/**
 * Turnstile token resolver — 三層優先策略：
 *
 *  1. 自建 Playwright 求解器（playwright_solver_url 已設定）
 *  2. CapSolver API（capsolver_api_key 已設定）
 *  3. 回退 bypass token（必然失敗，但有清楚錯誤訊息）
 *
 * Token 快取 4.5 分鐘（geminigen.ai Turnstile token 約 5 分鐘有效）。
 */

import { db, configTable } from "@workspace/db";
import { eq } from "drizzle-orm";

const CAPSOLVER_URL = "https://api.capsolver.com";
const YESCAPTCHA_URL = "https://api.yescaptcha.com";
const TURNSTILE_SITE_KEY = "0x4AAAAAACDBydnKT0zYzh2H";
const TURNSTILE_PAGE_URL = "https://geminigen.ai";
const TOKEN_TTL_MS = 270_000; // 4.5 minutes

interface CachedToken {
  token: string;
  expiresAt: number;
}

let cachedToken: CachedToken | null = null;

// ─── DB helper ────────────────────────────────────────────────────────────────

async function getConfig(key: string): Promise<string | null> {
  try {
    const rows = await db
      .select()
      .from(configTable)
      .where(eq(configTable.key, key))
      .limit(1);
    return rows[0]?.value?.trim() || null;
  } catch {
    return null;
  }
}

// ─── Strategy 1: Self-hosted Playwright solver ────────────────────────────────

async function solveWithPlaywright(solverUrl: string): Promise<string | null> {
  try {
    const solverSecret = await getConfig("playwright_solver_secret");
    const headers: Record<string, string> = {
      "Content-Type": "application/json",
    };
    if (solverSecret) headers["X-Solver-Secret"] = solverSecret;

    console.log(`[captcha] Calling Playwright solver: ${solverUrl}`);
    const resp = await fetch(solverUrl, {
      method: "POST",
      headers,
      body: JSON.stringify({}),
      signal: AbortSignal.timeout(55_000),
    });

    const data = (await resp.json()) as {
      token?: string;
      cached?: boolean;
      solvedInMs?: number;
      error?: string;
    };

    if (!resp.ok || !data.token) {
      console.error(
        `[captcha] Playwright solver error (${resp.status}): ${data.error || "no token"}`
      );
      return null;
    }

    console.log(
      `[captcha] Playwright solved — cached=${data.cached}, ms=${data.solvedInMs ?? "N/A"}`
    );
    return data.token;
  } catch (err: any) {
    console.error(`[captcha] Playwright solver fetch error: ${err?.message}`);
    return null;
  }
}

// ─── Strategy 2: CapSolver API ────────────────────────────────────────────────

async function solveWithCapsolver(apiKey: string): Promise<string | null> {
  try {
    const createResp = await fetch(`${CAPSOLVER_URL}/createTask`, {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({
        clientKey: apiKey,
        task: {
          type: "AntiTurnstileTaskProxyless",
          websiteURL: TURNSTILE_PAGE_URL,
          websiteKey: TURNSTILE_SITE_KEY,
        },
      }),
    });

    const createData = (await createResp.json()) as {
      errorId?: number;
      errorCode?: string;
      errorDescription?: string;
      taskId?: string;
    };

    if (createData.errorId || !createData.taskId) {
      console.error(
        `[captcha] CapSolver create error: ${createData.errorCode} — ${createData.errorDescription}`
      );
      return null;
    }

    const taskId = createData.taskId;
    console.log(`[captcha] CapSolver task created: ${taskId}`);

    const maxWait = 120_000;
    const start = Date.now();
    while (Date.now() - start < maxWait) {
      await new Promise((r) => setTimeout(r, 3000));

      const resultResp = await fetch(`${CAPSOLVER_URL}/getTaskResult`, {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ clientKey: apiKey, taskId }),
      });

      const resultData = (await resultResp.json()) as {
        errorId?: number;
        errorCode?: string;
        status?: string;
        solution?: { token?: string };
      };

      if (resultData.errorId) {
        console.error(`[captcha] CapSolver result error: ${resultData.errorCode}`);
        return null;
      }

      if (resultData.status === "ready") {
        const token = resultData.solution?.token;
        if (token) {
          console.log(`[captcha] CapSolver solved! Token: ${token.substring(0, 20)}...`);
          return token;
        }
        return null;
      }
    }

    console.error("[captcha] CapSolver timed out after 120s");
    return null;
  } catch (err: any) {
    console.error(`[captcha] CapSolver error: ${err?.message}`);
    return null;
  }
}

