/**
 * Process Manager
 *
 * Manages spawning and monitoring of Sway and Chromium processes
 */

import { runCommand } from '../utils/command.ts';
import type { DisplayInfo } from './system-info.ts';

export interface SwayConfig {
  runtimeDir: string;
  backends: string;
  allowSoftwareRendering: boolean;
  headless?: boolean;
  headlessOutputs?: number;
  renderer?: string;
  resolution?: string;
}

export interface BrowserConfig {
  runtimeDir: string;
  waylandDisplay: string;
  url: string;
  kiosk?: boolean;
}

export class ProcessManager {
  private user: string;
  private swayProcess: Deno.ChildProcess | null = null;
  private browserProcess: Deno.ChildProcess | null = null;
  private swaySocket: string | null = null;

  constructor(user: string) {
    this.user = user;
  }

  /**
   * Find the Sway IPC socket path in the runtime directory
   * Sway creates sockets like: sway-ipc.$UID.$PID.sock
   */
  async findSwaySocket(runtimeDir: string): Promise<string | null> {
    try {
      for await (const entry of Deno.readDir(runtimeDir)) {
        if (entry.name.startsWith('sway-ipc.') && entry.name.endsWith('.sock')) {
          const socketPath = `${runtimeDir}/${entry.name}`;
          console.log(`[sway] Found IPC socket: ${socketPath}`);
          return socketPath;
        }
      }
    } catch (error) {
      console.error(`[sway] Error finding socket: ${error}`);
    }
    return null;
  }

  getSwaySocket(): string | null {
    return this.swaySocket;
  }

  setSwaySocket(socket: string | null): void {
    this.swaySocket = socket;
  }

  /**
   * Generate Sway configuration content for kiosk mode
   */
  private generateSwayConfig(config: SwayConfig): string {
    const resolution = config.resolution || '1920x1080';

    return `# EcoOS Sway Configuration (generated by eco-daemon)
# Kiosk mode operation

# Variables
set $mod Mod4

# Output configuration
output * {
    bg #000000 solid_color
    resolution ${resolution}
}

# For headless backend virtual outputs
output HEADLESS-1 {
    resolution ${resolution}
    position 0 0
}

# Input configuration
input * {
    events enabled
}

# Disable screen blanking for kiosk mode
exec_always swaymsg "output * dpms on"

# No window decorations for fullscreen kiosk
default_border none
default_floating_border none

# Focus follows mouse
focus_follows_mouse yes

# Force all windows fullscreen for kiosk mode
for_window [app_id=".*"] fullscreen enable
for_window [app_id="chromium-browser"] fullscreen enable
`;
  }

  /**
   * Write Sway config to user's config directory
   */
  private async writeSwayConfig(config: SwayConfig): Promise<string> {
    const configDir = `/home/${this.user}/.config/sway`;
    const configPath = `${configDir}/config`;

    // Create config directory
    await runCommand('mkdir', ['-p', configDir]);
    await runCommand('chown', [`${this.user}:${this.user}`, `/home/${this.user}/.config`]);
    await runCommand('chown', [`${this.user}:${this.user}`, configDir]);

    // Write config file
    const configContent = this.generateSwayConfig(config);
    await Deno.writeTextFile(configPath, configContent);
    await runCommand('chown', [`${this.user}:${this.user}`, configPath]);

    console.log(`[sway] Config written to ${configPath}`);
    return configPath;
  }

  async startSway(config: SwayConfig): Promise<void> {
    // Write sway config before starting
    const configPath = await this.writeSwayConfig(config);

    const env: Record<string, string> = {
      XDG_RUNTIME_DIR: config.runtimeDir,
      WLR_BACKENDS: config.backends,
    };

    if (config.allowSoftwareRendering) {
      env.WLR_RENDERER_ALLOW_SOFTWARE = '1';
    }

    // Headless mode configuration
    if (config.headless) {
      env.WLR_HEADLESS_OUTPUTS = String(config.headlessOutputs || 1);
      // Use libinput for input even in headless mode (for VNC/remote input)
      env.WLR_LIBINPUT_NO_DEVICES = '1';
    }

    // Force specific renderer (pixman for software rendering)
    if (config.renderer) {
      env.WLR_RENDERER = config.renderer;
    }

    // Build environment string for runuser
    const envString = Object.entries(env)
      .map(([k, v]) => `${k}=${v}`)
      .join(' ');

    const command = new Deno.Command('runuser', {
      args: ['-u', this.user, '--', 'sh', '-c', `${envString} sway -c ${configPath}`],
      stdout: 'piped',
      stderr: 'piped',
      stdin: 'null',
    });

    this.swayProcess = command.spawn();

