import path from "node:path";
import assert from "node:assert/strict";
import { describe, it } from "node:test";
import type { Request, Response } from "express";
import { migrate } from "drizzle-orm/better-sqlite3/migrator";
import { createDatabaseContext } from "../src/db/database-context.js";
import { UserRepository } from "../src/db/repositories/user.repository.js";
import {
  InvalidCredentialsError,
  LastAdminError,
  PasswordUnchangedError,
  UserService,
  UsernameTakenError,
  WrongPasswordError,
} from "../src/domain/services/user.service.js";
import { hashPassword, verifyPassword } from "../src/server/auth/password.js";
import { SessionStore } from "../src/server/auth/sessions.js";
import { LoginThrottle } from "../src/server/auth/login-throttle.js";
import { readCookie } from "../src/server/auth/cookie.js";
import { requireSameOriginForWrites } from "../src/server/auth/auth.middleware.js";
import type { AuthConfig } from "../src/server/auth/auth-config.js";
import { createUserSchema } from "../src/shared/validation/user.schemas.js";
import { loginSchema } from "../src/shared/validation/auth.schemas.js";
import {
  WRITE_REQUEST_HEADER_NAME,
  WRITE_REQUEST_HEADER_VALUE,
} from "../src/shared/constants/request-security.js";

const HOUR = 60 * 60 * 1000;

function createUserService() {
  const context = createDatabaseContext(":memory:");
  migrate(context.db, { migrationsFolder: path.resolve("src", "db", "migrations") });
  const repository = new UserRepository(context.db);
  const config: AuthConfig = {
    sessionTtlMs: 12 * HOUR,
    sessionMaxAgeMs: 7 * 24 * HOUR,
    cookieSecure: false,
    bootstrap: { username: "admin", password: "bootstrap-password-123" },
  };
  return {
    repository,
    service: new UserService(
      repository,
      { bootstrap: config.bootstrap },
      { hash: hashPassword, verify: verifyPassword }
    ),
  };
}

describe("password hashing", () => {
  it("verifies the right password and rejects a wrong one", async () => {
    const hash = await hashPassword("richtiges-passwort");
    assert.match(hash, /^scrypt\$16384\$8\$1\$[0-9a-f]{32}\$[0-9a-f]{128}$/);
    assert.equal(await verifyPassword("richtiges-passwort", hash), true);
    assert.equal(await verifyPassword("falsches-passwort", hash), false);
  });

  it("uses a fresh salt per hash", async () => {
    assert.notEqual(await hashPassword("gleich"), await hashPassword("gleich"));
  });

  it("rejects malformed stored hashes instead of throwing", async () => {
    assert.equal(await verifyPassword("x", "not-a-hash"), false);
    assert.equal(await verifyPassword("x", "scrypt$a$b$c$00$00"), false);
    assert.equal(
      await verifyPassword(
        "x",
        `scrypt$1073741824$8$1$${"00".repeat(16)}$${"00".repeat(64)}`
      ),
      false
    );
    assert.equal(
      await verifyPassword("x", `scrypt$16384$8$1$00$${"00".repeat(64)}`),
      false
    );
  });
});

describe("session store", () => {
  it("expires idle sessions and slides on activity", () => {
    let now = 0;
    const store = new SessionStore(1 * HOUR, 24 * HOUR, () => now);
    const session = store.create("user-1");
    now = 50 * 60 * 1000;
    assert.ok(store.get(session.id));
    now += 50 * 60 * 1000;
    assert.ok(store.get(session.id), "activity must have extended the idle window");
    now += 2 * HOUR;
    assert.equal(store.get(session.id), undefined);
  });

  it("never outlives the absolute lifetime, even when constantly used", () => {
    let now = 0;
    const store = new SessionStore(1 * HOUR, 3 * HOUR, () => now);
    const session = store.create("user-1");
    for (let step = 0; step < 5; step += 1) {
      now += 30 * 60 * 1000;
      store.get(session.id);
    }
    now = 3 * HOUR;
    assert.equal(store.get(session.id), undefined);
  });

