"""
api/routes/tasks.py - One-off scheduled task CRUD
"""

import uuid
import flask
import jwt
import os
from datetime import datetime

import core.postgres as postgres

JWT_SECRET = os.getenv("JWT_SECRET")


def _get_user_uuid(request):
    """Extract and validate user UUID from JWT token."""
    auth_header = request.headers.get("Authorization", "")
    if not auth_header.startswith("Bearer "):
        return None
    token = auth_header[7:]
    try:
        payload = jwt.decode(token, JWT_SECRET, algorithms=["HS256"])
        return payload.get("sub")
    except (jwt.ExpiredSignatureError, jwt.InvalidTokenError):
        return None


def register(app):

    @app.route("/api/tasks", methods=["GET"])
    def get_tasks():
        user_uuid = _get_user_uuid(flask.request)
        if not user_uuid:
            return flask.jsonify({"error": "unauthorized"}), 401
        status_filter = flask.request.args.get("status", "pending")
        if status_filter == "all":
            tasks = postgres.select(
                "tasks",
                where={"user_uuid": user_uuid},
                order_by="scheduled_datetime ASC",
            )
        else:
            tasks = postgres.select(
                "tasks",
                where={"user_uuid": user_uuid, "status": status_filter},
                order_by="scheduled_datetime ASC",
            )
        # Serialize datetimes for JSON
        for t in tasks:
            for key in ("scheduled_datetime", "created_at", "updated_at"):
                if key in t and hasattr(t[key], "isoformat"):
                    t[key] = t[key].isoformat()
        return flask.jsonify(tasks), 200

    @app.route("/api/tasks", methods=["POST"])
    def create_task():
        user_uuid = _get_user_uuid(flask.request)
        if not user_uuid:
            return flask.jsonify({"error": "unauthorized"}), 401
        data = flask.request.get_json()
        if not data:
            return flask.jsonify({"error": "missing body"}), 400
        title = data.get("title", "").strip()
        scheduled_datetime = data.get("scheduled_datetime", "").strip()
        if not title:
            return flask.jsonify({"error": "title is required"}), 400
        if not scheduled_datetime:
            return flask.jsonify({"error": "scheduled_datetime is required"}), 400
        task_id = str(uuid.uuid4())
        task = {
            "id": task_id,
            "user_uuid": user_uuid,
            "title": title,
            "description": data.get("description") or None,
            "scheduled_datetime": scheduled_datetime,
            "reminder_minutes_before": int(data.get("reminder_minutes_before", 15)),
            "status": "pending",
        }
        postgres.insert("tasks", task)
        return flask.jsonify(task), 201

    @app.route("/api/tasks/<task_id>", methods=["PATCH"])
    def update_task(task_id):
        user_uuid = _get_user_uuid(flask.request)
        if not user_uuid:
            return flask.jsonify({"error": "unauthorized"}), 401
        task = postgres.select_one("tasks", {"id": task_id, "user_uuid": user_uuid})
        if not task:
            return flask.jsonify({"error": "not found"}), 404
        data = flask.request.get_json() or {}
        updates = {}
        for field in ["title", "description", "scheduled_datetime", "reminder_minutes_before", "status"]:
            if field in data:
                updates[field] = data[field]
        updates["updated_at"] = datetime.utcnow().isoformat()
        postgres.update("tasks", updates, {"id": task_id})
        return flask.jsonify({**{k: (v.isoformat() if hasattr(v, "isoformat") else v) for k, v in task.items()}, **updates}), 200

    @app.route("/api/tasks/<task_id>", methods=["DELETE"])
    def delete_task(task_id):
        user_uuid = _get_user_uuid(flask.request)
        if not user_uuid:
            return flask.jsonify({"error": "unauthorized"}), 401
        task = postgres.select_one("tasks", {"id": task_id, "user_uuid": user_uuid})
        if not task:
            return flask.jsonify({"error": "not found"}), 404
        postgres.delete("tasks", {"id": task_id})
        return flask.jsonify({"success": True}), 200