// ABOUTME: PocketBase test harness for e2e tests - starts, configures, and stops PocketBase.
// ABOUTME: Provides ephemeral PocketBase instances with test data for Playwright tests.

import { type ChildProcess, execSync, spawn } from "node:child_process";
import { createCipheriv, randomBytes } from "node:crypto";
import * as fs from "node:fs";
import * as os from "node:os";
import * as path from "node:path";
import PocketBase from "pocketbase";
import {
  addUserFields,
  createCollection,
  getExistingCollectionNames,
  getMissingCollections,
  setupApiRules,
} from "../scripts/setup-db";

/**
 * Test user presets for different e2e test scenarios.
 */
export type TestUserPreset =
  | "onboarding"
  | "established"
  | "calendar"
  | "garmin"
  | "garminExpired";

/**
 * Configuration for each test user type.
 */
export const TEST_USERS: Record<
  TestUserPreset,
  { email: string; password: string }
> = {
  onboarding: {
    email: "e2e-onboarding@phaseflow.local",
    password: "e2e-onboarding-123",
  },
  established: {
    email: "e2e-test@phaseflow.local",
    password: "e2e-test-password-123",
  },
  calendar: {
    email: "e2e-calendar@phaseflow.local",
    password: "e2e-calendar-123",
  },
  garmin: {
    email: "e2e-garmin@phaseflow.local",
    password: "e2e-garmin-123",
  },
  garminExpired: {
    email: "e2e-garmin-expired@phaseflow.local",
    password: "e2e-garmin-expired-123",
  },
};

/**
 * Configuration for the test harness.
 */
export interface HarnessConfig {
  port: number;
  adminEmail: string;
  adminPassword: string;
  testUserEmail: string;
  testUserPassword: string;
}

/**
 * Default configuration for e2e tests.
 */
export const DEFAULT_CONFIG: HarnessConfig = {
  port: 8091,
  adminEmail: "admin@e2e-test.local",
  adminPassword: "admin-password-e2e-123",
  testUserEmail: "e2e-test@phaseflow.local",
  testUserPassword: "e2e-test-password-123",
};

/**
 * State of a running PocketBase harness instance.
 */
export interface HarnessState {
  process: ChildProcess;
  dataDir: string;
  url: string;
  config: HarnessConfig;
}

let currentState: HarnessState | null = null;

/**
 * Gets the URL for the PocketBase instance.
 */
function getPocketBaseUrl(port: number): string {
  return `http://127.0.0.1:${port}`;
}

/**
 * Creates a temporary directory for PocketBase data.
 */
function createTempDataDir(): string {
  const tempDir = fs.mkdtempSync(path.join(os.tmpdir(), "pocketbase-e2e-"));
  return tempDir;
}

/**
 * Waits for PocketBase to be ready by polling the health endpoint.
 */
async function waitForReady(url: string, timeoutMs = 30000): Promise<void> {
  const startTime = Date.now();
  const healthUrl = `${url}/api/health`;

  while (Date.now() - startTime < timeoutMs) {
    try {
      const response = await fetch(healthUrl);
      if (response.ok) {
        return;
      }
    } catch {
      // Server not ready yet, continue polling
    }
    await new Promise((resolve) => setTimeout(resolve, 100));
  }

  throw new Error(`PocketBase did not become ready within ${timeoutMs}ms`);
}

/**
 * Sleeps for the specified number of milliseconds.
 */
function sleep(ms: number): Promise<void> {
  return new Promise((resolve) => setTimeout(resolve, ms));
}

/**
 * Creates the admin superuser using the PocketBase CLI.
 * Retries on database lock errors since PocketBase may still be running migrations.
 */
async function createAdminUser(
  dataDir: string,
  email: string,
  password: string,
  maxRetries = 5,
): Promise<void> {
  let lastError: Error | null = null;

  for (let attempt = 0; attempt < maxRetries; attempt++) {
    try {
      execSync(
        `pocketbase superuser upsert ${email} ${password} --dir=${dataDir}`,
        {
          stdio: "pipe",
        },
      );
      return;
    } catch (err) {
      lastError = err as Error;
      const errorMsg = String(lastError.message || lastError);

      // Retry on database lock errors
      if (
        errorMsg.includes("database is locked") ||
        errorMsg.includes("SQLITE_BUSY")
      ) {
        await sleep(100 * (attempt + 1)); // Exponential backoff: 100ms, 200ms, 300ms...
        continue;
      }

      // For other errors, throw immediately
      throw err;
    }
  }

  throw lastError;
}

/**
 * Sets up the database collections using the SDK.
 */
async function setupCollections(pb: PocketBase): Promise<void> {
  // Add custom fields to users collection
  await addUserFields(pb);

  // Create period_logs and dailyLogs collections
  const existingNames = await getExistingCollectionNames(pb);
  const missing = getMissingCollections(existingNames);

  for (const collection of missing) {
    await createCollection(pb, collection);
  }

