import * as plugins from './plugins.js';
import type {
  IBrowserKvmOptions,
  IKvmDriver,
  IKvmFrame,
  IKvmTypeTextOptions,
  TKvmKey,
  TKvmKind,
} from './smartkvm.interfaces.js';

const defaultViewerSelector = 'video, canvas';

interface ICaptureMediaResult {
  captured: boolean;
  width?: number;
  height?: number;
  dataBase64?: string;
  error?: string;
  hasMediaElement?: boolean;
  mediaHasFrame?: boolean;
}

export class SmartBrowserKvm implements IKvmDriver {
  public readonly kind: TKvmKind;

  private options: IBrowserKvmOptions;
  private browser?: plugins.puppeteer.Browser;
  private page?: plugins.puppeteer.Page;

  constructor(options: IBrowserKvmOptions) {
    this.options = options;
    this.kind = options.kind ?? 'generic';
  }

  public async connect(): Promise<void> {
    if (this.browser && this.page) {
      return;
    }

    const timeoutMs = this.options.timeoutMs ?? 30000;
    const args: string[] = [];
    if (process.env.CI || process.getuid?.() === 0) {
      args.push('--no-sandbox', '--disable-setuid-sandbox');
    }

    this.browser = await plugins.puppeteer.launch({
      args,
      acceptInsecureCerts: this.options.ignoreHttpsErrors ?? false,
      defaultViewport: null,
      executablePath: this.options.executablePath,
      headless: this.options.headless ?? true,
      timeout: timeoutMs,
      userDataDir: this.options.userDataDir,
    });

    this.page = await this.browser.newPage();
    this.page.setDefaultTimeout(timeoutMs);
    this.page.setDefaultNavigationTimeout(timeoutMs);

    await this.page.goto(this.options.url, {
      waitUntil: 'domcontentloaded',
      timeout: timeoutMs,
    });

    await this.tryGenericLogin();
    await this.waitForViewerReady();
    await this.focusViewer();
  }

  public async disconnect(): Promise<void> {
    const browser = this.browser;
    this.page = undefined;
    this.browser = undefined;
    if (browser) {
      await browser.close();
    }
  }

  public async focusViewer(): Promise<void> {
    const page = this.requirePage();
    const viewerSelector = this.getViewerSelector();
    const viewerElement = await page.$(viewerSelector);
    if (!viewerElement) {
      throw new Error(`KVM viewer selector missing: ${viewerSelector}`);
    }
    await viewerElement.click();
  }

  public async captureFrame(): Promise<IKvmFrame> {
    const page = this.requirePage();
    const captureSelector = this.getCaptureSelector();
    const captureElement = await page.$(captureSelector);
    if (!captureElement) {
      throw new Error(`KVM capture selector missing: ${captureSelector}`);
    }

    const mediaResult = await page.evaluate((selector: string): ICaptureMediaResult => {
      const rootElement = document.querySelector(selector);
      if (!rootElement) {
        return {
          captured: false,
          error: `KVM capture selector missing: ${selector}`,
        };
      }

      const mediaElement = (rootElement.matches('video, canvas')
        ? rootElement
        : rootElement.querySelector('video, canvas')) as HTMLVideoElement | HTMLCanvasElement | null;

      if (!mediaElement) {
        return {
          captured: false,
          hasMediaElement: false,
        };
      }

      let width = 0;
      let height = 0;
      if (mediaElement instanceof HTMLVideoElement) {
        width = mediaElement.videoWidth;
        height = mediaElement.videoHeight;
      } else if (mediaElement instanceof HTMLCanvasElement) {
        width = mediaElement.width;
        height = mediaElement.height;
      }

      if (width <= 0 || height <= 0) {
        return {
          captured: false,
          hasMediaElement: true,
          mediaHasFrame: false,
        };
      }

      try {
        const canvasElement = document.createElement('canvas');
        canvasElement.width = width;
        canvasElement.height = height;
        const context = canvasElement.getContext('2d');
        if (!context) {
          return {
            captured: false,
            hasMediaElement: true,
            mediaHasFrame: true,
            error: 'Could not create canvas 2D context for KVM frame capture.',
          };
        }
        context.drawImage(mediaElement, 0, 0, width, height);
        const dataUrl = canvasElement.toDataURL('image/png');
        return {
          captured: true,
          width,
          height,
          dataBase64: dataUrl.slice(dataUrl.indexOf(',') + 1),
        };
      } catch (error) {
        return {
          captured: false,
          hasMediaElement: true,
          mediaHasFrame: true,
          error: error instanceof Error ? error.message : String(error),
        };
      }
    }, captureSelector);

    if (mediaResult.captured) {
      return {
        timestamp: Date.now(),
        width: mediaResult.width ?? 0,
        height: mediaResult.height ?? 0,
        mimeType: 'image/png',
        dataBase64: mediaResult.dataBase64 ?? '',
      };
    }

