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

namespace IdleSpectator;

/// <summary>
/// Saga depth card under the character beat caption: Cast + Legacy.
/// Bound to the hover preview id. The primary nametag identifies the hovered
/// Saga character, so no duplicate identity chrome is rendered here.
/// No portrait / name / title / stake chrome here - that space goes to Cast.
/// Width fills the stable rail chrome beside the live dossier portrait.
/// The body has fixed geometry: compact 3x2 Cast cells above a two-line Legacy.
/// Content changes never move the rail, nametag, portrait, or card edge.
/// </summary>
public static class LifeSagaPanel
{
    /// <summary>Full inner hover width; Cast starts beside the portrait, Legacy spans below it.</summary>
    public const float BodyWidthFixed = 232f;
    /// <summary>Fixed hover depth; never derived from Cast or Legacy content.</summary>
    public const float BodyHeightFixed = 82f;
    public const float BodyHeightMax = BodyHeightFixed;

    public const float BodyWidthMin = BodyWidthFixed;
    public const float BodyWidthMax = BodyWidthFixed;
    public const float BodyHeightMin = BodyHeightFixed;

    /// <summary>Visible Cast cells. The sixth cell becomes +N when candidates overflow.</summary>
    public const int MaxCast = 6;
    /// <summary>Relationships retained by the model before the visible grid is allocated.</summary>
    public const int MaxCastCandidates = 10;
    private const int MaxLegacy = 2;
    private const int CastPerRow = 3;

    private const float Pad = 3f;
    private const float CastFace = 14f;
    private const float CastSlotW = 59f;
    private const float CastSlotH = 18f;
    private const float SecLabelH = 9f;
    private const float LineH = 9f;
    private const float PortraitReserveW = 44f;
    private const int BodyFont = 7;
    private const int BuildVersion = 15;

    private static GameObject _root;
    private static RectTransform _rootRt;
    private static Text _castHead;
    private static Text _legacyHead;
    private static Text _legacyText;
    private static readonly CastSlot[] CastSlots = new CastSlot[MaxCast];
    private static readonly List<string> LegacyParts = new List<string>(MaxLegacy);
    private static long _boundId;
    private static string _speciesId = "";
    private static string _fingerprint = "";
    private static int _builtVersion;
    private static float _laidOutHeight = BodyHeightFixed;

    private sealed class CastSlot
    {
        public GameObject Root;
        public Image FaceBg;
        public Image Face;
        public Text Name;
        public Text Relation;
        public long UnitId;
    }

    public static bool Visible => _root != null && _root.activeSelf;
    public static float BodyHeight => _laidOutHeight;
    public static float BodyWidthPx => BodyWidthFixed;
    public static long BoundUnitId => _boundId;
    /// <summary>Saga hover reuses the dossier avatar for the hovered character.</summary>
    public static bool OwnsAvatar => true;
    public static string LastLayoutDebug { get; private set; } = "";
    /// <summary>Harness/UI diagnostic: rendered Cast relationship sublabels.</summary>
    public static int LastVisibleRelationCount { get; private set; }

    public static void EnsureBuilt(Transform parent)
    {
        if (parent == null)
        {
            return;
        }

        if (_root != null && _builtVersion == BuildVersion)
        {
            return;
        }

        if (_root != null)
        {
            UnityEngine.Object.Destroy(_root);
            _root = null;
            _rootRt = null;
            _castHead = null;
            _legacyHead = null;
            _legacyText = null;
        }

        _root = new GameObject("LifeSagaPanel", typeof(RectTransform));
        _root.transform.SetParent(parent, false);
        _rootRt = _root.GetComponent<RectTransform>();
        _rootRt.pivot = new Vector2(0f, 1f);
        _rootRt.anchorMin = new Vector2(0f, 1f);
        _rootRt.anchorMax = new Vector2(0f, 1f);
        _rootRt.sizeDelta = new Vector2(BodyWidthFixed, BodyHeightFixed);

