// Shared read-through for public site settings (site_base_url, facility_name).
// The settings GET is public (jwt optional), so the kiosk dashboard and the
// print views can read these without auth. Fetched once and cached per page.
import { settingsApi } from '@/api'
import { withBase } from '@/utils/basePath'

let settingsCache = null
let inFlight = null
let retryAfter = 0

// Whether the last resolved load actually produced settings. A caller cannot
// tell that from the value alone: a failed load and a site that simply has not
// configured a key both read as empty, and those want opposite handling -
// hide the feature vs try again.
export function settingsLoadFailed() {
  return settingsCache === null
}

// A failed load is cached briefly, not for the page session. A transient blip
// used to blank every settings-driven link until the operator reloaded, and
// they have no reason to know that would fix it. A short window still bounds a
// hard-down backend to two requests a minute per client.
const FAILURE_RETRY_MS = 30000

// The in-flight promise is cached alongside the result. Callers that arrive
// during the first load share one request instead of each firing their own;
// applyBranding() alone awaits five settings in sequence at bootstrap.
async function loadSettings() {
  if (settingsCache) return settingsCache
  if (inFlight) return inFlight
  if (retryAfter && Date.now() < retryAfter) return {}
  inFlight = settingsApi.list()
    .then((response) => {
      const items = response.data?.data || response.data || []
      const loaded = {}
      for (const s of items) loaded[s.key] = s.value
      settingsCache = loaded
      retryAfter = 0
      return loaded
    })
    .catch((error) => {
      console.error('Error loading site settings:', error)
      retryAfter = Date.now() + FAILURE_RETRY_MS
      return {}
    })
    .finally(() => { inFlight = null })
  return inFlight
}

export async function getSetting(key, fallback = '') {
  const settings = await loadSettings()
  const value = settings[key]
  return (value === undefined || value === null || value === '') ? fallback : value
}

// Public base URL for QR codes / absolute links. Falls back to the current
// browsing origin when a site has not set one.
export async function getSiteBaseUrl() {
  return getSetting('site_base_url', window.location.origin)
}

// Facility name shown on the shopfloor dashboard.
export async function getFacilityName() {
  return getSetting('facility_name', 'ShopDB')
}

// Environment channel label (e.g. 'DEV') injected by the backend from
// SHOPDB_ENV_LABEL. Empty on stable/main deployments, which renders no badge.
// Drives the red DEV tag in the sidebar so a bleeding-edge container is
// obviously distinct from a stable one running side by side.
export async function getEnvLabel() {
  return getSetting('env_label', '')
}

// Main site logo (sidebar, login, dashboard header). Fallback = shipped GE mark.
export async function getSiteLogo() {
  return withBase(await getSetting('site_logo', '/ge-aerospace-logo.svg'))
}

// Logo composited into the center of printer QR codes. Empty = no overlay.
// Note: '' is a valid "no overlay" value, so read the raw setting rather than
// getSetting (which swaps '' for the fallback).
export async function getQrLogo() {
  const settings = await loadSettings()
  const value = settings['qr_logo']
  return withBase((value === undefined || value === null) ? '/ge-monogram.svg' : value)
}

// Logo printed on machine inspection badges.
export async function getBadgeLogo() {
  return withBase(await getSetting('badge_logo', '/ge-aerospace-logo.svg'))
}

// Browser-tab favicon. Empty = keep the shipped /favicon.svg.
export async function getFavicon() {
  const value = await getSetting('site_favicon', '')
  return value ? withBase(value) : value
}

// Brand primary color override. Empty = built-in palette from style.css.
export async function getBrandPrimaryColor() {
  return getSetting('brand_primary_color', '')
}

// Primary hover/active color (--primary-dark). Empty = derive from primary.
export async function getBrandPrimaryDarkColor() {
  return getSetting('brand_primary_dark_color', '')
}

// Accent color (--secondary). Empty = built-in palette from style.css.
export async function getBrandAccentColor() {
  return getSetting('brand_accent_color', '')
}

// Sidebar background color (--sidebar-bg). Empty = built-in palette.
export async function getBrandSidebarColor() {
  return getSetting('brand_sidebar_color', '')
}

