/**
 * @license
 * Copyright 2025 Google LLC
 * SPDX-License-Identifier: Apache-2.0
 */

import yargs from 'yargs/yargs';
import { hideBin } from 'yargs/helpers';
import process from 'node:process';
import {
  Config,
  loadEnvironment,
  createServerConfig,
  loadServerHierarchicalMemory,
  ConfigParameters,
  setGeminiMdFilename as setServerGeminiMdFilename,
  getCurrentGeminiMdFilename,
  ApprovalMode,
} from '@gemini-code/core';
import { Settings } from './settings.js';
import { readPackageUp } from 'read-package-up';
import {
  getEffectiveModel,
  type EffectiveModelCheckResult,
} from '../utils/modelCheck.js';

// Simple console logger for now - replace with actual logger if available
const logger = {
  // eslint-disable-next-line @typescript-eslint/no-explicit-any
  debug: (...args: any[]) => console.debug('[DEBUG]', ...args),
  // eslint-disable-next-line @typescript-eslint/no-explicit-any
  warn: (...args: any[]) => console.warn('[WARN]', ...args),
  // eslint-disable-next-line @typescript-eslint/no-explicit-any
  error: (...args: any[]) => console.error('[ERROR]', ...args),
};

export const DEFAULT_GEMINI_MODEL = 'gemini-2.5-pro-preview-05-06';
export const DEFAULT_GEMINI_FLASH_MODEL = 'gemini-2.5-flash-preview-05-20';

interface CliArgs {
  model: string | undefined;
  sandbox: boolean | string | undefined;
  debug: boolean | undefined;
  prompt: string | undefined;
  all_files: boolean | undefined;
  show_memory_usage: boolean | undefined;
  yolo: boolean | undefined;
}

async function parseArguments(): Promise<CliArgs> {
  const argv = await yargs(hideBin(process.argv))
    .option('model', {
      alias: 'm',
      type: 'string',
      description: `Model`,
      default: process.env.GEMINI_MODEL || DEFAULT_GEMINI_MODEL,
    })
    .option('prompt', {
      alias: 'p',
      type: 'string',
      description: 'Prompt. Appended to input on stdin (if any).',
    })
    .option('sandbox', {
      alias: 's',
      type: 'boolean',
      description: 'Run in sandbox?',
    })
    .option('debug', {
      alias: 'd',
      type: 'boolean',
      description: 'Run in debug mode?',
      default: false,
    })
    .option('all_files', {
      alias: 'a',
      type: 'boolean',
      description: 'Include ALL files in context?',
      default: false,
    })
    .option('show_memory_usage', {
      type: 'boolean',
      description: 'Show memory usage in status bar',
      default: false,
    })
    .option('yolo', {
      alias: 'y',
      type: 'boolean',
      description:
        'Automatically accept all actions (aka YOLO mode, see https://www.youtube.com/watch?v=xvFZjo5PgG0 for more details)?',
      default: false,
    })
    .version() // This will enable the --version flag based on package.json
    .help()
    .alias('h', 'help')
    .strict().argv;

  const finalArgv: CliArgs = {
    ...argv,
    sandbox: argv.sandbox,
  };

  return finalArgv;
}

// This function is now a thin wrapper around the server's implementation.
// It's kept in the CLI for now as App.tsx directly calls it for memory refresh.
// TODO: Consider if App.tsx should get memory via a server call or if Config should refresh itself.
export async function loadHierarchicalGeminiMemory(
  currentWorkingDirectory: string,
  debugMode: boolean,
): Promise<{ memoryContent: string; fileCount: number }> {
  if (debugMode) {
    logger.debug(
      `CLI: Delegating hierarchical memory load to server for CWD: ${currentWorkingDirectory}`,
    );
  }
  // Directly call the server function.
  // The server function will use its own homedir() for the global path.
  return loadServerHierarchicalMemory(currentWorkingDirectory, debugMode);
}

export interface LoadCliConfigResult {
  config: Config;
  modelWasSwitched: boolean;
  originalModelBeforeSwitch?: string;
  finalModel: string;
}

export async function loadCliConfig(
  settings: Settings,
): Promise<LoadCliConfigResult> {
  loadEnvironment();

  const geminiApiKey = process.env.GEMINI_API_KEY;
  const googleApiKey = process.env.GOOGLE_API_KEY;
  const googleCloudProject = process.env.GOOGLE_CLOUD_PROJECT;
  const googleCloudLocation = process.env.GOOGLE_CLOUD_LOCATION;

