#!/usr/bin/env node

import { existsSync, readFileSync, writeFileSync } from "fs";
import { createInterface } from "readline";
import { getOAuthProvider, getOAuthProviders } from "./utils/oauth/index.js";
import type { OAuthCredentials, OAuthProviderId } from "./utils/oauth/types.js";

const AUTH_FILE = "auth.json";
const PROVIDERS = getOAuthProviders();

function prompt(
  rl: ReturnType<typeof createInterface>,
  question: string,
): Promise<string> {
  return new Promise((resolve) => rl.question(question, resolve));
}

function loadAuth(): Record<string, { type: "oauth" } & OAuthCredentials> {
  if (!existsSync(AUTH_FILE)) return {};
  try {
    return JSON.parse(readFileSync(AUTH_FILE, "utf-8"));
  } catch {
    return {};
  }
}

function saveAuth(
  auth: Record<string, { type: "oauth" } & OAuthCredentials>,
): void {
  writeFileSync(AUTH_FILE, JSON.stringify(auth, null, 2), "utf-8");
}

async function login(providerId: OAuthProviderId): Promise<void> {
  const provider = getOAuthProvider(providerId);
  if (!provider) {
    console.error(`Unknown provider: ${providerId}`);
    process.exit(1);
  }

  const rl = createInterface({ input: process.stdin, output: process.stdout });
  const promptFn = (msg: string) => prompt(rl, `${msg} `);

  try {
    const credentials = await provider.login({
      onAuth: (info) => {
        console.log(`\nOpen this URL in your browser:\n${info.url}`);
        if (info.instructions) console.log(info.instructions);
        console.log();
      },
      onPrompt: async (p) => {
        return await promptFn(
          `${p.message}${p.placeholder ? ` (${p.placeholder})` : ""}:`,
        );
      },
      onProgress: (msg) => console.log(msg),
    });

    const auth = loadAuth();
    auth[providerId] = { type: "oauth", ...credentials };
    saveAuth(auth);

    console.log(`\nCredentials saved to ${AUTH_FILE}`);
  } finally {
    rl.close();
  }
}

async function main(): Promise<void> {
  const args = process.argv.slice(2);
  const command = args[0];

  if (
    !command ||
    command === "help" ||
    command === "--help" ||
    command === "-h"
  ) {
    const providerList = PROVIDERS.map(
      (p) => `  ${p.id.padEnd(20)} ${p.name}`,
    ).join("\n");
    console.log(`Usage: npx @mariozechner/companion-ai <command> [provider]

Commands:
  login [provider]  Login to an OAuth provider
  list              List available providers

Providers:
${providerList}

Examples:
  npx @mariozechner/companion-ai login              # interactive provider selection
  npx @mariozechner/companion-ai login anthropic    # login to specific provider
  npx @mariozechner/companion-ai list               # list providers
`);
    return;
  }

  if (command === "list") {
    console.log("Available OAuth providers:\n");
    for (const p of PROVIDERS) {
      console.log(`  ${p.id.padEnd(20)} ${p.name}`);
    }
    return;
  }

  if (command === "login") {
    let provider = args[1] as OAuthProviderId | undefined;

    if (!provider) {
      const rl = createInterface({
        input: process.stdin,
        output: process.stdout,
      });
      console.log("Select a provider:\n");
      for (let i = 0; i < PROVIDERS.length; i++) {
        console.log(`  ${i + 1}. ${PROVIDERS[i].name}`);
      }
      console.log();

      const choice = await prompt(rl, `Enter number (1-${PROVIDERS.length}): `);
      rl.close();

      const index = parseInt(choice, 10) - 1;
      if (index < 0 || index >= PROVIDERS.length) {
        console.error("Invalid selection");
        process.exit(1);
      }
      provider = PROVIDERS[index].id;
    }

    if (!PROVIDERS.some((p) => p.id === provider)) {
      console.error(`Unknown provider: ${provider}`);
      console.error(
        `Use 'npx @mariozechner/companion-ai list' to see available providers`,
      );
      process.exit(1);
    }

    console.log(`Logging in to ${provider}...`);
    await login(provider);
    return;
  }

  console.error(`Unknown command: ${command}`);
  console.error(`Use 'npx @mariozechner/companion-ai --help' for usage`);
  process.exit(1);
}

main().catch((err) => {
  console.error("Error:", err.message);
  process.exit(1);
});