from fastapi import FastAPI, Request, Form, HTTPException, Depends, Response, BackgroundTasks
from fastapi.responses import HTMLResponse, RedirectResponse
from fastapi.staticfiles import StaticFiles
from fastapi.templating import Jinja2Templates
import uuid
import json
from pathlib import Path
import os
from typing import List

# Directories
BASE_DIR = Path(__file__).parent
DATA_DIR = BASE_DIR / "data"
FORMS_DIR = DATA_DIR / "forms"
SUBS_DIR = DATA_DIR / "submissions"
for d in (FORMS_DIR, SUBS_DIR): d.mkdir(parents=True, exist_ok=True)

# Admin key env
ADMIN_KEY = os.getenv("ADMIN_KEY", "admin123")

app = FastAPI()
app.mount("/static", StaticFiles(directory=BASE_DIR / "static"), name="static")
templates = Jinja2Templates(directory=BASE_DIR / "templates")

# Helper: read/write JSON

def save_json(path: Path, data):
    with path.open('w') as f: json.dump(data, f)

def load_json(path: Path):
    if not path.exists(): return None
    with path.open() as f: return json.load(f)

# Home: show history or welcome
@app.get("/", response_class=HTMLResponse)
async def home(request: Request):
    # read cookie
    history = request.cookies.get("form_history", "")
    ids = history.split(',') if history else []
    return templates.TemplateResponse("index.html", {"request": request, "form_ids": ids})

# New form builder page
@app.get("/new", response_class=HTMLResponse)
async def new_form(request: Request):
    return templates.TemplateResponse("new_form.html", {"request": request})

# Create form schema
@app.post("/create_form")
async def create_form(request: Request, response: Response,
                      title: str = Form(...),
                      fields: List[str] = Form(...)):
    form_id = str(uuid.uuid4())
    schema = {"id": form_id, "title": title, "fields": fields}
    save_json(FORMS_DIR / f"{form_id}.json", schema)
    # update history cookie
    history = request.cookies.get("form_history", "")
    ids = history.split(',') if history else []
    ids.append(form_id)
    response = RedirectResponse(url=f"/forms/{form_id}", status_code=302)
    response.set_cookie("form_history", ",".join(ids), httponly=True)
    return response

# Render form for users
@app.get("/forms/{form_id}", response_class=HTMLResponse)
async def view_form(request: Request, form_id: str):
    schema = load_json(FORMS_DIR / f"{form_id}.json")
    if not schema:
        raise HTTPException(404, "Form not found")
    return templates.TemplateResponse("view_form.html", {"request": request, "schema": schema})

# Handle submission
@app.post("/forms/{form_id}/submit")
async def submit_form(request: Request, form_id: str):
    schema = load_json(FORMS_DIR / f"{form_id}.json")
    if not schema:
        raise HTTPException(404, "Form not found")
    data = await request.form()
    entry = {field: data.get(field) for field in schema['fields']}
    # append submission
    sub_dir = SUBS_DIR / form_id
    sub_dir.mkdir(exist_ok=True)
    idx = len(list(sub_dir.iterdir())) + 1
    save_json(sub_dir / f"{idx}.json", entry)
    return RedirectResponse(url=f"/forms/{form_id}", status_code=302)

# Admin dashboard
def check_admin(key: str = Depends(lambda request: request.query_params.get('key'))):
    if key != ADMIN_KEY:
        raise HTTPException(401, "Unauthorized")
    return True

@app.get("/admin", response_class=HTMLResponse)
async def admin_dashboard(request: Request, authorized: bool = Depends(check_admin)):
    forms = []
    for p in FORMS_DIR.glob("*.json"):
        schema = load_json(p)
        subs = len(list((SUBS_DIR / schema['id']).glob("*.json"))) if (SUBS_DIR / schema['id']).exists() else 0
        forms.append({"id": schema['id'], "title": schema['title'], "submissions": subs})
    return templates.TemplateResponse("admin.html", {"request": request, "forms": forms})

# Delete form (admin)
@app.post("/admin/delete/{form_id}")
async def admin_delete(form_id: str, authorized: bool = Depends(check_admin)):
    fpath = FORMS_DIR / f"{form_id}.json"
    if fpath.exists(): fpath.unlink()
    subdir = SUBS_DIR / form_id
    if subdir.exists():
        for f in subdir.iterdir(): f.unlink()
        subdir.rmdir()
    return RedirectResponse(url="/admin?key=" + ADMIN_KEY, status_code=302)