/**
 * Stargue LinkedIn MCP Server — stdio transport.
 *
 * Pinned spec: MCP 2024-11-05.
 *
 * Tool wiring lives here; pure helpers (oauth, refresh-lock, kill-switch, tools)
 * are tested independently. The actual @modelcontextprotocol/sdk wiring requires
 * a runtime DB + LinkedIn credentials (gates 0.8 + 0.9), so this module exposes
 * a `createServer` factory that takes injected dependencies for testability.
 */

import { z } from "zod";
import { TOOL_NAMES, TOOL_SCHEMAS, type ToolName } from "./tools";
import { KillSwitch } from "./kill-switch";
import type { AdvisoryLock } from "./refresh-lock";

export const MCP_SERVER_NAME = "@stargue/mcp-linkedin";
export const MCP_SPEC_VERSION = "2024-11-05";

export interface ServerDeps {
  killSwitch: KillSwitch;
  advisoryLock: AdvisoryLock;
  // future: tokenStore, linkedInClient, dbPool — wired in Stage 3 live integration
}

export interface ToolCall {
  name: ToolName;
  args: unknown;
}

export interface ToolResult<T = unknown> {
  ok: boolean;
  data?: T;
  error?: { code: string; message: string };
}

/**
 * Validates a tool call against its registered schema. Returns parsed args or
 * a 400-style error result.
 */
export const validateToolCall = (call: ToolCall): { ok: true; args: unknown } | ToolResult => {
  const schema = TOOL_SCHEMAS[call.name as ToolName] as { input: z.ZodTypeAny } | undefined;
  if (!schema) {
    return { ok: false, error: { code: "UNKNOWN_TOOL", message: `Unknown tool: ${call.name}` } };
  }
  const parse = schema.input.safeParse(call.args);
  if (!parse.success) {
    return {
      ok: false,
      error: {
        code: "INVALID_ARGS",
        message: parse.error.issues.map((i) => `${i.path.join(".")}: ${i.message}`).join("; "),
      },
    };
  }
  return { ok: true, args: parse.data };
};

export const listTools = (): ReadonlyArray<{ name: ToolName; description: string }> =>
  TOOL_NAMES.map((name) => ({
    name,
    description: TOOL_SCHEMAS[name].description,
  }));

export const outletForAuthorUrn = (urn: string): "linkedin.member" | "linkedin.org" => {
  if (urn.startsWith("urn:li:person:")) return "linkedin.member";
  if (urn.startsWith("urn:li:organization:")) return "linkedin.org";
  throw new Error(`Cannot derive outlet from URN: ${urn}`);
};