using System;
using System.Collections.Generic;
using UnityEngine;

namespace MazeGen
{
    /// <summary>
    /// Displays a clickable list of all agents with their status. Allows the player to follow
    /// an agent's perspective. Narrates status as dead, reached exit, fighting, or exploring with HP.
    /// </summary>
    public class AgentPanelUI
    {
        private Vector2 scrollPosition;

        public AgentPanelUI()
        {
        }

        /// <summary>
        /// Draw the agent list panel. Returns the clicked agent (if any) or null.
        /// </summary>
        public MazeAgent Draw(List<MazeAgent> agents, MazeAgent currentlyFollowed, bool hasFollowedAgent, Action onStopFollowing)
        {
            GUILayout.BeginArea(new Rect(10, 360, 280, Screen.height - 380), GUI.skin.box);

            if (hasFollowedAgent && GUILayout.Button("Stop following"))
                onStopFollowing?.Invoke();

            GUILayout.Space(6);
            GUILayout.Label("Agents (click to follow):");
            scrollPosition = GUILayout.BeginScrollView(scrollPosition);

            MazeAgent clickedAgent = null;
            foreach (var agent in agents)
            {
                bool isFollowed = agent == currentlyFollowed;
                string status = DescribeStatus(agent);

                GUI.color = agent.IsDead ? new Color(0.55f, 0.55f, 0.55f) : Color.white;
                if (GUILayout.Button($"{(isFollowed ? "> " : "")}{agent.DisplayName} - {status}"))
                    clickedAgent = agent;
            }
            GUI.color = Color.white;
            GUILayout.EndScrollView();

            GUILayout.EndArea();
            return clickedAgent;
        }

        private string DescribeStatus(MazeAgent agent)
        {
            if (agent.IsDead) return "dead";
            if (agent.IsFinished) return "reached exit";
            if (agent.IsEngaged) return "fighting";
            return $"exploring ({agent.CharacterSheet.Stats.CurrentHealth:0}hp)";
        }
    }
}