from fastapi import FastAPI, Request
from fastapi.middleware.cors import CORSMiddleware
from fastapi.staticfiles import StaticFiles
from fastapi.responses import FileResponse, HTMLResponse
from contextlib import asynccontextmanager
from pathlib import Path
import asyncio
import os

from app.config import settings
from app.database import init_db
from app.routers import projects, edits, images, patches, generate, tools, ai_tools, print_tools


@asynccontextmanager
async def lifespan(app: FastAPI):
    """Initialize database on startup; auto-install Real-ESRGAN NCNN in background."""
    init_db()
    # Kick off NCNN install in background if no AI upscaler detected
    from app.services.upscale import probe_upscale_capabilities, ensure_ncnn_installed
    caps = probe_upscale_capabilities()
    if not caps["realesrgan_pytorch"] and not caps["realesrgan_ncnn"]:
        asyncio.create_task(ensure_ncnn_installed())
    yield


app = FastAPI(
    title="AI Photo Edit API",
    description="API for AI-powered photo editing with mask-scoped regeneration",
    version="1.0.0",
    lifespan=lifespan
)

# Configure CORS
app.add_middleware(
    CORSMiddleware,
    allow_origins=settings.cors_origins_list,
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# Include routers
app.include_router(projects.router)
app.include_router(edits.router)
app.include_router(images.router)
app.include_router(patches.router)
app.include_router(generate.router)
app.include_router(tools.router)
app.include_router(ai_tools.router)
app.include_router(print_tools.router)


@app.get("/api")
def api_root():
    """API info endpoint"""
    return {
        "name": "AI Photo Edit API",
        "version": "1.0.0",
        "status": "running"
    }


@app.get("/health")
def health():
    """Health check endpoint"""
    return {"status": "healthy"}


# Static files directory
STATIC_DIR = Path("/app/static")


# Serve static assets - mount subdirectories if they exist
if STATIC_DIR.exists():
    # React-style assets folder
    if (STATIC_DIR / "assets").exists():
        app.mount("/assets", StaticFiles(directory=STATIC_DIR / "assets"), name="assets")
    # miniPaint dist folder (webpack bundle)
    if (STATIC_DIR / "dist").exists():
        app.mount("/dist", StaticFiles(directory=STATIC_DIR / "dist"), name="dist")
    # miniPaint images folder
    if (STATIC_DIR / "images").exists():
        app.mount("/images", StaticFiles(directory=STATIC_DIR / "images"), name="images")
    # miniPaint CSS folder
    if (STATIC_DIR / "src").exists():
        app.mount("/src", StaticFiles(directory=STATIC_DIR / "src"), name="src")


@app.get("/", response_class=HTMLResponse)
async def serve_spa():
    """Serve miniPaint index.html"""
    index_path = STATIC_DIR / "index.html"
    if index_path.exists():
        return FileResponse(index_path)
    return HTMLResponse("<h1>Frontend not built. Run npm build in frontend/</h1>")


@app.get("/{full_path:path}")
async def serve_spa_routes(request: Request, full_path: str):
    """
    Catch-all route for serving static files.
    Serves static files if they exist, otherwise returns index.html.
    """
    # Don't catch API routes
    if full_path.startswith(("projects", "edits", "patches", "tools", "generate", "health", "docs", "openapi.json", "api")):
        return {"detail": "Not Found"}

    # Check if it's a static file
    static_file = STATIC_DIR / full_path
    if static_file.exists() and static_file.is_file():
        return FileResponse(static_file)

    # Otherwise serve index.html
    index_path = STATIC_DIR / "index.html"
    if index_path.exists():
        return FileResponse(index_path)

    return HTMLResponse("<h1>Frontend not built</h1>", status_code=404)