#!/usr/bin/env python3
"""
Fix RTI links in CMakeLists.txt files by wrapping them in IF(BUILD_RTI) blocks.

This script finds NGL_TARGET_LINK_LIBRARIES blocks that contain RTI:: references
and wraps them in IF(BUILD_RTI) conditionals if not already wrapped.
"""

import os
import re
import sys

def process_cmake_file(filepath):
    """Process a single CMakeLists.txt file and wrap RTI links in IF(BUILD_RTI)."""
    
    with open(filepath, 'r') as f:
        content = f.read()
    
    original_content = content
    lines = content.split('\n')
    
    # Track if we're inside an IF(BUILD_RTI) block
    build_rti_depth = 0
    i = 0
    
    while i < len(lines):
        line = lines[i]
        
        # Check for IF(BUILD_RTI) - increment depth
        if re.match(r'^\s*IF\s*\(\s*BUILD_RTI\s*\)\s*$', line, re.IGNORECASE):
            build_rti_depth += 1
            i += 1
            continue
        
        # Check for ENDIF(BUILD_RTI) - decrement depth
        if re.match(r'^\s*ENDIF\s*\(\s*BUILD_RTI\s*\)\s*$', line, re.IGNORECASE):
            build_rti_depth = max(0, build_rti_depth - 1)
            i += 1
            continue
        
        # Check for NGL_TARGET_LINK_LIBRARIES with RTI reference
        if re.match(r'^\s*NGL_TARGET_LINK_LIBRARIES\s*\(', line, re.IGNORECASE):
            # Find the complete block (matching parentheses)
            block_start = i
            paren_depth = 0
            block_end = i
            
            for j in range(i, len(lines)):
                paren_depth += lines[j].count('(') - lines[j].count(')')
                if paren_depth == 0:
                    block_end = j
                    break
            
            # Check if this block contains RTI:: reference
            block_content = '\n'.join(lines[block_start:block_end+1])
            has_rti = bool(re.search(r'RTI::', block_content))
            
            # Check if already inside IF(BUILD_RTI)
            already_wrapped = build_rti_depth > 0
            
            if has_rti and not already_wrapped:
                print(f"  Wrapping RTI link block at line {block_start+1}")
                
                # Insert IF(BUILD_RTI) before the block
                indent = ''
                if block_start > 0:
                    # Try to match indentation of the NGL_TARGET_LINK_LIBRARIES line
                    match = re.match(r'^(\s*)', lines[block_start])
                    if match:
                        indent = match.group(1)
                
                lines.insert(block_start, f'{indent}IF(BUILD_RTI)')
                
                # Insert ENDIF(BUILD_RTI) after the block
                # Adjust block_end because we inserted a line
                block_end += 1
                lines.insert(block_end + 1, f'{indent}ENDIF(BUILD_RTI)')
                
                # Skip past the block we just processed
                i = block_end + 2
                continue
        
        i += 1
    
    new_content = '\n'.join(lines)
    
    if new_content != original_content:
        with open(filepath, 'w') as f:
            f.write(new_content)
        return True
    return False

def find_cmake_files(root_dir):
    """Find all CMakeLists.txt files recursively."""
    cmake_files = []
    for dirpath, dirnames, filenames in os.walk(root_dir):
        # Skip .git directories
        if '.git' in dirpath:
            continue
        if 'CMakeLists.txt' in filenames:
            cmake_files.append(os.path.join(dirpath, 'CMakeLists.txt'))
    return cmake_files

def main():
    if len(sys.argv) < 2:
        print("Usage: fix_rti_links.py <directory>")
        sys.exit(1)
    
    root_dir = sys.argv[1]
    
    if not os.path.isdir(root_dir):
        print(f"Error: {root_dir} is not a directory")
        sys.exit(1)
    
    cmake_files = find_cmake_files(root_dir)
    print(f"Found {len(cmake_files)} CMakeLists.txt files")
    
    modified_count = 0
    for filepath in cmake_files:
        rel_path = os.path.relpath(filepath, root_dir)
        
        # Check if file contains RTI references before processing
        with open(filepath, 'r') as f:
            content = f.read()
        
        if 'RTI::' not in content:
            continue
        
        print(f"Processing: {rel_path}")
        if process_cmake_file(filepath):
            modified_count += 1
    
    print(f"\nModified {modified_count} files")

if __name__ == '__main__':
    main()