import re
import os
import sys

def is_text_prop(tag_str):
    """Check if the NButton tag has the `text` prop (bare, :text, or v-bind:text)."""
    # Remove attribute values to avoid false positives
    cleaned = re.sub(r'"[^"]*"', '', tag_str)
    cleaned = re.sub(r"'[^']*'", '', cleaned)
    return bool(re.search(r'(?:^|[\s>])(?::text|v-bind:text|text)(?=[\s=>/]|$)', cleaned))

def has_dynamic_class(tag_str):
    """Check if the tag uses :class or v-bind:class (dynamic class binding)."""
    cleaned = re.sub(r'"[^"]*"', '', tag_str)
    cleaned = re.sub(r"'[^']*'", '', cleaned)
    return bool(re.search(r'(?::class|v-bind:class)\s*=', cleaned))

def has_skybtn_class(tag_str):
    """Check if the tag already has sky-btn in its class attribute value."""
    for m in re.finditer(r'class\s*=\s*"([^"]*)"', tag_str):
        if 'sky-btn' in m.group(1):
            return True
    for m in re.finditer(r"class\s*=\s*'([^']*)'", tag_str):
        if 'sky-btn' in m.group(1):
            return True
    return False

def add_skybtn_to_tag(tag_str):
    """Add class="sky-btn" or append sky-btn to existing class."""
    # Check for existing class="..."
    m = re.search(r'class\s*=\s*"([^"]*)"', tag_str)
    if m:
        old_class = m.group(1).strip()
        new_class = (old_class + ' sky-btn') if old_class else 'sky-btn'
        return tag_str[:m.start(1)] + new_class + tag_str[m.end(1):]

    # Check for existing class='...'
    m = re.search(r"class\s*=\s*'([^']*)'", tag_str)
    if m:
        old_class = m.group(1).strip()
        new_class = (old_class + ' sky-btn') if old_class else 'sky-btn'
        return tag_str[:m.start(1)] + new_class + tag_str[m.end(1):]

    # No class attribute, add before closing >
    # Find the outermost > that closes the tag
    if tag_str.rstrip().endswith('/>'):
        insert_pos = tag_str.rstrip().rfind('/>')
        prefix = tag_str[:insert_pos].rstrip()
        suffix = tag_str[insert_pos:]
        return prefix + ' class="sky-btn" ' + suffix.lstrip()
    else:
        insert_pos = tag_str.rstrip().rfind('>')
        prefix = tag_str[:insert_pos].rstrip()
        suffix = tag_str[insert_pos:]
        return prefix + ' class="sky-btn"' + suffix

def process_vue_file(filepath):
    try:
        with open(filepath, 'r', encoding='utf-8') as f:
            content = f.read()
    except Exception as e:
        print(f"  Error reading {filepath}: {e}", file=sys.stderr)
        return False

    # Find the template section
    template_start_match = re.search(r'<template>', content)
    if not template_start_match:
        return False

    template_end_match = re.search(r'</template>', content)
    if not template_end_match:
        return False

    template_start = template_start_match.start()
    template_end = template_end_match.end()

    template_section = content[template_start:template_end]
    before = content[:template_start]
    after = content[template_end:]

    # Match NButton/n-button opening tags with attribute-aware regex
    tag_pattern = r'<([Nn]-[Bb]utton)\b((?:[^>"\']|"[^"]*"|\'[^\']*\')*)\s*/?>'

    modified_sections = []
    last_end = 0
    modified_count = 0

    for m in re.finditer(tag_pattern, template_section):
        modified_sections.append(template_section[last_end:m.start()])
        full_match = m.group(0)

        if is_text_prop(full_match):
            modified_sections.append(full_match)
        elif has_dynamic_class(full_match):
            modified_sections.append(full_match)
        elif has_skybtn_class(full_match):
            modified_sections.append(full_match)
        else:
            new_tag = add_skybtn_to_tag(full_match)
            modified_sections.append(new_tag)
            modified_count += 1

        last_end = m.end()

    modified_sections.append(template_section[last_end:])

    if modified_count > 0:
        new_template_section = ''.join(modified_sections)
        new_content = before + new_template_section + after
        with open(filepath, 'w', encoding='utf-8') as f:
            f.write(new_content)
        print(f"  Modified ({modified_count} changes): {os.path.relpath(filepath, os.getcwd())}")
        return True

    return False

def main():
    cwd = os.getcwd()
    print(f"Working directory: {cwd}")

    vue_files = []
    for root, dirs, files in os.walk(os.path.join(cwd, 'frontend', 'src')):
        for f in files:
            if f.endswith('.vue'):
                vue_files.append(os.path.join(root, f))

    print(f"Found {len(vue_files)} Vue files")

    changed_files = []
    for filepath in sorted(vue_files):
        if process_vue_file(filepath):
            changed_files.append(filepath)

    print(f"\nTotal files modified: {len(changed_files)}")
    for fp in changed_files:
        print(f"  {os.path.relpath(fp, cwd)}")

    return len(changed_files)

if __name__ == '__main__':
    main()