import { describe, expect, it } from "vitest";
import { rankCandidates } from "../../../../src/application/patterns/rank-candidates.js";
import type { Pattern } from "../../src/shared/value-objects/pattern.js";

describe("rankCandidates", () => {
	const now = "2026-03-21";

	it("should score candidates between 0 and 1", () => {
		const patterns: Pattern[] = [
			{ sequence: ["Read", "Edit"], count: 10, sessions: 5, projects: 3, lastSeen: now },
		];
		const result = rankCandidates(patterns, { totalProjects: 5, totalSessions: 20, now });
		expect(result[0].score).toBeGreaterThanOrEqual(0);
		expect(result[0].score).toBeLessThanOrEqual(1);
	});

	it("should rank high-frequency cross-project patterns higher", () => {
		const patterns: Pattern[] = [
			{ sequence: ["Read", "Edit"], count: 20, sessions: 15, projects: 5, lastSeen: now },
			{ sequence: ["Grep", "Bash"], count: 3, sessions: 2, projects: 1, lastSeen: now },
		];
		const result = rankCandidates(patterns, { totalProjects: 5, totalSessions: 20, now });
		expect(result[0].score).toBeGreaterThan(result[1].score);
	});

	it("should penalize old patterns via recency decay", () => {
		const patterns: Pattern[] = [
			{ sequence: ["Read", "Edit"], count: 10, sessions: 5, projects: 3, lastSeen: now },
			{ sequence: ["Grep", "Bash"], count: 10, sessions: 5, projects: 3, lastSeen: "2026-01-01" },
		];
		const result = rankCandidates(patterns, { totalProjects: 5, totalSessions: 20, now });
		expect(result[0].score).toBeGreaterThan(result[1].score);
	});

	it("should accept custom weights from settings", () => {
		const patterns: Pattern[] = [
			{
				sequence: ["Read", "Edit"],
				count: 10,
				sessions: 5,
				projects: 3,
				lastSeen: new Date().toISOString(),
			},
		];
		const customWeights = { frequency: 0.5, breadth: 0.1, recency: 0.2, consistency: 0.2 };
		const result = rankCandidates(patterns, {
			totalProjects: 5,
			totalSessions: 10,
			now: new Date().toISOString(),
			weights: customWeights,
		});
		expect(result).toHaveLength(1);
		const defaultResult = rankCandidates(patterns, {
			totalProjects: 5,
			totalSessions: 10,
			now: new Date().toISOString(),
		});
		expect(result[0].score).not.toBe(defaultResult[0].score);
	});

	it("should filter below threshold", () => {
		const patterns: Pattern[] = [
			{ sequence: ["Read", "Edit"], count: 1, sessions: 1, projects: 1, lastSeen: now },
		];
		const result = rankCandidates(patterns, {
			totalProjects: 10,
			totalSessions: 50,
			now,
			threshold: 0.5,
		});
		expect(result).toHaveLength(0);
	});
});