  const hasGeminiApiKey = !!geminiApiKey;
  const hasGoogleApiKey = !!googleApiKey;
  const hasVertexProjectLocationConfig =
    !!googleCloudProject && !!googleCloudLocation;

  if (!hasGeminiApiKey && !hasGoogleApiKey && !hasVertexProjectLocationConfig) {
    logger.error(
      'No valid API authentication configuration found. Please set ONE of the following combinations in your environment variables or .env file:\n' +
        '1. GEMINI_API_KEY (for Gemini API access).\n' +
        '2. GOOGLE_API_KEY (for Gemini API or Vertex AI Express Mode access).\n' +
        '3. GOOGLE_CLOUD_PROJECT and GOOGLE_CLOUD_LOCATION (for Vertex AI access).\n\n' +
        'For Gemini API keys, visit: https://ai.google.dev/gemini-api/docs/api-key\n' +
        'For Vertex AI authentication, visit: https://cloud.google.com/vertex-ai/docs/start/authentication\n' +
        'The GOOGLE_GENAI_USE_VERTEXAI environment variable can also be set to true/false to influence service selection when ambiguity exists.',
    );
    process.exit(1);
  }

  const argv = await parseArguments();
  const debugMode = argv.debug || false;

  // Set the context filename in the server's memoryTool module BEFORE loading memory
  // TODO(b/343434939): This is a bit of a hack. The contextFileName should ideally be passed
  // directly to the Config constructor in core, and have core handle setGeminiMdFilename.
  // However, loadHierarchicalGeminiMemory is called *before* createServerConfig.
  if (settings.contextFileName) {
    setServerGeminiMdFilename(settings.contextFileName);
  } else {
    // Reset to default if not provided in settings.
    setServerGeminiMdFilename(getCurrentGeminiMdFilename());
  }

  // Call the (now wrapper) loadHierarchicalGeminiMemory which calls the server's version
  const { memoryContent, fileCount } = await loadHierarchicalGeminiMemory(
    process.cwd(),
    debugMode,
  );

  const userAgent = await createUserAgent();
  const apiKeyForServer = geminiApiKey || googleApiKey || '';
  const useVertexAI = hasGeminiApiKey ? false : undefined;

  let modelToUse = argv.model || DEFAULT_GEMINI_MODEL;
  let modelSwitched = false;
  let originalModel: string | undefined = undefined;

  if (apiKeyForServer) {
    const checkResult: EffectiveModelCheckResult = await getEffectiveModel(
      apiKeyForServer,
      modelToUse,
    );
    if (checkResult.switched) {
      modelSwitched = true;
      originalModel = checkResult.originalModelIfSwitched;
      modelToUse = checkResult.effectiveModel;
    }
  } else {
    // logger.debug('API key not available during config load. Skipping model availability check.');
  }

  const configParams: ConfigParameters = {
    apiKey: apiKeyForServer,
    model: modelToUse,
    sandbox: argv.sandbox ?? settings.sandbox ?? argv.yolo ?? false,
    targetDir: process.cwd(),
    debugMode,
    question: argv.prompt || '',
    fullContext: argv.all_files || false,
    coreTools: settings.coreTools || undefined,
    toolDiscoveryCommand: settings.toolDiscoveryCommand,
    toolCallCommand: settings.toolCallCommand,
    mcpServerCommand: settings.mcpServerCommand,
    mcpServers: settings.mcpServers,
    userAgent,
    userMemory: memoryContent,
    geminiMdFileCount: fileCount,
    approvalMode: argv.yolo || false ? ApprovalMode.YOLO : ApprovalMode.DEFAULT,
    vertexai: useVertexAI,
    showMemoryUsage:
      argv.show_memory_usage || settings.showMemoryUsage || false,
  };

  const config = createServerConfig(configParams);
  return {
    config,
    modelWasSwitched: modelSwitched,
    originalModelBeforeSwitch: originalModel,
    finalModel: modelToUse,
  };
}

async function createUserAgent(): Promise<string> {
  try {
    const packageJsonInfo = await readPackageUp({ cwd: import.meta.url });
    const cliVersion = packageJsonInfo?.packageJson.version || 'unknown';
    return `GeminiCLI/${cliVersion} Node.js/${process.version} (${process.platform}; ${process.arch})`;
  } catch (error: unknown) {
    const message = error instanceof Error ? error.message : String(error);
    logger.warn(
      `Could not determine package version for User-Agent: ${message}`,
    );
    return `GeminiCLI/unknown Node.js/${process.version} (${process.platform}; ${process.arch})`;
  }
}