import { CheckExecutor } from './check-executor.ts';
import { DEFAULT_CONFIG_PATH, loadConfig, validateConfig, writeConfig } from './config.ts';
import type { IUptimeRunnerConfig, TCheckJob } from './interfaces.ts';
import { UptimeRunner } from './runner.ts';
import { UptimeRunnerSystemd } from './systemd.ts';
import denoConfig from '../deno.json' with { type: 'json' };

export class UptimeRunnerCli {
  public async parseAndExecute(argsArg: string[]): Promise<void> {
    const command = argsArg[0] ?? 'help';
    const commandArgs = argsArg.slice(1);

    switch (command) {
      case 'run':
        await this.run(commandArgs, false);
        break;
      case 'once':
        await this.run(commandArgs, true);
        break;
      case 'check':
        await this.check(commandArgs);
        break;
      case 'config':
        await this.config(commandArgs);
        break;
      case 'service':
        await this.service(commandArgs);
        break;
      case '--version':
      case '-v':
      case 'version':
        console.log(denoConfig.version);
        break;
      case 'help':
      case '--help':
      case '-h':
        this.showHelp();
        break;
      default:
        throw new Error(`Unknown command: ${command}`);
    }
  }

  private async run(argsArg: string[], onceArg: boolean): Promise<void> {
    const flags = parseFlags(argsArg);
    const config = await this.loadConfigFromFlags(flags);
    const runner = new UptimeRunner(config);

    if (onceArg) {
      const result = await runner.runOnce();
      console.log(JSON.stringify(result, null, 2));
      return;
    }

    await runner.run();
  }

  private async check(argsArg: string[]): Promise<void> {
    const url = argsArg.find((arg) => !arg.startsWith('--'));
    if (!url) {
      throw new Error('Usage: uptimerunner check <url>');
    }

    const check: TCheckJob = {
      id: `manual-${Date.now().toString(36)}`,
      type: 'http',
      url,
      expectedStatusCodes: [200],
    };
    const executor = new CheckExecutor('manual');
    const result = await executor.execute(check);
    console.log(JSON.stringify(result, null, 2));
    if (result.status !== 'ok') {
      Deno.exit(2);
    }
  }

  private async config(argsArg: string[]): Promise<void> {
    const subcommand = argsArg[0] ?? 'show';
    const flags = parseFlags(argsArg.slice(1));
    const configPath = flags.config ?? DEFAULT_CONFIG_PATH;

    switch (subcommand) {
      case 'show': {
        const config = await loadConfig(configPath);
        console.log(JSON.stringify({ ...config, token: mask(config.token) }, null, 2));
        break;
      }
      case 'write': {
        const config: IUptimeRunnerConfig = {
          instanceUrl: requiredFlag(flags, 'url'),
          runnerId: requiredFlag(flags, 'runner-id'),
          token: requiredFlag(flags, 'token'),
          pollIntervalMs: flags.interval ? Number(flags.interval) : 30000,
          labels: flags.labels?.split(',').map((labelArg) => labelArg.trim()).filter(Boolean),
          maxConcurrentChecks: flags.concurrency ? Number(flags.concurrency) : 8,
        };
        await writeConfig(config, configPath);
        console.log(`Config written to ${configPath}`);
        break;
      }
      default:
        throw new Error(`Unknown config command: ${subcommand}`);
    }
  }

  private async service(argsArg: string[]): Promise<void> {
    const subcommand = argsArg[0] ?? 'status';
    const systemd = new UptimeRunnerSystemd();

    switch (subcommand) {
      case 'install':
        await systemd.install();
        break;
      case 'uninstall':
        await systemd.uninstall();
        break;
      case 'start':
        await systemd.start();
        break;
      case 'stop':
        await systemd.stop();
        break;
      case 'restart':
        await systemd.restart();
        break;
      case 'status':
        await systemd.status();
        break;
      case 'logs':
        await systemd.logs();
        break;
      default:
        throw new Error(`Unknown service command: ${subcommand}`);
    }
  }

  private async loadConfigFromFlags(
    flagsArg: Record<string, string>,
  ): Promise<IUptimeRunnerConfig> {
    const configPath = flagsArg.config ?? DEFAULT_CONFIG_PATH;
    const fileConfig = await loadConfig(configPath).catch((error) => {
      if (flagsArg.url && flagsArg.token && flagsArg['runner-id']) {
        return {} as Partial<IUptimeRunnerConfig>;
      }
      throw error;
    });

    const config = {
      ...fileConfig,
      instanceUrl: flagsArg.url ?? fileConfig.instanceUrl,
      runnerId: flagsArg['runner-id'] ?? fileConfig.runnerId,
      token: flagsArg.token ?? fileConfig.token,
      pollIntervalMs: flagsArg.interval ? Number(flagsArg.interval) : fileConfig.pollIntervalMs,
      labels: flagsArg.labels
        ? flagsArg.labels.split(',').map((labelArg) => labelArg.trim()).filter(Boolean)
        : fileConfig.labels,
      maxConcurrentChecks: flagsArg.concurrency
        ? Number(flagsArg.concurrency)
        : fileConfig.maxConcurrentChecks,
    };
    validateConfig(config);
    return config;
  }

  private showHelp(): void {
    console.log(`uptimerunner ${denoConfig.version}

Usage:
  uptimerunner run [--config path] [--url https://uptime.link] [--token token] [--runner-id id]
  uptimerunner once [--config path]
  uptimerunner check <url>
  uptimerunner config write --url https://uptime.link --runner-id edge-1 --token token
  uptimerunner service install|start|stop|restart|status|logs|uninstall

Environment:
  UPTIMERUNNER_CONFIG
  UPTIMERUNNER_INSTANCE_URL
  UPTIMERUNNER_RUNNER_ID
  UPTIMERUNNER_TOKEN
  UPTIMERUNNER_LABELS
`);
  }
}

function parseFlags(argsArg: string[]): Record<string, string> {
  const flags: Record<string, string> = {};
  for (let index = 0; index < argsArg.length; index++) {
    const arg = argsArg[index];
    if (!arg.startsWith('--')) {
      continue;
    }
    const [rawName, inlineValue] = arg.slice(2).split('=', 2);
    flags[rawName] = inlineValue ?? argsArg[++index];
  }
  return flags;
}

function requiredFlag(flagsArg: Record<string, string>, nameArg: string): string {
  const value = flagsArg[nameArg];
  if (!value) {
    throw new Error(`Missing required --${nameArg} flag.`);
  }
  return value;
}

function mask(valueArg: string): string {
  return valueArg.length <= 8 ? '********' : `${valueArg.slice(0, 4)}...${valueArg.slice(-4)}`;
}