import { approvalPolicy } from "./capability-policy.ts";
import { z } from "zod";

export const MAX_MCP_CAPABILITIES = 500;
export const MAX_MCP_CATALOG_BYTES = 256 * 1024;
export const MAX_MCP_SCHEMA_BYTES = 32 * 1024;
const name = z
  .string()
  .min(1)
  .max(200)
  .refine((value) => value.trim().length > 0);
const fingerprint = z.string().regex(/^[0-9a-f]{64}$/);
const schema = z
  .record(z.string(), z.json())
  .refine(
    (value) =>
      new TextEncoder().encode(JSON.stringify(value)).byteLength <=
      MAX_MCP_SCHEMA_BYTES,
  );

// Discovery data and local choices share stable identities, but only local
// writes own choices. A semantic change requires a new decision.
export const mcpCapability = z.strictObject({
  kind: z.enum(["tool", "resource", "prompt"]),
  name,
  description: z.string().max(4000).optional(),
  title: name.optional(),
  annotations: z
    .record(z.string(), z.json())
    .refine(
      (value) =>
        new TextEncoder().encode(JSON.stringify(value)).byteLength <= 2048,
    )
    .optional(),
  uri: z.string().max(2048).optional(),
  mimeType: z.string().max(200).optional(),
  id: fingerprint.optional(),
  serverId: z
    .string()
    .regex(/^mcp-[0-9a-f-]{36}$/)
    .optional(),
  fingerprint: fingerprint.optional(),
  inputSchema: schema.optional(),
  outputSchema: schema.optional(),
  arguments: z
    .array(
      z.strictObject({
        name,
        description: z.string().max(4000).optional(),
        required: z.boolean().optional(),
      }),
    )
    .max(100)
    .optional(),
  issue: z.literal("invalid_schema").optional(),
  settings: z
    .strictObject({
      enabled: z.boolean(),
      approval: approvalPolicy.optional(),
    })
    .optional(),
});
export const mcpCatalog = z
  .array(mcpCapability)
  .max(MAX_MCP_CAPABILITIES)
  .refine(
    (items) =>
      new Set(items.map((item) => `${item.kind}:${item.uri ?? item.name}`))
        .size === items.length,
  )
  .refine(
    (items) =>
      new TextEncoder().encode(JSON.stringify(items)).byteLength <=
      MAX_MCP_CATALOG_BYTES,
  );
export const mcpCatalogRefresh = z.strictObject({
  added: z.array(fingerprint).max(MAX_MCP_CAPABILITIES),
  removed: z.array(fingerprint).max(MAX_MCP_CAPABILITIES),
  changed: z.array(fingerprint).max(MAX_MCP_CAPABILITIES),
  omitted: z.number().int().nonnegative(),
  invalid: z.number().int().nonnegative(),
});
export type McpCapability = z.infer<typeof mcpCapability>;
export type McpCatalogRefresh = z.infer<typeof mcpCatalogRefresh>;