import { execFileSync, spawn } from 'node:child_process';

type ToolResult = {
  content: Array<{ type: string; text: string }>;
  isError?: boolean;
};

type OnUpdate = (partial: { content: Array<{ type: string; text: string }> }) => void;

function update(onUpdate: OnUpdate | undefined, text: string): void {
  onUpdate?.({ content: [{ type: 'text', text }] });
}

function ensureFfmpeg(): boolean {
  try {
    execFileSync('ffmpeg', ['-version'], { stdio: 'ignore' });
    return true;
  } catch {
    try {
      execFileSync('sudo', ['apt-get', 'update'], { stdio: 'ignore', timeout: 60_000 });
      execFileSync('sudo', ['apt-get', 'install', '-y', 'ffmpeg'], { stdio: 'ignore', timeout: 120_000 });
      execFileSync('ffmpeg', ['-version'], { stdio: 'ignore' });
      return true;
    } catch {
      return false;
    }
  }
}

function parseArgs(argsString: string): string[] {
  const args: string[] = [];
  let current = '';
  let inSingle = false;
  let inDouble = false;

  for (let i = 0; i < argsString.length; i++) {
    const ch = argsString[i]!;

    if (ch === "'" && !inDouble) {
      inSingle = !inSingle;
    } else if (ch === '"' && !inSingle) {
      inDouble = !inDouble;
    } else if (ch === ' ' && !inSingle && !inDouble) {
      if (current.length > 0) {
        args.push(current);
        current = '';
      }
    } else {
      current += ch;
    }
  }

  if (current.length > 0) args.push(current);
  return args;
}

export async function execute(
  _toolCallId: string,
  params: { command: 'ffmpeg' | 'ffprobe'; args: string },
  _signal: AbortSignal | undefined,
  onUpdate?: OnUpdate,
): Promise<ToolResult> {
  const { command, args: argsString } = params;

  if (!argsString || argsString.trim().length === 0) {
    return {
      content: [{ type: 'text', text: 'No arguments provided. See tool documentation for usage examples.' }],
      isError: true,
    };
  }

  update(onUpdate, 'Checking ffmpeg installation...');

  if (!ensureFfmpeg()) {
    return {
      content: [{ type: 'text', text: 'Failed to install ffmpeg. Try manually: sudo apt-get update && sudo apt-get install -y ffmpeg' }],
      isError: true,
    };
  }

  const args = parseArgs(argsString);

  // For ffprobe, run synchronously and return output
  if (command === 'ffprobe') {
    update(onUpdate, `Running ffprobe...`);
    return new Promise((resolve) => {
      const proc = spawn('ffprobe', args, { stdio: ['ignore', 'pipe', 'pipe'] });
      let stdout = '';
      let stderr = '';

      proc.stdout.on('data', (chunk: Buffer) => { stdout += chunk.toString(); });
      proc.stderr.on('data', (chunk: Buffer) => { stderr += chunk.toString(); });

      proc.on('close', (code) => {
        if (code !== 0) {
          resolve({
            content: [{ type: 'text', text: `ffprobe failed (exit ${code}):\n${stderr.trim()}` }],
            isError: true,
          });
        } else {
          // ffprobe prints info to stderr by default, stdout for -print_format
          const output = stdout.trim() || stderr.trim();
          resolve({
            content: [{ type: 'text', text: output || 'No output' }],
          });
        }
      });

      proc.on('error', (err) => {
        resolve({
          content: [{ type: 'text', text: `ffprobe error: ${err.message}` }],
          isError: true,
        });
      });
    });
  }

  // For ffmpeg, stream progress
  update(onUpdate, `Running ffmpeg...`);

  return new Promise((resolve) => {
    const proc = spawn('ffmpeg', args, { stdio: ['ignore', 'pipe', 'pipe'] });
    let stdout = '';
    let stderr = '';
    let progressBuf = '';

    proc.stdout.on('data', (chunk: Buffer) => {
      stdout += chunk.toString();
    });

    proc.stderr.on('data', (chunk: Buffer) => {
      const text = chunk.toString();
      stderr += text;

      // Parse ffmpeg progress from stderr (time= field)
      progressBuf += text;
      const lines = progressBuf.split('\r');
      progressBuf = lines.pop() ?? '';
      for (const line of lines) {
        const timeMatch = line.match(/time=(\d{2}:\d{2}:\d{2}\.\d{2})/);
        const speedMatch = line.match(/speed=\s*([\d.]+x)/);
        if (timeMatch) {
          const progress = `Time: ${timeMatch[1]}${speedMatch ? ` | Speed: ${speedMatch[1]}` : ''}`;
          update(onUpdate, progress);
        }
      }
    });

    proc.on('close', (code) => {
      if (code !== 0) {
        // Extract the last meaningful error line from stderr
        const errLines = stderr.trim().split('\n');
        const lastLines = errLines.slice(-10).join('\n');
        resolve({
          content: [{ type: 'text', text: `ffmpeg failed (exit ${code}):\n${lastLines}` }],
          isError: true,
        });
      } else {
        const output = stdout.trim();
        resolve({
          content: [{ type: 'text', text: output ? `Done.\n\n${output}` : 'Done.' }],
        });
      }
    });

    proc.on('error', (err) => {
      resolve({
        content: [{ type: 'text', text: `ffmpeg error: ${err.message}` }],
        isError: true,
      });
    });
  });
}