import fs from "node:fs";
import path from "node:path";
import process from "node:process";
import { z } from "zod";

const cliAgentSchema = z.object({
  name: z.string().min(1),
  command: z.string().min(1),
  args: z.array(z.string()).default([]),
  inputMode: z.enum(["stdin", "arg"]).default("stdin"),
  timeoutMs: z.number().int().positive().default(120_000),
  outputMaxBytes: z.number().int().positive().default(64_000),
  cwd: z.string().optional()
});

const policySchema = z.object({
  allowedUsers: z.array(z.string()).default([]),
  allowedChats: z.array(z.string()).default([]),
  requireMentionInGroup: z.boolean().default(false)
});

const feishuSchema = z.object({
  enabled: z.boolean().default(false),
  appId: z.string().default(""),
  appSecret: z.string().default(""),
  verificationToken: z.string().default(""),
  botNames: z.array(z.string()).default([])
});

const wecomSchema = z.object({
  enabled: z.boolean().default(false),
  corpId: z.string().default(""),
  agentId: z.string().default(""),
  secret: z.string().default("")
});

const qqSchema = z.object({
  enabled: z.boolean().default(false),
  appId: z.string().default(""),
  clientSecret: z.string().default(""),
  botSecret: z.string().default(""),
  verifySignature: z.boolean().default(true),
  botNames: z.array(z.string()).default([])
});

const webhookSchema = z.object({
  enabled: z.boolean().default(true),
  secret: z.string().default("")
});

const weixinSchema = z.object({
  enabled: z.boolean().default(false),
  mode: z.enum(["external-webhook", "not-implemented"]).default("external-webhook"),
  secret: z.string().default("")
});

export const configSchema = z.object({
  server: z.object({
    host: z.string().default("0.0.0.0"),
    port: z.number().int().positive().max(65_535).default(3000),
    publicBaseUrl: z.string().default("")
  }).default({}),
  policy: policySchema.default({}),
  defaultAgent: z.string().min(1).default("echo"),
  agents: z.array(cliAgentSchema).min(1),
  platforms: z.object({
    feishu: feishuSchema.default({}),
    wecom: wecomSchema.default({}),
    qq: qqSchema.default({}),
    webhook: webhookSchema.default({}),
    weixin: weixinSchema.default({})
  }).default({})
});

export type AppConfig = z.infer<typeof configSchema>;
export type CliAgentConfig = z.infer<typeof cliAgentSchema>;
export type GatewayPolicy = z.infer<typeof policySchema>;

export function resolveConfigPath(configPath = process.env.GORI_GATEWAY_CONFIG): string {
  return path.resolve(configPath || "config.example.json");
}

export function parseConfig(rawConfig: unknown): AppConfig {
  const config = configSchema.parse(rawConfig);

  if (!config.agents.some((agent) => agent.name === config.defaultAgent)) {
    throw new Error(`defaultAgent '${config.defaultAgent}' is not present in agents`);
  }

  return config;
}

export function loadConfig(configPath = process.env.GORI_GATEWAY_CONFIG): AppConfig {
  return loadConfigFromPath(resolveConfigPath(configPath));
}

export function loadConfigFromPath(configPath: string): AppConfig {
  const raw = fs.readFileSync(configPath, "utf8");
  const parsed = JSON.parse(raw) as unknown;
  return parseConfig(parsed);
}