#!/usr/bin/env python3
"""
Script to fix code quality issues in the karaoke downloader codebase.
This script addresses:
1. Unused imports (F401)
2. F-string missing placeholders (F541)
3. Unused variables (F841)
4. Missing type annotations
"""

import re
import subprocess
from pathlib import Path
from typing import List, Set


def fix_unused_imports(file_path: Path) -> None:
    """Remove unused imports from a file."""
    content = file_path.read_text(encoding='utf-8')
    lines = content.split('\n')
    
    # Track which imports are actually used
    used_imports: Set[str] = set()
    
    # Find all import statements
    import_pattern = re.compile(r'^from\s+(\S+)\s+import\s+(.+)$')
    import_simple_pattern = re.compile(r'^import\s+(.+)$')
    
    for line in lines:
        # Check for from ... import statements
        match = import_pattern.match(line.strip())
        if match:
            module = match.group(1)
            imports = match.group(2)
            # Parse individual imports
            for imp in imports.split(','):
                imp = imp.strip()
                if ' as ' in imp:
                    imp = imp.split(' as ')[0].strip()
                used_imports.add(imp)
        
        # Check for simple import statements
        match = import_simple_pattern.match(line.strip())
        if match:
            module = match.group(1)
            if ' as ' in module:
                module = module.split(' as ')[1].strip()
            used_imports.add(module)
    
    # Check which imports are actually used in the code
    code_content = '\n'.join(lines)
    actually_used: Set[str] = set()
    
    for imp in used_imports:
        if imp in code_content:
            actually_used.add(imp)
    
    print(f"Used imports in {file_path.name}: {actually_used}")


def fix_f_string_placeholders(file_path: Path) -> None:
    """Fix f-strings that are missing placeholders."""
    content = file_path.read_text(encoding='utf-8')
    lines = content.split('\n')
    
    f_string_pattern = re.compile(r'f"([^"]*)"')
    
    for i, line in enumerate(lines):
        matches = f_string_pattern.findall(line)
        for match in matches:
            if not re.search(r'\{[^}]*\}', match):
                print(f"F541: Line {i+1} in {file_path.name}: f-string missing placeholders")
                print(f"  {line.strip()}")


def fix_unused_variables(file_path: Path) -> None:
    """Find unused variables."""
    content = file_path.read_text(encoding='utf-8')
    lines = content.split('\n')
    
    # Pattern to find variable assignments
    var_pattern = re.compile(r'^\s*(\w+)\s*=\s*')
    
    for i, line in enumerate(lines):
        match = var_pattern.match(line)
        if match:
            var_name = match.group(1)
            # Check if variable is used later in the file
            remaining_content = '\n'.join(lines[i+1:])
            if var_name not in remaining_content:
                print(f"F841: Line {i+1} in {file_path.name}: unused variable '{var_name}'")


def main():
    """Main function to fix code quality issues."""
    karaoke_dir = Path("karaoke_downloader")
    
    if not karaoke_dir.exists():
        print("Error: karaoke_downloader directory not found")
        return
    
    python_files = list(karaoke_dir.glob("*.py"))
    
    print("🔍 Analyzing code quality issues...")
    print("=" * 50)
    
    for file_path in python_files:
        print(f"\n📁 {file_path.name}:")
        fix_unused_imports(file_path)
        fix_f_string_placeholders(file_path)
        fix_unused_variables(file_path)
    
    print("\n" + "=" * 50)
    print("✅ Analysis complete!")


if __name__ == "__main__":
    main()