                        />
                      </OverrideCell>
                    </td>
                  </tr>
                  <tr>
                    <td>Fan speed</td>
                    <td>
                      <OverrideCell
                        checked={overrides.ac_occupied_fan_speed != null}
                        defaultLabel={`Default: ${hvacDefaults.ac_occupied.fan_speed}`}
                        onToggle={c => toggleOverride('ac_occupied_fan_speed', c)}
                      >
                        <select value={overrides.ac_occupied_fan_speed ?? 'medium'} onChange={e => setOverrideValue('ac_occupied_fan_speed', e.target.value)}>
                          {MHI_FAN_SPEEDS.map(f => <option key={f} value={f}>{f[0].toUpperCase() + f.slice(1)}</option>)}
                        </select>
                      </OverrideCell>
                    </td>
                    <td>
                      <OverrideCell
                        checked={overrides.ac_vacant_fan_speed != null}
                        defaultLabel={`Default: ${hvacDefaults.ac_vacant.fan_speed}`}
                        onToggle={c => toggleOverride('ac_vacant_fan_speed', c)}
                      >
                        <select value={overrides.ac_vacant_fan_speed ?? 'low'} onChange={e => setOverrideValue('ac_vacant_fan_speed', e.target.value)}>
                          {MHI_FAN_SPEEDS.map(f => <option key={f} value={f}>{f[0].toUpperCase() + f.slice(1)}</option>)}
                        </select>
                      </OverrideCell>
                    </td>
                  </tr>
                </tbody>
              </table>
            </div>

            <div style={{ fontWeight: 600, fontSize: 13, margin: '10px 0 6px' }}>TRVs</div>
            <div className="field-row">
              <div className="field">
                <label>Occupied setpoint (°C)</label>
                <OverrideCell
                  checked={overrides.occupied_temp != null}
                  defaultLabel={`Default: ${hvacDefaults.trv_occupied_temp}°C`}
                  onToggle={c => toggleOverride('occupied_temp', c)}
                >
                  <input
                    type="number" step="0.5" value={overrides.occupied_temp ?? 0}
                    onChange={e => setOverrideValue('occupied_temp', e.target.value)}
                  />
                </OverrideCell>
              </div>
              <div className="field">
                <label>Vacant setpoint (°C)</label>
                <OverrideCell
                  checked={overrides.vacant_temp != null}
                  defaultLabel={`Default: ${hvacDefaults.trv_vacant_temp}°C`}
                  onToggle={c => toggleOverride('vacant_temp', c)}
                >
                  <input
                    type="number" step="0.5" value={overrides.vacant_temp ?? 0}
                    onChange={e => setOverrideValue('vacant_temp', e.target.value)}
                  />
                </OverrideCell>
              </div>
            </div>

            <label className="field-check">
              <input type="checkbox" checked={autoMode} onChange={e => setAutoMode(e.target.checked)} />
              Auto mode (NewBook-driven scheduling)
            </label>
            <label className="field-check">
              <input type="checkbox" checked={syncValves} onChange={e => setSyncValves(e.target.checked)} />
              Sync guest adjustments across valves in this zone
            </label>
            <label className="field-check">
              <input type="checkbox" checked={excludeBathroom} onChange={e => setExcludeBathroom(e.target.checked)} />
              Exclude bathroom valve from sync
            </label>

            <div className="modal-actions">
              <button className="btn btn-primary" disabled={saving} onClick={save}>
                {saving ? 'Saving…' : 'Save'}
              </button>
            </div>
          </>
        )}

        {activity.length > 0 && (
          <>
            <div className="section-title"><History size={12} strokeWidth={1.75} style={{ verticalAlign: '-1px', marginRight: 4 }} />Recent activity</div>
            <div className="timeline">
              {activity.map(a => (
                <div key={a.id} className="timeline-item">
                  <div className="timeline-body">
                    {a.note}
                    <div className="timeline-meta">{new Date(a.created_at).toLocaleString()} · {a.source}</div>
                  </div>
                </div>
              ))}
            </div>
          </>
        )}
      </div>
    </div>
  )
}