export interface SessionSummary {
  id: string
  state: string
  model: string
  agent: string
  // Available in 9P mode, not in DBus list (fetch config for these)
  cwd?: string
  backend?: string
}

// Compat alias for components still using the old name.
export type IdxEntry = SessionSummary

export interface SessionConfig {
  model?: string
  backend?: string
  agent?: string
  cwd?: string
  state?: string
  [key: string]: string | undefined
}

export async function listSessions(): Promise<SessionSummary[]> {
  const r = await fetch('/sessions')
  if (!r.ok) return []
  const data = await r.json()
  return Array.isArray(data) ? (data as SessionSummary[]) : []
}

export async function getSessionCfg(id: string): Promise<SessionConfig> {
  const r = await fetch(`/sessions/${id}/config`)
  if (!r.ok) throw new Error(`config ${r.status}`)
  const data = await r.json()
  return (data && typeof data === 'object' && !Array.isArray(data))
    ? (data as SessionConfig)
    : {}
}

export async function getChatLines(id: string): Promise<string[]> {
  const r = await fetch(`/sessions/${id}/chat`)
  if (!r.ok) return []
  const text = await r.text()
  if (!text.trim()) return []
  return text.trimEnd().split('\n')
}

export async function getChatWithOffset(id: string, offset: number): Promise<{ text: string; newOffset: number }> {
  const r = await fetch(`/sessions/${id}/chat?offset=${offset}`)
  if (!r.ok) return { text: '', newOffset: offset }
  const text = await r.text()
  const newOffset = parseInt(r.headers.get('X-Chat-Offset') ?? String(offset), 10)
  return { text, newOffset }
}

export async function sendPrompt(id: string, prompt: string): Promise<void> {
  await fetch(`/sessions/${id}/submit`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ prompt }),
  })
}

export async function interruptSession(id: string): Promise<void> {
  await fetch(`/sessions/${id}/interrupt`, { method: 'POST' })
}

export async function createSession(params: {
  cwd?: string
  backend?: string
  model?: string
  agent?: string
}): Promise<string | null> {
  const r = await fetch('/sessions', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify(params),
  })
  if (!r.ok) return null
  const data = await r.json()
  return data.id ?? null
}

export async function killSession(id: string): Promise<void> {
  await fetch(`/sessions/${id}`, { method: 'DELETE' })
}

export async function renameSession(id: string, newName: string): Promise<void> {
  await fetch(`/sessions/${id}`, {
    method: 'PATCH',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ name: newName }),
  })
}

export async function setConfig(id: string, key: string, value: string): Promise<void> {
  await fetch(`/sessions/${id}/config`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ key, value }),
  })
}

export async function getState(id: string): Promise<string> {
  const r = await fetch(`/sessions/${id}/state`)
  if (!r.ok) return 'unknown'
  const data = await r.json()
  return data.state ?? 'unknown'
}

export async function getBackends(): Promise<string[]> {
  const r = await fetch('/backends')
  if (!r.ok) return []
  const data = await r.json()
  return Array.isArray(data) ? (data as string[]) : []
}

export async function getAgents(): Promise<string[]> {
  const r = await fetch('/agents')
  if (!r.ok) return []
  const data = await r.json()
  return Array.isArray(data) ? (data as string[]) : []
}

export async function getModels(sessionId: string): Promise<string[]> {
  const r = await fetch(`/sessions/${sessionId}/models`)
  if (!r.ok) return []
  const data = await r.json()
  return Array.isArray(data) ? (data as string[]) : []
}

export async function getUsage(id: string): Promise<string> {
  const r = await fetch(`/sessions/${id}/usage`)
  if (!r.ok) return ''
  const data = await r.json()
  return data.usage ?? ''
}

export async function getCost(id: string): Promise<string> {
  const r = await fetch(`/sessions/${id}/cost`)
  if (!r.ok) return ''
  const data = await r.json()
  return data.cost ?? ''
}

// --- Compat: sendCtl maps to interrupt for "stop" ---

export async function sendCtl(id: string, ctl: string): Promise<void> {
  if (ctl === 'stop') {
    await interruptSession(id)
  }
}

// --- Models cache (for NewSession) ---

const MODELS_CACHE_KEY = 'ollie:models'

export function loadModelsCache(): Record<string, string[]> {
  try {
    const raw = localStorage.getItem(MODELS_CACHE_KEY)
    if (raw) return JSON.parse(raw)
  } catch {}
  return {}
}

export async function fetchModels(): Promise<Record<string, string[]>> {
  // In dbus mode we don't have a global models endpoint.
  // Return cached data; individual session model lists are fetched via getModels().
  return loadModelsCache()
}

// --- 9P browsing stubs (not available in dbus mode) ---

export async function browse9p(_path: string): Promise<any> {
  return null
}

export async function write9p(_path: string, _content: string): Promise<boolean> {
  return false
}