        _castHead = MakeLabel(_root.transform, "CastHead", BodyFont, HudTheme.Muted, FontStyle.Bold);
        _castHead.text = "Cast";
        _legacyHead = MakeLabel(_root.transform, "LegacyHead", BodyFont, HudTheme.Muted, FontStyle.Bold);
        _legacyHead.text = "Legacy";
        _legacyText = MakeLabel(_root.transform, "LegacyBody", BodyFont, HudTheme.Body, FontStyle.Normal);
        _legacyText.horizontalOverflow = HorizontalWrapMode.Wrap;
        _legacyText.verticalOverflow = VerticalWrapMode.Overflow;

        for (int i = 0; i < MaxCast; i++)
        {
            CastSlots[i] = BuildCast(i);
        }

        _builtVersion = BuildVersion;
        _root.SetActive(false);
    }

    public static void Clear()
    {
        _boundId = 0;
        _speciesId = "";
        _fingerprint = "";
        LegacyParts.Clear();
        LastVisibleRelationCount = 0;
        _laidOutHeight = BodyHeightFixed;
        if (_root != null)
        {
            _root.SetActive(false);
        }
    }

    public static void SetVisible(bool visible)
    {
        if (_root == null)
        {
            return;
        }

        _root.SetActive(visible);
    }

    public static void Bind(LifeSagaViewModel model)
    {
        if (_root == null)
        {
            return;
        }

        if (model == null || model.UnitId == 0)
        {
            Clear();
            return;
        }

        string fp = Fingerprint(model);
        bool same = string.Equals(fp, _fingerprint, System.StringComparison.Ordinal) && _boundId == model.UnitId;
        _fingerprint = fp;
        _boundId = model.UnitId;
        _speciesId = model.SpeciesId ?? "";
        if (!same)
        {
            var eligibleCast = new List<LifeSagaCastMember>(model.Cast.Count);
            for (int i = 0; i < model.Cast.Count; i++)
            {
                LifeSagaCastMember member = model.Cast[i];
                if (member == null || member.UnitId == 0)
                {
                    continue;
                }

                eligibleCast.Add(member);
            }

            int visiblePeople = Mathf.Min(eligibleCast.Count, CastSlots.Length);
            bool hasOverflow = eligibleCast.Count > CastSlots.Length;
            if (hasOverflow)
            {
                visiblePeople = CastSlots.Length - 1;
            }

            int shownCast = 0;
            for (; shownCast < visiblePeople; shownCast++)
            {
                BindCast(CastSlots[shownCast], eligibleCast[shownCast]);
            }

            if (hasOverflow)
            {
                BindCastOverflow(CastSlots[shownCast], eligibleCast.Count - visiblePeople);
                shownCast++;
            }

            for (int i = shownCast; i < CastSlots.Length; i++)
            {
                CastSlots[i].Root.SetActive(false);
                CastSlots[i].UnitId = 0;
            }

            LegacyParts.Clear();
            var seen = new HashSet<string>();
            string stakeKey = (model.StakeLine ?? "").Trim().ToLowerInvariant();
            for (int i = 0; i < model.Legacy.Count && LegacyParts.Count < MaxLegacy; i++)
            {
                if (model.Legacy[i] == null || string.IsNullOrEmpty(model.Legacy[i].Line))
                {
                    continue;
                }

                string line = model.Legacy[i].Line.Trim();
                string key = line.ToLowerInvariant();
                if (!string.IsNullOrEmpty(stakeKey)
                    && string.Equals(key, stakeKey, System.StringComparison.Ordinal))
                {
                    continue;
                }

                if (!seen.Add(key))
                {
                    continue;
                }

                LegacyParts.Add(line);
            }

            _legacyText.text = LegacyParts.Count > 0
                ? string.Join("\n", LegacyParts)
                : "Their story is still unfolding";
        }

        Layout();
        _root.SetActive(true);
    }

    public static float Place(float y, float padX)
    {
        if (!Visible || _rootRt == null)
        {
            return y;
        }