    // Log output in background
    this.pipeOutput(this.swayProcess, 'sway');
  }

  /**
   * Run a swaymsg command to control Sway
   */
  async swaymsg(config: { runtimeDir: string; waylandDisplay: string }, command: string): Promise<boolean> {
    // Find socket if not already found
    if (!this.swaySocket) {
      this.swaySocket = await this.findSwaySocket(config.runtimeDir);
    }

    if (!this.swaySocket) {
      console.error('[swaymsg] No Sway IPC socket found');
      return false;
    }

    const env: Record<string, string> = {
      XDG_RUNTIME_DIR: config.runtimeDir,
      SWAYSOCK: this.swaySocket,
    };

    const envString = Object.entries(env)
      .map(([k, v]) => `${k}=${v}`)
      .join(' ');

    const cmd = new Deno.Command('runuser', {
      args: [
        '-u',
        this.user,
        '--',
        'sh',
        '-c',
        `${envString} swaymsg '${command}'`,
      ],
      stdout: 'piped',
      stderr: 'piped',
    });

    try {
      const result = await cmd.output();
      if (!result.success) {
        const stderr = new TextDecoder().decode(result.stderr);
        console.error(`[swaymsg] Command failed: ${stderr}`);
      }
      return result.success;
    } catch (error) {
      console.error(`[swaymsg] Error: ${error}`);
      return false;
    }
  }

  /**
   * Start Chromium browser in kiosk mode
   */
  async startBrowser(config: BrowserConfig): Promise<void> {
    const env: Record<string, string> = {
      HOME: `/home/${this.user}`,
      XDG_RUNTIME_DIR: config.runtimeDir,
      WAYLAND_DISPLAY: config.waylandDisplay,
      XDG_CONFIG_HOME: `/home/${this.user}/.config`,
      XDG_DATA_HOME: `/home/${this.user}/.local/share`,
    };

    // Chromium arguments for kiosk mode on Wayland
    // Hardware acceleration is enabled where available but falls back gracefully
    const browserArgs = [
      // Wayland/Ozone configuration
      '--ozone-platform=wayland',
      '--enable-features=UseOzonePlatform',
      // Kiosk mode settings
      '--kiosk',
      '--no-first-run',
      '--disable-infobars',
      '--disable-session-crashed-bubble',
      '--disable-restore-session-state',
      '--noerrdialogs',
      // Disable unnecessary features for kiosk
      '--disable-background-networking',
      '--disable-sync',
      '--disable-translate',
      '--disable-features=TranslateUI',
      '--disable-hang-monitor',
      '--disable-breakpad',
      '--disable-component-update',
      config.url,
    ];

    // Build environment string for runuser
    const envString = Object.entries(env)
      .map(([k, v]) => `${k}=${v}`)
      .join(' ');

    const command = new Deno.Command('runuser', {
      args: [
        '-u',
        this.user,
        '--',
        'sh',
        '-c',
        `${envString} chromium-browser ${browserArgs.join(' ')}`,
      ],
      stdout: 'piped',
      stderr: 'piped',
      stdin: 'null',
    });

    this.browserProcess = command.spawn();

    // Log output in background
    this.pipeOutput(this.browserProcess, 'chromium');

    // Force fullscreen via swaymsg after Chromium window appears (backup)
    this.forceFullscreenAfterDelay(config);
  }

  /**
   * Force fullscreen for Chromium window after a delay (backup for kiosk mode)
   */
  private async forceFullscreenAfterDelay(config: { runtimeDir: string; waylandDisplay: string }): Promise<void> {
    // Wait for Chromium window to appear
    await new Promise((resolve) => setTimeout(resolve, 3000));

    console.log('[chromium] Forcing fullscreen via swaymsg');

    // Try multiple selectors to ensure we catch the window
    const selectors = [
      '[app_id="chromium-browser"]',
      '[app_id="chromium"]',
    ];

    for (const selector of selectors) {
      await this.swaymsg(config, `${selector} fullscreen enable`);
    }