    if (mediaResult.error?.startsWith('KVM capture selector missing')) {
      throw new Error(mediaResult.error);
    }

    if (mediaResult.hasMediaElement && mediaResult.mediaHasFrame === false) {
      throw new Error(`KVM media element has no frame: ${captureSelector}`);
    }

    const boundingBox = await captureElement.boundingBox();
    if (!boundingBox || boundingBox.width <= 0 || boundingBox.height <= 0) {
      throw new Error(`KVM capture selector has no visible frame: ${captureSelector}`);
    }

    const screenshot = await captureElement.screenshot({
      type: 'png',
    });

    return {
      timestamp: Date.now(),
      width: Math.round(boundingBox.width),
      height: Math.round(boundingBox.height),
      mimeType: 'image/png',
      dataBase64: Buffer.from(screenshot).toString('base64'),
    };
  }

  public async typeText(text: string, options?: IKvmTypeTextOptions): Promise<void> {
    const page = this.requirePage();
    await this.focusViewer();
    await page.keyboard.type(text, {
      delay: options?.delayMs,
    });
  }

  public async pressKey(key: TKvmKey): Promise<void> {
    const page = this.requirePage();
    await this.focusViewer();
    await page.keyboard.press(key as plugins.puppeteer.KeyInput);
  }

  public async pressShortcut(keys: TKvmKey[]): Promise<void> {
    const page = this.requirePage();
    await this.focusViewer();

    const pressedKeys: TKvmKey[] = [];
    try {
      for (const key of keys) {
        await page.keyboard.down(key as plugins.puppeteer.KeyInput);
        pressedKeys.push(key);
      }
    } finally {
      for (const key of pressedKeys.reverse()) {
        await page.keyboard.up(key as plugins.puppeteer.KeyInput);
      }
    }
  }

  public async wait(milliseconds: number): Promise<void> {
    await new Promise<void>((resolve) => setTimeout(resolve, milliseconds));
  }

  private async tryGenericLogin(): Promise<void> {
    if (!this.options.username || !this.options.password) {
      return;
    }

    const page = this.requirePage();
    const usernameElement = await this.findFirstElement([
      'input[name="username"]',
      'input[autocomplete="username"]',
      'input[type="email"]',
      'input[type="text"]',
    ]);
    const passwordElement = await this.findFirstElement([
      'input[name="password"]',
      'input[autocomplete="current-password"]',
      'input[type="password"]',
    ]);

    if (!usernameElement || !passwordElement) {
      return;
    }

    await usernameElement.click({ clickCount: 3 });
    await usernameElement.type(this.options.username);
    await passwordElement.click({ clickCount: 3 });
    await passwordElement.type(this.options.password);
    await passwordElement.press('Enter');

    await Promise.race([
      page
        .waitForNavigation({
          waitUntil: 'domcontentloaded',
          timeout: Math.min(this.options.timeoutMs ?? 30000, 10000),
        })
        .catch(() => undefined),
      this.wait(1000),
    ]);
  }

  private async waitForViewerReady(): Promise<void> {
    const page = this.requirePage();
    const viewerSelector = this.getViewerSelector();
    await page.waitForFunction(
      (selector: string) => {
        const rootElement = document.querySelector(selector);
        if (!rootElement) {
          return false;
        }

        const mediaElement = (rootElement.matches('video, canvas')
          ? rootElement
          : rootElement.querySelector('video, canvas')) as HTMLVideoElement | HTMLCanvasElement | null;

        if (mediaElement instanceof HTMLVideoElement) {
          return mediaElement.videoWidth > 0 && mediaElement.videoHeight > 0;
        }

        if (mediaElement instanceof HTMLCanvasElement) {
          return mediaElement.width > 0 && mediaElement.height > 0;
        }

        const boundingRect = rootElement.getBoundingClientRect();
        return boundingRect.width > 0 && boundingRect.height > 0;
      },
      {
        timeout: this.options.timeoutMs ?? 30000,
      },
      viewerSelector
    );
  }

  private async findFirstElement(
    selectors: string[]
  ): Promise<plugins.puppeteer.ElementHandle<Element> | null> {
    const page = this.requirePage();
    for (const selector of selectors) {
      const element = await page.$(selector);
      if (element) {
        return element;
      }
    }
    return null;
  }

  private getViewerSelector(): string {
    return this.options.viewerSelector ?? defaultViewerSelector;
  }

  private getCaptureSelector(): string {
    return this.options.captureSelector ?? this.options.viewerSelector ?? defaultViewerSelector;
  }

  private requirePage(): plugins.puppeteer.Page {
    if (!this.page) {
      throw new Error('SmartBrowserKvm is not connected. Call connect() first.');
    }
    return this.page;
  }
}