using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using RimWorld;
using UnityEngine;
using Verse;

namespace WulaFallenEmpire.EventSystem.AI.Tools
{
    public class Tool_CallPrefabAirdrop : AITool
    {
        public override string Name => "call_prefab_airdrop";
        public override string Description => "Calls a large prefab building airdrop at the specified coordinates. " +
                                              "You must specify the prefabDefName (e.g., 'WULA_NewColonyBase') and the coordinates (x, z). " +
                                              "TIP: Use the 'get_available_prefabs' tool first to see which structures are available. " +
                                              "The default skyfaller animation is 'WULA_Prefab_Incoming'.";
        public override string UsageSchema => "{\"prefabDefName\":\"WULA_NewColonyBase\",\"skyfallerDef\":\"WULA_Prefab_Incoming\",\"x\":10,\"z\":20}";
        public override Dictionary<string, object> GetParametersSchema()
        {
            var properties = new Dictionary<string, object>
            {
                ["prefabDefName"] = SchemaString("PrefabDef defName.", nullable: true),
                ["skyfallerDef"] = SchemaString("Skyfaller ThingDef defName.", nullable: true),
                ["x"] = SchemaInteger("Target cell X.", nullable: true),
                ["z"] = SchemaInteger("Target cell Z.", nullable: true)
            };
            return SchemaObject(properties, RequiredList("prefabDefName", "skyfallerDef", "x", "z"));
        }

        public override string Execute(string args)
        {
            try
            {
                var parsed = ParseJsonArgs(args);

                if (!TryGetString(parsed, "prefabDefName", out string prefabDefName) || string.IsNullOrWhiteSpace(prefabDefName))
                {
                    return "Error: Missing 'prefabDefName'.";
                }

                if (!TryGetInt(parsed, "x", out int x) || !TryGetInt(parsed, "z", out int z))
                {
                    return "Error: Missing or invalid target coordinates. Provide 'x' and 'z'.";
                }

                string skyfallerDefName = TryGetString(parsed, "skyfallerDef", out string sd) && !string.IsNullOrWhiteSpace(sd)
                    ? sd.Trim()
                    : "WULA_Prefab_Incoming";

                Map map = Find.CurrentMap;
                if (map == null) return "Error: No active map.";

                IntVec3 targetCell = new IntVec3(x, 0, z);
                if (!targetCell.InBounds(map)) return $"Error: Target {targetCell} is out of bounds.";

                // Check if prefab exists
                PrefabDef prefabDef = DefDatabase<PrefabDef>.GetNamed(prefabDefName, false);
                if (prefabDef == null)
                {
                    return $"Error: PrefabDef '{prefabDefName}' not found.";
                }

                // Check if skyfaller exists
                ThingDef skyfallerDef = DefDatabase<ThingDef>.GetNamed(skyfallerDefName, false);
                if (skyfallerDef == null)
                {
                    return $"Error: Skyfaller ThingDef '{skyfallerDefName}' not found.";
                }

                // Auto-Scan for valid position
                IntVec3 validCell = targetCell;
                bool foundSpot = false;

                // Get prefab size from its size field. If not set, default to 1x1 (though prefabs are usually larger)
                IntVec2 size = prefabDef.size;

                // Simple check function for a given center cell
                bool IsPositionValid(IntVec3 center, Map m, IntVec2 s)
                {
                    if (!center.InBounds(m)) return false;

                    CellRect rect = GenAdj.OccupiedRect(center, Rot4.North, s);
                    if (!rect.InBounds(m)) return false;

                    foreach (IntVec3 c in rect)
                    {
                        // 1. Check Terrain Passability (water/impassable usually bad for buildings)
                        TerrainDef terr = c.GetTerrain(m);
                        if (terr.passability == Traversability.Impassable || terr.IsWater) return false;

                        // 2. Check Thick Roof (airdrops can't penetrate)
                        if (m.roofGrid.RoofAt(c) == RoofDefOf.RoofRockThick) return false;

                        // 3. Check Existing Buildings
                        if (c.GetFirstBuilding(m) != null) return false;
                    }
                    return true;
                }

                // Try original spot first
                if (IsPositionValid(targetCell, map, size))
                {
                    validCell = targetCell;
                    foundSpot = true;
                }
                else
                {
                    // Spiral scan for a nearby valid spot.
                    // Radius ~20 should be enough to find a spot without deviating too far.
                    foreach (IntVec3 c in GenRadial.RadialCellsAround(targetCell, 20f, useCenter: false))
                    {
                        if (IsPositionValid(c, map, size))
                        {
                            validCell = c;
                            foundSpot = true;
                            break;
                        }
                    }
                }

                if (!foundSpot)
                {
                    return $"Error: Could not find a valid clear space for '{prefabDefName}' (Size: {size.x}x{size.z}) near {targetCell}. Area may be blocked by thick roofs, water, or other buildings.";
                }

                // Spawning must happen on main thread
                string resultMessage = $"Success: Scheduled airdrop for '{prefabDefName}' at valid position {validCell} (adjusted from {targetCell}) using {skyfallerDefName}.";

                // Use the found valid cell
                string pDef = prefabDefName;
                ThingDef sDef = skyfallerDef;
                IntVec3 cell = validCell;
                Map targetMap = map;

                LongEventHandler.ExecuteWhenFinished(() =>
                {
                    try
                    {
                        var skyfaller = (Skyfaller_PrefabSpawner)SkyfallerMaker.MakeSkyfaller(sDef);
                        skyfaller.prefabDefName = pDef;
                        GenSpawn.Spawn(skyfaller, cell, targetMap);
                        WulaLog.Debug($"[WulaAI] Prefab airdrop spawned: {pDef} at {cell}");
                    }
                    catch (Exception ex)
                    {
                        WulaLog.Debug($"[WulaAI] Failed to spawn prefab airdrop on main thread: {ex.Message}");
                    }
                });

                return resultMessage;
            }
            catch (Exception ex)
            {
                return $"Error: {ex.Message}";
            }
        }
    }
}