using System;
using System.Collections.Generic;
using System.Text;
using Helpers;
using UI.Map;
using UnityEngine;

namespace S3.Modules.Popout;

internal struct MapViewPreset
{
    public string name;
    public float  x, z, zoom, rotationY;
}

internal static class MapViewPresets
{
    private static bool  _stashValid;
    private static float _stashX, _stashZ, _stashZoom, _stashRot;

    public static void PushList(int handle)
    {
        try
        {
            var presets = List();
            if (presets.Count == 0)
            {
                Native.RRPOPOUT_SetPresetList(handle, "");
                return;
            }
            var sb = new StringBuilder();
            for (int i = 0; i < presets.Count; i++)
            {
                if (i > 0) sb.Append('\n');
                sb.Append(string.IsNullOrEmpty(presets[i].name) ? $"View {i + 1}" : presets[i].name);
            }
            Native.RRPOPOUT_SetPresetList(handle, sb.ToString());
        }
        catch (Exception ex)
        {
            S3.Core.Log.Error($"[popout] preset list push failed: {ex.Message}");
        }
    }

    private static string ReadRename(int handle)
    {
        try
        {
            var buf = new StringBuilder(128);
            Native.RRPOPOUT_GetPresetRenameName(handle, buf, 128);
            return buf.ToString().Trim();
        }
        catch (Exception ex)
        {
            S3.Core.Log.Error($"[popout] preset rename read failed: {ex.Message}");
            return "";
        }
    }

    public static bool TryHandleCommand(UICmd cmd, float y, int handle, Camera? cam,
        Action<float> applyRotation, Action disableFollow)
    {
        int index = (int)y;
        switch (cmd)
        {
            case UICmd.PresetAdd:
                if (cam == null) return true;
                AddCurrent(cam);
                PushList(handle);
                return true;
            case UICmd.PresetApply:
                if (cam == null) return true;
                disableFollow();
                Apply(index, cam, applyRotation);
                return true;
            case UICmd.PresetDelete:
                Delete(index);
                CancelStash(cam, applyRotation);
                PushList(handle);
                return true;
            case UICmd.PresetRename:
                Rename(index, ReadRename(handle));
                PushList(handle);
                return true;
            case UICmd.PresetPreview:
                if (cam == null) return true;
                disableFollow();
                Preview(index, cam, applyRotation);
                return true;
            case UICmd.PresetCommitEdit:
                if (cam == null) return true;
                Rename(index, ReadRename(handle));
                CommitEdit(index, cam, applyRotation);
                PushList(handle);
                return true;
            case UICmd.PresetCancelEdit:
                CancelStash(cam, applyRotation);
                return true;
            default:
                return false;
        }
    }

    private static List<MapViewPreset> List()
    {
        var s = PopoutModule.Settings;
        var names = s.presetNames ?? Array.Empty<string>();
        var xs    = s.presetX     ?? Array.Empty<float>();
        var zs    = s.presetZ     ?? Array.Empty<float>();
        var zooms = s.presetZoom  ?? Array.Empty<float>();
        var rots  = s.presetRot   ?? Array.Empty<float>();
        int n = Math.Min(names.Length, Math.Min(xs.Length, Math.Min(zs.Length, Math.Min(zooms.Length, rots.Length))));
        var list = new List<MapViewPreset>(n);
        for (int i = 0; i < n; i++)
            list.Add(new MapViewPreset
            {
                name = names[i] ?? $"View {i + 1}",
                x = xs[i], z = zs[i], zoom = zooms[i], rotationY = rots[i]
            });
        return list;
    }

    private static void Save(List<MapViewPreset> list)
    {
        int n = list.Count;
        var names = new string[n];
        var xs    = new float[n];
        var zs    = new float[n];
        var zooms = new float[n];
        var rots  = new float[n];
        for (int i = 0; i < n; i++)
        {
            names[i] = list[i].name ?? "";
            xs[i]    = list[i].x;
            zs[i]    = list[i].z;
            zooms[i] = list[i].zoom;
            rots[i]  = list[i].rotationY;
        }
        var s = PopoutModule.Settings;
        s.presetNames = names;
        s.presetX     = xs;
        s.presetZ     = zs;
        s.presetZoom  = zooms;
        s.presetRot   = rots;
        PopoutModule.Persist();
    }

    private static MapViewPreset Capture(Camera cam)
    {
        MigrateLegacyIfNeeded(cam);
        ToGameXZ(cam.transform.position, out float x, out float z);
        return new MapViewPreset
        {
            name      = "",
            x         = x,
            z         = z,
            zoom      = cam.orthographicSize,
            rotationY = cam.transform.eulerAngles.y,
        };
    }

    private static void Apply(int index, Camera cam, Action<float> applyRotation)
    {
        MigrateLegacyIfNeeded(cam);
        var presets = List();
        if (index < 0 || index >= presets.Count) return;
        ApplyPreset(presets[index], cam, applyRotation);
    }

    private static void ApplyPreset(MapViewPreset p, Camera cam, Action<float> applyRotation)
    {
        SetCameraXZ(cam, p.x, p.z, PopoutModule.Settings.presetUseGameCoords);
        cam.orthographicSize = Mathf.Clamp(p.zoom, 25f, 10000f);
        applyRotation(p.rotationY);
        PanelFinder.UpdateMapForZoom();
    }

