"""TTS Voice Creator - Clone and Design — FastAPI entry point (thin wrapper)."""
from __future__ import annotations

import logging
import os
from logging.handlers import RotatingFileHandler
from pathlib import Path
from contextlib import asynccontextmanager

from urllib.parse import parse_qs

from fastapi import FastAPI
from fastapi.staticfiles import StaticFiles
from fastapi.middleware.gzip import GZipMiddleware
from starlette.datastructures import MutableHeaders

from core.constants import STATIC_DIR, _BufferHandler
from core.config import _load_settings
from core.voice_index import refresh_voice_index_background
from routes import admin, settings, library, stt, sources, docker, tts, conversation, reader, characters, rehearsals_db

logger = logging.getLogger("uvicorn.error")

# ── App ───────────────────────────────────────────────────────────────────────

@asynccontextmanager
async def lifespan(app: FastAPI):
    # Uvicorn resets loggers during startup when run via CLI.
    # We must attach our handlers here to ensure they capture the active logs.
    for name in ("uvicorn", "uvicorn.error", "uvicorn.access", "fastapi"):
        l = logging.getLogger(name)
        if _buf_handler not in l.handlers:
            l.addHandler(_buf_handler)
        if "_file_handler" in globals() and _file_handler not in l.handlers:
            l.addHandler(_file_handler)
    try:
        refresh_voice_index_background(_load_settings())
    except Exception as exc:
        logger.warning("Could not start voice index refresh: %s", exc)
    yield

app = FastAPI(title="TTS Voice Creator - Clone and Design", lifespan=lifespan)

# ── Response compression ──────────────────────────────────────────────────────
# Gzip text assets (JS/CSS/HTML/JSON) above 1 KB — ~75% smaller transfer for the
# large JS bundle and voice-list JSON. Skips already-compressed audio/images.
app.add_middleware(GZipMiddleware, minimum_size=1024)

# ── In-memory log buffer handler ──────────────────────────────────────────────

_buf_handler = _BufferHandler()
_buf_handler.setLevel(logging.DEBUG)
logging.getLogger().addHandler(_buf_handler)

# ── File log handler (rotates at 5 MB, keeps 3 files) ────────────────────────

_LOG_DIR = Path(os.environ.get("LOG_DIR", "/logs"))
try:
    _LOG_DIR.mkdir(parents=True, exist_ok=True)
    _file_handler = RotatingFileHandler(
        _LOG_DIR / "app.log",
        maxBytes=5 * 1024 * 1024,
        backupCount=3,
        encoding="utf-8",
    )
    _file_handler.setLevel(logging.INFO)
    _file_handler.setFormatter(logging.Formatter(
        "%(asctime)s %(levelname)-8s %(name)s: %(message)s",
        datefmt="%Y-%m-%d %H:%M:%S",
    ))
    logging.getLogger().addHandler(_file_handler)
except Exception as _log_err:
    logger.warning("Could not set up file logging at %s: %s", _LOG_DIR, _log_err)

# ── Static-asset caching middleware ──────────────────────────────────────────
# JS and CSS are served with ?v=<version> by loader.js — safe to cache for 1 year.
# Section HTML uses ?v=<timestamp> (always fresh) so no long-term cache there.
#
# Pure ASGI middleware, not @app.middleware("http") (= Starlette's
# BaseHTTPMiddleware) — that implementation wraps every request in a task
# group around call_next(), and a client disconnecting mid-StreamingResponse
# (e.g. the live-attribution SSE stream hitting its idle timeout) races that
# task group and raises "RuntimeError: No response returned." This class
# only touches response headers via the raw `send` callable, so it never
# holds the response open the way call_next() does.
class StaticCacheHeadersMiddleware:
    def __init__(self, app):
        self.app = app

    async def __call__(self, scope, receive, send):
        if scope["type"] != "http":
            await self.app(scope, receive, send)
            return
        path = scope["path"]
        has_version = "v" in parse_qs((scope.get("query_string") or b"").decode())

        async def send_wrapper(message):
            if message["type"] == "http.response.start":
                headers = MutableHeaders(scope=message)
                if has_version and (path.startswith("/static/js/") or path.endswith(".css")):
                    headers["Cache-Control"] = "public, max-age=31536000, immutable"
                elif path.startswith("/static/sections/"):
                    headers["Cache-Control"] = "no-store"
                elif path.startswith("/static/vendor/"):
                    headers["Cache-Control"] = "public, max-age=86400"
                elif path.startswith("/static/") and not has_version:
                    # Bootstrap files (style.css, loader.js, nav.js, …) are loaded without a ?v= query.
                    # Revalidate on every load so GUI edits appear after a normal reload — the server
                    # returns 304 when the file is unchanged, so this stays cheap.
                    headers["Cache-Control"] = "no-cache"
            await send(message)

        await self.app(scope, receive, send_wrapper)


app.add_middleware(StaticCacheHeadersMiddleware)


# ── Routers ───────────────────────────────────────────────────────────────────

app.include_router(admin.router)
app.include_router(settings.router)
app.include_router(library.router)
app.include_router(stt.router)
app.include_router(sources.router)
app.include_router(docker.router)
app.include_router(tts.router)
app.include_router(conversation.router)
app.include_router(reader.router)
app.include_router(characters.router)
app.include_router(rehearsals_db.router)

# ── Static files ──────────────────────────────────────────────────────────────

app.mount("/static", StaticFiles(directory=str(STATIC_DIR)), name="static")

# ── Dev runner ────────────────────────────────────────────────────────────────

if __name__ == "__main__":
    import uvicorn
    uvicorn.run(app, host="0.0.0.0", port=7890, log_level="info")