import { createHash, randomBytes } from "node:crypto";
import { eq } from "drizzle-orm";
import { beforeAll, describe, expect, it } from "vitest";
import { SessionManager } from "../src/auth/session";
import type { Database } from "../src/db/client";
import { sessions, users } from "../src/db/schema";
import { makeConfig, openTestDb } from "./helpers";

function sha256Hex(value: string): string {
  return createHash("sha256").update(value).digest("hex");
}

function newToken(): string {
  return randomBytes(32).toString("hex");
}

describe("SessionManager", () => {
  let db: Database;
  let manager: SessionManager;
  let userId: number;

  beforeAll(async () => {
    db = await openTestDb();
    manager = new SessionManager(db, makeConfig());
    const inserted = await db
      .insert(users)
      .values({ username: "alice", passwordHash: "x" })
      .returning();
    const user = inserted[0];
    if (user === undefined) throw new Error("utilisateur de test non inséré");
    userId = user.id;
  });

  it("create : token + CSRF 256 bits, getValid renvoie le contexte", async () => {
    const { token, csrfToken } = await manager.create(userId);
    expect(token).toMatch(/^[a-f0-9]{64}$/);
    expect(csrfToken).toMatch(/^[a-f0-9]{64}$/);
    const ctx = await manager.getValid(token);
    expect(ctx?.userId).toBe(userId);
    expect(ctx?.username).toBe("alice");
    expect(ctx?.sessionExpiresAt).toBeInstanceOf(Date);
  });

  it("getValid : token absent ou inconnu → null", async () => {
    expect(await manager.getValid(undefined)).toBeNull();
    expect(await manager.getValid(newToken())).toBeNull();
  });

  it("le token est stocké haché (pas en clair)", async () => {
    const { token } = await manager.create(userId);
    const rows = await db
      .select()
      .from(sessions)
      .where(eq(sessions.tokenHash, sha256Hex(token)));
    expect(rows).toHaveLength(1);
    expect(rows[0]?.tokenHash).not.toBe(token);
  });

  it("TTL glissant : expiration = maintenant + ttl", async () => {
    const { token } = await manager.create(userId);
    const before = Date.now();
    const ctx = await manager.getValid(token);
    expect(ctx?.sessionExpiresAt.getTime()).toBeGreaterThanOrEqual(before + 8 * 3600 * 1000 - 2000);
    expect(ctx?.sessionExpiresAt.getTime()).toBeLessThanOrEqual(before + 8 * 3600 * 1000 + 5000);
  });

  it("TTL glissant borné par l'expiration absolue", async () => {
    const m = new SessionManager(
      db,
      makeConfig({ sessionTtlMs: 3_600_000, sessionAbsoluteTtlMs: 300_000 }),
    );
    const { token } = await m.create(userId);
    const before = Date.now();
    const ctx = await m.getValid(token);
    expect(ctx?.sessionExpiresAt.getTime()).toBeGreaterThanOrEqual(before + 300_000 - 1_000);
    expect(ctx?.sessionExpiresAt.getTime()).toBeLessThanOrEqual(before + 300_000 + 1_000);
  });

  it("expiration absolue dépassée → null + ligne supprimée", async () => {
    const token = newToken();
    const past = new Date(Date.now() - 1000);
    await db.insert(sessions).values({
      tokenHash: sha256Hex(token),
      userId,
      createdAt: past,
      expiresAt: past,
      absoluteExpiryAt: past,
      lastActivityAt: past,
    });
    expect(await manager.getValid(token)).toBeNull();
    const rows = await db
      .select()
      .from(sessions)
      .where(eq(sessions.tokenHash, sha256Hex(token)));
    expect(rows).toHaveLength(0);
  });

  it("destroy invalidate le token", async () => {
    const { token } = await manager.create(userId);
    await manager.destroy(token);
    expect(await manager.getValid(token)).toBeNull();
  });

  it("5 sessions max par utilisateur (exactement 5 des 6 restent valides)", async () => {
    const inserted = await db
      .insert(users)
      .values({ username: "bob", passwordHash: "x" })
      .returning();
    const bob = inserted[0];
    if (bob === undefined) throw new Error("utilisateur bob non inséré");
    const m2 = new SessionManager(db, makeConfig());
    const tokens: string[] = [];
    for (let i = 0; i < 6; i += 1) {
      tokens.push((await m2.create(bob.id)).token);
    }
    const rows = await db.select().from(sessions).where(eq(sessions.userId, bob.id));
    expect(rows).toHaveLength(5);
    let validCount = 0;
    for (const t of tokens) {
      const ctx = await m2.getValid(t);
      if (ctx !== null) validCount += 1;
    }
    expect(validCount).toBe(5);
  });
});