  // Set up API rules
  await setupApiRules(pb);
}

/**
 * Retries an async operation with exponential backoff.
 */
async function retryAsync<T>(
  operation: () => Promise<T>,
  maxRetries = 5,
  baseDelayMs = 100,
): Promise<T> {
  let lastError: Error | null = null;

  for (let attempt = 0; attempt < maxRetries; attempt++) {
    try {
      return await operation();
    } catch (err) {
      lastError = err as Error;
      const errorMsg = String(lastError.message || lastError);

      // Retry on transient errors (database busy, connection issues)
      if (
        errorMsg.includes("database is locked") ||
        errorMsg.includes("SQLITE_BUSY") ||
        errorMsg.includes("Failed to create record")
      ) {
        await sleep(baseDelayMs * (attempt + 1));
        continue;
      }

      // For other errors, throw immediately
      throw err;
    }
  }

  throw lastError;
}

/**
 * Encrypts a string using AES-256-GCM (matches src/lib/encryption.ts format).
 * Uses the test encryption key from playwright.config.ts.
 */
function encryptForTest(plaintext: string): string {
  const key = Buffer.from(
    "e2e-test-encryption-key-32chars".padEnd(32, "0").slice(0, 32),
  );
  const iv = randomBytes(16);
  const cipher = createCipheriv("aes-256-gcm", key, iv);

  let encrypted = cipher.update(plaintext, "utf8", "hex");
  encrypted += cipher.final("hex");

  const authTag = cipher.getAuthTag();
  return `${iv.toString("hex")}:${authTag.toString("hex")}:${encrypted}`;
}

/**
 * Creates the onboarding test user (no period data).
 */
async function createOnboardingUser(pb: PocketBase): Promise<string> {
  const { email, password } = TEST_USERS.onboarding;

  const user = await retryAsync(() =>
    pb.collection("users").create({
      email,
      password,
      passwordConfirm: password,
      emailVisibility: true,
      verified: true,
      cycleLength: 28,
      notificationTime: "07:00",
      timezone: "UTC",
    }),
  );

  return user.id;
}

/**
 * Creates the established test user with period data (default user).
 */
async function createEstablishedUser(pb: PocketBase): Promise<string> {
  const { email, password } = TEST_USERS.established;
  const fourteenDaysAgo = new Date();
  fourteenDaysAgo.setDate(fourteenDaysAgo.getDate() - 14);
  const lastPeriodDate = fourteenDaysAgo.toISOString().split("T")[0];

  const user = await retryAsync(() =>
    pb.collection("users").create({
      email,
      password,
      passwordConfirm: password,
      emailVisibility: true,
      verified: true,
      lastPeriodDate,
      cycleLength: 28,
      notificationTime: "07:00",
      timezone: "UTC",
    }),
  );

  await retryAsync(() =>
    pb.collection("period_logs").create({
      user: user.id,
      startDate: lastPeriodDate,
    }),
  );

  return user.id;
}

/**
 * Creates the calendar test user with period data and calendar token.
 */
async function createCalendarUser(pb: PocketBase): Promise<string> {
  const { email, password } = TEST_USERS.calendar;
  const fourteenDaysAgo = new Date();
  fourteenDaysAgo.setDate(fourteenDaysAgo.getDate() - 14);
  const lastPeriodDate = fourteenDaysAgo.toISOString().split("T")[0];

  const user = await retryAsync(() =>
    pb.collection("users").create({
      email,
      password,
      passwordConfirm: password,
      emailVisibility: true,
      verified: true,
      lastPeriodDate,
      cycleLength: 28,
      notificationTime: "07:00",
      timezone: "UTC",
      calendarToken: "e2e-test-calendar-token-12345678",
    }),
  );

  await retryAsync(() =>
    pb.collection("period_logs").create({
      user: user.id,
      startDate: lastPeriodDate,
    }),
  );

  return user.id;
}

/**
 * Creates the Garmin test user with period data and valid Garmin tokens.
 */
async function createGarminUser(pb: PocketBase): Promise<string> {
  const { email, password } = TEST_USERS.garmin;
  const fourteenDaysAgo = new Date();
  fourteenDaysAgo.setDate(fourteenDaysAgo.getDate() - 14);
  const lastPeriodDate = fourteenDaysAgo.toISOString().split("T")[0];

