import { describe, it, expect } from "vitest";
import { parseCommaList, formatAgentList } from "../agent.js";
import type { AgentConfig } from "../agent.js";

describe("parseCommaList", () => {
    it("returns undefined for undefined input", () => {
        expect(parseCommaList(undefined)).toBe(undefined);
    });
    
    it("returns undefined for null input", () => {
        expect(parseCommaList(null)).toBe(undefined);
    });
    
    it("returns undefined for empty string", () => {
        expect(parseCommaList("")).toBe(undefined);
    });
    
    it("returns a single-element array for a single path", () => {
        expect(parseCommaList("path/a")).toEqual(["path/a"]);
    });
    
    it("splits a comma-separated string into an array", () => {
        expect(parseCommaList("path/a, path/b")).toEqual(["path/a", "path/b"]);
    });
    
    it("trims whitespace from each segment", () => {
        expect(parseCommaList("  path/a  ,  path/b  ")).toEqual(["path/a", "path/b"]);
    });
    
    it("returns undefined when all segments are empty after filtering", () => {
        expect(parseCommaList(",")).toBe(undefined);
    });
    
    it("returns undefined for non-string non-null input", () => {
        expect(parseCommaList(42)).toBe(undefined);
    });
});

describe("formatAgentList", () => {
    const makeAgent = (name: string): AgentConfig => ({
        name,
        description: `${name} description`,
        systemPrompt: "",
        source: "user",
        filePath: `/agents/${name}.md`,
    });
    
    it("returns 'none' for an empty array", () => {
        expect(formatAgentList([], 10)).toEqual({ text: "none", remaining: 0 });
    });
    
    it("lists all agents when count is below maxItems", () => {
        const agents = [makeAgent("alpha"), makeAgent("beta")];
        const result = formatAgentList(agents, 10);
        expect(result.remaining).toBe(0);
        expect(result.text).toContain("alpha (user): alpha description");
        expect(result.text).toContain("beta (user): beta description");
    });
    
    it("limits output to maxItems and reports remaining count", () => {
        const agents = [makeAgent("a"), makeAgent("b"), makeAgent("c")];
        const result = formatAgentList(agents, 2);
        expect(result.remaining).toBe(1);
        expect(result.text).toContain("a (user)");
        expect(result.text).toContain("b (user)");
        expect(result.text).not.toContain("c (user)");
    });
    
    it("formats each agent as 'name (source): description'", () => {
        const agents = [makeAgent("my-agent")];
        const result = formatAgentList(agents, 10);
        expect(result.text).toBe("my-agent (user): my-agent description");
    });
});