import type { ProviderAdapter, RunOpts, RunResult, AvailabilityCheck } from './types';
import { estimateCostUsd } from '../pricing';
import { execFileSync } from 'child_process';
import * as fs from 'fs';
import * as path from 'path';
import * as os from 'os';

/**
 * Grok adapter — wraps the `grok` CLI via -p / --single.
 *
 * Auth readiness is boolean only: CLI present + (~/.grok/auth.json OR
 * XAI_API_KEY / GROK_API_KEY env names present). Never log token values.
 */
export class GrokAdapter implements ProviderAdapter {
  readonly name = 'grok';
  readonly family = 'grok' as const;

  async available(): Promise<AvailabilityCheck> {
    // Boolean PATH presence only — never log secrets
    let hasBinary = false;
    try {
      execFileSync('which', ['grok'], { encoding: 'utf-8', stdio: ['ignore', 'pipe', 'ignore'] });
      hasBinary = true;
    } catch {
      try {
        execFileSync('grok', ['--version'], {
          encoding: 'utf-8',
          stdio: ['ignore', 'pipe', 'ignore'],
          timeout: 2000,
        });
        hasBinary = true;
      } catch {
        hasBinary = false;
      }
    }
    if (!hasBinary) {
      return {
        ok: false,
        reason: 'grok CLI not found on PATH. Install Grok Build from xAI, or ensure `grok` is on PATH.',
      };
    }

    const authPath = path.join(os.homedir(), '.grok', 'auth.json');
    const hasAuthFile = fs.existsSync(authPath);
    // Presence of env *names* only — never read/log values
    const hasKey = !!(process.env.XAI_API_KEY || process.env.GROK_API_KEY);
    if (!hasAuthFile && !hasKey) {
      return {
        ok: false,
        reason: 'No Grok auth found. Log in via `grok` interactive session, or export XAI_API_KEY / GROK_API_KEY.',
      };
    }
    return { ok: true };
  }

  async run(opts: RunOpts): Promise<RunResult> {
    const start = Date.now();
    // Short single-turn: -p / --single. Prefer file-free short prompts for benchmark.
    const args = ['--single', opts.prompt];
    if (opts.model) args.push('--model', opts.model);
    if (opts.extraArgs) args.push(...opts.extraArgs);

    try {
      const out = execFileSync('grok', args, {
        cwd: opts.workdir,
        timeout: opts.timeoutMs,
        encoding: 'utf-8',
        maxBuffer: 32 * 1024 * 1024,
        env: { ...process.env, GSTACK_HEADLESS: '1' },
      });
      return {
        output: typeof out === 'string' ? out : String(out),
        tokens: { input: 0, output: 0 },
        durationMs: Date.now() - start,
        toolCalls: 0,
        modelUsed: opts.model || 'grok',
      };
    } catch (err: unknown) {
      const durationMs = Date.now() - start;
      const e = err as { code?: string; stderr?: Buffer; signal?: string; message?: string };
      const stderr = e.stderr?.toString() ?? '';
      if (e.signal === 'SIGTERM' || e.code === 'ETIMEDOUT') {
        return this.emptyResult(durationMs, { code: 'timeout', reason: `exceeded ${opts.timeoutMs}ms` }, opts.model);
      }
      if (/unauthorized|auth|login|api.?key/i.test(stderr)) {
        return this.emptyResult(durationMs, { code: 'auth', reason: stderr.slice(0, 400) }, opts.model);
      }
      if (/rate[- ]?limit|429/i.test(stderr)) {
        return this.emptyResult(durationMs, { code: 'rate_limit', reason: stderr.slice(0, 400) }, opts.model);
      }
      if (/ENOENT|not found/i.test(e.message ?? '') || e.code === 'ENOENT') {
        return this.emptyResult(durationMs, { code: 'binary_missing', reason: 'grok CLI not found' }, opts.model);
      }
      return this.emptyResult(durationMs, { code: 'unknown', reason: (e.message ?? stderr ?? 'unknown').slice(0, 400) }, opts.model);
    }
  }

  estimateCost(tokens: { input: number; output: number; cached?: number }, model?: string): number {
    return estimateCostUsd(tokens, model ?? 'grok');
  }

  private emptyResult(durationMs: number, error: RunResult['error'], model?: string): RunResult {
    return {
      output: '',
      tokens: { input: 0, output: 0 },
      durationMs,
      toolCalls: 0,
      modelUsed: model || 'grok',
      error,
    };
  }
}