        _rootRt.anchoredPosition = new Vector2(padX, -y);
        _rootRt.sizeDelta = new Vector2(BodyWidthFixed, _laidOutHeight);
        return y + _laidOutHeight + 2f;
    }

    private static void Layout()
    {
        float fullX = Pad;
        float fullW = BodyWidthFixed - Pad * 2f;
        float y = Pad;
        float yMax = BodyHeightFixed - Pad;

        int castN = 0;
        LastVisibleRelationCount = 0;
        for (int i = 0; i < CastSlots.Length; i++)
        {
            if (CastSlots[i].Root.activeSelf)
            {
                castN++;
                if (CastSlots[i].Relation != null
                    && !string.IsNullOrEmpty(CastSlots[i].Relation.text))
                {
                    LastVisibleRelationCount++;
                }
            }
        }

        float castX0 = PortraitReserveW;
        float castW = BodyWidthFixed - castX0 - Pad;
        _castHead.text = castN > 0 ? "Cast" : "Cast · No close ties recorded";
        PlaceText(_castHead, castX0, y, castW, SecLabelH);
        y += SecLabelH;
        float castX = castX0;
        int col = 0;
        for (int i = 0; i < CastSlots.Length; i++)
        {
            if (!CastSlots[i].Root.activeSelf)
            {
                continue;
            }

            if (col >= CastPerRow)
            {
                y += CastSlotH + 2f;
                castX = castX0;
                col = 0;
            }

            RectTransform rt = CastSlots[i].Root.GetComponent<RectTransform>();
            rt.anchoredPosition = new Vector2(castX, -y);
            rt.sizeDelta = new Vector2(CastSlotW, CastSlotH);
            CastSlots[i].Root.transform.SetAsLastSibling();
            castX += CastSlotW + 1f;
            col++;
        }

        // Reserve both Cast rows even when sparse so Legacy never moves between characters.
        y = 52f;
        float legacyBudget = Mathf.Max(LineH, yMax - y - SecLabelH);
        int omittedLegacy = 0;
        string fittedLegacy = FitLegacyToHeight(fullW, legacyBudget, out omittedLegacy);
        _legacyText.text = fittedLegacy;
        bool hasLegacy = LegacyParts.Count > 0;
        PlaceText(_legacyHead, fullX, y, fullW, SecLabelH);
        y += SecLabelH;
        PlaceText(_legacyText, fullX, y, fullW, Mathf.Min(2f * LineH, yMax - y));
        _legacyText.horizontalOverflow = HorizontalWrapMode.Overflow;
        _legacyText.verticalOverflow = VerticalWrapMode.Truncate;

        _laidOutHeight = BodyHeightFixed;

        if (_rootRt != null)
        {
            _rootRt.sizeDelta = new Vector2(BodyWidthFixed, _laidOutHeight);
        }

        LastLayoutDebug =
            $"w={BodyWidthFixed} h={_laidOutHeight:0.#} cast={castN} legacy={(hasLegacy ? 1 : 0)} omitted={omittedLegacy} castFirst=1";
    }

    private static string FitLegacyToHeight(float width, float maxHeight, out int omitted)
    {
        omitted = Mathf.Max(0, LegacyParts.Count - MaxLegacy);
        if (_legacyText == null || maxHeight < LineH)
        {
            return "";
        }

        if (LegacyParts.Count == 0)
        {
            return "Their story is still unfolding";
        }

        int lineCount = Mathf.Min(MaxLegacy, Mathf.FloorToInt(maxHeight / LineH));
        var lines = new List<string>(lineCount);
        int maxChars = Mathf.Max(12, Mathf.FloorToInt(width / 4.2f));
        for (int i = 0; i < LegacyParts.Count && lines.Count < lineCount; i++)
        {
            lines.Add(Ellipsize(LegacyParts[i], maxChars));
        }

        omitted = Mathf.Max(0, LegacyParts.Count - lines.Count);
        return string.Join("\n", lines);
    }

    private static string Ellipsize(string value, int maxChars)
    {
        string clean = (value ?? "").Replace('\n', ' ').Replace('\r', ' ').Trim();
        return clean.Length <= maxChars
            ? clean
            : clean.Substring(0, Mathf.Max(1, maxChars - 1)).TrimEnd() + "…";
    }

    private static CastSlot BuildCast(int index)
    {
        GameObject root = new GameObject("Cast" + index, typeof(RectTransform));
        root.transform.SetParent(_root.transform, false);
        RectTransform rootRt = root.GetComponent<RectTransform>();
        rootRt.pivot = new Vector2(0f, 1f);
        rootRt.anchorMin = new Vector2(0f, 1f);
        rootRt.anchorMax = new Vector2(0f, 1f);

