import os
import shutil
from fastapi import FastAPI, Request, File, UploadFile, Form
from fastapi.responses import HTMLResponse, RedirectResponse
from fastapi.templating import Jinja2Templates
from fastapi.staticfiles import StaticFiles

# =====================================================================
# MODIFICATION START: REMOVED ROOT_PATH
# Reason: We removed the `root_path="/patch-manager"` argument. 
# Because Nginx already strips the prefix before passing traffic to 
# this container, setting it here was causing FastAPI to double-process 
# the route and throw internal 404s. Standard FastAPI initialization is best.
# =====================================================================
app = FastAPI()
# =====================================================================
# MODIFICATION END
# =====================================================================

# Failsafe: Create the directory inside the container if it somehow gets missed
os.makedirs("static", exist_ok=True)
app.mount("/static", StaticFiles(directory="static"), name="static")

templates = Jinja2Templates(directory="templates")

# The persistent directory for your custom code
OVERLAY_DIR = "/srv"

@app.get("/", response_class=HTMLResponse)
async def index(request: Request):
    files = []
    if os.path.exists(OVERLAY_DIR):
        for root, dirs, filenames in os.walk(OVERLAY_DIR):
            for filename in filenames:
                rel_path = os.path.relpath(os.path.join(root, filename), OVERLAY_DIR)
                files.append(rel_path)
    return templates.TemplateResponse("index.html", {"request": request, "files": sorted(files)})

@app.post("/upload")
async def upload_file(file: UploadFile = File(...), target_path: str = Form("")):
    save_dir = os.path.join(OVERLAY_DIR, target_path.strip("/"))
    os.makedirs(save_dir, exist_ok=True)
    file_location = os.path.join(save_dir, file.filename)
    with open(file_location, "wb+") as file_object:
        shutil.copyfileobj(file.file, file_object)
        
    # =====================================================================
    # MODIFICATION START: EXPLICIT NGINX REDIRECTS
    # Reason: Since we removed root_path, we must explicitly tell the 
    # user's browser to redirect back to the Nginx URL ("/patch-manager/") 
    # after a successful action, otherwise it redirects to the internal "/" 
    # and gets lost on the main ArduPilot page.
    # =====================================================================
    return RedirectResponse(url="/patch-manager/", status_code=303)
    # =====================================================================
    # MODIFICATION END
    # =====================================================================

@app.post("/delete")
async def delete_file(filepath: str = Form(...)):
    target = os.path.join(OVERLAY_DIR, filepath)
    if os.path.exists(target):
        os.remove(target)
        target_dir = os.path.dirname(target)
        if not os.listdir(target_dir) and target_dir != OVERLAY_DIR:
            os.rmdir(target_dir)
    return RedirectResponse(url="/patch-manager/", status_code=303)

@app.get("/edit", response_class=HTMLResponse)
async def edit_file(request: Request, filepath: str):
    target = os.path.join(OVERLAY_DIR, filepath)
    content = ""
    if os.path.exists(target):
        with open(target, "r", encoding="utf-8", errors="ignore") as f:
            content = f.read()
    return templates.TemplateResponse("edit.html", {"request": request, "filepath": filepath, "content": content})

@app.post("/edit")
async def save_file(filepath: str = Form(...), content: str = Form(...)):
    target = os.path.join(OVERLAY_DIR, filepath)
    if os.path.exists(target):
        with open(target, "w", encoding="utf-8") as f:
            f.write(content)
    return RedirectResponse(url="/patch-manager/", status_code=303)