using UnityEngine;

namespace MazeGen
{
    /// <summary>
    /// Placeholder marker for a single Exit, positioned just outside its owning room's
    /// edge in the exit's direction. Purely informational now that agents move
    /// autonomously - colored relative to whichever agent the camera is currently
    /// following, so the doors that actually matter stand out among a cluster of nearby
    /// rooms: green = usable from the followed agent's room, not yet leading anywhere
    /// explored; blue = usable from there but leads to an already-visited room; transparent
    /// gray = not on the followed room at all (or no agent is being followed).
    /// </summary>
    [RequireComponent(typeof(SpriteRenderer), typeof(CircleCollider2D))]
    public class ExitMarker : MonoBehaviour
    {
        private static readonly Color UnexploredColor = Color.green;
        private static readonly Color ExploredColor = new Color(0.25f, 0.55f, 1f);
        private static readonly Color OtherRoomColor = new Color(0.5f, 0.5f, 0.5f, 0.6f);

        public Exit ExitData { get; private set; }

        public void Initialize(Room room, Exit exit)
        {
            ExitData = exit;
            transform.position = (Vector2)room.Position + exit.Direction * (room.Radius + 0.35f);
            transform.localScale = Vector3.one * 0.3f;

            var sr = GetComponent<SpriteRenderer>();
            sr.sprite = RoomView.SharedSquareSprite;
            sr.sortingOrder = 1;

            var col = GetComponent<CircleCollider2D>();
            col.radius = 0.5f;
            col.isTrigger = true;

            UpdateVisual(null, null);
        }

        /// <summary>
        /// Recolors this marker relative to whichever room the agent is currently standing
        /// in. `currentRoom`/`agent` may be null before the agent has spawned yet.
        /// </summary>
        public void UpdateVisual(Room currentRoom, MazeAgent agent)
        {
            var sr = GetComponent<SpriteRenderer>();

            bool isOnCurrentRoom = currentRoom != null && ExitData.OwnerRoomId == currentRoom.Id;
            if (!isOnCurrentRoom)
            {
                sr.color = OtherRoomColor;
                return;
            }

            bool leadsToExploredRoom = ExitData.ConnectedRoomId.HasValue
                && agent != null && agent.HasVisited(ExitData.ConnectedRoomId.Value);
            sr.color = leadsToExploredRoom ? ExploredColor : UnexploredColor;
        }
    }
}