/** SiteForge session/API boundary. Do not use Art demo login tokens as SiteForge credentials. */
export interface SiteRef { id:string; name:string; domain?:string }
export interface SiteForgeCapabilities { role:string; view:boolean; edit:boolean; review:boolean; deploy:boolean; manage_members:boolean; create_site:boolean; manage_users:boolean }
export interface SiteForgeBootstrap {
  version:string; user:string; superadmin:boolean; sites:SiteRef[]; selected_site_id:string|null;
  capabilities:SiteForgeCapabilities;
  navigation:Array<{key:string;title:string;path:string;requires_site:boolean}>
}
let csrfCache:string|undefined
const key='siteforge:art-selected-site'

export class SiteForgeError extends Error {
  constructor(message:string,readonly status:number){super(message);this.name='SiteForgeError'}
}
export async function sfApi<T>(path:string, init:RequestInit={}):Promise<T>{
  if(!path.startsWith('/api/') || path.startsWith('//'))throw new Error('仅允许调用本站 SiteForge API')
  const method=(init.method||'GET').toUpperCase()
  const headers=new Headers(init.headers)
  if(!['GET','HEAD'].includes(method)){
    if(!csrfCache){const me=await sfApi<{csrf:string}>('/api/auth/me');csrfCache=me.csrf}
    headers.set('X-SiteForge-CSRF',csrfCache)
  }
  const res=await fetch(path,{...init,method,headers,credentials:'same-origin',redirect:'follow'})
  if(res.status===401){csrfCache=undefined;throw new SiteForgeError('SiteForge 登录已过期，请从统一登录页重新登录',401)}
  const contentType=res.headers.get('content-type')||''
  if(!contentType.includes('application/json'))throw new SiteForgeError('接口返回了非 JSON 响应，请检查同域 API 代理配置',502)
  const data=await res.json()
  if(!res.ok){
    const detail=typeof data?.detail==='string'?data.detail:JSON.stringify(data?.detail||'请求失败')
    throw new SiteForgeError(detail,res.status)
  }
  return data as T
}
export async function session(){const me=await sfApi<{csrf:string;user:string}>('/api/auth/me');csrfCache=me.csrf;return me}
export function preferredSite<T extends SiteRef>(sites:T[]):string{
  const params=new URLSearchParams(window.location.search)
  const proposed=params.get('site') || sessionStorage.getItem(key) || ''
  const chosen=sites.find(s=>s.id===proposed) || sites[0]
  if(chosen)sessionStorage.setItem(key,chosen.id)
  return chosen?.id||''
}
export function rememberSite(siteId:string){if(siteId)sessionStorage.setItem(key,siteId)}
export async function bootstrap():Promise<SiteForgeBootstrap>{
  const preferred=sessionStorage.getItem(key)||''
  try {
    return await sfApi<SiteForgeBootstrap>('/api/console/bootstrap'+(preferred?'?site_id='+encodeURIComponent(preferred):''))
  } catch(e){
    if(e instanceof SiteForgeError && e.status===403){sessionStorage.removeItem(key);return sfApi<SiteForgeBootstrap>('/api/console/bootstrap')}
    throw e
  }
}
export function postJson(body:unknown):RequestInit{return {method:'POST',headers:{'Content-Type':'application/json'},body:JSON.stringify(body)}}
export function patchJson(body:unknown):RequestInit{return {method:'PATCH',headers:{'Content-Type':'application/json'},body:JSON.stringify(body)}}