import hashlib
import re
from pathlib import Path

from fastapi import FastAPI
from fastapi.responses import FileResponse, JSONResponse, PlainTextResponse
from gtts import gTTS

ROOT = Path(__file__).resolve().parent
STATIC_DIR = ROOT / "static"
SLIDES_DIR = ROOT / "slides"
AUDIO_DIR = ROOT / "audio"
SCRIPT_FILE = ROOT / "scripts.txt"

AUDIO_DIR.mkdir(exist_ok=True)

app = FastAPI()


def read_slide_data():
    """
    scripts.txt에서 ## 제목과 「원고」를 추출합니다.
    slides/0.png ~ slides/19.png와 index 번호로 연결됩니다.
    """
    if not SCRIPT_FILE.exists():
        return []

    text = SCRIPT_FILE.read_text(encoding="utf-8")

    titles = re.findall(r"##\s*(.+)", text)
    speeches = re.findall(r"「([\s\S]*?)」", text)

    slides = []

    for i, speech in enumerate(speeches):
        title = titles[i].strip() if i < len(titles) else f"Slide {i}"
        image_name = f"{i}.png"
        image_path = SLIDES_DIR / image_name

        slides.append({
            "index": i,
            "title": title,
            "speech": speech.strip(),
            "image": f"/slides/{image_name}",
            "image_exists": image_path.exists(),
            "audio": f"/api/audio/{i}"
        })

    return slides


@app.get("/")
def index():
    return FileResponse(STATIC_DIR / "index.html")


@app.get("/style.css")
def css():
    return FileResponse(STATIC_DIR / "style.css", media_type="text/css")


@app.get("/app.js")
def js():
    return FileResponse(STATIC_DIR / "app.js", media_type="application/javascript")


@app.get("/api/slides")
def api_slides():
    return JSONResponse(read_slide_data())


@app.get("/slides/{image_name}")
def slide_image(image_name: str):
    """
    slides/0.png ~ slides/19.png 제공.
    허용된 파일명 패턴만 제공합니다.
    """
    if not re.fullmatch(r"\d+\.png", image_name):
        return PlainTextResponse("Invalid image name", status_code=400)

    image_path = SLIDES_DIR / image_name

    if not image_path.exists():
        return PlainTextResponse(f"Image not found: {image_name}", status_code=404)

    return FileResponse(image_path, media_type="image/png")


@app.get("/api/audio/{slide_index}")
def api_audio(slide_index: int):
    """
    현재 페이지 원고를 gTTS로 mp3 생성 후 반환합니다.
    한 번 생성된 mp3는 audio/에 캐시됩니다.
    """
    slides = read_slide_data()

    if slide_index < 0 or slide_index >= len(slides):
        return PlainTextResponse("Invalid slide index", status_code=404)

    text = slides[slide_index]["speech"]

    if not text:
        return PlainTextResponse("Empty script", status_code=400)

    key = hashlib.md5(f"{slide_index}-{text}".encode("utf-8")).hexdigest()
    mp3_path = AUDIO_DIR / f"slide_{slide_index:02d}_{key}.mp3"

    if not mp3_path.exists():
        try:
            tts = gTTS(text=text, lang="en", slow=False)
            tts.save(str(mp3_path))
        except Exception as e:
            return PlainTextResponse(f"TTS generation failed: {e}", status_code=500)

    return FileResponse(mp3_path, media_type="audio/mpeg")


@app.get("/health")
def health():
    return JSONResponse({
        "status": "ok",
        "scripts_txt": SCRIPT_FILE.exists(),
        "slides_dir": SLIDES_DIR.exists(),
        "static_dir": STATIC_DIR.exists(),
        "slide_count": len(read_slide_data())
    })