import os
import sys
from pathlib import Path
from typing import List, Optional

from fastapi import FastAPI, HTTPException, Request
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import FileResponse
from pydantic import BaseModel

# Add parent directory to sys.path to allow importing the brain package
sys.path.append(str(Path(__file__).resolve().parents[2]))

from brain.paths import get_brains_dir, get_brain_path
from brain.config import load_config, save_config
from brain.templates.brain_instance import scaffold_brain_instance

app = FastAPI(title="Ever Brain API")

# Configure CORS
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],  # In production, specify the actual frontend URL
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

class BrainCreateRequest(BaseModel):
    name: str

class BrainUseRequest(BaseModel):
    name: str

class BrainStatusResponse(BaseModel):
    active_brain: Optional[str]
    brains_path: str
    brain_count: int

@app.get("/status", response_model=BrainStatusResponse)
async def get_status():
    config = load_config()
    brains_dir = get_brains_dir()
    brains = [d.name for d in brains_dir.iterdir() if d.is_dir()]
    
    active_path_str = config.get("active_brain")
    active_brain_name = Path(active_path_str).name if active_path_str else None
    
    return {
        "active_brain": active_brain_name,
        "brains_path": str(brains_dir),
        "brain_count": len(brains)
    }

@app.get("/brains", response_model=List[str])
async def list_brains():
    brains_dir = get_brains_dir()
    return [d.name for d in brains_dir.iterdir() if d.is_dir()]

@app.post("/brains")
async def create_brain(request: BrainCreateRequest):
    brain_path = get_brain_path(request.name)
    
    if brain_path.exists():
        raise HTTPException(status_code=400, detail=f"Brain instance '{request.name}' already exists.")
    
    try:
        scaffold_brain_instance(brain_path)
        return {"message": f"Brain '{request.name}' created successfully.", "path": str(brain_path)}
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

@app.post("/brains/use")
async def use_brain(request: BrainUseRequest):
    brain_path = get_brain_path(request.name)
    
    if not brain_path.exists():
        raise HTTPException(status_code=404, detail=f"Brain instance '{request.name}' not found.")
    
    from brain.config import set_active_brain
    set_active_brain(brain_path)
    
    return {"message": f"Active brain set to '{request.name}'."}

@app.get("/download")
async def download_cli():
    # Path to the pre-packaged binary
    binary_path = Path(__file__).resolve().parents[2] / "dist" / "ever-brain.exe"
    
    if not binary_path.exists():
        raise HTTPException(status_code=404, detail="CLI binary not found. Please run the packaging script.")
    
    return FileResponse(
        path=binary_path,
        filename="ever-brain.exe",
        media_type="application/octet-stream"
    )

@app.get("/download/setup")
async def download_setup():
    # Path to the GUI installer
    setup_path = Path(__file__).resolve().parents[2] / "dist" / "EverBrainSetup.exe"
    
    if not setup_path.exists():
        raise HTTPException(status_code=404, detail="GUI Setup installer not found. Please compile the .iss script.")
    
    return FileResponse(
        path=setup_path,
        filename="EverBrainSetup.exe",
        media_type="application/octet-stream"
    )

@app.get("/install.ps1")
async def download_install_script(request: Request):
    # Path to the web installation script
    script_path = Path(__file__).resolve().parents[2] / "scripts" / "web_install.ps1"
    
    if not script_path.exists():
        raise HTTPException(status_code=404, detail="Installation script not found.")
    
    # Read script and inject the current host URL
    content = script_path.read_text(encoding="utf-8")
    
    # Hugging Face usually has 'x-forwarded-proto' and 'host' headers
    protocol = request.headers.get("x-forwarded-proto", "http")
    host = request.headers.get("host", "localhost:8000")
    base_url = f"{protocol}://{host}"
    
    content = content.replace('http://localhost:8000', base_url)
    
    from fastapi.responses import Response
    return Response(
        content=content,
        media_type="text/plain",
        headers={"Content-Disposition": "attachment; filename=install.ps1"}
    )

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