using System;
using NeoModLoader.services;
using UnityEngine;

namespace IdleSpectator;

public static class CameraDirector
{
    public static string LastWatchLabel { get; private set; } = "";
    public static string LastWatchAssetId { get; private set; } = "";
    public static string LastFormattedWatchTip { get; private set; } = "";

    public static void FocusUnit(Actor actor, bool updateCaption = true)
    {
        if (actor != null && actor.isAlive())
        {
            RetargetFollow(actor);
            if (updateCaption && SpectatorMode.Active)
            {
                WatchCaption.SetFromActor(actor);
            }
        }
    }

    public static void Watch(InterestEvent interest)
    {
        if (interest == null || !interest.HasValidPosition)
        {
            return;
        }

        if (!Config.game_loaded || World.world == null)
        {
            return;
        }

        string tip = FormatWatchTip(interest);
        string label = interest.Label ?? "";
        string assetId = interest.AssetId ?? "";
        // AssetId-only churn (live_combat ↔ live_battle) must not re-log the same tip.
        bool tipChanged = !string.Equals(tip, LastFormattedWatchTip, StringComparison.Ordinal)
                          || !string.Equals(label, LastWatchLabel, StringComparison.Ordinal);
        bool framingOnly = tipChanged
                           && (EventReason.IsHeadcountOnlyChange(LastWatchLabel, label)
                               || EventReason.IsCombatFramingOnlyChange(LastWatchLabel, label));
        LastFormattedWatchTip = tip;
        // LastWatchLabel is tip/harness telemetry only - never dossier reason truth.
        LastWatchLabel = label;
        LastWatchAssetId = assetId;
        // Sticky Mass tips tick headcounts / side-order / Battle↔Mass often - log structure only.
        if (tipChanged && !framingOnly)
        {
            LogService.LogInfo($"[IdleSpectator] {tip}");
        }

        Actor follow = ResolveFollowUnit(interest);
        if (follow != null && follow.isAlive())
        {
            // Focus first, then nametag - same order as FocusUnit, so tip/focus/dossier
            // never diverge across a handoff frame.
            RetargetFollow(follow);
            // Same subject: skip full UnitDossier.FromActor rebuild (was walking every
            // alive unit for species counts on every Mass headcount tip refresh).
            // WatchCaption.Update already refreshes reason/task/identity live.
            long followId = EventFeedUtil.SafeId(follow);
            if (followId == 0 || followId != WatchCaption.CurrentUnitId)
            {
                WatchCaption.SetFromActor(follow);
            }

            return;
        }

        // No accepted living follow: tip already logged. Do not bind a rejected FollowUnit
        // (dead / species mismatch) as the dossier subject.
        if (!interest.HasFollowUnit)
        {
            WatchCaption.SetFromInterest(interest);
        }

        if (!MoveCamera.hasFocusUnit())
        {
            PanCamera(interest.Position);
        }
    }

    private static Actor ResolveFollowUnit(InterestEvent interest)
    {
        if (interest == null)
        {
            return null;
        }

        Actor follow = interest.HasFollowUnit ? interest.FollowUnit : null;

        // Species discovery: only attach a species-matched unit, never a random stranger.
        bool speciesTip = interest.Label != null
                          && interest.Label.StartsWith("New species:");
        if (follow == null
            && speciesTip
            && !string.IsNullOrEmpty(interest.AssetId)
            && interest.AssetId != "live_battle"
            && interest.AssetId != "scored_unit")
        {
            follow = WorldActivityScanner.FindNearestAliveUnit(interest.Position, 24f, interest.AssetId);
        }

        if (follow == null || !follow.isAlive())
        {
            return null;
        }

        if (speciesTip
            && !string.IsNullOrEmpty(interest.AssetId)
            && follow.asset != null
            && follow.asset.id != interest.AssetId)
        {
            return WorldActivityScanner.FindNearestAliveUnit(interest.Position, 24f, interest.AssetId);
        }

        return follow;
    }

    public static string FormatWatchTip(InterestEvent interest)
    {
        if (interest == null || string.IsNullOrEmpty(interest.Label))
        {
            return "Watching";
        }

        return "Watching: " + interest.Label;
    }

    public static void ClearFollow()
    {
        MoveCamera.clearFocusUnitOnly();
    }

    public static void PanTo(Vector3 pos)
    {
        PanCamera(pos);
    }

    private static void RetargetFollow(Actor actor)
    {
        if (MoveCamera.isCameraFollowingUnit(actor))
        {
            return;
        }

        bool firstFocus = !MoveCamera.hasFocusUnit();
        MoveCamera.setFocusUnit(actor);
        Chronicle.NoteFocus(actor);

        MoveCamera cam = MoveCamera.instance;
        if (cam == null)
        {
            return;
        }

        // Same as vanilla killer handoff: reset ease so the camera lerps to the new unit.
        cam._focus_timer = 0f;
        if (firstFocus)
        {
            cam._target_zoom = 15f;
            cam._focus_zoom = 15f;
        }
    }

    private static void PanCamera(Vector3 pos)
    {
        MoveCamera cam = MoveCamera.instance;
        if (cam == null)
        {
            World.world.locatePosition(pos);
            return;
        }

        pos.z = cam.transform.position.z;
        cam.transform.position = pos;
        cam._target_zoom = 15f;
        cam._focus_zoom = 15f;
    }
}