import pytest
from pathlib import Path
import re

# Base directory for language files
LANG_DIR = Path(__file__).resolve().parent.parent / "app" / "lang"

def get_structure(file_path: Path):
    """
    Returns a list of (line_number, key/header) for a TOML file.
    Only captures keys and section headers, ignoring the values.
    """
    structure = []
    # Regex to capture "key" = or [header]
    key_pattern = re.compile(r'^\s*"?([^"\s=]+)"?\s*=')
    header_pattern = re.compile(r'^\s*\[([^\]]+)\]')
    
    with open(file_path, "r", encoding="utf-8") as f:
        for i, line in enumerate(f, 1):
            line = line.strip()
            if not line:
                structure.append((i, "<empty>"))
                continue
            
            # Check for header [section]
            header_match = header_pattern.match(line)
            if header_match:
                structure.append((i, f"[{header_match.group(1)}]"))
                continue
                
            # Check for key "name" =
            key_match = key_pattern.match(line)
            if key_match:
                structure.append((i, key_match.group(1)))
                continue
                
            # Comments or anything else
            structure.append((i, "<other/comment>"))
            
    return structure

def test_i18n_files_exist():
    assert LANG_DIR.exists(), f"Language directory {LANG_DIR} not found"
    en_file = LANG_DIR / "en.toml"
    assert en_file.exists(), "English language file (en.toml) must exist as baseline"

def test_i18n_synchronization():
    """
    Ensures all language files have the same keys/headers on the same lines
    as the baseline en.toml.
    """
    en_path = LANG_DIR / "en.toml"
    en_structure = get_structure(en_path)
    
    other_files = list(LANG_DIR.glob("*.toml"))
    other_files.remove(en_path)
    
    for lang_file in other_files:
        lang_name = lang_file.name
        lang_structure = get_structure(lang_file)
        
        # Check line count
        assert len(lang_structure) == len(en_structure), \
            f"{lang_name} length mismatch: expected {len(en_structure)} lines, got {len(lang_structure)}"
            
        # Check line-by-line sync
        for (en_line, en_key), (lang_line, lang_key) in zip(en_structure, lang_structure):
            assert en_key == lang_key, \
                f"Sync error at {lang_name}:{lang_line}. Expected '{en_key}', found '{lang_key}'"

if __name__ == "__main__":
    # Allow running directly as a script
    pytest.main([__file__])