  it("ends all sessions of a user except an optional one", () => {
    const store = new SessionStore(HOUR, 24 * HOUR);
    const first = store.create("user-1");
    const second = store.create("user-1");
    const other = store.create("user-2");
    store.destroyAllForUser("user-1", second.id);
    assert.equal(store.get(first.id), undefined);
    assert.ok(store.get(second.id));
    assert.ok(store.get(other.id));
  });

  it("bounds the number of sessions per user by dropping the oldest", () => {
    let now = 0;
    const store = new SessionStore(HOUR, 24 * HOUR, () => now);
    const oldest = store.create("user-1");
    for (let index = 0; index < 20; index += 1) {
      now += 1;
      store.create("user-1");
    }
    assert.equal(store.get(oldest.id), undefined);
  });
});

describe("login throttle", () => {
  it("blocks a username after repeated failures and releases it after the window", () => {
    let now = 0;
    const throttle = new LoginThrottle(3, 15 * 60 * 1000, 100, () => now);
    for (let attempt = 0; attempt < 3; attempt += 1) {
      assert.equal(throttle.retryAfterMs("Admin"), 0);
      throttle.recordFailure("admin ");
    }
    assert.ok(throttle.retryAfterMs("ADMIN") > 0, "normalized usernames share a counter");
    assert.equal(throttle.retryAfterMs("someone-else"), 0);
    now = 15 * 60 * 1000 + 1;
    assert.equal(throttle.retryAfterMs("admin"), 0);
  });

  it("resets the counter after a successful login", () => {
    const throttle = new LoginThrottle(2);
    throttle.recordFailure("admin");
    throttle.recordSuccess("admin");
    throttle.recordFailure("admin");
    assert.equal(throttle.retryAfterMs("admin"), 0);
  });
});

describe("cookie parsing", () => {
  it("reads the session cookie and ignores malformed encodings", () => {
    assert.equal(readCookie("a=1; lb_session=abc; b=2", "lb_session"), "abc");
    assert.equal(readCookie("lb_session=%E0%A4%A", "lb_session"), undefined);
    assert.equal(readCookie(undefined, "lb_session"), undefined);
  });
});

describe("same-origin guard for writes", () => {
  function run(method: string, fetchSite?: string, includeApplicationHeader = true) {
    let status: number | undefined;
    let passed = false;
    const req = {
      method,
      headers: {
        ...(fetchSite ? { "sec-fetch-site": fetchSite } : {}),
        ...(includeApplicationHeader
          ? { [WRITE_REQUEST_HEADER_NAME.toLowerCase()]: WRITE_REQUEST_HEADER_VALUE }
          : {}),
      },
      get(name: string) {
        return this.headers[name.toLowerCase() as keyof typeof this.headers];
      },
    } as unknown as Request;
    const res = {
      status(code: number) {
        status = code;
        return this;
      },
      json() {
        return this;
      },
    } as unknown as Response;
    requireSameOriginForWrites()(req, res, () => {
      passed = true;
    });
    return { passed, status };
  }

  it("lets reads and same-origin writes through", () => {
    assert.equal(run("GET", "cross-site", false).passed, true);
    assert.equal(run("POST", "same-origin").passed, true);
    assert.equal(run("POST").passed, true, "scripts can send the explicit application header");
  });

  it("rejects writes without the application header or from another origin", () => {
    assert.deepEqual(run("POST", undefined, false), { passed: false, status: 403 });
    assert.deepEqual(run("POST", "cross-site"), { passed: false, status: 403 });
    assert.deepEqual(run("PATCH", "same-site"), { passed: false, status: 403 });
    assert.deepEqual(run("DELETE", "same-site"), { passed: false, status: 403 });
  });
});

describe("input validation", () => {
  it("rejects look-alike and whitespace usernames and normalizes case", () => {
    const base = { name: "Test", role: "user", initialPassword: "start-passwort" };
    assert.equal(createUserSchema.safeParse({ ...base, username: "admіn" }).success, false);
    assert.equal(createUserSchema.safeParse({ ...base, username: "ad min" }).success, false);
    const parsed = createUserSchema.parse({ ...base, username: " Max.Muster@Firma.de " });
    assert.equal(parsed.username, "max.muster@firma.de");
  });