        GameObject bgGo = new GameObject("FaceBg", typeof(RectTransform), typeof(Image));
        bgGo.transform.SetParent(root.transform, false);
        Image bg = bgGo.GetComponent<Image>();
        bg.color = new Color(0.12f, 0.13f, 0.16f, 0.95f);
        bg.raycastTarget = false;
        RectTransform bgRt = bgGo.GetComponent<RectTransform>();
        bgRt.pivot = new Vector2(0f, 1f);
        bgRt.anchorMin = new Vector2(0f, 1f);
        bgRt.anchorMax = new Vector2(0f, 1f);
        bgRt.anchoredPosition = Vector2.zero;
        bgRt.sizeDelta = new Vector2(CastFace, CastFace);

        GameObject faceGo = new GameObject("Face", typeof(RectTransform), typeof(Image));
        faceGo.transform.SetParent(bgGo.transform, false);
        Image face = faceGo.GetComponent<Image>();
        face.preserveAspect = true;
        face.raycastTarget = false;
        RectTransform faceRt = faceGo.GetComponent<RectTransform>();
        faceRt.pivot = new Vector2(0.5f, 0.5f);
        faceRt.anchorMin = new Vector2(0.5f, 0.5f);
        faceRt.anchorMax = new Vector2(0.5f, 0.5f);
        faceRt.anchoredPosition = Vector2.zero;
        faceRt.sizeDelta = new Vector2(CastFace - 2f, CastFace - 2f);

        Text name = MakeLabel(root.transform, "Name", BodyFont, HudTheme.Body, FontStyle.Normal);
        Text relation = MakeLabel(root.transform, "Rel", BodyFont, HudTheme.Muted, FontStyle.Normal);
        RectTransform nameRt = name.rectTransform;
        nameRt.anchoredPosition = new Vector2(CastFace + 2f, 0f);
        nameRt.sizeDelta = new Vector2(CastSlotW - CastFace - 2f, 9f);
        RectTransform relRt = relation.rectTransform;
        relRt.anchoredPosition = new Vector2(CastFace + 2f, -9f);
        relRt.sizeDelta = new Vector2(CastSlotW - CastFace - 2f, 9f);

        root.SetActive(false);
        return new CastSlot
        {
            Root = root,
            FaceBg = bg,
            Face = face,
            Name = name,
            Relation = relation
        };
    }

    private static void BindCast(CastSlot slot, LifeSagaCastMember member)
    {
        slot.UnitId = member.UnitId;
        string name = string.IsNullOrEmpty(member.Name) ? "Someone" : member.Name;
        string rel = string.IsNullOrEmpty(member.Relation) ? "Linked" : member.Relation;
        FitCastText(slot.Name, name);
        FitCastText(slot.Relation, rel);

        Actor live = member.Alive ? EventFeedUtil.FindAliveById(member.UnitId) : null;
        Sprite sprite = HudIcons.FromActorRailFace(live, member.SpeciesId)
                        ?? HudIcons.FromSpeciesId(member.SpeciesId)
                        ?? HudIcons.FromUiIcon("iconCitizen");
        slot.Face.sprite = sprite;
        slot.Face.enabled = sprite != null;
        slot.Face.color = sprite != null ? Color.white : new Color(0.35f, 0.36f, 0.4f, 1f);
        slot.FaceBg.color = member.Alive
            ? new Color(0.12f, 0.13f, 0.16f, 0.95f)
            : new Color(0.18f, 0.12f, 0.12f, 0.95f);
        slot.Root.SetActive(true);
    }

    private static void BindCastOverflow(CastSlot slot, int omitted)
    {
        slot.UnitId = 0;
        slot.Face.sprite = null;
        slot.Face.enabled = false;
        slot.FaceBg.color = new Color(0.12f, 0.13f, 0.16f, 0.95f);
        FitCastText(slot.Name, "+" + Mathf.Max(1, omitted));
        FitCastText(slot.Relation, "more ties");
        slot.Root.SetActive(true);
    }