// ─── Strategy 3: YesCaptcha API ──────────────────────────────────────────────

async function solveWithYesCaptcha(apiKey: string): Promise<string | null> {
  try {
    const createResp = await fetch(`${YESCAPTCHA_URL}/createTask`, {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({
        clientKey: apiKey,
        task: {
          type: "TurnstileTaskProxylessM1",
          websiteURL: TURNSTILE_PAGE_URL,
          websiteKey: TURNSTILE_SITE_KEY,
        },
      }),
    });

    const createData = (await createResp.json()) as {
      errorId?: number;
      errorCode?: string;
      errorDescription?: string;
      taskId?: string;
    };

    if (createData.errorId || !createData.taskId) {
      console.error(
        `[captcha] YesCaptcha create error: ${createData.errorCode} — ${createData.errorDescription}`
      );
      return null;
    }

    const taskId = createData.taskId;
    console.log(`[captcha] YesCaptcha task created: ${taskId}`);

    const maxWait = 120_000;
    const start = Date.now();
    while (Date.now() - start < maxWait) {
      await new Promise((r) => setTimeout(r, 3000));

      const resultResp = await fetch(`${YESCAPTCHA_URL}/getTaskResult`, {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ clientKey: apiKey, taskId }),
      });

      const resultData = (await resultResp.json()) as {
        errorId?: number;
        errorCode?: string;
        status?: string;
        solution?: { token?: string };
      };

      if (resultData.errorId) {
        console.error(`[captcha] YesCaptcha result error: ${resultData.errorCode}`);
        return null;
      }

      if (resultData.status === "ready") {
        const token = resultData.solution?.token;
        if (token) {
          console.log(`[captcha] YesCaptcha solved! Token: ${token.substring(0, 20)}...`);
          return token;
        }
        return null;
      }
    }

    console.error("[captcha] YesCaptcha timed out after 120s");
    return null;
  } catch (err: any) {
    console.error(`[captcha] YesCaptcha error: ${err?.message}`);
    return null;
  }
}

// ─── Public API ───────────────────────────────────────────────────────────────

/**
 * Get a valid Cloudflare Turnstile token for geminigen.ai.
 *
 * Priority:
 *   1. Self-hosted Playwright solver  (playwright_solver_url in config)  — 免費
 *   2. YesCaptcha API                 (yescaptcha_api_key in config)     — 有免費額度
 *   3. CapSolver API                  (capsolver_api_key in config)      — 付費備援
 *   4. Bypass placeholder             (will fail — no solver configured)
 */
export async function getTurnstileToken(): Promise<string> {
  if (cachedToken && cachedToken.expiresAt > Date.now()) {
    console.log("[captcha] Using cached Turnstile token");
    return cachedToken.token;
  }

  let token: string | null = null;

  // Strategy 1: Self-hosted Playwright solver
  const solverUrl = await getConfig("playwright_solver_url");
  if (solverUrl) {
    token = await solveWithPlaywright(solverUrl);
    if (token) {
      cachedToken = { token, expiresAt: Date.now() + TOKEN_TTL_MS };
      return token;
    }
    console.warn("[captcha] Playwright solver failed — trying YesCaptcha");
  }

  // Strategy 2: YesCaptcha
  const yescaptchaKey = await getConfig("yescaptcha_api_key");
  if (yescaptchaKey) {
    token = await solveWithYesCaptcha(yescaptchaKey);
    if (token) {
      cachedToken = { token, expiresAt: Date.now() + TOKEN_TTL_MS };
      return token;
    }
    console.warn("[captcha] YesCaptcha failed — trying CapSolver");
  }

  // Strategy 3: CapSolver
  const capsolverKey = await getConfig("capsolver_api_key");
  if (capsolverKey) {
    token = await solveWithCapsolver(capsolverKey);
    if (token) {
      cachedToken = { token, expiresAt: Date.now() + TOKEN_TTL_MS };
      return token;
    }
    console.warn("[captcha] CapSolver failed — no further fallback");
  }

  if (!solverUrl && !yescaptchaKey && !capsolverKey) {
    console.warn(
      "[captcha] No Turnstile solver configured — set playwright_solver_url, yescaptcha_api_key, or capsolver_api_key in Admin → Config"
    );
  }

  return "TURNSTILE_BYPASS";
}

/** Force-clear the cached token (e.g., if geminigen.ai rejects it) */
export function invalidateTurnstileToken(): void {
  cachedToken = null;
}