import { useMemo, useSyncExternalStore } from "react"
import { NostrStreamProvider, adaptPublisher } from "@/providers"
import { useLogin } from "./login"
import { ExternalStore } from "@snort/shared"
import type { EventPublisher, NostrEvent } from "@snort/system"
import { ZAP_STREAM_PUBKEY } from "@/const"

export interface StreamProviderConfig {
  name: string
  url: string
  description?: string
  pubkey: string
  event?: NostrEvent
  recommendations: Array<NostrEvent>
  // A score by WoT distance, lower is better
  score: number
}

const DEFAULT_CONFIG: StreamProviderConfig = {
  name: "zap.stream",
  url: "https://api-core.zap.stream/api/v1",
  pubkey: ZAP_STREAM_PUBKEY,
  recommendations: [],
  score: 0,
}

const STORAGE_KEY = "stream-provider"

class ProviderStorage extends ExternalStore<StreamProviderConfig> {
  #currentConfig: StreamProviderConfig

  constructor() {
    super()
    try {
      const stored = localStorage.getItem(STORAGE_KEY)
      this.#currentConfig = stored ? JSON.parse(stored) : DEFAULT_CONFIG
    } catch {
      this.#currentConfig = DEFAULT_CONFIG
    }
  }

  getProvider(pub: EventPublisher | undefined) {
    const signer = pub ? adaptPublisher(pub) : undefined
    return new NostrStreamProvider(this.#currentConfig.name, this.#currentConfig.url, signer)
  }

  setProvider(cfg: StreamProviderConfig) {
    this.#currentConfig = cfg
    localStorage.setItem(STORAGE_KEY, JSON.stringify(this.#currentConfig))
    this.notifyChange()
  }

  takeSnapshot(): StreamProviderConfig {
    return {
      ...this.#currentConfig,
    }
  }
}

const Storage = new ProviderStorage()

export function useStreamProvider() {
  const login = useLogin()
  const config = useSyncExternalStore(
    c => Storage.hook(c),
    () => Storage.snapshot(),
  )

  return useMemo(
    () => {
      const pub = login?.publisher?.()
      const signer = pub ? adaptPublisher(pub) : undefined
      return {
        provider: new NostrStreamProvider(config.name, config.url, signer),
        config,
        updateStreamProvider: (cfg: StreamProviderConfig) => {
          Storage.setProvider(cfg)
        },
        resetToDefault: () => {
          Storage.setProvider(DEFAULT_CONFIG)
        },
      }
    },
    [config],
  )
}