"""
KV-Pix FastAPI Backend

A secure and intuitive API backend for the KV-Pix image generation application.
Provides endpoints for:
- Whisk image and video generation
- Meta AI image generation
- Prompt library management
- Reference image uploads
- Upload history

API Documentation available at /docs (Swagger UI) and /redoc (ReDoc)
"""
from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware
from contextlib import asynccontextmanager
import sys
from pathlib import Path

# Add backend to path for imports
sys.path.insert(0, str(Path(__file__).parent))

from routers import generate, video, references, meta, prompts, history


@asynccontextmanager
async def lifespan(app: FastAPI):
    """Startup and shutdown events"""
    print("🚀 KV-Pix FastAPI Backend starting...")
    print("📚 Swagger UI available at: http://localhost:8000/docs")
    print("📖 ReDoc available at: http://localhost:8000/redoc")
    yield
    print("👋 KV-Pix FastAPI Backend shutting down...")


import os

# Detect if running behind nginx proxy (via env var)
# When behind nginx at /api, set root_path so Swagger knows correct URL prefix
ROOT_PATH = os.getenv("API_ROOT_PATH", "")

app = FastAPI(
    title="KV-Pix API",
    description="""
## KV-Pix Image Generation API

A powerful API for AI image generation using multiple providers.

### Features
- **Whisk API**: Google's experimental image generation with reference images
- **Meta AI**: Meta's Imagine model for creative images
- **Prompt Library**: Curated prompts with categories
- **Upload History**: Track and reuse uploaded references

### Authentication
All generation endpoints require provider-specific cookies passed in the request body.
See the Settings page in the web app for cookie configuration instructions.
    """,
    version="3.2.0",
    lifespan=lifespan,
    docs_url="/docs",
    redoc_url="/redoc",
    root_path=ROOT_PATH,
)

# CORS middleware - allow Next.js frontend
app.add_middleware(
    CORSMiddleware,
    allow_origins=[
        "http://localhost:3000",
        "http://127.0.0.1:3000",
        "http://localhost:3001",
    ],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# Include routers
app.include_router(generate.router)
app.include_router(video.router)
app.include_router(references.router)
app.include_router(meta.router)
app.include_router(prompts.router)
app.include_router(history.router)


@app.get("/", tags=["Health"])
async def root():
    """Health check endpoint"""
    return {
        "status": "healthy",
        "service": "kv-pix-api",
        "version": "1.0.0",
        "docs": "/docs"
    }


@app.get("/health", tags=["Health"])
async def health_check():
    """Detailed health check"""
    return {
        "status": "healthy",
        "endpoints": {
            "generate": "/generate",
            "video": "/video/generate",
            "references": "/references/upload",
            "meta": "/meta/generate",
            "prompts": "/prompts",
            "history": "/history"
        },
        "documentation": {
            "swagger": "/docs",
            "redoc": "/redoc"
        }
    }


if __name__ == "__main__":
    import uvicorn
    uvicorn.run(app, host="0.0.0.0", port=8000, reload=True)