  // Token expires 90 days in the future
  const expiresAt = new Date();
  expiresAt.setDate(expiresAt.getDate() + 90);

  const oauth1Token = encryptForTest(
    JSON.stringify({
      oauth_token: "test-oauth1-token",
      oauth_token_secret: "test-oauth1-secret",
    }),
  );

  const oauth2Token = encryptForTest(
    JSON.stringify({
      access_token: "test-access-token",
      refresh_token: "test-refresh-token",
      token_type: "Bearer",
      expires_in: 7776000,
    }),
  );

  const user = await retryAsync(() =>
    pb.collection("users").create({
      email,
      password,
      passwordConfirm: password,
      emailVisibility: true,
      verified: true,
      lastPeriodDate,
      cycleLength: 28,
      notificationTime: "07:00",
      timezone: "UTC",
      garminConnected: true,
      garminOauth1Token: oauth1Token,
      garminOauth2Token: oauth2Token,
      garminTokenExpiresAt: expiresAt.toISOString(),
    }),
  );

  await retryAsync(() =>
    pb.collection("period_logs").create({
      user: user.id,
      startDate: lastPeriodDate,
    }),
  );

  return user.id;
}

/**
 * Creates the Garmin expired test user with period data and expired Garmin tokens.
 */
async function createGarminExpiredUser(pb: PocketBase): Promise<string> {
  const { email, password } = TEST_USERS.garminExpired;
  const fourteenDaysAgo = new Date();
  fourteenDaysAgo.setDate(fourteenDaysAgo.getDate() - 14);
  const lastPeriodDate = fourteenDaysAgo.toISOString().split("T")[0];

  // Token expired 1 day ago
  const expiredAt = new Date();
  expiredAt.setDate(expiredAt.getDate() - 1);

  const oauth1Token = encryptForTest(
    JSON.stringify({
      oauth_token: "test-expired-oauth1-token",
      oauth_token_secret: "test-expired-oauth1-secret",
    }),
  );

  const oauth2Token = encryptForTest(
    JSON.stringify({
      access_token: "test-expired-access-token",
      refresh_token: "test-expired-refresh-token",
      token_type: "Bearer",
      expires_in: 7776000,
    }),
  );

  const user = await retryAsync(() =>
    pb.collection("users").create({
      email,
      password,
      passwordConfirm: password,
      emailVisibility: true,
      verified: true,
      lastPeriodDate,
      cycleLength: 28,
      notificationTime: "07:00",
      timezone: "UTC",
      garminConnected: true,
      garminOauth1Token: oauth1Token,
      garminOauth2Token: oauth2Token,
      garminTokenExpiresAt: expiredAt.toISOString(),
    }),
  );

  await retryAsync(() =>
    pb.collection("period_logs").create({
      user: user.id,
      startDate: lastPeriodDate,
    }),
  );

  return user.id;
}

/**
 * Creates all test users for e2e tests.
 */
async function createAllTestUsers(pb: PocketBase): Promise<void> {
  await createOnboardingUser(pb);
  await createEstablishedUser(pb);
  await createCalendarUser(pb);
  await createGarminUser(pb);
  await createGarminExpiredUser(pb);
}

/**
 * Starts a fresh PocketBase instance for e2e testing.
 */
export async function start(
  config: HarnessConfig = DEFAULT_CONFIG,
): Promise<HarnessState> {
  if (currentState) {
    throw new Error(
      "PocketBase harness is already running. Call stop() first.",
    );
  }

  const dataDir = createTempDataDir();
  const url = getPocketBaseUrl(config.port);

  // Start PocketBase process
  const pbProcess = spawn(
    "pocketbase",
    ["serve", `--dir=${dataDir}`, `--http=127.0.0.1:${config.port}`],
    {
      stdio: "pipe",
      detached: false,
    },
  );

  // Handle process errors
  pbProcess.on("error", (err) => {
    console.error("PocketBase process error:", err);
  });

  // Wait for PocketBase to be ready
  await waitForReady(url);

  // Create admin user via CLI (with retry for database lock during migrations)
  await createAdminUser(dataDir, config.adminEmail, config.adminPassword);

  // Connect to PocketBase as admin
  const pb = new PocketBase(url);
  pb.autoCancellation(false);
  await pb
    .collection("_superusers")
    .authWithPassword(config.adminEmail, config.adminPassword);

  // Set up collections
  await setupCollections(pb);

  // Create all test users for different e2e scenarios
  await createAllTestUsers(pb);

  currentState = {
    process: pbProcess,
    dataDir,
    url,
    config,
  };

  return currentState;
}

/**
 * Stops the running PocketBase instance and cleans up.
 */
export async function stop(): Promise<void> {
  if (!currentState) {
    return;
  }

  const { process: pbProcess, dataDir } = currentState;

  // Kill the PocketBase process
  pbProcess.kill("SIGTERM");

  // Wait a moment for graceful shutdown
  await new Promise((resolve) => setTimeout(resolve, 500));

  // Force kill if still running
  if (!pbProcess.killed) {
    pbProcess.kill("SIGKILL");
  }

  // Clean up the temporary data directory
  fs.rmSync(dataDir, { recursive: true, force: true });

  currentState = null;
}

/**
 * Gets the current harness state if running.
 */
export function getState(): HarnessState | null {
  return currentState;
}