    // Old presets stored Unity world XZ. After a floating-origin rebase those
    // numbers no longer map to the same place on the railroad. Convert the
    // whole list the first time we save in game space.
    private static void MigrateLegacyIfNeeded(Camera cam)
    {
        var s = PopoutModule.Settings;
        if (s.presetUseGameCoords) return;
        var list = List();
        for (int i = 0; i < list.Count; i++)
        {
            var p = list[i];
            var world = new Vector3(p.x, cam.transform.position.y, p.z);
            ToGameXZ(world, out p.x, out p.z);
            list[i] = p;
        }
        s.presetUseGameCoords = true;
        if (list.Count > 0) Save(list);
        else PopoutModule.Persist();
    }

    internal static void ToGameXZ(Vector3 world, out float x, out float z)
    {
        try
        {
            var g = WorldTransformer.WorldToGame(world);
            x = g.x; z = g.z;
        }
        catch
        {
            x = world.x; z = world.z;
        }
    }

    internal static void SetCameraXZ(Camera cam, float x, float z, bool gameSpace)
    {
        var t = cam.transform;
        if (!gameSpace)
        {
            t.position = new Vector3(x, t.position.y, z);
            return;
        }
        try
        {
            var world = WorldTransformer.GameToWorld(new Vector3(x, 0f, z));
            world.y = t.position.y;
            t.position = world;
        }
        catch
        {
            t.position = new Vector3(x, t.position.y, z);
        }
    }

    private static void AddCurrent(Camera cam)
    {
        var list = List();
        var p = Capture(cam);
        p.name = NextName(list);
        list.Add(p);
        Save(list);
    }

    private static string NextName(List<MapViewPreset> list)
    {
        int n = list.Count + 1;
        string name = $"View {n}";
        var used = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
        foreach (var p in list)
            if (!string.IsNullOrEmpty(p.name)) used.Add(p.name);
        while (used.Contains(name))
        {
            n++;
            name = $"View {n}";
        }
        return name;
    }

    private static void Delete(int index)
    {
        var list = List();
        if (index < 0 || index >= list.Count) return;
        list.RemoveAt(index);
        Save(list);
    }

    private static void Rename(int index, string name)
    {
        if (string.IsNullOrWhiteSpace(name)) return;
        var list = List();
        if (index < 0 || index >= list.Count) return;
        var p = list[index];
        p.name = name.Trim();
        list[index] = p;
        Save(list);
    }

    private static void Preview(int index, Camera cam, Action<float> applyRotation)
    {
        if (!_stashValid)
        {
            var cur = Capture(cam);
            _stashX = cur.x; _stashZ = cur.z; _stashZoom = cur.zoom; _stashRot = cur.rotationY;
            _stashValid = true;
        }
        Apply(index, cam, applyRotation);
    }

    private static void CommitEdit(int index, Camera cam, Action<float> applyRotation)
    {
        var list = List();
        if (index < 0 || index >= list.Count)
        {
            CancelStash(cam, applyRotation);
            return;
        }
        var p = Capture(cam);
        p.name = list[index].name;
        list[index] = p;
        Save(list);
        RestoreStash(cam, applyRotation);
    }

    private static void CancelStash(Camera? cam, Action<float> applyRotation)
    {
        if (cam != null) RestoreStash(cam, applyRotation);
        else _stashValid = false;
    }

    private static void RestoreStash(Camera cam, Action<float> applyRotation)
    {
        if (!_stashValid) return;
        ApplyPreset(new MapViewPreset
        {
            x = _stashX, z = _stashZ, zoom = _stashZoom, rotationY = _stashRot
        }, cam, applyRotation);
        _stashValid = false;
    }
}

/// <summary>
/// Remembers the map camera between overlay/popout close and the next open.
/// MapEnhancer patches OnWindowShown to snap the camera to the player; we
/// capture before teardown and write the view back after Show() returns.
/// </summary>
internal static class MapCameraMemory
{
    public static void Capture(Camera? cam, float rotationY)
    {
        if (cam == null) return;
        var s = PopoutModule.Settings;
        MapViewPresets.ToGameXZ(cam.transform.position, out s.lastViewX, out s.lastViewZ);
        s.lastViewZoom = cam.orthographicSize;
        s.lastViewRot  = rotationY;
        s.lastViewValid = true;
        s.lastViewIsGame = true;
        PopoutModule.Persist();
    }

    public static bool TryRestore(Camera? cam, Action<float> applyRotation)
    {
        if (cam == null) return false;
        var s = PopoutModule.Settings;
        if (!s.lastViewValid) return false;
        MapViewPresets.SetCameraXZ(cam, s.lastViewX, s.lastViewZ, s.lastViewIsGame);
        cam.orthographicSize = Mathf.Clamp(s.lastViewZoom, 25f, 10000f);
        applyRotation(s.lastViewRot);
        PanelFinder.UpdateMapForZoom();
        return true;
    }
}