  it("caps login input length so huge bodies never reach scrypt", () => {
    assert.equal(
      loginSchema.safeParse({ username: "admin", password: "x".repeat(201) }).success,
      false
    );
  });
});

describe("user service", () => {
  it("creates the bootstrap admin only while the table is empty", async () => {
    const { repository, service } = createUserService();
    await service.ensureBootstrapAdmin();
    await service.ensureBootstrapAdmin();
    const users = await repository.list();
    assert.equal(users.length, 1);
    assert.equal(users[0].role, "admin");
    assert.equal(users[0].mustChangePassword, true);
  });

  it("rejects unknown users, wrong passwords and deactivated accounts alike", async () => {
    const { service } = createUserService();
    const user = await service.createUser({
      username: "max",
      name: "Max",
      role: "user",
      initialPassword: "start-passwort",
    });
    assert.ok(user);
    await assert.rejects(service.authenticate("niemand", "egal"), InvalidCredentialsError);
    await assert.rejects(service.authenticate("max", "falsch"), InvalidCredentialsError);
    assert.equal((await service.authenticate("MAX", "start-passwort")).id, user.id);
    await service.updateRoleAndActive(user.id, { active: false });
    await assert.rejects(service.authenticate("max", "start-passwort"), InvalidCredentialsError);
  });

  it("refuses duplicate usernames", async () => {
    const { service } = createUserService();
    const input = { username: "max", name: "Max", role: "user" as const, initialPassword: "start-passwort" };
    await service.createUser(input);
    await assert.rejects(service.createUser(input), UsernameTakenError);
  });

  it("never removes the last active admin", async () => {
    const { repository, service } = createUserService();
    await service.ensureBootstrapAdmin();
    const [admin] = await repository.list();
    await assert.rejects(service.updateRoleAndActive(admin.id, { role: "user" }), LastAdminError);
    await assert.rejects(service.updateRoleAndActive(admin.id, { active: false }), LastAdminError);

    const second = await service.createUser({
      username: "zweiter",
      name: "Zweiter",
      role: "admin",
      initialPassword: "start-passwort",
    });
    assert.ok(second);
    await service.updateRoleAndActive(admin.id, { role: "user" });
    await assert.rejects(service.updateRoleAndActive(second.id, { active: false }), LastAdminError);
  });

  it("preserves one active admin across concurrent updates", async () => {
    const { repository, service } = createUserService();
    await service.ensureBootstrapAdmin();
    const second = await service.createUser({
      username: "zweiter-admin",
      name: "Zweiter Admin",
      role: "admin",
      initialPassword: "start-passwort",
    });
    assert.ok(second);
    const [first] = (await repository.list()).filter((user) => user.username === "admin");

    const results = await Promise.allSettled([
      service.updateRoleAndActive(first.id, { role: "user" }),
      service.updateRoleAndActive(second.id, { role: "user" }),
    ]);
    assert.equal(results.filter((result) => result.status === "fulfilled").length, 1);
    assert.equal(results.filter((result) => result.status === "rejected").length, 1);
    const activeAdmins = (await repository.list()).filter(
      (user) => user.role === "admin" && user.active
    );
    assert.equal(activeAdmins.length, 1);
  });

  it("requires the current password and a different new one", async () => {
    const { service } = createUserService();
    const user = await service.createUser({
      username: "max",
      name: "Max",
      role: "user",
      initialPassword: "start-passwort",
    });
    assert.ok(user);
    await assert.rejects(
      service.changeOwnPassword(user.id, "falsch", "neues-passwort"),
      WrongPasswordError
    );
    await assert.rejects(
      service.changeOwnPassword(user.id, "start-passwort", "start-passwort"),
      PasswordUnchangedError
    );
    const changed = await service.changeOwnPassword(user.id, "start-passwort", "neues-passwort");
    assert.equal(changed?.mustChangePassword, false);

    const reset = await service.resetPassword(user.id, "admin-vergeben");
    assert.equal(reset?.mustChangePassword, true);
  });
});