// ========= Copyright 2025-2026 @ Eigent.ai All Rights Reserved. =========
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// ========= Copyright 2025-2026 @ Eigent.ai All Rights Reserved. =========

import fs from 'fs';
import os from 'os';
import path from 'path';

const MCP_CONFIG_DIR = path.join(os.homedir(), '.eigent');
const MCP_CONFIG_PATH = path.join(MCP_CONFIG_DIR, 'mcp.json');

type McpServerConfig =
  | {
      command: string;
      args: string[];
      description?: string;
      env?: Record<string, string>;
    }
  | {
      url: string;
    };

type McpServersConfig = {
  [name: string]: McpServerConfig;
};

export type ConfigFile = {
  mcpServers: McpServersConfig;
};

export function getMcpConfigPath() {
  return MCP_CONFIG_PATH;
}

function getDefaultConfig(): ConfigFile {
  return { mcpServers: {} };
}

export function readMcpConfig(): ConfigFile {
  try {
    if (!fs.existsSync(MCP_CONFIG_PATH)) {
      // init config file
      writeMcpConfig(getDefaultConfig());
      return getDefaultConfig();
    }
    const data = fs.readFileSync(MCP_CONFIG_PATH, 'utf-8');
    const parsed = JSON.parse(data);
    // compatible with old format
    if (!parsed.mcpServers || typeof parsed.mcpServers !== 'object') {
      return getDefaultConfig();
    }

    // Normalize args field - ensure it's always an array
    Object.keys(parsed.mcpServers).forEach((serverName) => {
      const server = parsed.mcpServers[serverName];
      if (server.args) {
        const args = server.args as any;
        if (typeof args === 'string') {
          try {
            // Try to parse as JSON string first
            server.args = JSON.parse(args);
          } catch (_error) {
            // If parsing fails, split by comma as fallback
            server.args = args
              .split(',')
              .map((arg: string) => arg.trim())
              .filter((arg: string) => arg !== '');
          }
        }
        // Ensure it's always an array of strings
        if (Array.isArray(server.args)) {
          server.args = server.args.map((arg: any) => String(arg));
        }
      }
    });

    return parsed;
  } catch (_error) {
    return getDefaultConfig();
  }
}

export function writeMcpConfig(config: ConfigFile): void {
  if (!fs.existsSync(MCP_CONFIG_DIR)) {
    fs.mkdirSync(MCP_CONFIG_DIR, { recursive: true });
  }
  fs.writeFileSync(MCP_CONFIG_PATH, JSON.stringify(config, null, 2), 'utf-8');
}

export function addMcp(name: string, mcp: McpServerConfig): void {
  const config = readMcpConfig();
  if (!config.mcpServers[name]) {
    // Ensure args is an array before adding
    const normalizedMcp = { ...mcp };
    if ('args' in normalizedMcp && normalizedMcp.args) {
      const args = normalizedMcp.args as any;
      if (typeof args === 'string') {
        try {
          normalizedMcp.args = JSON.parse(args);
        } catch (_error) {
          normalizedMcp.args = args
            .split(',')
            .map((arg: string) => arg.trim())
            .filter((arg: string) => arg !== '');
        }
      }
      if (Array.isArray(normalizedMcp.args)) {
        normalizedMcp.args = normalizedMcp.args.map((arg: any) => String(arg));
      }
    }
    config.mcpServers[name] = normalizedMcp;
    writeMcpConfig(config);
  }
}

export function removeMcp(name: string): void {
  const config = readMcpConfig();
  console.log('removeMcp', name);
  if (config.mcpServers[name]) {
    delete config.mcpServers[name];
    writeMcpConfig(config);
  }
}

export function updateMcp(name: string, mcp: McpServerConfig): void {
  const config = readMcpConfig();
  // Ensure args is an array before updating
  const normalizedMcp = { ...mcp };
  if ('args' in normalizedMcp && normalizedMcp.args) {
    const args = normalizedMcp.args as any;
    if (typeof args === 'string') {
      try {
        normalizedMcp.args = JSON.parse(args);
      } catch (_error) {
        normalizedMcp.args = args
          .split(',')
          .map((arg: string) => arg.trim())
          .filter((arg: string) => arg !== '');
      }
    }
    if (Array.isArray(normalizedMcp.args)) {
      normalizedMcp.args = normalizedMcp.args.map((arg: any) => String(arg));
    }
  }
  config.mcpServers[name] = normalizedMcp;
  writeMcpConfig(config);
}