import { serve, type CommandChild } from "./cli"
import { DEFAULT_SERVER_URL_KEY, WSL_ENABLED_KEY } from "./constants"
import { store } from "./store"

export type WslConfig = { enabled: boolean }

export type HealthCheck = { wait: Promise<void> }

export function getDefaultServerUrl(): string | null {
  const value = store.get(DEFAULT_SERVER_URL_KEY)
  return typeof value === "string" ? value : null
}

export function setDefaultServerUrl(url: string | null) {
  if (url) {
    store.set(DEFAULT_SERVER_URL_KEY, url)
    return
  }

  store.delete(DEFAULT_SERVER_URL_KEY)
}

export function getWslConfig(): WslConfig {
  const value = store.get(WSL_ENABLED_KEY)
  return { enabled: typeof value === "boolean" ? value : false }
}

export function setWslConfig(config: WslConfig) {
  store.set(WSL_ENABLED_KEY, config.enabled)
}

export function spawnLocalServer(hostname: string, port: number, password: string) {
  const { child, exit, events } = serve(hostname, port, password)

  const wait = (async () => {
    const url = `http://${hostname}:${port}`

    const ready = async () => {
      while (true) {
        await new Promise((resolve) => setTimeout(resolve, 100))
        if (await checkHealth(url, password)) return
      }
    }

    const terminated = async () => {
      const payload = await exit
      throw new Error(
        `Sidecar terminated before becoming healthy (code=${payload.code ?? "unknown"} signal=${
          payload.signal ?? "unknown"
        })`,
      )
    }

    await Promise.race([ready(), terminated()])
  })()

  return { child, health: { wait }, events }
}

export async function checkHealth(url: string, password?: string | null): Promise<boolean> {
  let healthUrl: URL
  try {
    healthUrl = new URL("/global/health", url)
  } catch {
    return false
  }

  const headers = new Headers()
  if (password) {
    const auth = Buffer.from(`opencode:${password}`).toString("base64")
    headers.set("authorization", `Basic ${auth}`)
  }

  try {
    const res = await fetch(healthUrl, {
      method: "GET",
      headers,
      signal: AbortSignal.timeout(3000),
    })
    return res.ok
  } catch {
    return false
  }
}

export type { CommandChild }