"""Flask frontend application."""
import functools

import httpx
from flask import (
    Flask,
    flash,
    jsonify,
    redirect,
    render_template,
    request,
    session,
    url_for,
)

from .config import Config

app = Flask(__name__)
app.config.from_object(Config)


# ---------------------------------------------------------------------------
# Helpers
# ---------------------------------------------------------------------------

def _backend(path: str) -> str:
    return f"{app.config['BACKEND_URL']}{path}"


def _api(method: str, path: str, *, token: str | None = None, **kwargs):
    headers = kwargs.pop("headers", {})
    if token:
        headers["Authorization"] = f"Bearer {token}"
    return httpx.request(method, _backend(path), headers=headers, timeout=30, **kwargs)


def login_required(view):
    @functools.wraps(view)
    def wrapped(*args, **kwargs):
        if "access_token" not in session:
            return redirect(url_for("login"))
        return view(*args, **kwargs)
    return wrapped


def admin_required(view):
    @functools.wraps(view)
    def wrapped(*args, **kwargs):
        if "access_token" not in session:
            return redirect(url_for("login"))
        if session.get("user_role") != "admin":
            flash("Admin access required.", "error")
            return redirect(url_for("dashboard"))
        return view(*args, **kwargs)
    return wrapped


# ---------------------------------------------------------------------------
# Auth routes
# ---------------------------------------------------------------------------

@app.get("/")
def index():
    if "access_token" in session:
        return redirect(url_for("dashboard"))
    return redirect(url_for("login"))


@app.route("/login", methods=["GET", "POST"])
def login():
    if request.method == "POST":
        email = request.form["email"]
        password = request.form["password"]
        resp = _api("POST", "/auth/login",
                    json={"email": email, "password": password})
        if resp.status_code == 200:
            data = resp.json()
            session["access_token"] = data["access_token"]
            session["refresh_token"] = data["refresh_token"]
            me = _api("GET", "/users/me", token=data["access_token"])
            if me.status_code == 200:
                u = me.json()
                session["user_email"] = u.get("email", "")
                session["user_role"] = u.get("role", "user")
            return redirect(url_for("dashboard"))
        flash("Invalid email or password.", "error")
    return render_template("login.html")


@app.route("/register", methods=["GET", "POST"])
def register():
    if request.method == "POST":
        email = request.form["email"]
        password = request.form["password"]
        resp = _api("POST", "/auth/register",
                    json={"email": email, "password": password})
        if resp.status_code == 201:
            flash("Account created. Please log in.", "success")
            return redirect(url_for("login"))
        detail = resp.json().get("detail", "Registration failed.")
        flash(detail, "error")
    return render_template("register.html")


@app.get("/logout")
def logout():
    refresh_token = session.get("refresh_token")
    if refresh_token:
        _api("POST", "/auth/logout", json={"refresh_token": refresh_token})
    session.clear()
    return redirect(url_for("login"))


# ---------------------------------------------------------------------------
# Authenticated routes
# ---------------------------------------------------------------------------

@app.get("/dashboard")
@login_required
def dashboard():
    token = session["access_token"]
    resp = _api("GET", "/users/me", token=token)
    user = resp.json() if resp.status_code == 200 else {}
    return render_template("dashboard.html", user=user)


# ── Generate ──────────────────────────────────────────────────────────────

@app.get("/generate")
@login_required
def generate():
    return redirect(url_for("generate_text"))


@app.route("/generate/text", methods=["GET", "POST"])
@login_required
def generate_text():
    result = error = None
    if request.method == "POST":
        resp = _api("POST", "/generate/text", token=session["access_token"], json={
            "model": request.form.get("model", "").strip(),
            "prompt": request.form.get("prompt", "").strip(),
        })
        if resp.status_code == 200:
            result = resp.json()
        else:
            error = resp.json().get("detail", "Generation failed.")
    return render_template("generate_text.html", result=result, error=error)


