import os
import re
import asyncio
from app.core.deepseek_client import chat_with_openai
from app.models.lyric_romanji_translator import FileResult

semaphore = asyncio.Semaphore(5)
timestamp_pattern = re.compile(r"^\[\d{2}:\d{2}\.\d{2}\]")

def needs_romaji(lines, idx):
    if idx + 1 < len(lines) and not timestamp_pattern.match(lines[idx + 1]):
        return False
    return True

async def get_romaji(text: str) -> str:
    messages = [
        {"role": "system", "content": "Convert Japanese text into romaji only. Output romaji without explanation."},
        {"role": "user", "content": text}
    ]
    return await chat_with_openai(messages)

async def process_lrc_file(filepath: str) -> FileResult:
    added_lines = 0
    with open(filepath, "r", encoding="utf-8") as f:
        lines = f.readlines()

    new_lines = []
    for idx, line in enumerate(lines):
        new_lines.append(line)

        if timestamp_pattern.match(line) and needs_romaji(lines, idx):
            japanese = line.strip().split("]", 1)[-1].strip()
            if japanese:
                romaji = await get_romaji(japanese)
                new_lines.append(f"{romaji}\n")
                added_lines += 1

    if added_lines > 0:
        with open(filepath, "w", encoding="utf-8") as f:
            f.writelines(new_lines)

    return FileResult(file=filepath, processed=added_lines > 0, added_lines=added_lines)

async def safe_process(filepath):
    async with semaphore:
        print(f"Processing: {filepath}")
        return await process_lrc_file(filepath)

async def translate_lyric_romanji(folder_path: str):
    results = []

    if not os.path.exists(folder_path):
        return {"results": [], "status": f"error: folder not found {folder_path}"}

    tasks = []
    for root, _, files in os.walk(folder_path):
        for file in files:
            if file.endswith(".lrc"):
                filepath = os.path.join(root, file)
                tasks.append(asyncio.create_task(safe_process(filepath)))

    if not tasks:
        return {"results": [], "status": "no .lrc files found"}

    # Run them all concurrently
    results = await asyncio.gather(*tasks)

    return {"results": results, "status": "completed"}