"""
api/routes/ai.py - AI-powered generation endpoints
"""

import asyncio
import flask
import jwt
import os

import ai.parser as ai_parser

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/ai/generate-steps", methods=["POST"])
    def api_generate_steps():
        """
        Generate ADHD-friendly routine steps from a goal description.
        Body: {"goal": string}
        Returns: {"steps": [{"name": string, "duration_minutes": int}]}
        """
        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

        goal = data.get("goal", "").strip()
        if not goal:
            return flask.jsonify({"error": "missing required field: goal"}), 400
        if len(goal) > 500:
            return flask.jsonify({"error": "goal too long (max 500 characters)"}), 400

        try:
            result = asyncio.run(ai_parser.parse(goal, "step_generator"))
        except Exception as e:
            return flask.jsonify({"error": f"AI service error: {str(e)}"}), 500

        if "error" in result:
            return flask.jsonify({"error": result["error"]}), 500

        steps = result.get("steps", [])
        validated = []
        for s in steps:
            if not isinstance(s, dict):
                continue
            name = str(s.get("name", "")).strip()
            if not name:
                continue
            try:
                dur = max(1, min(60, int(s.get("duration_minutes", 5))))
            except (ValueError, TypeError):
                dur = 5
            validated.append({"name": name, "duration_minutes": dur})

        if len(validated) < 2:
            return flask.jsonify({"error": "AI failed to generate valid steps"}), 500

        return flask.jsonify({"steps": validated}), 200