@app.route("/generate/image", methods=["GET", "POST"])
@login_required
def generate_image():
    result = error = None
    if request.method == "POST":
        resp = _api("POST", "/generate/image", token=session["access_token"], json={
            "model": request.form.get("model", "").strip(),
            "prompt": request.form.get("prompt", "").strip(),
            "n": int(request.form.get("n", 1)),
            "size": request.form.get("size", "1024x1024"),
            "aspect_ratio": request.form.get("aspect_ratio", "").strip() or None,
            "image_size": request.form.get("image_size", "").strip() or None,
        })
        if resp.status_code == 200:
            result = resp.json()
        else:
            error = resp.json().get("detail", "Generation failed.")
    return render_template("generate_image.html", result=result, error=error)


@app.route("/generate/video", methods=["GET", "POST"])
@login_required
def generate_video():
    result = error = None
    if request.method == "POST":
        mode = request.form.get("mode", "text")
        token = session["access_token"]
        duration_raw = request.form.get("duration_seconds", "")
        duration = int(
            duration_raw) if duration_raw.strip().isdigit() else None
        resolution = request.form.get("resolution", "").strip() or None
        if mode == "image":
            resp = _api("POST", "/generate/video/from-image", token=token, json={
                "model": request.form.get("model", "").strip(),
                "image_url": request.form.get("image_url", "").strip(),
                "prompt": request.form.get("prompt", "").strip(),
                "aspect_ratio": request.form.get("aspect_ratio", "16:9"),
                "duration_seconds": duration,
                "resolution": resolution,
            })
        else:
            resp = _api("POST", "/generate/video", token=token, json={
                "model": request.form.get("model", "").strip(),
                "prompt": request.form.get("prompt", "").strip(),
                "aspect_ratio": request.form.get("aspect_ratio", "16:9"),
                "duration_seconds": duration,
                "resolution": resolution,
            })
        if resp.status_code == 200:
            result = resp.json()
        else:
            error = resp.json().get("detail", "Generation failed.")
    return render_template("generate_video.html", result=result, error=error)


@app.get("/generate/video/status")
@login_required
def generate_video_status():
    """Proxy video status polling to the backend."""
    polling_url = request.args.get("polling_url", "")
    if not polling_url:
        return jsonify({"error": "polling_url required"}), 400
    resp = _api(
        "GET", "/generate/video/status",
        token=session["access_token"],
        params={"polling_url": polling_url},
    )
    return jsonify(resp.json()), resp.status_code


# ── Admin ─────────────────────────────────────────────────────────────────

@app.get("/admin")
@admin_required
def admin():
    token = session["access_token"]
    stats_resp = _api("GET", "/admin/stats", token=token)
    users_resp = _api("GET", "/users", token=token)
    stats = stats_resp.json() if stats_resp.status_code == 200 else {}
    users = users_resp.json() if users_resp.status_code == 200 else []
    return render_template("admin.html", stats=stats, users=users)


@app.post("/admin/users/<user_id>/role")
@admin_required
def admin_set_role(user_id: str):
    role = request.form.get("role", "user")
    _api("PUT", f"/users/{user_id}/role",
         token=session["access_token"], json={"role": role})
    flash(f"Role updated to '{role}'.", "success")
    return redirect(url_for("admin"))


@app.post("/admin/users/<user_id>/delete")
@admin_required
def admin_delete_user(user_id: str):
    _api("DELETE", f"/users/{user_id}", token=session["access_token"])
    flash("User deleted.", "success")
    return redirect(url_for("admin"))


# ── Profile ───────────────────────────────────────────────────────────────

@app.route("/users/profile", methods=["GET", "POST"])
@login_required
def profile():
    token = session["access_token"]
    if request.method == "POST":
        payload: dict = {}
        new_email = request.form.get("email", "").strip()
        new_password = request.form.get("password", "").strip()
        if new_email:
            payload["email"] = new_email
        if new_password:
            payload["password"] = new_password
        if payload:
            resp = _api("PUT", "/users/me", token=token, json=payload)
            if resp.status_code == 200:
                updated = resp.json()
                session["user_email"] = updated.get(
                    "email", session.get("user_email", ""))
                flash("Profile updated.", "success")
            else:
                flash(resp.json().get("detail", "Update failed."), "error")
        return redirect(url_for("profile"))
    resp = _api("GET", "/users/me", token=token)
    user = resp.json() if resp.status_code == 200 else {}
    return render_template("profile.html", user=user)