    // Also try to focus the window
    await this.swaymsg(config, '[app_id="chromium-browser"] focus');
  }

  isSwayRunning(): boolean {
    return this.swayProcess !== null;
  }

  async isBrowserRunning(): Promise<boolean> {
    // Check if any chromium process is running (Chromium forks, so we can't just track the parent)
    try {
      const cmd = new Deno.Command('pgrep', { args: ['-f', 'chromium'], stdout: 'null', stderr: 'null' });
      const result = await cmd.output();
      return result.success;
    } catch {
      return false;
    }
  }

  async stopSway(): Promise<void> {
    if (this.swayProcess) {
      try {
        this.swayProcess.kill('SIGTERM');
        await this.swayProcess.status;
      } catch {
        // Process may already be dead
      }
      this.swayProcess = null;
      this.swaySocket = null; // Reset socket so we find new one on restart
    }
  }

  async stopBrowser(): Promise<void> {
    if (this.browserProcess) {
      try {
        this.browserProcess.kill('SIGTERM');
        await this.browserProcess.status;
      } catch {
        // Process may already be dead
      }
      this.browserProcess = null;
    }
  }

  /**
   * Get connected displays via swaymsg
   */
  async getDisplays(config: { runtimeDir: string; waylandDisplay: string }): Promise<DisplayInfo[]> {
    // Find socket if not already found
    if (!this.swaySocket) {
      this.swaySocket = await this.findSwaySocket(config.runtimeDir);
    }

    if (!this.swaySocket) {
      console.error('[displays] No Sway IPC socket found');
      return [];
    }

    const env: Record<string, string> = {
      XDG_RUNTIME_DIR: config.runtimeDir,
      SWAYSOCK: this.swaySocket,
    };

    const envString = Object.entries(env)
      .map(([k, v]) => `${k}=${v}`)
      .join(' ');

    const cmd = new Deno.Command('runuser', {
      args: ['-u', this.user, '--', 'sh', '-c', `${envString} swaymsg -t get_outputs`],
      stdout: 'piped',
      stderr: 'piped',
    });

    try {
      const result = await cmd.output();
      if (!result.success) {
        const stderr = new TextDecoder().decode(result.stderr);
        console.error(`[displays] Failed to get outputs: ${stderr}`);
        return [];
      }

      const outputs = JSON.parse(new TextDecoder().decode(result.stdout));
      return outputs.map((output: {
        name: string;
        make: string;
        model: string;
        serial: string;
        active: boolean;
        current_mode?: { width: number; height: number; refresh: number };
        focused: boolean;
      }) => ({
        name: output.name,
        make: output.make || 'Unknown',
        model: output.model || 'Unknown',
        serial: output.serial || '',
        active: output.active,
        width: output.current_mode?.width || 0,
        height: output.current_mode?.height || 0,
        refreshRate: Math.round((output.current_mode?.refresh || 0) / 1000),
        isPrimary: output.focused,
      }));
    } catch (error) {
      console.error(`[displays] Error: ${error}`);
      return [];
    }
  }

  /**
   * Enable or disable a display
   */
  async setDisplayEnabled(
    config: { runtimeDir: string; waylandDisplay: string },
    name: string,
    enabled: boolean
  ): Promise<boolean> {
    const command = `output ${name} ${enabled ? 'enable' : 'disable'}`;
    console.log(`[displays] ${command}`);
    return this.swaymsg(config, command);
  }

  /**
   * Move the kiosk browser to a specific display
   */
  async setKioskDisplay(
    config: { runtimeDir: string; waylandDisplay: string },
    name: string
  ): Promise<boolean> {
    console.log(`[displays] Setting primary display to ${name}`);

    // Focus the chromium window and move it to the target output
    const commands = [
      `[app_id="chromium-browser"] focus`,
      `move container to output ${name}`,
      `focus output ${name}`,
      `[app_id="chromium-browser"] fullscreen enable`,
    ];

    for (const cmd of commands) {
      await this.swaymsg(config, cmd);
    }

    return true;
  }

  private async pipeOutput(
    process: Deno.ChildProcess,
    name: string
  ): Promise<void> {
    const decoder = new TextDecoder();

    // Pipe stdout
    (async () => {
      for await (const chunk of process.stdout) {
        const text = decoder.decode(chunk);
        for (const line of text.split('\n').filter((l) => l.trim())) {
          console.log(`[${name}] ${line}`);
        }
      }
    })();

    // Pipe stderr
    (async () => {
      for await (const chunk of process.stderr) {
        const text = decoder.decode(chunk);
        for (const line of text.split('\n').filter((l) => l.trim())) {
          console.error(`[${name}:err] ${line}`);
        }
      }
    })();

    // Monitor process exit - only nullify if still the same process (prevents race condition on restart)
    process.status.then((status) => {
      console.log(`[${name}] Process exited with code ${status.code}`);
      if (name === 'sway' && this.swayProcess === process) {
        this.swayProcess = null;
        this.swaySocket = null; // Reset socket so we find new one on restart
      } else if (name === 'chromium' && this.browserProcess === process) {
        this.browserProcess = null;
      }
    });
  }
}