import { generatePKCE } from "@openauthjs/openauth/pkce"
import { Auth } from "./index"

export namespace AuthAnthropic {
  const CLIENT_ID = "9d1c250a-e61b-44d9-88ed-5944d1962f5e"

  export async function authorize() {
    const pkce = await generatePKCE()
    const url = new URL("https://claude.ai/oauth/authorize", import.meta.url)
    url.searchParams.set("code", "true")
    url.searchParams.set("client_id", CLIENT_ID)
    url.searchParams.set("response_type", "code")
    url.searchParams.set("redirect_uri", "https://console.anthropic.com/oauth/code/callback")
    url.searchParams.set("scope", "org:create_api_key user:profile user:inference")
    url.searchParams.set("code_challenge", pkce.challenge)
    url.searchParams.set("code_challenge_method", "S256")
    url.searchParams.set("state", pkce.verifier)
    return {
      url: url.toString(),
      verifier: pkce.verifier,
    }
  }

  export async function exchange(code: string, verifier: string) {
    const splits = code.split("#")
    const result = await fetch("https://console.anthropic.com/v1/oauth/token", {
      method: "POST",
      headers: {
        "Content-Type": "application/json",
      },
      body: JSON.stringify({
        code: splits[0],
        state: splits[1],
        grant_type: "authorization_code",
        client_id: CLIENT_ID,
        redirect_uri: "https://console.anthropic.com/oauth/code/callback",
        code_verifier: verifier,
      }),
    })
    if (!result.ok) throw new ExchangeFailed()
    const json = await result.json()
    await Auth.set("anthropic", {
      type: "oauth",
      refresh: json.refresh_token as string,
      access: json.access_token as string,
      expires: Date.now() + json.expires_in * 1000,
    })
  }

  export async function access() {
    const info = await Auth.get("anthropic")
    if (!info || info.type !== "oauth") return
    if (info.access && info.expires > Date.now()) return info.access
    const response = await fetch("https://console.anthropic.com/v1/oauth/token", {
      method: "POST",
      headers: {
        "Content-Type": "application/json",
      },
      body: JSON.stringify({
        grant_type: "refresh_token",
        refresh_token: info.refresh,
        client_id: CLIENT_ID,
      }),
    })
    if (!response.ok) return
    const json = await response.json()
    await Auth.set("anthropic", {
      type: "oauth",
      refresh: json.refresh_token as string,
      access: json.access_token as string,
      expires: Date.now() + json.expires_in * 1000,
    })
    return json.access_token as string
  }

  export class ExchangeFailed extends Error {
    constructor() {
      super("Exchange failed")
    }
  }
}
