import fs from 'fs';
import path from 'path';
import { z } from 'zod';
import {
  DEFAULT_CODE_MODE_DISABLED_TOOLS,
  POD_EXEC_TOOL_NAME,
  normalizeToolName,
} from './ToolPolicy.js';

export const CodeModeConfigSchema = z.object({
  workspaceDir: z.string().default('./workspace'),
  enablePII: z.boolean().default(false),
  disabledTools: z.array(z.string().min(1)).default([...DEFAULT_CODE_MODE_DISABLED_TOOLS]),
  sandbox: z
    .object({
      memoryLimitMb: z.number().default(256),
      timeoutMs: z.number().default(5000),
    })
    .prefault({}),
  servers: z
    .array(
      z.object({
        name: z.string(),
        command: z.string(),
        args: z.array(z.string()).optional(),
        env: z.record(z.string(), z.string()).optional(),
        timeoutMs: z.number().optional(),
      }),
    )
    .default([]),
});

export type CodeModeConfig = z.infer<typeof CodeModeConfigSchema>;

export function loadCodeModeConfig(cwd: string = process.cwd()): CodeModeConfig {
  const configFiles = ['kube-mcp.code-mode.json', 'kube-mcp.code-mode.example.json'];

  for (const file of configFiles) {
    const configPath = path.resolve(cwd, file);
    if (fs.existsSync(configPath)) {
      const content = fs.readFileSync(configPath, 'utf-8');
      const json = JSON.parse(content);
      return applyDisabledToolsEnvironment(CodeModeConfigSchema.parse(json));
    }
  }

  // Return defaults if no config found
  return applyDisabledToolsEnvironment(CodeModeConfigSchema.parse({}));
}

function applyDisabledToolsEnvironment(config: CodeModeConfig): CodeModeConfig {
  const envValue = process.env.MCP_CODE_MODE_DISABLED_TOOLS;
  const configured =
    envValue === undefined
      ? config.disabledTools
      : envValue
          .split(',')
          .map((name) => name.trim())
          .filter(Boolean);
  const disabledTools = Array.from(new Set(configured.map(normalizeToolName)));

  if (disabledTools.includes(POD_EXEC_TOOL_NAME)) {
    throw new Error(
      `${POD_EXEC_TOOL_NAME} is permanently guarded and must not be listed in disabledTools`,
    );
  }

  return { ...config, disabledTools };
}