    /// <summary>Harness: Cast membership is independent of the transient orange Beat.</summary>
    internal static bool HarnessProbeStableCastSnapshot(out string detail)
    {
        var model = new LifeSagaViewModel { UnitId = 10, Name = "Parent" };
        model.Cast.Add(new LifeSagaCastMember
        {
            UnitId = 20,
            Name = "Child",
            Relation = "Child",
            Alive = true
        });
        string before = Fingerprint(model);
        string after = Fingerprint(model);
        bool pass = before == after
                    && model.Cast.Count == 1
                    && model.Cast[0].UnitId == 20;
        detail = $"pass={pass} fingerprintStable={before == after} cast={model.Cast.Count} member={model.Cast[0].UnitId}";
        return pass;
    }

    private static void FitCastText(Text text, string value)
    {
        if (text == null)
        {
            return;
        }

        string fitted = value ?? "";
        const int maxReadableChars = 11;
        if (fitted.Length > maxReadableChars)
        {
            fitted = fitted.Substring(0, maxReadableChars - 1).TrimEnd() + "…";
        }

        text.text = fitted;
        text.resizeTextForBestFit = true;
        text.resizeTextMinSize = 6;
        text.resizeTextMaxSize = BodyFont;
        text.horizontalOverflow = HorizontalWrapMode.Overflow;
        text.verticalOverflow = VerticalWrapMode.Truncate;
    }

    private static Text MakeLabel(Transform parent, string name, int fontSize, Color color, FontStyle style)
    {
        int fitSize = fontSize < 7 ? 7 : fontSize;
        Text text = HudCanvas.MakeText(parent, name, "", fitSize);
        text.color = color;
        text.fontStyle = style;
        text.alignment = TextAnchor.UpperLeft;
        text.horizontalOverflow = HorizontalWrapMode.Overflow;
        text.verticalOverflow = VerticalWrapMode.Overflow;
        text.raycastTarget = false;
        RectTransform rt = text.rectTransform;
        rt.pivot = new Vector2(0f, 1f);
        rt.anchorMin = new Vector2(0f, 1f);
        rt.anchorMax = new Vector2(0f, 1f);
        return text;
    }

    private static void PlaceText(Text text, float x, float y, float w, float h)
    {
        if (text == null)
        {
            return;
        }

        text.resizeTextForBestFit = false;
        text.enabled = true;
        Color c = text.color;
        if (c.a < 0.99f)
        {
            c.a = 1f;
            text.color = c;
        }

        RectTransform rt = text.rectTransform;
        rt.anchoredPosition = new Vector2(x, -y);
        rt.sizeDelta = new Vector2(w, h);
        text.gameObject.SetActive(!string.IsNullOrEmpty(text.text));
    }

    private static string Fingerprint(LifeSagaViewModel model)
    {
        var sb = new StringBuilder(192);
        sb.Append(model.UnitId).Append('|').Append(model.Name).Append('|').Append(model.StakeLine);
        for (int i = 0; i < model.Cast.Count; i++)
        {
            var c = model.Cast[i];
            if (c == null)
            {
                continue;
            }

            sb.Append('|').Append(c.UnitId).Append(':').Append(c.Relation).Append(':').Append(c.Name);
        }

        for (int i = 0; i < model.Legacy.Count; i++)
        {
            if (model.Legacy[i] != null)
            {
                sb.Append('#').Append(model.Legacy[i].Line);
            }
        }

        return sb.ToString();
    }

}