// Darken a #rrggbb hex color by the given fraction (0.15 = 15% darker).
// Returns null for anything that is not a 6-digit hex so callers can skip it.
function darkenHexColor(hex, fraction) {
  const match = /^#([0-9a-fA-F]{6})$/.exec(hex)
  if (!match) return null
  const num = parseInt(match[1], 16)
  const scale = 1 - fraction
  const red = Math.round(((num >> 16) & 0xff) * scale)
  const green = Math.round(((num >> 8) & 0xff) * scale)
  const blue = Math.round((num & 0xff) * scale)
  const toHex = (channel) => channel.toString(16).padStart(2, '0')
  return `#${toHex(red)}${toHex(green)}${toHex(blue)}`
}

// ServiceNow ticket-link config. Returns the enabled flag, incident/change URL
// templates, and the global-search URL template (all with a {ticket}
// placeholder).
//
// The defaults are BLANK and the integration ships OFF, matching the server.
// They used to be one organisation's QA ServiceNow tenant, so any site that had
// not configured ServiceNow still rendered ticket links - pointing its
// technicians at a tenant they cannot reach and, for an adopting site, at
// somebody else's. A blank URL renders tickets as plain text, which is the
// correct behaviour for "not configured".
export async function getServicenowUrls() {
  const enabledRaw = await getSetting('servicenow_enabled', 'false')
  const enabled = enabledRaw !== 'false' && enabledRaw !== '0' && enabledRaw !== false
  const incidentUrl = await getSetting('servicenow_incident_url', '')
  const changeUrl = await getSetting('servicenow_change_url', '')
  const searchUrl = await getSetting('servicenow_search_url', '')
  return { enabled, incidentUrl, changeUrl, searchUrl }
}

// Deep links into the Azure portal for a device ShopDB knows the Entra ids of.
//
// Both are TEMPLATES held in settings rather than built here, because the host
// is a tenant fact: this site is on the US Government cloud (portal.azure.us)
// and the commercial cloud is portal.azure.com. Microsoft also moves these
// blade paths from time to time, and a site can fix that itself by editing a
// setting instead of waiting for a release.
//
// Empty is the default and means "no link" - the id still renders as text.
//
// `loaded` distinguishes a real answer from a failed fetch. Both return empty
// strings, but only one of them means "this site has no portal links".
export async function getEntraDeviceUrls() {
  const entraUrl = await getSetting('entra_device_url', '')
  const intuneUrl = await getSetting('intune_device_url', '')
  const lapsUrl = await getSetting('laps_device_url', '')
  return { entraUrl, intuneUrl, lapsUrl, loaded: !settingsLoadFailed() }
}

// Printer hostname template. {ip} is replaced with the dash-separated IP.
export async function getPrinterHostnameTemplate() {
  return getSetting('printer_hostname_template', 'Printer-{ip}.printer.geaerospace.net')  // ADR-015-OK: GE Aerospace-wide domain, and only the DEFAULT of a documented setting every site can override.
}

// Email domain appended to a contact SSO to build email/Teams links
// (sso@domain). Unset falls back to geaerospace.com; an explicit blank value
// means "disable contact action buttons", so read the raw setting rather than
// getSetting (which swaps '' for the fallback).
export async function getContactEmailDomain() {
  const settings = await loadSettings()
  const value = settings['contact_email_domain']
  return (value === undefined || value === null) ? 'geaerospace.com' : value
}

// Apply per-site favicon + brand color at bootstrap. Empty settings keep the
// shipped defaults. Do not touch the style.css palette here.
export async function applyBranding() {
  const favicon = await getFavicon()
  if (favicon) {
    let link = document.querySelector('link[rel="icon"]')
    if (!link) {
      link = document.createElement('link')
      link.rel = 'icon'
      document.head.appendChild(link)
    }
    link.href = favicon
  }
  const rootStyle = document.documentElement.style
  const primaryColor = await getBrandPrimaryColor()
  if (primaryColor) {
    rootStyle.setProperty('--primary', primaryColor)
  }
  // Hover color: use the explicit value, else darken primary ~15%.
  const primaryDarkColor = await getBrandPrimaryDarkColor()
  if (primaryDarkColor) {
    rootStyle.setProperty('--primary-dark', primaryDarkColor)
  } else if (primaryColor) {
    const derived = darkenHexColor(primaryColor, 0.15)
    if (derived) rootStyle.setProperty('--primary-dark', derived)
  }
  const accentColor = await getBrandAccentColor()
  if (accentColor) {
    rootStyle.setProperty('--secondary', accentColor)
  }
  const sidebarColor = await getBrandSidebarColor()
  if (sidebarColor) {
    rootStyle.setProperty('--sidebar-bg', sidebarColor)
  }
}