/**
 * Base test class providing common test utilities and lifecycle hooks
 * Extend this class to create test suites with automatic setup/teardown
 */

import { assertExists } from "@std/assert";

export interface TestContext {
  /** Unique temporary directory for this test */
  tempDir: string;
  /** Test name */
  name: string;
}

/**
 * Abstract base class for tests
 * Provides lifecycle hooks and common utilities
 */
export abstract class BaseTest {
  private static testCounter = 0;
  protected context: TestContext | null = null;

  /**
   * Run before all tests in this suite (optional)
   * Override this in your test class if needed
   */
  protected beforeAll(): void | Promise<void> {
    // Override in subclass if needed
  }

  /**
   * Run after all tests in this suite (optional)
   * Override this in your test class if needed
   */
  protected afterAll(): void | Promise<void> {
    // Override in subclass if needed
  }

  /**
   * Run before each individual test (optional)
   * Override this in your test class if needed
   */
  protected beforeEach(_context: TestContext): void | Promise<void> {
    // Override in subclass if needed
  }

  /**
   * Run after each individual test (optional)
   * Override this in your test class if needed
   */
  protected afterEach(_context: TestContext): void | Promise<void> {
    // Override in subclass if needed
  }

  /**
   * Create a temporary directory for a test
   * Automatically cleaned up after test completes
   */
  protected async createTempDir(testName: string): Promise<string> {
    const counter = BaseTest.testCounter++;
    const timestamp = Date.now();
    const sanitizedName = testName.replace(/[^a-zA-Z0-9]/g, "_");
    const tempDir =
      `/tmp/profilarr-tests/${sanitizedName}_${timestamp}_${counter}`;
    await Deno.mkdir(tempDir, { recursive: true });
    return tempDir;
  }

  /**
   * Clean up a temporary directory and all its contents
   */
  protected async cleanupTempDir(tempDir: string): Promise<void> {
    try {
      await Deno.remove(tempDir, { recursive: true });
    } catch (error) {
      // Ignore errors during cleanup
      console.warn(`Failed to cleanup temp dir ${tempDir}:`, error);
    }
  }

  /**
   * Assert that a file exists at the given path
   */
  protected async assertFileExists(
    filePath: string,
    message?: string,
  ): Promise<void> {
    try {
      const stat = await Deno.stat(filePath);
      assertExists(stat, message ?? `File should exist: ${filePath}`);
    } catch (error) {
      throw new Error(
        message ??
          `Expected file to exist: ${filePath}, but got error: ${error}`,
      );
    }
  }

  /**
   * Assert that a file does NOT exist at the given path
   */
  protected async assertFileNotExists(
    filePath: string,
    message?: string,
  ): Promise<void> {
    try {
      await Deno.stat(filePath);
      throw new Error(message ?? `Expected file to NOT exist: ${filePath}`);
    } catch (error) {
      if (!(error instanceof Deno.errors.NotFound)) {
        throw error;
      }
      // File doesn't exist - this is what we want
    }
  }

  /**
   * Assert that a file contains specific text
   */
  protected async assertFileContains(
    filePath: string,
    expectedText: string,
    message?: string,
  ): Promise<void> {
    const content = await Deno.readTextFile(filePath);
    if (!content.includes(expectedText)) {
      throw new Error(
        message ??
          `Expected file ${filePath} to contain "${expectedText}", but it didn't.\nFile content: ${content}`,
      );
    }
  }

  /**
   * Assert that a file matches a regex pattern
   */
  protected async assertFileMatches(
    filePath: string,
    pattern: RegExp,
    message?: string,
  ): Promise<void> {
    const content = await Deno.readTextFile(filePath);
    if (!pattern.test(content)) {
      throw new Error(
        message ??
          `Expected file ${filePath} to match pattern ${pattern}, but it didn't.\nFile content: ${content}`,
      );
    }
  }

  /**
   * Read and parse JSON log file
   */
  protected async readJsonLines(filePath: string): Promise<unknown[]> {
    const content = await Deno.readTextFile(filePath);
    const lines = content.split("\n").filter((line) => line.trim());
    return lines.map((line) => JSON.parse(line));
  }

  /**
   * Wait for a condition to become true with timeout
   */
  protected async waitFor(
    condition: () => boolean | Promise<boolean>,
    timeoutMs = 5000,
    checkIntervalMs = 100,
  ): Promise<void> {
    const startTime = Date.now();
    while (Date.now() - startTime < timeoutMs) {
      if (await condition()) {
        return;
      }
      await this.sleep(checkIntervalMs);
    }
    throw new Error(`Timeout waiting for condition after ${timeoutMs}ms`);
  }

  /**
   * Wait for a file to exist
   */
  protected async waitForFile(
    filePath: string,
    timeoutMs = 5000,
  ): Promise<void> {
    await this.waitFor(async () => {
      try {
        await Deno.stat(filePath);
        return true;
      } catch {
        return false;
      }
    }, timeoutMs);
  }

  /**
   * Sleep for specified milliseconds
   */
  protected async sleep(ms: number): Promise<void> {
    await new Promise((resolve) => setTimeout(resolve, ms));
  }

  /**
   * Register and run a test with automatic setup/teardown
   */
  protected test(
    name: string,
    fn: (context: TestContext) => Promise<void> | void,
  ): void {
    Deno.test({
      name: `${this.constructor.name}: ${name}`,
      fn: async () => {
        // Create temp directory for this test
        const tempDir = await this.createTempDir(name);
        const context: TestContext = { tempDir, name };
        this.context = context;

        try {
          // Run beforeEach hook
          await this.beforeEach(context);

          // Run the actual test
          await fn(context);
        } finally {
          // Run afterEach hook
          await this.afterEach(context);

          // Cleanup temp directory
          await this.cleanupTempDir(tempDir);

          this.context = null;
        }
      },
    });
  }

  /**
   * Run the test suite
   * Call this method to execute all tests defined in your subclass
   */
  async run(): Promise<void> {
    // Run beforeAll hook
    await this.beforeAll();

    // Tests are registered via this.test() calls in the subclass constructor or setup method
    // Deno.test will handle running them

    // Note: afterAll will be called by the Deno test runner after all tests complete
    // We can't easily hook into this without using the unstable API
    // For now, tests should clean up in afterEach
  }
}